Biomedical subjects

S J Martin

Publications and source records attributed to S J Martin.

At least 145 records · Page 8Linked to original sources

PubMed1979

Preparation of human leukocytes for SEM observation: a modified technique.

Variations in the mode of preparation, type of fixation and leukocyte collection can plan an important part in the determination of the surface structure of a given population, and can result in modifications of the microprojections, and their number, evident on the cell surface. We present preparatory modes that circumvent these difficulties, and the results obtained clearly show that the techniques are profitable, appear essential for the preservation of cell population and integrity, and allow accurate scanning electron microscopy observations without resort to time consuming procedures. Indeed, the entire process can be completed in one day.

Erythrocytes↗

PubMed1977

The role of defective interfering particles in persistent infection of Vero cells by measles virus.

Persistent infections by measles virus were rapidly established in the majority of Vero cells when monolayers were infected with virus stocks that had been passed three to five times from an undiluted inoculum. These virus stocks had low infectivity titres but normal haemagglutinin titres and were able to cause interference. The ability of such virus stocks to establish persistent infections seems to be due to the presence of defective interfering particles rather than of virus mutants. Measles virus released from a persistently infected Vero cell line at the 93rd passage had properties similar to the undiluted passage virus that generated persistent infections.

Animals↗

PubMed1976

Persistent infection of tissue culture cells by RNA viruses.

In this paper, the characteristics of cultured cells persistently infected with RNA viruses, other than leuko viruses are described. The roles that the host cell, interferon, virus mutants and defective interfering particles may play in the establishment and maintenance of persistent infection are discussed. It is proposed that the interaction of viruses with certain types of host cells can lead to persistent infection. The differences in virus-host interactions may be attributable to differences in membrane properties of various cells. Defective interfering particles may play a role in the establishment of persistent infections in cells which normally undergo lytic virus development. Mutant types of virus appear to be prominent in the virus released from persistently infected cells, but the role that various mutants play in the maintenance of persistent infections remains unclear.

Antibodies, Viral↗

PubMed1976

A rapid method for the quantitative study of RNA from canine distemper virus infected cells.

Centrifugation through CsCl was used to isolate 32P-labelled RNA in a one-step purification procedure. The method is suitable for quantitative as well as preparative studies and appears to have considerable advantages over conventional methods of RNA extraction. We have used this procedure to investigate the RNA synthesized in Vero cells infected with canine distemper virus (CDV). We show that the combination of CsCl centrifugation and affinity chromatography on poly-U Sepharose provides a rapid method for isolating messenger RNA from virus infected cells.

Cell Line↗

PubMed1976

Genesis and maintenance of a persistent infection by canine distemper virus.

Vero cells were persistently infected with canine distemper virus by continuous undiluted passage of virus harvests. The cells were refractory to superinfection by both measles virus and canine distemper virus. These persistently infected cells produced and released into the medium a labile component which had a potent and selective inhibitory effect on the replication of canine distemper and measles virus. The inhibitory agent was not inactivated by u.v.-irradiation or sedimented by ultracentrifugation. Antisera against canine distemper virus or SSPE sera were able to block this inhibitory effect. We propose that these persistently infected cells produce an excess of a virus-induced regulatory protein.

Antiviral Agents↗

PubMed1975

Determination of the molecular weight of bovine enterovirus RNA by nuclease digestion.

The mol. wt. of a [32P]-labelled bovine enterovirus RNA has been determined by digesting with pancreatic RNase and separating the resulting oligonucleotides using a two-stage fractionation method on DEAE-Sephadex in 7 M-urea at pH 7-6 and pH 3-0. We have estimated the number of nucleotides as 8612 plus or minus 55. This corresponds to a mol. wt. of 2-93 plus or minus 0-02 X 10-6 which is in aggrement with estimates obtained by sedimentation and gel electrophoresis techniques.

Animals↗

PubMed1975

Acanthoma fissuratum--spectacle frame acanthoma.

The development of a cutaneous nodule at the site of friction of spectacles has been discussed by several authors. In all but one case the lesion occurred behind the ears. The only previous report of this acquired tumour occurring on the nose is that of Farrell & Wilson (4). It is suggested that this problem is relatively common and most frequently presents when mistaken for basal cell epithelioma or when identified in medical personnel. A further six cases of this neglected tumour occurring on the nose are described.

Adult↗

PubMed1974