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Biomedical subjects

D Hoover

Publications and source records attributed to D Hoover.

47 records · Page 3Linked to original sources
PubMed1983

Depressed macrophage functions at temperatures below 37 degrees C.

Immunobiological properties of guinea pig and human peritoneal macrophages were studied at temperatures ranging from 25 degrees C to 37 degrees C. Glass adherence, random migration, response to MIF and killing of Salmonella typhimurium and Saccharomyces cerevesiae by guinea pig macrophages were decreased with temperatures below 37 degrees C. Killing of Sacch. cerevesiae by human macrophages was also reduced at temperatures less than 37 degrees C. Acid phosphatase and beta-N-acetylglucosaminidase (NAG) activity assayed at 37 degrees C did not change when the cells were preincubated for 1 and 5 hours at various temperatures. Impaired macrophage function with subnormal temperatures may contribute to enhanced susceptibility to infection of patients with chronic diseases such as renal failure and cirrhosis.

Acetylglucosaminidase↗
PubMed1983

Immunologic and ionophore-induced generation of leukotriene B4 from mouse bone marrow-derived mast cells.

Mouse bone marrow-derived mast cells differentiated in vitro and sensitized with monoclonal IgE respond to antigen-initiated activation-secretion with the generation of leukotriene B4 (LTB4), a highly potent chemotactic factor. The antigen-initiated net percent release of the secretory granule marker beta-hexosaminidase and the generation of immunoreactive LTB4 and of immunoreactive leukotriene C4 (LTC4) were not diminished by washing the cells before challenge, indicating that interaction of the antigen occurred with the IgE fixed on cell membranes and was not due to phagocytosis of immune complexes formed in the fluid phase. The parallel dose-response relationship for the antigen-induced release of the performed mediator and the generation of both leukotrienes along with the superimposable time courses of their extracellular appearance indicate the origin of these mediators from a common cell type with IgE receptors. Resolution by reverse phase-high performance liquid chromatography (RP-HPLC) of the leukotrienes released from unsensitized cells by ionophore A23187 and from sensitized cells by the specific antigen revealed that the generation of LTB4 was accompanied by the production of the two diastereoisomers of 6-trans-LTB4, which were not immunoreactive. The immunoreactive LTB4 eluted from RP-HPLC at the same retention time as synthetic LTB4 was present in similar nanogram quantities when measured by either radioimmunoassay or integrated absorbance at 269 nm and exhibited a chemotactic activity for human neutrophils on a weight basis comparable to that of synthetic LTB4. The overall recoveries after RP-HPLC of immunoreactive LTB4 released from ionophore A23187-activated, bone marrow-derived mast cells and of added tritiated synthetic LTB4 in separate experiments with ionophore-activated cells were comparable and greater than 78%. The maximum generation of LTB4 by ionophore A23187-activated cells of 7.9 +/- 2.5 ng/10(6) cells (mean +/- SD), occurring at 40 min, was greater than the maximum generation of 4.5 +/- 0.8 ng/10(6) cells, with immunologic stimulation occurring 5 min after antigen challenge of sensitized cells. The initial rate of LTB4 generation after perturbation of the IgE-Fc receptors, however, exceeded that following ionophore A23187 stimulation and may represent one important variable in establishing a significant chemotactic gradient.

Animals↗
PubMed1982

Radioimmunoassay for leukotriene B4.

A rabbit immunized with leukotriene B(4) [LTB(4); (5S,12R)-6, 14-cis-8, 10-trans-icosatetraenoic acid] coupled to bovine serum albumin via the 12-oxy function of the lipid produced antibodies having an average association constant (K(a)) for [14,15-(3)H]LTB(4) of 3.2 x 10(9) M(-1) at 37 degrees C and in a concentration of 0.37 mug/ml of the immune plasma. When 10 mul of anti-LTB(4) and 3.9 nCi of [14,15-(3)H]LTB(4) (28 Ci/mmol; 1 Ci = 3.7 x 10(10) becquerels) were incubated in a volume of 250 mul, 50% inhibition of radioligand binding was achieved with 0.31 ng of LTB(4) and with 1.95 ng of (5S,12S)-6-trans-8-cis-LTB(4). The sulfidopeptide leukotrienes, LTC(4) and LTD(4), displaced the radioligand from this antibody with less than 1/100th the activity of LTB(4), and the diastereoisomers of 6-trans-LTB(4), 5-L-hydroxy-6-trans-8,11,14-cis-icosatetraenoic acid (5-HETE), and three prostaglandins were minimally effective. The specificity of this radioimmunoassay was further shown by assessment of the immunoreactive products generated from calcium ionophore (A23187)-activated rat serosal mast cells and human neutrophils after reversed-phase HPLC. Resolution of the supernatants from each cell type yielded a single immunoreactive peak that coeluted with synthetic LTB(4) and quantitatively correlated with the physical measurement by integrated A(269) in that peak; UV-absorbing peaks eluting at other retention times were not immunoreactive. The immunoreactive LTB(4) generated averaged 4.6 ng per 10(6) rat mast cells and resolution of the supernatants by reversed-phase HPLC without a prior extraction step gave a recovery of 54%, validating the direct applicability of this sensitive and specific assay for LTB(4), a highly potent chemotactic factor, to unfractionated biologic fluids.

Animals↗
PubMed1979

Immunity of cholera in man: relative role of antibacterial versus antitoxic immunity.

Purified cholera toxoid is antigenic when given enterally and orally. Purified toxoid fails to provide protection against experimental challenge. Clinical cholera confers formidable protection against homologous or heterologous rechallenge. Failure to culture vibrios from intestinal fluid or stool of re-challenge volunteers suggests that the predominant immune mechanism is antibacterial rather than antitoxic.

Antibodies, Bacterial↗
PubMed1979

The problem of emesis during oral glucose-electrolytes therapy given from the onset of severe cholera.

In an attempt to obviate the need for intravenous fluids by preventing dehydration, 57 adult volunteers who experienced induced clinical cholera during a vaccine development programme were treated from the onset of diarrhoea with oral glucose-electrolytes therapy. 44 individuals with mild to moderately profuse diarrhoea (less than 8 L. total volume) were maintained in normal water and electrolyte balance with oral therapy alone. 13 individuals with severe diarrhoea (greater than 8 L. total volume) could not be maintained in balance with oral therapy alone, due chiefly to emesis during the first day of illness. Emesis occurred in the absence of significant dehydration or acidosis. Since emesis precludes effective early oral therapy in severe cases, domiciliary oral therapy is unlikely to eliminate cholera mortality. Rural diarrhoea treatment centres using oral therapy with limited amounts of intravenous fluids when needed, could reduce case fatality from cholera and related diarrhoeas virtually to zero with least expense.

Adolescent↗
PubMed1978

Cholera, non-vibrio cholera, and stomach acid.

Fasting and postprandial stomach acid production were low in 16 of 37 Bangalees convalescing from cholera or non-vibrio cholera. Gastric juice of hypochlorhydric patients did not kill cholera vibrios in vitro, whereas that from normochlorhydric patients rapidly killed vibrios in concentrations up to 10(10)/ml. To determine whether hypoacidity resulted from cholera or was a common predisposing factor, basal and betazole-hydrochloride-stimulated acid production were measured before and after cholera in a second group of patients consisting of American volunteers participating in a vaccine development programme. Cholera did not alter the stomach acid secretion of American volunteers, but low precholera basal acid production predispose to severe cholera. The results indicate that hypochlorhydria observed in convalescent Bangalee cholera patients is not caused by cholera, and must therefore have preceded it. Idiopathic tropical hypochlorhydria may be a major factor accounting for the high incidence of diarrhoea due to acid-sensitive pathogens in developing countries.

Achlorhydria↗
PubMed1978

An immunologic investigation of atypical gingivostomatitis.

A fluorescent antibody investigation was conducted to determine first the difference, if any, in the presence of tissue-bound antibodies in normal gingiva and atypical gingivostomatitis gingiva, and second to determine if the serum of atypical gingivostomatitis patients had auto-antibodies directed against any specific structures of normal gingiva. The immunofluorescent tests produced two signficant results: 1. Most of the mononuclear inflammatory cells present in AGS gingiva had an antibody halo on the cell membrane surface. This could indicate that AGS is the result of hypersensitivity reaction. 2. The serum of AGS patients did not contain detectable auto-antibodies for normal gingiva which would be one indication that AGS is not an autoimmune disease.

Adult↗
PubMedDate not supplied

Impaired personal boundaries: a proposed nursing diagnosis.

TOPIC: How impaired personal boundaries play a significant role in mental illnesses and co-dependency. PURPOSE: To demonstrate the value of having a formal nursing diagnosis of "impaired personal boundaries." SOURCE: A concept analysis of personal boundaries, which describes the physical, emotional, intellectual, and spiritual dimensions of personal boundaries. CONCLUSION: The author recommends a new nursing diagnosis of "impaired personal boundaries," which provides a basis for the plan of care for clients with this difficulty.

Assertiveness↗
PubMedDate not supplied

Validation study for impaired personal boundaries, proposed nursing diagnosis.

The authors propose a new nursing diagnosis of impaired personal boundaries based on their experience in psychiatric nursing, a concept analysis of the literature and diagnostic content validation by a panel of experts. Impaired personal boundaries are common in a number of mental disorders including, schizophrenia, borderline personality, substance abuse and enabling. Recognition of this patient problem has implications for further research and nursing interventions.

Codependency, Psychological↗