Biomedical subjects
Publications and source records attributed to S R Weiss.
Normative data are reported for the visual acuity, luminance-difference threshold and size-difference threshold of pigeons (Columba livia). The mean visual acuity was 12.66 c/deg or 2.53 min (N = 54), the mean log luminance-difference threshold was 0.11 (N = 105) and the mean size-difference threshold was 0.94 mm (N = 20).
cDNA clones that represent various portions of the coronavirus mouse hepatitis virus strain A59 genome RNA have been constructed. cDNAs were synthesized by transcription of genome RNA by using either oligo(dT) or random oligomers of calf thymus DNA as primers. These cDNAs were converted into double-stranded DNA and cloned into pBR322 by standard techniques. The resulting cloned viral DNA fragments were mapped to viral genes by hybridization with Northern blots of intracellular RNA from mouse hepatitis virus strain A59-infected cells. These cDNA clones map in six of the seven viral genes. Clone g344, 1.8 kilobases, is the largest and encompasses gene 5 (which encodes a nonstructural protein) and gene 6 (which encodes the E1 viral glycoprotein) as well as the intergenic regions preceding genes 5, 6, and 7. Sequencing of parts of this cloned DNA show that these three intergenic regions contain a common 11-nucleotide sequence. This sequence shares homology with the 3' end of the viral mRNA leader sequence. Thus, this common intergenic sequence may contain a binding site for a leader RNA that hybridizes to negative-strand viral RNA at the beginning of each gene to prime mRNA synthesis. The different degrees of homology between the leader and its putative binding site may influence the differential rates of transcription of the various viral mRNAs.
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Mouse hepatitis virus strain A59 produces chronic central nervous system demyelination in rodents. As late as 6 months after intracerebral inoculation of mice 4 to 6 weeks old, when infectious virus cannot be recovered and viral antigens cannot be detected in the central nervous systems and livers of these animals, primary demyelination is still evident. Using cloned virus-specific DNAs and the highly sensitive and specific technique of in situ hybridization, we have detected low levels of mouse hepatitis virus A59 RNA in the central nervous systems and livers of mice 10 months after inoculation. We suggest that viral persistence may play a role in mouse hepatitis virus A59-induced chronic demyelination.
CSF concentrations of serotonin and dopamine metabolites in 16 patients with anorexia nervosa were measured before and after probenecid administration, and the patients were studied before and at intervals after weight recovery. After probenecid administration, the weight-recovered nonbulimic anorexic patients had a higher concentration of the serotonin metabolite, 5-hydroxyindoleacetic acid, than the weight-recovered bulimic patients but no significant differences in CSF homovanillic acid. This finding is consistent with evidence that suggests a role for brain serotonin metabolism in carbohydrate and mood regulation.
Intracerebral inoculation of 4- to 6-week-old C57BL/6 mice with the A59 strain of mouse hepatitis virus (MHV), a murine coronavirus, produced biphasic disease. Acute hepatitis and mild meningoencephalitis were followed by subacute spastic paralysis with demyelinating lesions in the brain and spinal cord as determined by Epon-embedded toluidine-blue-stained sections and by electronmicroscopy. MHV-A59 was cultured by plaque assay from the blood, brain, spinal cord, and liver of infected mice during the acute phase, but not in the chronic stage. MHV-A59 antigen was detected by immunofluorescence (IF) until 3 months postinfection (PI). Serum anti-MHV-A59 antibodies were detected from 7 days to 5 months PI. The induction of demyelination by MHV-A59 provides a suitable system to study virus-induced demyelination further.
Lithium carbonate appears to inhibit the development of cocaine-induced behavioral sensitization while it does not inhibit the development of amygdala kindling. Lithium chloride did not inhibit kindled seizures. Carbamazepine does not inhibit cocaine-induced motor activity or the development of behavioral sensitization in the rat. Carbamazepine is highly effective in blocking completed amygdala-kindled seizures, but does not block their development in the rat. Lithium carbonate and carbamazepine, two drugs of use in the prophylactic treatment of affective illness, appear to have differential effects on sensitization and kindling.
Research has demonstrated that obesity is far more complex than simply eating too much. Although the individual who is only modestly overweight is probably guilty of overindulgence, the grossly obese individual is the victim of a far more complex disorder with genetic, metabolic, psychosocial, and perhaps central nervous system malfunctions all interacting in a poorly understood fashion. The medical consequences of morbid obesity are considerable and demand the patient's and the physician's attention. This article discusses pathogenesis, consequences, and approaches to treatment.
A cDNA probe representing the genome of mouse hepatitis virus (MHV) strain A59 (MHV-A59) was used to measure nucleotide sequence homologies among murine and human coronaviruses and the SD and SK coronaviruses isolated by Burks et al. Since SD and SK were isolated by inoculation of multiple sclerosis (MS) central nervous system (CNS) tissue into mice or cultured mouse cells, it is important to determine their relationships to other murine and human coronavirus isolates. Our results indicate that SD and SK share almost complete nucleotide homology (approximately 90%) with MHV-A59 and generate subgenomic RNAs of the same sizes as MHV-A59. The human coronavirus (HCV) strains tested show less homology with MHV-A59. The immunologically unrelated HCV-229E shows no nucleotide homology with MHV-A59. The immunologically cross-reactive HCV-OC43 shows nucleotide homology with MHV-A59 by blot hybridization but not when hybridized in solution and assayed by S1 nuclease digestion.
This study compares psychological traits, physical traits, behavior, demographic data, incidence of family pathology, incidence of life stress, and scores on eating disorder scales in a sample of normal-weight female bulimics with a sample of normal-weight female controls. The groups, matched for age, socioeconomic status, and I.Q. were found to have comparable physical traits, family demographics, incidence of family pathology, and incidence of life stress. However, bulimics demonstrated significantly higher levels of psychological pathology and impulsive behavior. There were significantly more suicide attempts, psychiatric hospitalizations, episodes of stealing, use of drugs, and menstrual disturbances among the bulimics than the controls. The bulimics consistently rated themselves sicker than the controls on all psychometric scales. Most notable were the depression, anxiety, obsessive-compulsive, and interpersonal sensitivity factors on the Symptom Checklist 90, and the internal control score on the Nowicki-Strickland Locus of Control Scale. The discussion includes a brief description of weight set-point theory and its role in the maintenance of bulimia.
Genome RNA of mouse hepatitis virus (MHV) strain A59 has been used as a template to synthesize two virus-specific probes: cDNArep, representing the majority of sequences of the genome RNA and cDNA3', representing the 3' end of the genome RNA. Molecular hybridization with these cDNAs was used to characterize both genome RNA and intracellular virus-specific RNAs. Hybridization of genome RNAs of MHV strains A59, JHM, and MHV-3 with A59 cDNArep showed that, although these three strains exhibit different pathogenicities, they contain closely related nucleotide sequences. Hybridization of intracellular RNA from MHV-infected cells with virus-specific cDNA shows that (i) the majority of virus-specific RNA is polyadenylated, (ii) virus-specific intracellular RNA contains six subgenomic species of the same polarity as genome RNA and (iii) all subgenomic RNAs contain the same 3' sequences as the genome RNA and thus form a nested set of RNAs.
The coding assignments of the intracellular murine hepatitis virus-specific subgenomic RNA species and murine hepatitis virion RNA have been investigated by cell-free translation. The six murine hepatitis virus-specific subgenomic RNAs were partially purified by agarose gel electrophoresis and translated in an mRNA-dependent rabbit reticulocyte lysate, and the cell-free translation products were characterized by gel electrophoresis, immunoprecipitation, and tryptic peptide mapping. These studies have shown that RNA 7 codes for the nucleocapsid protein, RNA 6 codes for the E1 protein, RNA 3 codes for the E2 protein, and RNA 2 codes for a 35,000-dalton nonstructural protein. Genomic RNA directs the cell-free synthesis of three structurally related polypeptides of greater than 200,000 in molecular weight.
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A four-year-old boy presented with a soft tissue mass containing ringlet calcifications associated with fracture and irregular osteolysis of the underlying public ramus. Although the radiographic appearance suggested malignancy, the evolution of the lesion confirmed that it was post-traumatic.