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J T SYVERTON

Publications and source records attributed to J T SYVERTON.

At least 73 records · Page 4Linked to original sources
PubMed1953

Studies on the propagation in vitro of poliomyelitis viruses. IV. Viral multiplication in a stable strain of human malignant epithelial cells (strain HeLa) derived from an epidermoid carcinoma of the cervix.

The cells of a human epithelial cancer cultivated en masse have been shown to support the multiplication of all three types of poliomyelitis virus. These cells (strain HeLa of Gey) have been maintained in vitro since their derivation from an epidermoid carcinoma of the cervix in February, 1951. As the virus multiplied it caused in from 12 to 96 hours degeneration and destruction of the cancer cells. The specific destructive effect of the virus was prevented by adding homotypic antibody to the cultures but not by adding heterotypic antibodies. Methods for the preparation of large numbers of replicate cultures with suspensions of strain HeLa cells were described. The cells in suspension were readily quantitated by direct counts in a hemocytometer. A synthetic solution that maintains cellular viability was employed for viral propagation. The experimental results demonstrate the usefulness of strain HeLa cells for (a) the quantitation of poliomyelitis virus, (b) the measurement of poliomyelitis antibodies, and (c) the production of virus.

Antibodies↗
PubMed1952

Studies on the propagation in vitro of poliomyelitis viruses. I. Viral multiplications in tissue cultures employing monkey and human testicular cells.

Poliomyelitis virus was propagated in vitro successfully in extraneural tissues. Suspended tissue fragment cultures and combined plasma clot-suspended tissue fragment cultures of monkey or human testicular tissues were employed. Five strains representative of poliomyelitis virus were maintained for from 36 to 263 days in the suspended tissue fragment type of culture. The dilution factors calculated by tissue replacements for the eight serial passages ranged from 10(7.8) to 10(44.5) and when assessed by fluid replacements, from 10(15) to 10(95.3). The LD(50) for each strain of Type 2 virus was determined for selected transfers. The identify of each strain of virus was established by neutralization tests and histopathological findings in monkeys dead from the injection of tissue culture virus. Control experiments and other tests made known that propagation of poliomyelitis virus did not occur in the absence of viable testicular cells and that an extraneous virus was not inadvertently acquired during the course of these studies.

Animals↗
PubMed1952

Studies on the propagation in vitro of poliomyelitis viruses. II. A description of the growth curve and its relation to the cytopathogenicity of poliomyelitis virus.

The growth of poliomyelitis virus, Type 2, Yale-SK strain, in cultures of monkey testicular tissue was observed to occur in discrete cycles. Growth curves showed that each cycle was composed of (a) an initial lag phase when little or no virus was released from the cells, (6) a phase of viral production, and (c) a plateau which represented a decrement in the rate of viral production. This pattern of viral multiplication occurred in monkey testicular tissue cultures which have as the liquid phase either ox serum ultrafiltrate or monkey serum-chicken embryonic extract medium. The presence of a solid medium composed of chicken plasma, clotted either with chicken embryonic extract or bovine thrombin, did not alter the pattern of viral multiplication. The shape of the growth curve as established by any of four different techniques for tissue cultivation, was shown to be independent of the cultural technique employed. For cultures of monkey testicular tissue, the amount of virus in the tissue was as much as tenfold greater than that in the liquid of the same cultures. Moreover, viral production was evident earlier and was detectable for a longer period of time in the tissue than in the liquid phase. The rapidly incremental phase of the growth cycle, when large quantities of virus were released into the liquid phase, coincided in time with the destruction of the spindle-shaped cells, which extended from the explants. Although destruction of outgrowth cells was marked, there remained cells within the explants capable of supporting the growth of poliomyelitis virus.

Humans↗
PubMed1952

Studies on the propagation in vitro of poliomyelitis viruses. III. The propagation of poliomyelitis viruses in tissue cultures devoid of nerve cells.

Cells like fibroblasts, having no resemblance whatever to nerve cells were obtained in morphologically pure cultures from monkey testicular tissue and were found to support the growth in vitro of poliomyelitis virus, Type 2, Yale-SK strain. Moreover, these cells were destroyed as a result of the multiplication of this virus within them. Similarly, "fibroblasts" propagated in primary explant cultures of testicle were destroyed by poliomyelitis viruses, Types 1 and 2. Type specific antibodies neutralized the pathogenic effect of poliomyelitis virus on monkey testicular fibroblasts.

Fibroblasts↗