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Biomedical subjects

L A Caliguiri

Publications and source records attributed to L A Caliguiri.

At least 19 recordsLinked to original sources
PubMed1997

Profile of children requiring emergency treatment for asthma.

BACKGROUND: Emergency department care for asthma is expensive and continuity of care is often inefficient. Identification of patients-at-risk for emergency treatment is required in order to intervene before visits to the emergency department. OBJECTIVE: To identify the antecedent factors in patients requiring emergency department treatment for wheezing and to determine the level of care before emergency visits. METHODS: A prospective survey of patients treated for wheezing in the emergency department of an academic children's hospital from January 1, 1994 to December 31, 1994. Data were compiled from a data from completed from the information obtained from the medical record, phone calls and letters. RESULTS: During 1994, 1474 patients were treated for asthma and accounted for 1870 visits to the emergency department. Thirty-six percent of the total number of visits were made by 16% of the patients who made repeat visits. Two-thirds of the patients were 5 years of younger. Over 190 patients had been hospitalized for wheezing during the preceding 12-month period. Forty-four percent of the patients were referred to the emergency department by primary care physicians and 6.7% were referred by asthma specialists, either allergists or pulmonologists. The major predisposing factor was a family history of asthma in 70%. Beta agonists were the medications most frequently used prior to the emergency visits. Inhaled corticosteroids were used daily by 16% of the patients and oral corticosteroids were used daily by 7% of the patients. CONCLUSION: Thirty-six percent of the visits were due to 16% of patients who were seen repeatedly in the emergency department for wheezing and a number of patients (192) had been admitted previously for wheezing. These findings suggest that there is a subset of patients who are known to have recurrent wheezing, but lack adequate management to avoid expensive hospital services. Very few of these patients were followed by asthma specialists and there was a marked underuse of anti-inflammatory drugs. This study characterized a subset of patients-at-risk for requiring emergency treatment for wheezing. There is a need to institute aggressive interventions to improve the quality of care and prevent costly emergency department visits.

Administration, Inhalation↗
PubMed1989

Increases in plasma concentrations of a prostaglandin metabolite in acute airway obstruction.

Plasma concentrations of a stable prostaglandin F2 alpha metabolite were measured by radioimmunoassay during and after recovery from acute airway obstruction in 15 infants. Mean (SEM) metabolite concentrations (ng/l) in plasma obtained both before (1033 (418)) and after (1470 (413)) initial treatment for airway obstruction were significantly higher than those obtained from the same subjects after resolution of the obstruction--25.5 (6.6)--and those obtained from two comparison groups. Infants positive for respiratory syncytial virus (mean 1122 (227)) had significantly higher concentrations than those who were negative (207.6 (46)). Additionally, seven subjects with a history of recurrent wheezing after resolution of airway obstruction had a significantly higher mean level (3500 (1400)) during attacks of airway obstruction than those without (600 (100)). These data suggest that prostaglandin F2 alpha mediates respiratory inflammation in airway obstruction and that trials of specific anti-inflammatory agents for the treatment of airway obstruction may be warranted.

Airway Obstruction↗
PubMed1987

Transient chemotactic defect in a child with elevated IgE.

Leukocyte function was studied in a child with elevated IgE and many infections. At age 7 months, chemotaxis was decreased, but improved first toward formylated peptides and finally toward complement. Polarization and nitroblue tetrazolium reduction also were transiently impaired. Functional and clinical improvements were concomitant although IgE remained elevated.

Chemotaxis, Leukocyte↗
PubMed1984

Unphosphorylated gelsolin is localized in regions of cell-substratum contact or attachment in Rous sarcoma virus-transformed rat cells.

Regions associated with cell-substratum contact or attachment in Rous sarcoma virus (RSV)-transformed rat fibroblasts (RR1022 cells) were identified by reflection-interference microscopy. Electron microscopy of such regions revealed the presence of discrete membrane-associated structures composed of a paracrystalline lattice of hexagons and pentagons to which actin filaments appear to be attached. Staining of actin by biotin-labeled heavy meromyosin showed that transformed cells, unlike normal fibroblasts, lack prominent actin fibers, and that, instead, much of the fluorescence is concentrated in loci corresponding to locations of transient association between the cell and the substratum. In stationary cells, such loci were found in rosette formation, predominantly in the region beneath the nucleus. In cells engaged in active movement, such as during migration into a wound, the actin-containing spots were concentrated in the region of the leading edge. A similar pattern of staining was observed with antibody to gelsolin, a 91,000-dalton Ca2+-dependent actin filament-shortening protein. Since the action of gelsolin on actin is reversible and dependent on physiologically relevant changes in calcium concentration, the localization of gelsolin, together with actin-bundling proteins such as alpha-actinin, in the regions containing many small microfilament bundles on the ventral side of cytoplasm suggests that gelsolin may be a component of the mechanism for the disassembly and assembly of actin during the dissolution and reformation of structures for cell-substratum contact during cell locomotion. Regulation of gelsolin activity was not dependent on protein phosphorylation, as shown by lack of 32P-incorporation into gelsolin in either transformed or normal fibroblasts.

Actins↗
PubMed1983

Reduced synthesis of pp60src and expression of the transformation-related phenotype in interferon-treated Rous sarcoma virus-transformed rat cells.

Treatment of Rous sarcoma virus-transformed rat cells with rat interferon-alpha (specific activity, 10(6) U/mg of protein) for 24 h caused a 50% reduction in intracellular pp60src-associated protein kinase activity. Staphylococcus aureus V8 protease digestion of pp60src, derived from 32P-labeled monolayer cultures incubated with or without interferon, revealed no differences either in the phosphopeptide pattern or in the phosphoserine-phosphotyrosine ratio. However, [3H]leucine pulse-labeling experiments showed that the synthesis of pp60src was reduced by 42 to 48%, relative to the level of bulk protein synthesis, in the interferon-treated cultures. Rat interferon-alpha also reduced the growth rate of Rous sarcoma virus-transformed rat cells in a dose-dependent manner over a 72-h period. The decrease in growth rate was accompanied by increases in the thickness and number of actin fibers per cell and by a decline in intracellular tyrosine phosphorylation by pp60src. The results suggest that interferon can inhibit the expression of the transformation-related phenotype by selectively reducing the synthesis of the Rous sarcoma virus transforming gene product. However, the interferon effects on the cytoskeletal organization and proliferation of Rous sarcoma virus-transformed cells may be due at least in part to the predominance of interferon-induced phenotypic changes over those caused by pp60src.

Actins↗
PubMed1976

Action of dichlorobenzimidazole riboside on RNA synthesis in L-929 and HeLa cells.

5,6-Dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) inhibits RNA synthesis in L-929 cells (mouse fibroblast line) and HeLa cells (human epitheloid carcinoma line) within 2 min of addition of the compound to the medium. By removing DRB from the medium, the inhibition is promptly and completely reversed after treatment of cells for as long as 1 h or even longer. The inhibitory effect of DRB on the overall rate of RNA synthesis is similar in L and HeLa cells and is markedly concentration-dependent in the low dose range (5-20 muM or 1.6-6.4 mug/ml), but not as higher concentrations of DRB. At a concentration of 12 muM, DRB has a highly selective inhibitory effect on the synthesis of nuclear heterogenous RNA in L cells. At higher concentrations, there is also inhibition of 45 S ribosomal precursor RNA synthesis, but at all concentrations the effect on heterogeneous RNA synthesis in L cells in considerably greater than that on preribosomal RNA synthesis. In HeLa cells, too, DRB has a selective effect on heterogeneous RNA synthesis, but quantitatively the selectivity of action is somewhat less pronounced. In both L and HeLa cells, the inhibition of synthesis of nuclear heterogeneous RNA is incomplete even at very high concentrations of DRB (150 muM). Thus, while DRB is a selective inhibitor of nuclear heterogeneous RNA synthesis, not all such RNA synthesis is sensitive to inhibition. It is proposed that messenger precursor RNA synthesis may largely be sensitive to inhibition by DRB. In short-term experiments, DRB has no effect on protein synthesis in L or HeLa cells. DRB has a slight to moderate inhibitory effect on uridine uptake into L cells and a moderate to marked effect on uptake of uridine into HeLa cells.

Benzimidazoles↗
PubMed1974

Analysis of the in vitro product of an RNA-dependent RNA polymerase isolated from influenza virus-infected cells.

The products synthesized in vitro by an RNA-dependent RNA polymerase isolated from influenza virus-infected BHK21-F cells were analyzed by velocity sedimentation, annealing techniques, and acrylamide-agarose gel electrophoresis. Approximately 50% of the RNA synthesized in vitro remains associated with the 50 to 70S ribonucleoprotein complex containing polymerase activity; the remainder of the RNA polymerase product sediments heterogeneously with a peak at 13S. At least 90% of the in vitro product hybridizes with virion RNA. If polypeptides are labeled early in the growth cycle, both the P and NP polypeptides are detected in the ribonucleoprotein complex by acrylamide gel electrophoresis. The results suggest that the polypeptide composition and the products of the cell-associated RNA polymerase are similar to those of the RNA transcriptase associated with influenza virus particles.

Animals↗
PubMed1973

Isolation and properties of an RNA polymerase from influenza virus-infected cells.

Structures with RNA polymerase activity were isolated from influenza virus-infected cells, and consisted of ribonucleoprotein (RNP) complexes, similar in morphology to the viral internal component or nucleocapsid. The isolation procedure involved fractionation of infected cells in a discontinuous sucrose gradient, in which enzyme activity was concentrated in a fraction of intermediate density which contains both smooth and rough cytoplasmic membranes. The RNPs with polymerase activity were further purified in a velocity gradient, after which the peak fractions showed a 35-fold purification of the polymerase activity when compared with cytoplasmic extracts. The NP polypeptide, which is the subunit of the virion RNP, was the only virus-specific polypeptide detected in these RNP structures.

Animals↗