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Biomedical subjects

A Brown

Publications and source records attributed to A Brown.

At least 523 records · Page 29Linked to original sources
PubMed1982

Mouse EcoRI satellite DNA contains a sequence homologous to the long terminal repeat of the intracisternal A particle gene.

EcoRI restriction endonuclease fragments from the mouse 1,350-base-pair EcoRI satellite sequence were cloned in pBR322 plasmid. One of these fragments, SAT-1, was hybridized to various restriction fragments from cloned mouse intracisternal type A particle (IAP) genes and to mouse total genomic DNA. Hybridization occurred between the SAT-1 sequence and each of the IAP clones. The common region of hybridization in each of the clones was the long terminal repeat region of the IAP genes.

Animals↗
PubMed1982

Pharmacokinetics of single-dose erythromycin in normal and alcoholic liver disease subjects.

Six normal males and eight male subjects with alcoholic liver disease (ALD) and ascites were given a single 500-mg dose of erythromycin base. Twelve serum samples were collected at 0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 16, and 24 h after dosing and assayed microbiologically for erythromycin concentration. Absorption was characterized by a zero-order model for both groups. ALD subjects demonstrated a shorter lag time (2.0 versus 3.0 h), an earlier peak (4.6 versus 6.3 h, P less than 0.05), and higher peak concentrations (2.04 versus 1.50 micrograms/ml) than normal subjects. Previously unreported biphasic elimination kinetics after oral dosing were observed in five and four ALD subjects. In the ALD group, the mean half lives for the first (alpha) and terminal (beta) phases were 1.6 and 4.5 h, respectively, and in normal subjects, were 1.3 and 6.6 h. The difference in alpha between groups was significant, P less than 0.05. The clinical significance of this finding for ALD patients receiving prolonged courses of erythromycin is discussed.

Absorption↗
PubMed1982

Isolation of Pittsburgh pneumonia agent from a hospital shower.

Tatlockia (Legionella) micdadei, the Pittsburgh pneumonia agent, was isolated from a hospital shower. Although it was not possible, at the current time, to establish an epidemiological link to disease acquisition, this information may be significant because it provides further evidence that a water-associated reservoir of this organism exists within the hospital.

Hospitals↗
PubMed1982

Comparison of specific and cross-reactive antigens of alphaviruses on virions and infected cells.

Rabbit hyperimmune antisera against Sindbis (SIN) or Semliki Forest (SF) virus were absorbed with purified SIN virus or SIN virus-infected cells, or with SF virus or SF virus-infected cells. Residual antibody titers were determined by hemagglutination inhibition (HAI) and antibody-dependent, complement-mediated cytolysis (ADCMC) assays. It appeared that absorption with virus-infected cells removed ADCMC-detectable cross-reactive antibody much more efficiently than did absorption with either virus. HAI assays with the same absorbed antisera indicated that both virus and virus-infected cells removed HAI-detectable cross-reactive antibody. On the basis of these and other data, there appeared to be a cross-reactive antigen present on virus-infected cells which was detectable by ADCMC and was distinct from the cross-reactive antigen assayed by HAI.

Animals↗
PubMed1982

Cross-reactive, cell-associated antigen on L929 cells infected with temperature-sensitive mutants of sindbis virus.

Temperature-sensitive (ts) mutants of Sindbis virus (SIN) were used to aid in the identification of alphavirus cross-reactive proteins on the surface of infected cells by antibody-dependent, complement-mediated cytolysis. Antisera prepared in rabbits against purified SIN or Semliki Forest viruses were highly cytotoxic for cells infected with wild-type SIN and for cells infected at the permissive temperature with maturation-defective, ts mutants of SIN belonging to several distinct complementation groups. When these SIN mutants were analyzed by antibody-dependent, complement-mediated cytolysis at the restrictive temperature only cells infected with the SIN mutant of complementation group E, ts20, participated in both homologous (with anti-SIN serum) and heterologous (with anti-Semliki Forest virus serum) antibody-dependent, complement-mediated cytolysis reactions. These data and the known defect of ts20 suggested that the cell-associated viral E1 glycoprotein was a functional target antigen for homologous and cross-immunoreactivity in alphavirus-infected cells. At the restrictive temperature there were quantitative differences in antibody-dependent, complement-mediated cytolysis reactivity of ts20- versus wild type-infected cells consistent with the suggestion that ts20-infected cells do not fully express all of the homologous or the cross-reactive antigenic determinants found in wild-type infection. Additional potential sites for antigenic determinants involved in alphavirus-immune cross-reactivity are discussed in relation to events in virus maturation.

Animals↗
PubMed1982

Serological and genotypic diversity among serogroup 5- reacting environmental Legionella isolates.

Five strains of bacteria (strains 684, 687, U7W, U8W, and MICU-B) that were biochemically and morphologically indistinguishable from Legionella pneumophila were recovered from the environment. Strains U7W, U8W, and MICU-B were antigenically identical to L. pneumophila strain Dallas 1E (serogroup 5), as determined by direct fluorescent antibody staining and immunodiffusion. Although strains 694 and 687 shared antigenic determinants with L. pneumophila Dallas 1E, they could be distinguished by immunodiffusion and differential absorption studies. However, as determined by DNA hybridization, the antigenically distinct strains 684 belong to the same DNA homology cluster as previously described authentic strains of L. pneumophila, whereas strain U7W, U8W, and MICU-B belong to a separate homology group. Therefore, two groups could be identified among these environmental isolates; one represents an antigenic subclass of serogroup 5 L. pneumophila (strains 684, and 687), and the other, although antigenically indistinguishable from serogroup 5 L. pneumophila, probably represents a new Legionella species (strains U7W, U8W, and MICU-B).

Antigens, Bacterial↗
PubMed1982

Plasmid and surface antigen markers of endemic and epidemic Legionella pneumophila strains.

Environmental and clinical isolates of Legionella pneumophila obtained from the Pittsburgh Veterans Administration Medical Center were studied for the presence of plasmids and for unique surface antigens. The majority of environmental isolates contained a single 80-megadalton plasmid. After an epidemic of nosocomial Legionnaires disease subsided in the Spring of 1981, plasmid-bearing environmental isolates persisted in the environment. Whereas L. pneumophila could not be reisolated from most sites with plasmidless isolates. During this epidemic the attack rate was highest on wards with plasmidless isolates. All clinical isolates were plasmidless. Strains were serotyped by the indirect immunofluorescence method with serum from a single immunized rat which was used both without absorption and after absorption with various plasmid-bearing and plasmidless isolates. These studies suggested that a plasmid-associated surface antigen was present and that the most common plasmidless environmental serotype was similar to the epidemic clinical serotype.

Antigens, Bacterial↗
PubMed1982

Complement activation and complement control proteins in acute pancreatitis.

Serum levels of the complement proteins C3, C4, C1 inhibitor (C1 INH), factor I (C3b inactivator) and factor H (BIH) and plasma levels of cleavage products of C3 (C3c) and factor B were measured in 26 patients with acute pancreatitis. Breakdown of C3 occurred in 19 patients, as shown by a reduction in C3 level and the presence of C3c. C4 levels, however, did not fall and factor B breakdown products were not detected, thus suggesting that enzymatic cleavage of C3 occurred without significant involvement of either the early classical pathway or the alternative pathway. C1 INH and factor H both showed increases, presumably reflecting an acute phase response. Factor I showed an initial fall followed by a rise. There was no correlation between the presence or extent of C3 breakdown and the clinical condition of the patients. It is concluded that C3 cleavage in pancreatitis probably results from tryptic activity and that the measurement of complement components has no part to play in the management of the disease.

Acute Disease↗
PubMed1982

Buspirone and diazepam in anxiety: a controlled study.

The anxiolytic properties of buspirone were assessed in a 4-week double-blind study in 240 anxious patients, 81 of whom received buspirone, 81 diazepam, and 78 placebo. Patients were required to have scores greater than or equal to 9 on the Covi and greater than or equal to 18 on the Hamilton Rating Scale for Anxiety, and to endorse at least 5 items on a 17-item Anxiety Entry Checklist. Among 212 evaluable patients, those who improved most were married, well-educated females who had both a positive family adjustment and a low level of depression. Diazepam produced relatively equal improvement in females and males. Diazepam seems more effective in reducing somatic symptoms, while buspirone appears more effective in reducing symptoms associated with cognitive and interpersonal problems. Main differences between the drugs were seen in side effect profiles.

Adult↗
PubMed1982

Chronologic neuropathology of relapsing experimental allergic encephalomyelitis in the mouse.

The neuropathology has been described of chronic, relapsing experimental allergic encephalomyelitis produced in SJL/J mice given two injections of isogeneic spinal cord in complete Freund's adjuvant, 1 week apart. The inducing inoculum contained no Bordetella pertussis. The central nervous system changes included hemorrhagic lesions and significant nerve fiber depletion during the early stages of disease, demyelination followed by remyelination, influxes of polymorphonuclear leukocytes and hemorrhage with each acute episode, extensive gliosis, and some Schwann cell invasion and myelination within the central nervous system. Since the mouse is a highly accessible species that is immunologically well understood, this model might lend itself to fuller dissection of autoimmune events associated with recurrent demyelination, problems of considerable significance to multiple sclerosis research.

Animals↗
PubMed1982

Legionnaires' disease: new clinical perspective from a prospective pneumonia study.

In an attempt to ascertain the incidence of Legionnaires' disease at our hospital, a prospective case-control pneumonia study was conducted for 11 months. Specialized diagnostic tests for Legionella pneumophila, including serologic study, direct immunofluorescent examination, and selective culture, were made routinely available in our hospital. To our surprise, L. pneumophila was the most common cause of pneumonia (22.5 percent) attributable to a single pathogen, followed by Streptococcus pneumoniae (10.6 percent). In 68.8 percent of the cases, Legionnaires' pneumonia was hospital-acquired. In contrast to other investigators, we found that abdominal pain, diarrhea, neurologic signs, abnormal liver function results, hypophosphatemia, and hematuria did not occur significantly more frequently in pneumonia caused by L. pneumophila than in that caused by other microorganisms. However, hyponatremia within five days of onset of pneumonia occurred significantly more frequently in Legionnaires' disease (p less than 0.0001). Since the clinical presentation is nonspecific, specialized laboratory tests are necessary to make the diagnosis. As a result of our experience, we suggest an approach using serologic tests as a screen to determine whether more specialized tests for Legionnaires' disease should be introduced into a hospital without previously recognized cases of Legionnaires' disease.

Diagnosis, Differential↗