George Klein

Summary An exceptional Burkitt lymphoma patient, a 16-year-old boy, yielded tumor biopsy cells and derived tissue culture lines that displayed a strong surface accumulation of IgM heavy and kappa light chain specificities judged by direct membrane fluorescence and cytotoxicity tests. This property was maintained unchanged in the course of more than 5 months of serial passage in vitro . A fourth biopsy, obtained from the patient after massive necrosis had been induced in the tumor by cytosine arabinoside chemotherapy, did not show this property at either the biopsy stage or in the derived cell line. The possibility that the neoplastic transformation of lymphoid cells may have afflicted a cell specialized to carry immunoglobulin on its surface may be considered. The phenomenon has to be distinguished from immunoglobulin coating in vivo seen with certain biopsy samples from this and other patients. The latter type of coating can be of IgM, IgG, or IgA nature and disappears rapidly on cultivation in vitro .

Six renal transplant recipients with abnormal lymphoproliferative disorders were studied in an attempt to define their clinical features and the role of Epstein-Barr virus (EBV) in their pathogenesis. Patients were either teenage (three) or in the sixth decade (three). The younger patients presented an average of 3 months after transplantation with fever, sore throat, and lymphadenopathy; had been markedly immunosuppressed; frequently had preceding or concomitant cytomegalovirus infections; and two of three had a rapidly fatal course. The older patients presented an average of 5 years after transplantation while on maintenance immunosuppressive drugs; in two of three cases with an oropharyngeal tumor; and had a more indolent, but frequently fatal, clinical course. The most frequent sites of biopsy-proven involvement in these patients were lymph nodes (three), the oropharynx (three), liver (three), bone marrow (three), transplanted kidney (three), colon (two), and central nervous system (two). EBV-specific antibody titers including anti-viral capsid antigen IgG, anti-viral capsid antigen IgM, anti-early antigen, and anti-Epstein-Barr nuclear antigen were serially measured in all patients. Four patients demonstrated serological evidence of a primary (one) or reactivation (three) EBV infection. No patient had significant changes in anti-early antigen or anti-Epstein-Barr nuclear antigen titers. All three patients tested for oropharyngeal shedding of EBV were positive. A touch imprint of one tumor was stained for the presence of Epstein-Barr nuclear antigen, and a majority of cells were positive. EBV complementary RNA/DNA filter hybridization and/or viral DNA/DNA reassociation analysis performed on tumor biopsy specimens in five patients demonstrated multiple EBV genome equivalents per cell in all eight specimens tested. Clinical, pathological, serological, and molecular hybridization studies provide substantial evidence that EBV was the cause of these lymphoproliferative disorders occurring after renal transplantation. Impaired host defenses allow the EBV-transformed B-lymphocytes to escape normal control mechanisms. This impairment is invariable and influenced by many factors resulting in the observed spectrum of disease. Cytogenetic changes, however, may also be important.

Abstract Examination of numerous sera from patients with infectious mononucleodis (IM), Burkitt's lymphoma (BL) or nasopharyngeal carcinoma (NPC) for antibodieh to Epstein‐Barr virus (EBV) induced early antigens (EA) revealed two distinct patterns of immunofluorescence in abortively EBV‐infected Raji cells. One showed diguse (D) staining of the nucleus and cytoplasm of invaded cells, the other (R) was restricted to masses in the cytoplasm. Although D‐ or R‐reactive Raji cells became detectable at similar times after exposure to EBV, the percentages of D‐positive cells initially exceeded R‐positive cells but ultimately both were nearly equal in number. R‐positive cells almost invariably contained also D. In EBV‐exposed RPM1 64–10 cells, frequently only D was synthesized. D antigen, in contrast to R, resisted fixation by methanol or ethanol, whereas R proved more resistant than D to proteolytic enzymes. Comparative serum titration on acetone, respectively ethanol‐fixed Raji‐EBV cell smears revealed that the transitory anti‐EA response observed in many IM patients was restricted almost exclusively to anti‐D. Anti‐EA positive sera from NPC patients also showed dominantly anti‐D activity whereas, in BL sera, anti‐R was usually, but not always, dominant, often being the only antibody to the EA complex present. Preliminary tests with pronase‐treated Raji‐EBV cell smears indicated that dominantly anti‐D reactive sera from IM patients were free of anti‐R whereas such sera from NPC or BL patients usually gave positive reactions which in part, however, failed to conform with the R pattern. The possible implications of these results have been discussed.

Virus-induced lymphomas of the mouse contain tumor-specific antigens, as evidenced by the rejection of small numbers of viable neoplastic cells by preimmunized, genetically compatible animals; and the concomitant appearance of antibodies, demonstrated by the cytotoxic reaction in vitro, or by the membrane immunofluorescence reaction with living target cells.'-10 In the course of previous studies, we have been particularly interested in lymnphomas induced by the Moloney virus.5' 10 When adult mice are inoculated with this agent, they develop high titers of antibodies, capable of reacting with Moloney lymphoma target cells in immunofluorescence and cytotoxic tests, but not crossreacting with lymphomas induced by the Gross or Graffi viruses.5' 11, 12 Mice inoculated with the Moloney agent when newborn often develop tolerance.13 Virus-neutralizing, cytotoxic, or fluorescent antibodies fail to appear and cannot be induced by a second virus inoculation at adult age.14 Mlice inoculated as newborn develop leukemia earlier and in a higher incidence than mice that received the agent for the first time at adult age. Animals of the latter category show a decrease of their usually high antibody titer when they develop generalized leukenlia. If leukemia is inhibited by chemotherapy, the antibody levels may rise again.15 Whether similar reactions occur in human malignancies of the lymphatic system is of interest. The Burkitt lymphoma has attracted much interest during recent years due to serious consideration of a possible virus etiology. All virus-induced murine neoplasms studied have been found to contain tumor-specific antigens capable of inducing host rejection reactions, with common specificity shared by all neoplasms induced by the same virus. The possible antigenicity of the Burkitt tumor is also indicated by the total regression of the disease after chemotherapy in a considerable proportion of cases and the absence of recurrence during observation periods up to 4-6 years. Such durable remissions have been obtained by different agents and even in cases where treatment was incomplete. According to Burkitt,'6 these good results cannot be attributed to an unusual susceptibility of the tumor to cytotoxic agents since this cannot explain spontaneous or temporary remissions following serum transfusions alone.24 It has therefore been postulated that some immunological mechanism operates. The purpose of the present study was to look for possible tumor-specific reactions in Burkitt lymphoma and, if found, to assess their significance. The choice of materials and methods was based on our experience in the Moloney system. Since different Moloney lymphomas showed great variation with regard to surface antigen concentration, and since variants with a decreased antigen concentration could be selected during passage in vitro or in vivo, we have worked with fresh biopsy material rather than with established cell lines. The membrane immunofluorescence

Abstract The intertidal sand bars of the Minas Basin, Nova Scotia, are asymmetrical in cross-section and linear in plan. They are formed and reworked by tidal currents which are characterized by an asymmetric time-velocity profile. A causal connection between time-velocity asymmetry of tidal currents and bar topography is demonstrated. Average bottom ebb current velocities (90 cm/sec) were found to exceed average bottom flood current velocities (65 cm/sec) over gently-sloping (2 to 3 degree) bar surfaces, whereas over steep-sloping (8 degree) bar surfaces, average bottom flood current velocities (90 cm/sec) were found to exceed average bottom ebb current velocities (65 cm/sec). Both bar topography and zones of flood- or ebb-dominated bottom tidal currents control the distribution of sediment texture and sedimentary structures. On steeper bar slopes, the sediment is fine-grained sand and is characterized by airholes, planar lamination, and surface dunes and ripples. On the gentler bar slopes, the texture of the sediment is medium-grained and coarse-grained sand which has been fashioned into current ripples, simple dunes, complex dunes, simple sand waves and complex sand waves. The internal organization of some dunes and sand waves is extremely complex, inasmuch as thickness of internal sets of cross-stratification is considerably less than dune and sand wave height. A total of 14 sedimentary bar facies are defined from combinations of texture, internal cross-stratification and surface bedforms. Both topography and zones of ebb- and flood-dominated bottom tidal currents control the orientation of directional current structures. Over steep faces of bars, the slip faces of sand waves are oriented in the same direction as flow directions of bottom flood tidal currents, although they do show evidence of reworking by ebb currents. Over gently sloping bar surfaces, slip faces of both dunes and sandwaves are oriented parallel to the direction of flow of bottom ebb current systems. Because dunes and sand waves migrate only during a single phase (ebb or flood) of a tidal cycle, their orientation is generally unimodal. Current ripples are formed in depths of water less than 0.6 meters, during late-stage sheet-like runoff that is controlled by local slope changes on the bar. Individual tracer grains are dispersed in a radial-elliptical pattern form a point source. The size of directional properties is hierarchically sensitive to dispersal history. Tracer grains (modeling mineral indicator grains) are dispersed in a radial-elliptical pattern from a point source. Trimodal, highly variant, current ripple slip face orientation develops during late stage sheet runoff at low water depths; this flow is controlled by local bar slope. Unimodal, low variant dune slip faces, sand wave slip faces and associated maximum dip direction of cross-stratification are aligned parallel to tidal current flow and basinal topographic trend. The sand bars are aligned parallel to basinal topographic trend and in turn segregate zones of flood- and ebb-dominated bottom current systems. The tidal sand bars of the Minas Basin are equilibrium forms. Sand is dispersed alternately around the bar through zones of ebb- and flood-dominated bottom tidal currents. As a consequence, the sedimentary facies distribution on the bars has remained essentially unchanged since 1938. Comparison of low-tide airphotos taken in 1938, 1947 and 1963 in one of the study areas shows a slight erosional regime. This erosional regime controls the extreme reworking of sediments, and the formation of an erosional sand wave bedform by wave processes. Physical criteria characteristic of tide-dominated sand bodies include: sharp erosional contacts between sets of cross-stratification; rounded upper set boundaries of cross-stratification; unimodal and bimodal distributions of orientation of cross-stratification; bimodal distributions of set thickness and dip angles of cross-stratification; orientation of dunes, sand waves and cross-stratification in the dominant direction of flood or ebb tidal flow, basinal topographic trend and sand body axis; trimodal orientation of current ripples; oblique or 90 degrees superposition of smaller current ripples on larger current ripples; double-crested current ripples; superposition of current ripples at 90 degrees or 180 degrees on slip faces and crests of dunes and sand waves; complex organization of internal cross-stratification in sand waves; etch marks on slip faces of dunes and sand waves; and alignment of the long axis of sand bodies parallel to tidal current flow, basinal topographic trend and basin axis.