African Green Research Articles

Vitamin B 12 binding proteins in monkey serum and red cells

The vitamin B- 12 binding proteins in Rhesus and African Green monkey serum and red cells were isolated by ion-exchange and molecular sieve chromatography. Vitamin B 12 added in vitro to monkey serum and lysed red cells was bound by monkey Transcobalamin II and a red cell binder, respectively, and these vitamin B 12 binding substances cross-reacted with antisera to their human homologues. Most of the native vitamin B 12 in monkey serum was also attached to monkey Transcobalamin II rather than to Transcobalamin I which is the predominant binder of native vitamin B 12 in human serum.

Identification and properties of complex forms of SV40 DNA isolated from SV40-infected african green monkey (BSC-1) cells

1. 1. The occurrence of complex forms of SV40 virus DNA has been studied in African Green monkey kidney (BSC-1) cells infected with SV40 virus. Covalently closed circular duplex DNA was isolated from SV40-infected BSC-1 cells with a procedure based upon the selective resistance of such molecules to irreversible alkali denaturation. Electron microscopic and ultracentrifugal examinations of this DNA revealed the presence of circular forms of multiple viral length. The intracellular SV40 DNA isolated 60 h after infection was found to contain about 1 % each of catenated dimers and circular dimers. A similar frequency of circular trimers was found. The trimer-sized molecules may be in part mitochondrial DNA molecules of identical size. 2. 2. Viral growth in the presence of 10 μg/ml ethidium bromide had no effect on the relative frequencies of these oligomeric forms, and little or no effect on the over-all yield of intracellular SV40 DNA or progeny virions. Both infected and non-infected BSC-1 cells were also found to contain a heterogeneous population of “minicircular” DNA's.

麻しんウイルスのVero細胞へのPenetration その測定および2, 3の性質について

Penetration of measles virus (Toyoshima strain) in African Green monkey kidney-derived Vero cells was studied in detail.Treatment of cell-virus complex with pH 3.0, 5 minutes' pulse was found effective to exterminate viral infectivity without leaving any disturbance on viabilities of cell and infective center. Hyperimmune antiserum of guinea pig against measles virus was not potent enough in eliminating free and cell-attached viruses from reaction mixture in a short time.Therefore, ‘penetrated virus’ is defined in this paper as a survived infective center after the low pH treatment.Penetration, thus determined, followed the first order kinetics, and its initial velocity was enhanced by centrifugal force applied to the cell-virus complex.This process was found being dependent on reaction temperature, nutritional condition of the cell, inhibited by added monoiodoacetate and sodium fluoride, not by potassium cyanide or sodium malonate.Anticellular guinea pig serum, when treated prior to viral adsorption, suppressed the penetration markedly.These findings strongly suggested the identity of the most part of this process to the well-established phagocytotic activity of cells.Trials to locate the site where specificity of viral infection being regulated are now underway.

Differences in cytopathic effects of adenovirus in monkey kidney tissue culture.

Prototype strains for human adenovirus types 1 to 18 have been inoculated into primary Rhesus (Macacca mulatta) and African Green (Cercopithecus aethiops) monkey kidney cultures and give rise to two distinct types and a less obvious type of CPE. Rhesus kidney cultures give better resolution than do African Green. Types 1 to 18 are placed into 3 groups on the basis of the kind of CPE elicited and with a single exception these groups are identical to those suggested by Rosen(6) based on hemagglutination. Fourteen strains from type 12 were tested and all gave identical CPE, indicating that differences are probably type rather than strain oriented. Viruses from 2 different groups can be mixed with specific antiserum for one of the pair and the antiserum will selectively inhibit the CPE of only the homologous virus.

Comparative Observations on Experimental Schistosoma mansoni Infections in African Green and Rhesus Monkeys

The pattern of egg excretion and the number of schistosomes are compared in five African green (Cercopithecus aethiops pygerythrus and C. aethiops sabaeus) and five rhesus monkeys. Egg excretion in the green monkey was lower during the acute phase and declined more slowly thereafter. The green monkeys maintained a significantly higher number of worms over a period of many months. The number of eggs passed by green monkeys during chronic infections was much less than would be expected from the number of live worms recovered at autopsy. Although primate hosts are valuable in schistosomiasis research, rhesus monkeys, which have been used mostly, rapidly develop strong immunity to schistosomes which reduces the worm burden and egg excretion (Meleney and Moore, 1954; Vogel, 1958; Naimark et al., 1960; Meisenhelder, Olszewski, and Thompson, 1960; Sadun et al., 1961; Thompson, Meisenhelder, and Najarian, 1962). Although improvisations permit the evaluation of drugs against Schistosoma mansoni infection in the rhesus monkey (Thompson et al., 1962), acquired immunity limits its value for this and many other purposes. The importance of searching for a primate host better than the rhesus monkey has been emphasized in a report to the World Health Organization (1959). Vogel (1958) stated, without elaboration, that the survival of S. mansoni and the duration of its egg excretion is much longer in African green monkeys than in the rhesus. These considerations stimulated the present observations dealing with the course of S. mansoni infection in African green monkeys relative to rhesus monkeys. MATERIALS AND METHODS The animals infected during this work included three Cercopithecus aethiops pygerythrus (the East African green monkey) and two C. aethiops sabaeus (the West African green monkey). Four of these were studied in parallel as pairs with a monkey of each subspecies in each pair, i.e., numbers 25 and 138, 38 and 39. Received for publication 9 January 1963. As detailed accounts appear elsewhere (Najarian and Thompson, 1958; Thompson et al., 1962), the materials and techniques will be described only briefly. The monkeys were anesthetized intravenously with sodium thiamylal (Surital ?, Parke, Davis and Co.) and exposed percutaneously for 45 min to S. mansoni cercariae (Puerto Rican strain) collected from 30 or more Australorbis glabratus. The course of infection was followed by semiquantitative stool examinations for eggs; acidether preparations of 1 ml of feces were examined twice weekly from the 5th week after exposure until autopsy. Egg counts were not adjusted for the water content of the feces. Infections were assessed terminally by the number of live worms found at autopsy; following perfusion, the mesenteric and portal veins, the ground liver, and the perfusate were examined for schistosomes.

Two variants of tick-borne encephalitis virus showing different plaque morphology

Dengue virus type 2 from infected human serum has been adapted to DBS-FRhL-2 and WI-38 cells which are candidate substrates for virus vaccine production. Initially, the infected DBS-FRhL-2 monolayers were refed with maintenance medium and were reharvested after prolonged incubation. With WI-38 cells, virus could be recovered only if previously passaged in DBS-FRhL-2 or primary African Green monkey kidney cells. Peak titers of 106 per 0·2 ml were obtained with DBS-FRhL-2 cells whereas maximum titers of 105 per 0·2 ml were obtained with WI-38 cells. After six passages in the two cell strains there appeared to be no attenuation of the virus in terms of mouse neurovirulence.