Natan Goldblum

Isolation of Vipera palestinae hemorrhagin and distinction between its hemorrhagic and proteolytic activities

Abstract The hemorrhagin of Vipera palestinae venom was isolated by sequential application of DEAE-cellulose column chromatography, (NH4)2SO4 precipitation, chromatography on Sephadex G-200 and chromatography on DEAE-Sephadex pretreated with soybean trypsin inhibitor. The purified hemorrhagin was homogeneous on immunodiffusion, rechromatography on DEAE-Sephadex and in ultracentrifugal analysis. The hemorrhagin is an acidic protein with an estimated mol. wt. of 44000, a sedimentation coefficient s 20,w 3.44 S and diffusion coefficient D 20,w 7.6·10−7. The purified hemorrhagin has gelatinase activity which can be inhibited by soybean trypsin inhibitor or DFP, while leaving the hemorrhagic activity intact.

The phase-separation method for the concentration and detection of viruses in water☆

Abstract This paper reports on the further development and refinement of the Phase-Separation Method for concentrating and detecting enteroviruses in water. In this method a water sample of several litres to be tested for viruses is mixed with a combination of organic polymers, which after detention in a separatory funnel produce two phases. The small bottom phase concentrates the viruses of the sample and can be easily drained off. The procedure is repeated to achieve a concentration factor of 500. Virus recovery efficiency is high and as few as 1–2 virus infectious units per litre of sample can be effectively detected. Field surveys of sewage and water samples illustrate the application of this low cost and efficient method which should provide a valuable tool for epidemiological investigations, studies of the virus removal efficiency of various treatment processes, as well as in the routine monitoring of potable water supplies for virus contamination.

Effect of withdrawal of arginine and other amino acids on the synthesis of tumour and viral antigens of SV 40 virus.

In recent years the role of arginine in the replication of certain intranuclear DNA viruses has been well documented. Rouse, Bonifas & Schlesinger (1963) demonstrated that arginine is required for the replication of type 2 adenovirus and Tankersley (1964) and Sharon (1966) showed that it is essential for the multiplication of herpes virus. More recently, Rouse & Schlesinger (1967) showed for type 2 adenovirus, Russell & Becker (1968) for type 5 adenovirus and Becker, Olshevsky & Levitt (1967) for herpes virus that arginine is not required in the early steps of virus replication which include synthesis of viral DNA, but is essential for the production of complete infectious virions. The purpose of this communication is to report on the effect of depletion in arginine and other amino acids on the replication of SV 40 virus, and on the synthesis of the early ‘T’ antigen (Pope & Rowe, 1964) and late viral coat proteins of this virus in BSC 1 cells.

Viscosity-density gradient for purification of foot-and-mouth disease virus

A simple and unique negative viscosity —positive density gradient has been devised which enables an effective single step purification of foot-and-mouth disease virus (FMDV) directly from cytoplasmic lysates. Using this gradient system, the recovery of infectious virus was greater than 95%. In addition, the isolated viral preparation was virtually free of contaminating cellular macromolecules. Further, the ratio of the volume of sample to gradient could be varied up to about two with a high degree of recovery and concentration.

Transformation of BSC1 Cells following Chronic Infection with SV40

Summary The BSC/SV 40 virus carrier state was established by infecting monolayers of BSC1 cells with high concentrations of SV40. In these carrier cultures, only 4% of the cells contained intranuclear tumour (T) antigen as determined by the immunofluorescent method, but every cell produced infectious virus. During passage of the BSC/SV40 cultures, a cell line was selected in which all the cells exhibited T antigen and only 0.2–1% of the cells produced infectious virus (transformed state). The BSC1 transformed cells were like the BSC1 parent cells sensitive to challenge with heterologous viruses (attenuated polio 1, herpes simplex and vaccinia), but were resistant to superinfection by the homologous SV40. Cytosine arabinoside, actinomycin D and antiserum to SV40 inhibited virus and T antigens in the BSC/SV40 carrier cultures. In the transformed cells, infectious virus and virus antigen only were inhibited but synthesis of the T antigen remained unaffected. By cell cloning, two virus-free clones were obtained.

A comparative study of human cell lines derived from patients with lymphoma, leukemia and infectious mononucleosis. Membrane properties, ultrastructure, and surface morphology

The membrane properties of different cultured lymphoid cell lines were studied using Concanavalin A (Con A) cap‐forming ability and agglutinability and scanning electron microscopy (SEM) as probes. In addition, enzyme content and ultrastructural features were characterized by cytochemistry and transmission electron microscopy. Cell lines derived from patients with infectious mononucleosis (IM line), Hodgkins lymphoma (LB‐129), African and non‐African Burkitts lymphoma (Bu‐4, Raji and DG‐75) and acute lymphoblastic leukemia (Molt‐4) were compared. Cells derived from patients with Burkitts lymphoma were spherical in shape, had a relatively uniform morphology, showed abundant lipid droplets, and exhibited a low Con‐A cap‐forming ability. The EBV (Epstein‐Barr Virus) genome negative, DG‐75 cells derived from a patient with non‐African Burkitts lymphoma were similar to Bu‐4 and Raji in many respects, but showed a high cap‐forming ability. Cells from IM and LB‐129 lines had a less stereotyped morphology and differed from the Burkitts lymphoma cells in their growth characteristics, response to Con A, and ultra‐structure. Cells were either rounded or elongated with a “hand mirror” shape and lacked multiple cytoplasmic lipid droplets so typical of Burkitts cells. Under SEM most cells from the above lines had varying numbers of microvilli, while IM and LB‐129 also displayed marginal ruffles, some blebs, and rare uropods. All the above mentioned cell lines were readily identified as B lymphocyte in type by immunologic methods, but DG‐75 cells lacked EBNA (EBV‐determined nuclear antigen) and EBV receptors. The Molt 4 cells derived from a patient with lymphoblastic leukemia were different in all respects. They were identified as T lymphocytes and displayed relatively smooth surfaces with few microvilli. The significance of these findings is discussed and it is suggested that some of the different membrane properties exhibited may be useful in characterizing the various established cultured lymphoid cells.

Detoxification of Snake Venoms and Venom Fractions by Formaldehyde.

Summary The effect of formaldehyde on the toxicity of Vipera palestinae and Echis colorata and their chromatographic fractions was investigated. The detoxification was found to be pH dependent. Vipera palestinae hemorrhagin was detoxified over a wide pH range, from 5.5 to 9.2, but its antigenicity was preserved at acidic pH only. The neurotoxin of Vipera palestinae was detoxified by formaldehyde at alkaline pH only. The detoxified neurotoxin was devoid of immunogenic activity. Treatment of Echis colorata venom with formaldehyde over a wide pH range did not result in complete detoxification although its separated hemorrhagins were detoxified.

Phosphonoformate inhibits synthesis of epstein-barr virus (EBV) capsid antigen and transformation of human cord blood lymphocytes by EBV☆

Abstract Phosphonoformic acid trisodium salt (PF) and ethyl diethylphosphonoformate (Et-PF) inhibited Epstein—Barr virus (EBV) viral capsid antigen (VCA) synthesis in B.95-8 cells, at concentrations which were nontoxic to cells. PF inhibited 96.7% of VCA synthesis when used at 500 μM whereas Et-PF inhibited only 68.9% of VCA synthesis when used at 2000 μM. The synthesis of EBV nuclear antigen (EBNA) was not inhibited by PF or Et-PF. PF inhibited the transformation of human cord blood lymphocytes (CBL) by EBV as detected by [ 3 H]thymidine uptake. The inhibition of transformation was a function of the dose of PF used. A concentration of 2000 μM PF completely inhibited the transformation; the same concentration of ET-PF had almost no effect.

Synthesis of Vaccinia Virus Polypeptides in the Presence of Isatin-β-Thiosemicarbazone

Isatin-β-thiosemicarbazone (IBT) at a concentration of 14 μM inhibited the multiplication of vaccinia virus in HeLa cells. For the first 3 h after infection, viral deoxyribonucleic acid (DNA) was synthesized in the presence of IBT at the same rate as in the control culture; the replication rate declined at a later stage. The DNA failed to be coated with proteins and to become resistant to deoxyribonuclease unless IBT was removed. “Early” and “late” viral polypeptides were formed in the presence of IBT, as revealed by polyacrylamide gel electrophoresis. The formation from precursor of a core polypeptide, a reaction blocked by rifampin, was not affected by IBT. Therefore, it is suggested that a maturation step later than the one blocked by rifampin is involved in the inhibition of vaccinia virus by IBT. Images

Isolation and Characterization of an IBT-Dependent Mutant of Vaccinia Virus

The antiviral activity of thiosemicarbazones against poxviruses was reported by Hamre, Bernstein & Donovick (1950). Thiosemicarbazone derivatives are clinically used in India and Africa. Appearance of drug-resistant and drug-dependent mutants in the course of viral therapy is a potential danger. Appleyard & Way (1966) and Ghendon & Chernos (1972) observed the selection of thiosemicarbazone-derivatives resistant mutants, during growth of the wild-type strain in the presence of these drugs. We shall describe here the isolation and characterization of an isatin-β-thiosemicarbazone (IBT)-dependent mutant (IBTD) of vaccinia virus, which needs IBT for its growth. The characteristics of this mutant are compared with these of the wild-type (wt) strain and an IBT-resistant mutant (IBTR), isolated in our laboratory. The two vaccinia mutants IBTD and IBTR were isolated after treatment of cells infected with wt virus with the mutagenic agent iododeoxyuridine in the presence of IBT.