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D L Rock

Publications and source records attributed to D L Rock.

At least 73 records · Page 4Linked to original sources
PubMed1993

Virulent African swine fever virus isolates are neutralized by swine immune serum and by monoclonal antibodies recognizing a 72-kDa viral protein.

Convalescent swine serum to African swine fever virus (ASFV) isolate E75 neutralized the infectivity of virulent ASFV isolates E75, E70, Lisbon 60, Malawi Lil 20/1 and a low passage tissue culture adapted variant of E75, E75CV/V3, by 86-97% in Vero and macrophage cell cultures. A monoclonal antibody, mAb-135D4, recognizing an ASFV protein of 72 kDa also exhibited strong neutralizing activity with these viruses. Unexpectedly, both E75 immune sera and mAb-135D4 failed to neutralize high passage tissue culture adapted ASFV variants including Lisbon 60, Haiti, Dominican Republic I, Dominican Republic II, and Brazil II, even though mAb-135D4 reacted with all viruses. These results suggest that tissue culture adaptation of ASFV isolates may be associated with loss of specific determinants associated with virus neutralization. To our knowledge, this is the first report of an ASFV neutralizing epitope.

Adaptation, Biological↗
PubMed1993

Three adjacent genes of African swine fever virus with similarity to essential poxvirus genes.

Nucleotide sequencing of the right end of the SalIj fragment of the highly virulent Malawi Lil20/1 strain of African swine fever virus (ASFV) has revealed three adjacent genes with similarity to: serine-threonine protein kinases; members of the putative helicase superfamily SF2; and the vaccinia virus 56 kDa abortive late protein. All three genes are transcribed to the left with respect to the orientation of the ASFV genome. Gene L19IL predicts a protein similar to serine-threonine protein kinases including vaccinia virus gene B1R. Gene L19KL predicts a protein that is likely to be a nucleic acid-dependent ATPase, as it has similarity to both the poxvirus 70 kDa early transcription factor subunit and the poxvirus nucleoside triphosphatase I gene. Gene L19LL has extensive similarity to the vaccinia virus 56 kDa abortive late protein.

African Swine Fever Virus↗
PubMed1993

An African swine fever virus gene with similarity to the proto-oncogene bcl-2 and the Epstein-Barr virus gene BHRF1.

An open reading frame, LMW5-HL, in the African swine fever virus genome displays a high degree of similarity to the proto-oncogene bcl-2 and, to a lesser degree, the Epstein-Barr virus gene BHRF1. A highly conserved central region is found in all three proteins. LMW5-HL encodes a protein of 18 kDa that is present in infected porcine macrophages at both early and late times postinfection. The similarity of LMW5-HL to bcl-2 and BHRF1 suggests a role for it in cell maintenance during productive or persistent viral infection.

African Swine Fever Virus↗
PubMed1992

Characterization of p30, a highly antigenic membrane and secreted protein of African swine fever virus.

We have identified and characterized a 30-kDa phosphoprotein (p30) of African Swine Fever Virus (ASFV) that is synthesized, membrane localized, and released into the culture medium at early times after infection. Sequence analysis of the p30 open reading frame predicts a highly antigenic protein with putative phosphorylation, glycosylation, and membrane attachment sites.

African Swine Fever Virus↗
PubMed1992

A murine model of pseudorabies virus latency.

The mouse is a useful laboratory animal for studying various aspects of pseudorabies virus (PRV) virulence. Mice are highly susceptible hosts for PRV infection and are unable to survive acute viral infection. Because of this, mouse models have not been useful for studying PRV latent infections. Here, we report an efficient strategy for establishing latent PRV infections in laboratory mice. Passive transfer of high titered neutralizing antibodies to mice prior to inoculation with highly lethal doses of PRV (Bartha) resulted in survival rates of at least 60% with establishment of latent infections in survivors. Latent PRV infection in mice was demonstrated by: (1) recovery of infectious PRV-Bartha from explants of trigeminal ganglion (TG), and (2) detection of PRV nucleic acids in latently infected TGs by in situ hybridization and polymerase chain reaction (PCR), between 2-8 months post-infection. This PRV latency model indicates that attenuated PRV strains, those currently used extensively in vaccination programs worldwide, can establish a reactivatable latent infection in an experimental host. The mouse model may be particularly useful for examining the molecular bases of PRV latency and reactivation.

Animals↗
PubMed1992

An empirical evaluation of three components of the tetrahedron model of clinical judgment.

The tetrahedron model of clinical judgment (Rock, Bransford, Maisto, and Morey, Clin. Psychol. Rev. 7:645-661, 1987; Rock, Bransford, Morey, and Maisto, Clin. Psychol. Rev. 8:411-416, 1988) provides a framework for identifying factors that may influence the judgments of psychotherapists (e.g., clinical and counseling psychologists, psychiatrists, social workers, etc). Three parameters of the model were experimentally manipulated: mode of of presentation of clinical information, patient, and judgment task. Sixteen clinical psychology graduate student therapists evaluated two patients on axis I and axis II of the DSM-III. Judgmental accuracy was influenced by main effects and two- and three-way disordinal interactions among the three model parameters. Additionally, we found that judgemental accuracy was positively related to experience and training. This relationship was evident only when experience was assessed with specific rather than general measures, and when the clinical materials were presented in an audiovideo format and hence resembled the conditions under which the clinicians in the study acquired that training and experience. Implications for the design of training programs that facilitate competency in clinical judgment are discussed.

Adult↗
PubMed1992

Identification of an African swine fever virus gene with similarity to a myeloid differentiation primary response gene and a neurovirulence-associated gene of herpes simplex virus.

Here we describe an open reading frame (LMW23-NL) in the African swine fever virus genome that possesses striking similarity to a murine myeloid differentiation primary response gene (MyD116) and the neurovirulence-associated gene (ICP34.5) of herpes simplex virus. In all three proteins, a centrally located acidic region precedes a highly conserved, hydrophilic 56-amino-acid domain located at the carboxy terminus. LMW23-NL predicts a highly basic protein of 184 amino acids with an estimated molecular mass of 21.3 kDa. The similarity of LMW23-NL to genes involved in myeloid cell differentiation and viral host range suggests a role for it in African swine fever virus host range.

African Swine Fever Virus↗
PubMed1990

Detection of latent pseudorabies virus in swine using in situ hybridization.

We have examined methods for detection of pseudorabies virus (PRV) latency in three groups of swine; naturally infected animals obtained from a field case; animals which have been experimentally infected with Becker or Iowa strains of PRV; and single reactors (single seropositive animals within PRV-free herds). In situ hybridization was shown to be more sensitive than explanation/co-cultivation for the detection of latent virus. Nervous tissues, in particular the trigeminal ganglia, were found to be the most reliable source for detecting latent PRV. The presence of latent PRV was not detected in lymphoid tissues examined.

Animals↗
PubMed1988

Empirically derived Symptom Checklist 90 subgroups of chronic pain patients: a cluster analysis.

Four hundred fifty-three chronic pain patients completed a Symptom Checklist 90 (SCL-90) and a comprehensive pain evaluation questionnaire. All patients were evaluated by a physician and rated on degree of pain pathology and pain behavior. The SCL-90 data were analyzed using two clustering procedures and replicated over two similar samples. Three distinct profiles emerged and represented high, medium, and low scores on the SCL-90. No differences were found between subgroups on demographic characteristics, compensation status, pain duration, or pain ratings. Patients in the high-profile subgroup showed the most emotional distress, reported that their pain interfered the most with all activities, and were most often judged to have high pain behavior. Little evidence was found to support a "denial" profile, as previously predicted. Further support was found for using the SCL-90 in assessing chronic pain patients.

Activities of Daily Living↗
PubMed1987

The derivation and validation of six Multidimensional Health Locus of Control Scale clusters.

The purpose of this research was twofold. First, to determine if eight Multidimensional Health Locus of Control types hypothesized by Wallston and Wallston (1982) existed. Second, to assess the reliability, validity, and clinical utility of the control types. Two investigations were conducted based on research procedures designed for the discovery of clusters. The first study involved the derivation and replication of MHLC clusters with a sample of 400 healthy undergraduate men and women. The results of Study 1 suggested the existence of six MHLC clusters: pure internal; double external; pure chance; yea sayer; nay sayer, and believer in control. The sample for Study 2 consisted of 90 female undergraduate and graduate students. The six-cluster solution was replicated in this second cross-validation study. Furthermore, construct validity of the clusters was established through computer simulation. Finally, relationships between clusters and the Krantz Health Opinion Survey suggested the clusters have a theoretical as well as a empirical foundation. The implications of these findings for clinical practice, for the development of the health locus of control construct, and for future research on the MHLC Scale are discussed.

Adolescent↗
PubMed1987

Latent herpes simplex virus type 1 DNA is not extensively methylated in vivo.

The methylation pattern of herpes simplex virus type 1 (HSV-1) DNA, present in the central nervous system of latently infected mice, was examined by digestion of the DNA with methylation-sensitive restriction endonucleases and Southern blot hybridization. Using the enzymes SmaI, XmaI, SalI and SacII, the data indicate no extensive methylation of latent HSV-1 DNA in vivo. Thus, extensive methylation of the viral genome is not a necessary condition for, or a consequence of maintaining, the latent state in vivo.

Animals↗
PubMed1987

Detection of latency-related viral RNAs in trigeminal ganglia of rabbits latently infected with herpes simplex virus type 1.

Using a combination of in situ hybridization and Northern (RNA) blot analysis, we investigated herpes simplex virus type 1 (HSV-1) transcriptional activity in an ocular rabbit model of HSV-1 latency. Radioactively labeled cloned fragments, representing virtually the entire HSV-1 genome, were individually hybridized to RNA in sections of trigeminal ganglia taken from rabbits during the latent phase of infection with HSV-1 (McKrae). Our results suggest that two discrete latency-related RNAs (LR-RNAs) may be present. The LR-RNAs were localized mainly in the nuclei of neurons. The more abundant LR-RNA was detected in approximately 3% of all neurons examined and was designated major LR-RNA. The other LR-RNA, designated minor LR-RNA, was detected in approximately 0.3% of neurons from latently infected rabbits. The genes for the LR-RNAs mapped in the vicinity of the immediate-early gene ICP0 (also designated IE110). The gene for the major LR-RNA partially overlapped the left (3') end of the ICP0 gene. In situ hybridization with single-stranded RNA probes showed that this LR-RNA was of complementary sense to that of ICP0 mRNA. Northern blot analysis gave an approximate size for this LR-RNA of 1.8 to 2.2 kilobases. The minor LR-RNA mapped to or near the right (5') end of the ICP0 gene. The detection of LR-RNAs suggests the possibility that these RNAs or their products may play significant roles in the initiation and/or maintenance of HSV-1 latency.

Animals↗
PubMed1987

Mapping bovine herpesvirus type 1 latency-related RNA in trigeminal ganglia of latently infected rabbits.

Here we have used the bovine herpesvirus type 1 (BHV-1) rabbit model together with in situ nucleic acid hybridization to identify and map viral RNA present in latently infected neurons. Radioactively labeled cloned HindIII fragments representing most of the BHV-1 genome (Cooper strain) were individually hybridized to sections of trigeminal ganglia taken from rabbits during acute and latent stages of infection. Whereas all viral genomic fragments hybridized to lytically infected tissue culture cells and to acutely infected ganglia, only HindIII fragment D (map units 0.734 to 0.842) hybridized to latently infected ganglionic neurons. Additional in situ hybridization experiments using subcloned fragments of HindIII-D further mapped the latency-related viral RNA to a 1.9-kilobase region (map units 0.734 to 0.748) of the viral genome. These results indicate that BHV-1 gene transcription is restricted during the latent phase of infection; further, they suggest that specific viral transcription may be involved in establishment or maintenance of latent BHV-1 infection.

Animals↗