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Biomedical subjects

E Goldstein

Publications and source records attributed to E Goldstein.

At least 91 records · Page 5Linked to original sources
PubMed1984

Genetically determined conidial longevity is positively correlated with superoxide dismutase, catalase, glutathione peroxidase, cytochrome c peroxidase, and ascorbate free radical reductase activities in Neurospora crassa.

Aging of post-mitotic cells, the conidia, of Neurospora crassa is defined as the time-dependent loss of viability under a constant laboratory environment which probably resembles the organism's tropical habitat; namely, at 30 degrees C, 85-100% relative humidity under white light. Median lifespan is defined as the age at which survival of a conidial population has declined to 50% of that of a fully viable population at birth. A collection of short (age-) and long-lived (age+) mutants were previously selected from the wild-type whose median lifespan is 22 days. Thus, five groups of strains with distinct lifespans of 7, 22, 36, 50 and 60 days were defined. The purposes of the present investigation were to determine if the activities of anti-oxygenic enzymes are correlated with lifespan and to elucidate the function of the cellular longevity determinant genes. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were highly-correlated with lifespan; whereas glutathione reductase and non-specific peroxidase activities were not correlated. The short-lived mutants were also deficient in cytochrome c peroxidase (CPX) and ascorbate free radical reductase (AFR), but not deficient in dehydroascorbate reductase. (These latter three enzymes were not examined in age+ mutants.) By isoelectric focusing analysis, the deficiencies of SOD, CAT, and GPX activities of age- mutants were defined in terms of specific isozymes. The mutants were specifically deficient in a cyanide-resistant mitochondrial isozyme of SOD. Sixteen age- genes, called the age-1 complex, were previously mapped on one arm of the seven chromosomes. On the basis of mapping and complementation data, it was inferred that the genes are spatially and functionally redundant. The hypothesis of functional redundancy is also supported by the enzyme data. Of seven mutants examined, representing seven of the age- genes, all were deficient in SOD, CAT and CPX, and six were deficient in AFR. Of four mutants examined, representing four of the genes, all were deficient in GPX. The results indicate a molecular basis for the previously observed photosensitivity of the mutants.(ABSTRACT TRUNCATED AT 400 WORDS)

Catalase↗
PubMed1984

Regulation of bacterial DNA supercoiling: plasmid linking numbers vary with growth temperature.

The level of DNA supercoiling can be altered either by breaking-rejoining reactions that change the DNA linking number or by environmental changes that alter the helical pitch of DNA. In vitro, temperature changes alter helical pitch and, thus, supercoiling. We find that plasmids isolated from bacteria grown at different temperatures exhibit differences in DNA linking numbers. The differences in plasmid linking numbers offset the effect temperature is expected to have on supercoiling. These results are consistent with the hypothesis that fine control of DNA topology in bacterial cells is brought about by changes in linking number to maintain a constant value for supercoiling.

DNA, Superhelical↗
PubMed1984

Effect of 0.64 ppm ozone on rats with chronic pulmonary bacterial infection.

Rats were chronically infected with Pseudomonas aeruginosa by entrapping viable bacteria in agar beads and intratracheally inoculating the beads into the left lung. The infection was allowed to stabilize over a 10-d period and the animals were then placed in environmental chambers and exposed to either filtered air or 0.64 ppm ozone (23 h/d) for 14 or 28 d. Rats exposed to ozone had reduced body weight and increased lung sizes and lung weights when compared with animals breathing filtered air. Rats inoculated with beads containing live P. aeruginosa had increased lung weights when compared with rats inoculated with beads containing heat-killed P. aeruginosa or controls. Quantitation of total viable bacteria in rats exposed to ozone or to filtered air revealed no significant differences in bacterial numbers. Thus, in this model, chronic exposure to ozone produces increases in lung volume and weight but does not enhance a smoldering Pseudomonas infection.

Animals↗
PubMed1984

Comparison of lavaged and intrapulmonary alveolar macrophages in respect to lysozyme content and size in the rat.

Lavaged and in situ rat alveolar macrophages were compared with respect to lysozyme content and size in order to assess the extent to which macrophages from pulmonary lavages reflect the in situ cell population. This relationship was studied in normal rats and in rats with pulmonary granulomas induced by glucan stimulation (10 mg/kg given intravenously on Days 5, 3, and 1 before being killed). Alveolar macrophages in pulmonary lavages and histologic sections were stained for lysozyme by the immunoperoxidase method using rabbit antiserum to rat lysozyme. Enzyme content and cell size were measured with a conventional scanning cytospectrophotometer and an automated image analysis system (LEYTAS). Scanning cytospectrophotometry measurements showed that 26% of in situ alveolar macrophages from glucan-treated rats contained more lysozyme than did control cells and that 31% possessed larger areas. Fewer large alveolar macrophages containing increased amounts of lysozyme were detected in lavages of glucan-treated rats. Frequency histograms of lysozyme content and cell size were similar for lavaged and in situ macrophages from control rats. Measurements with LEYTAS confirmed the results. These experiments demonstrate that alveolar macrophages obtained by lavage are representative of their in situ counterparts in normal but not in glucan-treated rats.

Animals↗
PubMed1984

Febrile gastroenteritis due to Salmonella thompson. Report of an outbreak.

Salmonella thompson, a common pathogen of poultry, has received scant attention as a cause of human gastroenteritis. At least 45 persons were infected with S thompson in Sacramento, California, after eating at a chicken restaurant and 38 became symptomatic. Ten required admission to hospital, and all were treated with antibiotics and improved. In 19 cases cultures of stool specimens for S thompson over a 60-day period showed slower but statistically insignificant differences in salmonellal elimination in 7 patients who received antibiotics when compared with 12 who were untreated. We report this outbreak to increase awareness of the virulence and prevalence of gastroenteritis due to S thompson.

Gastroenteritis↗
PubMed1983

Effect of virulent and less virulent strains of Nocardia asteroides on acid-phosphatase activity in alveolar and peritoneal macrophages maintained in vitro.

Since virulent strains of Nocardia asteroides grow within macrophages, experiments were designed to determine whether this intracellular pathogen affects lysosomal enzyme levels. Peritoneal and alveolar macrophages from mice were infected in vitro with live or killed N asteroides of the virulent strain GUH-2 or with live nocardiae of the less virulent strain 10905, which is killed by macrophages. The activity of acid phosphatase in individual macrophages was quantitated by means of a computer-assisted cytospectrophotometry system. Slide preparations were Gram stained for quantitation of ingested nocardiae in the same macrophages. The level of acid phosphatase activity in alveolar and peritoneal macrophages was decreased by infection with live cells of the virulent strain; the level of activity was inversely proportional to the number of nocardiae ingested. This effect was not seen with killed bacteria of this strain or with live bacteria of the less virulent strain. These results demonstrate a relation between the virulence of N asteroides strains and the extent of reductions in lysosomal acid-phosphatase activity of macrophages.

Acid Phosphatase↗
PubMed1983

Aspergillus endophthalmitis in an intravenous drug user.

A 27-year-old male drug user administered methamphetamine hydrochloride solution intravenously (IV) from a storage vial. Within two weeks he was admitted with a fungal endophthalmitis of the right eye. A diagnostic and therapeutic vitrectomy was performed. Aspergillus fumigatus was cultured from the drug storage vial and the vitreous biopsy specimen. The endophthalmitis was not controlled by IV and intravitreal amphotericin B. Pathological examination revealed fungal abscesses in the vitreous and subretinal space.

Adult↗
PubMed1983

Coccidioidomycosis: early immunologic findings.

T and B lymphocyte number and lymphocyte response to phytohemagglutinin, pokeweed mitogen, concanavalin A, coccidioidin and streptokinase-streptodornase (SKSD), plus monocyte ingestion of coccidioidin- and IgG-coated chicken erythrocytes were measured in 5 patients with coccidioidal meningitis, 11 with nonmeningeal extrapulmonary cocidioidomycosis and 5 with localized pulmonary infections. These cases were evaluated within six months of the onset of infection. Lymphocytic responses to phytohemagglutinin, pokeweed mitogen, concanavalin A, SKSD and coccidioidin and monocytic ingestion of coccidioidin- and IgG-coated chicken erythrocytes were severely decreased in patients with meningeal and nonmeningeal, extrapulmonary coccidioidomycosis but not in patients with localized pulmonary infections. T and B cell numbers, however, were normal in all groups. Thus, defects in cellular immunity are involved in the pathogenesis of extrapulmonary coccidioidomycosis and measurements of lymphocytic and monocytic function may identify patients prone to extrapulmonary infection.

Adult↗
PubMed1983

Glucan alteration of pulmonary antibacterial defense.

Particulate yeast glucan, prepared by the methods of Northcote and Horne and Peat et al, was studied in rats and mice to determine its protective capacity in respiratory infection. Glucan was administered intravenously to rodents prior to infection with aerosols of bacteria. Glucan-treated rats had significantly increased rates of phagocytosis and killing of Staphylococcus aureus immediately after infection and minimal increases at 4 h. In contrast, pulmonary killing of Klebsiella pneumoniae in rats was markedly enhanced by glucan at 4 h. Glucan treatment of mice provided only transient protection against pulmonary infection with group C streptococci. Histological studies demonstrated greatly increased numbers of macrophages in the lungs of glucan-treated rats; the lungs of glucan-treated mice appeared normal. These results show that glucan can enhance intrapulmonary bacterial killing. In rats, this is due to the ability of glucan to increase the number of lung macrophages resulting in increased bacterial ingestion. Glucan-induced protection in mice is less clear.

Animals↗
PubMed1982

Group B streptococcal lung infection in neonatal rabbits.

The interaction of alveolar macrophages (AMs) and group B streptococci (GBS) was investigated in 1 and 2-day-old rabbits following infection in an exposure chamber containing 10(7) streptococci per cubic foot of air. The % of streptococci within AMs was similar at 0 and 4 h (36 and 65%) after infection for the two groups of rabbits. Twenty-four h after infection, the 2-day-old rabbits had a significantly higher % of ingested GBS (86 versus 68%). Sixty % of inspired GBS were inactivated by the older rabbits within 4 h after infection. This clearance persisted in the younger rabbits until 48 h (mean negative clearance of -17, -276, and -79% at 4, 24, and 48 h) before their numbers were reduced by inflammation. Sixty of 78 1-day-old rabbits had inflammatory responses between 24 and 72 h versus only 5 of 50 older rabbits. At 24 h after infection, AMs of 1-day-old rabbits contained significantly increased numbers of intracellular GBS microcolonies (17/20) than did AMs from 2-day-old rabbits (5/19). These observations suggest that the enhanced susceptibility to GBS infection in the immediate postnatal period is caused at least in part by ineffective intracellular killing by AMs.

Age Factors↗
PubMed1981

Effect of ozone on concentrations of lysozyme in phagocytizing alveolar macrophages.

Demonstration of lysozyme by the immunoperoxidase method was used to determine whether ozone-induced defects in phagocytic killing of inhaled Staphylococcus aureus by rat alveolar macrophages were associated with absence of this important bactericidal enzyme. Rats were infected with aerosols of S. aureus and then exposed for 5 hr to 2.5 ppm of ozone. Left lungs were cultured for staphylococci; right lungs were stained for lysozyme and bacteria. Compared with control animals, rats exposed to ozone showed diminished rates of bacterial killing; a larger percentage of extracellular, uningested bacteria; an increased number of intracellular staphylococcal clumps; and absence of lysozyme in macrophages permitting staphylococcal proliferation. These results, in which absence of enzyme activity occurred in macrophages subjected to the dual insults of ozone exposure and ingested bacteria, provide an explanation for the inability of phagocytes to kill ingested bacteria after exposure to ozone.

Animals↗
PubMed1981

Successful treatment of gram-negative bacillary meningitis with moxalactam.

Meningitis caused by enteric gram-negative bacilli is relatively uncommon but is very difficult to treat despite susceptibility in vitro to many antimicrobics. A major problem appears to be poor entry of many drugs into the central nervous system. Moxalactam is an investigational cephalosporin that attains concentrations in the cerebrospinal fluid that are 15% to 30% of contemporaneous serum concentrations; moreover, it is quite active against many of the enteric gram-negative bacilli. We used moxalactam to treat meningitis caused by Enterobacter cloacae, Klebsiella pneumoniae, and Escherichia coli in four adults and one child, giving up to 100 mg/kg body weight per day by intravenous injection. The concentrations of moxalactam in serum, lumbar, and ventricular cerebrospinal fluid exceeded the minimal lethal concentrations of all causative bacteria. The patients were cured. In this small series, moxalactam, when administered intravenously as the sole agent of therapy, was effective in the treatment of meningitis caused by susceptible gram-negative bacilli.

Adult↗
PubMed1981

Use of radiologic modalities in coccidioidal meningitis.

The diagnostic utility of pentetate indium trisodium in 111 CSF studies, technetium Tc 99m brain scans, and computerized tomographic (CT) scans was evaluated in eight patients in whom coccidioidal meningitis developed following a dust storm in the Central Valley of California. The 111In flow studies and the CT scans demonstrated hydrocephalus in five patients with clinical findings suggesting this complication. Ventriculitis has not previously been diagnosed before death in patients with coccidioidal meningitis; however, it was demonstrated in two patients by the technetium Tc 99m brain scan. Basal meningitis, which is indicative of fungal infection, is also detectable on contrast-enhanced CT scan. The finding that communicating hydrocephalus occurs early in meningitis and interferes with CSF flow into infected basilar regions has important therapeutic implications in that antifungal agents injected into the lumbar subarachnoid space may not reach these regions.

Adolescent↗
PubMed1980

Treatment of coccidioidomycosis with miconazole.

Miconazole was injected intravenously in six patients with coccidioidomycosis. Two patients received 101 and 185 g, respectively, without clinical response and with persistence of positive cultures for Coccidioides immitis. In one patient, symptoms were suppressed when amphotericin B was given with miconazole, but new lesions developed with miconazole alone (total dose, 963 g). Three patients received smaller doses: 30.6 g before death from an unrelated complication; 17 and 22.3 g before development of severe allergic reactions. Because of the high rate of initial failures and relapses, miconazole is not recommended as primary therapy for coccidioidomycosis.

Adult↗