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Biomedical subjects

R B Tenser

Publications and source records attributed to R B Tenser.

At least 55 records · Page 3Linked to original sources
PubMed1983

Thymidine plaque autoradiography of thymidine kinase-positive and thymidine kinase-negative herpesviruses.

Plaques formed by herpes simplex virus (HSV), pseudorabies virus, and varicella-zoster virus were studied by plaque autoradiography after [14C]thymidine labeling. Standard thymidine kinase-positive (TK+) viruses and TK- mutants of HSV types 1 and 2 and pseudorabies virus were studied, including cell cultured viruses and viruses isolated from animals. Autoradiography was performed with X-ray film with an exposure time of 5 days. After development of films, TK+ plaques showed dark rims due to isotope incorporation, whereas TK- plaques were minimally labeled. Plaque autoradiography of stock TK- viruses showed reversion frequencies to the TK+ phenotype of less than 10(-3). Autoradiography indicated that TK- virus retained the TK- phenotype after replication in vivo. In addition, it was shown that TK- HSV could be isolated from mouse trigeminal ganglion tissue after corneal inoculation of TK- HSV together with TK+ HSV. The plaque autoradiographic procedure was very useful to evaluate proportions of TK+ and TK- virus present in TK+-TK- virus mixtures.

Animals↗
PubMed1982

Detection of herpes simplex virus mRNA in latently infected trigeminal ganglion neurons by in situ hybridization.

Latent infection of the trigeminal ganglion with herpes simplex virus type 2 (HSV-2) was studied in guinea pigs by in situ DNA hybridization. Frozen ganglion sections from animals killed during the period of latent virus infection were studied under nondenaturing conditions. Some sections were treated with deoxyribonuclease (DNase) or ribonuclease (RNase) before incubation with HSV DNA probes. HSV probes consisted of viral DNA nick translated and labeled in vitro with tritiated nucleotides. Bacteriophage lambda DNA, similarly prepared, was used as a control probe. The lambda probe was negative in all situations, including HSV-2-infected monolayer cells in cell culture. HSV-2 probes produced heavy label and, therefore, evidence of hybridization with HSV-2-infected monolayer cells. When HSV-2 probes were incubated with latently infected ganglion sections, hybridization was detected in 71% of guinea pigs and 46% of ganglia. Label was seen only in neurons, and in positive ganglia 0.3 to 5% of neurons were labeled. The amount of label was markedly decreased by pretreatment of ganglion sections with RNase but not DNase, indicating that the DNA probes hybridized to HSV messenger RNA in the latently infected ganglia.

Acute Disease↗
PubMed1982

Nevoid basal cell carcinoma syndrome and epilepsy.

Four patients affected with the nevoid basal cell carcinoma syndrome and recurrent seizures are described and the pertinent literature is reviewed. Three of the patients had multiple basal cell carcinomas and cutaneous nevi, dentigerous cysts, and skeletal anomalies characteristic of the syndrome. The seizures had their onset in childhood and were generalized tonic-clonic in three patients and both tonic-clonic and complex partial in the fourth. Focal neurological deficits were found in only one patient. Pneumoencephalography in two patients and head CT scan in a third were negative. Electroencephalography showed focal spike discharges in one patient, bilateral anterior paroxysmal slowing in another, and nonspecific shifting temporal theta transients in the other two cases. Psychometric testing yielded full-scale scores ranging from 39 to 84. In addition to mental retardation, congenital communicating hydrocephalus, and medulloblastoma, seizures should be included among the neurological manifestations of the nevoid basal cell carcinoma syndrome.

Basal Cell Nevus Syndrome↗
PubMed1981

Rescue of a cytopathic paramyxovirus from peripheral blood leukocytes in subacute sclerosing panencephalitis.

An infectious, cytopathic paramyxovirus was rescued from the peripheral blood leukocytes of a patient with subacute sclerosing panencephalitis (SSPE) by cocultivation procedures. Cells infected with the virus (1) demonstrated polykaryocytosis, (2) contained cytoplasmic inclusion bodies of paramyxoviral nucleocapsids, (3) hemadsorbed monkey erythrocytes, and (4) reacted with fluorescein-conjugated antisera to measles virus. On the basis of these observations, the virus was initially believed to be measles-like virus similar to those that have been rescued from other patients with SSPE. However, subsequent immunologic and molecular studies showed that the virus was distinct from measles virus and was more closely related to simian virus 5. These findings suggest that paramyxoviruses other than measles virus can be nonproductively carried by patients with SSPE and should not be designated as "measles like" or "measles related" solely on the basis of their biologic characteristics.

Adolescent↗
PubMed1980

Mechanisms of herpes simplex virus infectivity enhanced by ultracentrifugal inoculation.

Ultracentrifugation of very dilute suspensions of herpes simplex virus directly onto monolayer cells grown in centrifuge tubes was studied. Enhanced infectivity by ultracentrifugation was similar at 4 degrees C and at 35 to 37 degrees C. The high infectivity levels of cultures centrifuged at 4 degrees C were further examined by infectious center assays. At 4 degrees C, the numbers of infectious centers in control (noncentrifuged) cultures were almost 100-fold fewer than in control cultures at 37 degrees C. However, the numbers of infectious centers in cultures ultracentrifuged at 4 degrees C were similar to those ultracentrifuged at 37 degrees C. The great difference in the numbers of infectious centers between 4 and 37 degrees C control cultures, in contrast to the similarity between 4 and 37 degrees C ultracentrifuged cultures, indicated that ultracentrifugation at 4 degrees C enhanced infectivity possibly by facilitation of herpes simplex virus penetration into monolayer cells.

Animals↗
PubMed1979

Trigeminal ganglion infection by thymidine kinase-negative mutants of herpes simplex virus.

The incidence of trigeminal ganglion infection after corneal inoculation of guinea pigs with thymidine kinase-negative mutants of herpes simplex virus was markedly reduced compared to infection after inoculation of thymidine kinase-positive virus. Thymidine kinase-negative herpes simplex virus replicated well in ocular tissues in which dividing or potentially dividing cells were present, but not in trigeminal ganglion infection of nondividing neurons. Thymidine kinase-positive virus, however, replicated well in ocular tissues as well as in trigeminal ganglion. These results suggest that thymidine kinase expression of herpes simplex virus may be important in infections of sensory ganglia.

Animals↗
PubMed1978

Oncornavirus particles in neurons of guinea pig trigeminal ganglion.

Virus-like particles morphologically similar to oncornaviruses were observed in trigeminal ganglion neurons of two normal, random-bred, adult Hartley guinea pigs. Only a few neurons showed virus particles, but the particles were numerous in the cells in which they were present. Extracellular virus particles were not observed. Similar oncornavirus particles were observed in trigeminal ganglion explant cultures derived from normal guinea pigs after treatment with bromodeoxyuridine. Both intracellular and extracellular particles were frequently observed in and around supporting cells. Intracytoplasmic oncornavirus-like particles were occasionally observed within neurons. These results support consideration that trigeminal ganglion and other sensory ganglion neurons may be primary sites for latent oncornavirus infection of the nervous system.

Animals↗
PubMed1978

Ultracentrifugal inoculation of herpes simplex virus.

By ultracentrifugation of 30 ml of highly dilute suspensions of herpes simplex virus (HSV) directly onto monolayer cultures grown in centrifuge tubes, infectivity was significantly greater than without centrifugation. Ultracentrifugation at 20,000 to 25,000 rpm (28,000 to 45,000 X g) for 1.5 to 2.3 h was utilized with good preservation of cultures. With low-speed centrifugation at 3,000 rpm (1,100 X g), infectivity was almost 10-fold greater than without centrifugation. With ultracentrifugal inoculation, infectivity was about 100-fold greater than without centrifugation. Ultracentrifugal inoculation permitted the detection of HSV at concentrations as low as 0.05 plaque-forming units per ml. Similarly, ultracentrifugal inoculation of cultures was almost 100-fold more sensitive a method of detecting infectious HSV than was pelleting HSV from dilute suspensions followed by resuspension and inoculation of cultures. Ultracentrifugal inoculation of cultures may permit the isolation of HSV in situations where virus cannot be detected by ordinary means and may prove applicable to the study of other viruses.

Cells, Cultured↗
PubMed1977

Pathogenesis of latent herpes simplex virus infection of the trigeminal ganglion in guinea pigs: effects of age, passive immunization, and hydrocortisone.

Latent herpes simplex virus (HSV) infection of the trigeminal ganglion, after corneal inoculation of virus, was investigated in guinea pigs. The effects of several factors on the establishment of ganglionic latency were investigated. Latently infected guinea pigs were clinically normal, and virus was isolated from the trigeminal ganglia by co-cultivation. It was found that newborn guinea pigs were significantly more susceptible than adult animals to the development of latent HSV infection of the trigeminal ganglion. The susceptibility of newborn guinea pigs was very much decreased, however, if they received passive immunization with immune serum or if they were born of actively immunized mothers. On the other hand, the susceptibility of adult animals, usually somewhat resistant to the development of latent HSV ganglionic infection, was markedly increased by the parenteral administration of hydrocortisone.

Aging↗
PubMed1976

Comparison of guinea pig cytomegalovirus and guinea pig herpes-like virus: growth characteristics and antigentic relationship.

The growth characteristics of guinea pig cytomegalovirus (GPCMV) and guinea pig herpes-like virus (GPHLV) in cell cultures were compared. Guinea pig fibroblast cells were highly susceptible to infection with both viruses, whereas guinea pig kidney cells were sensitive only to GPHLV. No cytopathic effect was observed in the latter cell system after infection with GPCMV,nor was there an increase in virus titer, although the cirus persisted in the kidney cells for 2 to 3 weeks postinfection. Electron microscope studies showed nonvirion tubular structures in GPCMV -infected fibroblast cells, but not in GPHLV- infected cells. Large packages of enveloped nuclear virus particles were commonly seen in GPHLV -infected cells, especially kidney epithelial cells, but none were found in the GPCMV -infected fibroblasts. Complete enveloped extracellular virus particles were present in both virus-cell systems. Both viruses showed narrow host spectra and replicated well only in guinea pig cells although GPHLV multiplied to some degree in rabbit cells. No antigenic relationship could be demonstrated between the two viruses using antisera specific for each virus that was produced in rabbits and guinea pigs. Rabbits produced high neutralizing antibody titers to GPHLV, whereas guinea pigs were the animals of choice for GPCMV antiserum production.

Animals↗
PubMed1976

Comparison of guinea pig cytomegalovirus and guinea pig herpes-like virus: pathogenesis and persistence in experimentally infected animals.

The pathogenesis of guinea pig cytomegalovirus (GPCMV) and guinea pig herpes-like virus (GPHLV) in guinea pigs was compared. Animals were inoculated with the two viruses by different routes and sacrificed after varying periods of time. GPCMV was consistently isolated from salivary gland 2 weeks postinoculation and thereafter following intraperitoneal or subcutaneous incoulaton. Virus was less frequently found in other tissues including blood, spleen, and kidney. Intranuclear inclusions were seen in tissue sections of salivary gland after inoculation with GPCMV- infected tissue suspension, but were only rarely found after inoculation with tissue culture virus. In GPHLV-infected guinea pigs, consistent latent infection of leukocytes and other tissues was detected by cocultivation techniques. Intranuclear inclusions were not found in the spleen, salivary gland, or other infected tissues after GPHLV infection with either tissue culture virus or infected tissue suspension. Guinea pigs inoculated with GPCMV produced high titers of specific neutralizing antibody to the homologous virus; those inoculated with GPHLV developed long-term viremia accompanied by minimal neutralizing antibody levels to the virus.

Animals↗