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Biomedical subjects

D A Levy

Publications and source records attributed to D A Levy.

At least 55 records · Page 3Linked to original sources
PubMed1993

Management of urinary stones in the patient with spinal cord injury.

The main objective of the urologist treating patients with spinal cord injury is to preserve renal function. In order to minimize morbidity, all attempts must be made to maintain a low bladder pressure, sterile urine, and a non-obstructed drainage system. These patients remain at increased risk of infection and stone formation despite all clinical intervention. Diligence in routine follow-up and careful evaluations will provide the best possible results. In the face of urolithiasis, ESWL, percutaneous nephrolithotomy, and chemolysis are effective means of treatment with acceptable morbidity. With future technologic advancements and implementation of neurostimulators to improve the urodynamic profiles, the incidence of renal insufficiency, urolithiasis, and overall morbidity in patients with spinal cord injury is likely to decrease.

Female↗
PubMed1993

Contagion: a theoretical and empirical review and reconceptualization.

We have reviewed theories and research in the area of contagion with an emphasis on definitions of contagion. The review shows that a great deal of the confusion surrounding the term is due to the fact that the phenomena involved in contagion are extremely heterogeneous, yet they typically have been placed under homogeneous rubrics. Accordingly, we propose herein that contagion should be conceptualized as a general type, social contagion, and three subtypes: disinhibitory, echo, and hysterical. In this article, we have distinguished social contagion and its subtypes from other types of social influence phenomena and reclassified theoretical and research articles under the newly proposed definitions. The proposed reconceptualization shows how contradictions in the literature can be resolved by distinguishing the type of contagion in question and provides the foundation for a more comprehensive and useful psychology of contagion.

Arousal↗
PubMed1992

The house dust mite Dermatophagoides pteronyssinus is the most important allergen on the island of Mauritius.

To determine the relative importance of mites as a cause of allergic sensitivity and asthma on the western Indian Ocean island of Mauritius, we measured specific IgE antibodies to common inhalant allergens in sera from Mauritians claiming to have allergic symptoms and we examined house dust samples for evidence of mites and their allergens. Seventy-two of the 110 sera tested (65%) contained detectable IgE antibody to at least one mite, mould or pollen allergenic extract. By far the most prevalent was antibody to one or both of the common house dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae, being present in 67 (61%) of the 110 sera. Allergy to pollens, including the locally prevalent Bermuda grass and sugar cane, was infrequent. Antibody to a limited number of moulds was detected in 22% of the sera tested. Of 81 subjects whose clinical history was known, 60 were asthmatic, and 75% of these asthmatic individuals had IgE antibody to mites. In contrast, only 35% of the subjects with rhinitis without asthma were sensitive to mites. Different mite species, including D. pteronyssinus but not D. farinae, were identified microscopically in samples of local house dust. Mite antigen Der p I but not antigen Der f I was detected with specific monoclonal antibodies in extracts of these dust samples. On the bases of this serological and environmental survey, we conclude that our data support the hypothesis that the house dust mite D. pteronyssinus is the principal cause of allergic sensitivity and asthma in that tropical environment.

Adolescent↗
PubMed1992

Allergy to latex.

Explore the source record for details and available documents.

Allergens↗
PubMed1992

Evidence for the interaction between antacid and gastric mucosa using an "artificial stomach" model including gastric mucosa.

In light of evidence that certain aluminum-based antacids adhere to the gastric mucosa, we modified our previously described "artificial stomach" (AS) model by including a piece of hog stomach and compared the antacid activity of six aluminum-containing antacid products in the model with and without gastric mucosa. The activity of three of these, Maalox, Riopan and Supralox, was not significantly different in the two systems. In contrast, the activity of the other three, Aludrox, Phosphalugel and Simeco, was significantly greater with mucosa. Antacid activity of one product from each set (Supralox, Phosphalugel) was evaluated in two in vivo methods in human volunteers. For both antacids, results in vivo were similar to those obtained with the AS-containing mucosa. Without mucosa, in vivo and in vitro results were dissimilar for Phosphalugel, thus validating the modified AS. The difference between the two sets of antacids can be explained by 1) the fact that the Al:Mg ratio in the set affected by mucosa is greater than that of unaffected antacids, and 2) a weaker antacid load than in unaffected Supralox. We suggest that in an acid milieu, aluminum ions in antacids like Aludrox, Phosphalugel and Simeco are bound to sialic acid residues in mucus glycoproteins, thus retarding the transit of these antacids through both the AS and the real stomach and prolonging their activity in both situations. When the Al:Mg ratio is low or when the amount of antacid salts is large, aluminum ions tend to be buried in complexes, giving them less chance to interact with gastric mucus, so they transit the stomach more quickly.

Adult↗
PubMed1989

Phase II study of D.651, an oral vaccine designed to prevent recurrences of vulvovaginal candidiasis.

A vaccine has been prepared with ribosomes of Candida albicans serotypes a and b plus, as adjuvant, membrane proteoglycan from a nonencapsulated Klebsiella pneumoniae. A preliminary phase II trial without placebo control was conducted in 22 women with a history of frequent recurrences of vulvovaginal candidiasis (VVC). Initially, all the patients were treated locally with an antimycotic cream. Beginning at the same time, vaccine was taken orally in capsules containing 0.55 microgram active components. It was administered intermittently over six months, groups of women taking doses of two, three, six or nine capsules. Tolerance was excellent except for mild nausea, probably due to the excipients, in two patients taking nine capsules. Twenty patients completed the study. Only seven of them had a documented recurrence of VVC during the 6 months on vaccine. No recurrence occurred in the eight women taking six or nine capsules per day. Before the study, these 20 patients had had an average of 3.59 attacks of VVC per 6 months. On vaccine, the average rate of recurrence was only 0.55 attacks per 6 months. A multicentre placebo-controlled study of the efficacy of this vaccine is in progress to validate these encouraging preliminary results.

Administration, Oral↗
PubMed1989

Stereotypes of professional roles.

To determine the current public image of the nursing profession, this survey investigated the nature of stereotyping. Subjects approached in a shopping mall (N = 110) were asked to rate the degree to which 12 characteristics typify individuals in 14 professions. The results indicate that the public image of the nurse continues to turn on feminine and nurturant characteristics. The need for increased public awareness that nurses are scholars and leaders is underscored. Asserting the right to practice may produce a new stereotype of the nurse as intelligent and autonomous.

Adolescent↗
PubMed1989

Relationship between bacteria and IgE.

In this preliminary report, we describe our inability to induce IgE antibody to a well-characterized bacterial component, the membrane proteoglycan of Klebsiella pneumoniae and its major protein fraction FIII-B in BALB/c mice. In contrast, an immunomodulatory effect of membrane proteoglycan of K. pneumoniae on the IgE and IgG antibody responses to ovalbumin could be demonstrated.

Allergens↗
PubMed1987

Interleukin-1 induces mucus secretion from mouse intestinal explants.

Secretion of goblet cell (GC) mucus occurs during immune reactions in the gut. As human macrophages produce a substance that induces mucus secretion from lung explants, we tested the effect of macrophage-derived factor(s) on mucus secretion from intestinal explants. Fragments of mouse duodenum were incubated with macrophage culture supernatants and purified interleukin-1 (IL-1) preparations, and the amount of mucus released was estimated by an enzyme-linked lectin assay. Both the culture supernatants and the IL-1 preparations induced dose- and time-dependent mucus release. Lipopolysaccharide-induced culture fluids were shown to contain IL-1. Thus, stimulation of mucus secretion from GC can be added to the list of biological activities attributable to IL-1.

Animals↗
PubMed1986

Antigenic peptides on the surface of Dirofilaria immitis microfilariae.

Various methods of radioiodination were employed to identify peptides on the surface of Dirofilaria immitis microfilariae. Optimum surface radiolabelling occurred with the lactoperoxidase-catalyzed reaction. Two major peptides of 16 and 14 kDa were labelled by this method. These peptides were soluble in Nonidet P-40, were not glycosylated, and showed no signs of disulfide linkages. These peptides were immunoprecipitated by sera from D. immitis-infected dogs, but not by sera from uninfected dogs or sera from dogs with potentially cross-reactive nematode infections. Analysis of the 14 and 16 kDa peptides by two-dimensional gel electrophoresis revealed that the 16 kDa peptide was a single unit with a pI of 5.25 whereas the 14 kDa band was composed of three individual peptides with pI values ranging from 5.6 to 6.1. Iodination by chloramine T resulted in the same panel of labelled peptides but suffered from poor efficiency of 125I incorporation. The viability of microfilariae labelled by the standard Bolton-Hunter method decreased by 50% following the reaction which resulted in the labelling of a variety of internal components.

Animals↗
PubMed1985

The immune response to a schistosomacide, amoscanate. I. Serum antibody responses.

A potent antischistosomal drug, Amoscanate, was found to be immunogenic to mice and Cebus apella monkeys. The drug was readily haptenated to proteins under relatively mild conditions. The Amoscanate-protein conjugates were observed to be immunogenic when injected into the footpads of several strains of mice. However, such protein conjugates were not found to raise IgE antibody to the drug in high-responder strains using several procedures. When the formulated drug (dissolved in oil) was fed to CD 1 mice, a rise in serum antibody against the drug was noted 1 week following the primary dose. This is preliminary evidence that the drug, or a cross-reactive metabolite, becomes covalently bound to proteins in vivo. Cebus apella monkeys fed the drug exhibited a rise in anti-Amoscanate antibody one month after a second oral dose. These data suggest that the immunogenicity of Amoscanate is readily detected; furthermore, since there is no lasting immunity to schistosomiasis, thus necessitating multiple administration of the drug, the possibility that serum antibody titers to Amoscanate may interfere with its therapeutic efficacy cannot be overlooked.

Aniline Compounds↗
PubMed1985

The immune response to a schistosomacide, amoscanate. II. Cell-mediated immune responses.

A potent antischistosomal drug, Amoscanate, was found to induce vigorous serum antibody responses when either fed or administered parenterally as a drug-protein conjugate. Because of preliminary evidence that the drug could bind covalently to proteins in vivo, we decided to investigate the possibility that the drug could act as a contact sensitizing agent like DNCB. It was found that Amoscanate could induce a delayed-type hypersensitivity (DTH) response when painted on the shaved skin of guinea pigs. Moreover, the type of DTH response elicited was found to be cutaneous basophilic hypersensitivity (CBH). The significance of these findings are discussed.

Aniline Compounds↗
PubMed1985

Quantitative and qualitative changes in the humoral response of dogs through the course of infection with Dirofilaria immitis.

The present study compared the humoral response of dogs which developed microfilaremic or occult forms of dirofilariasis following experimental infection with Dirofilaria immitis L3 larvae. Quantitative analysis by ELISA revealed that antibody levels to adult somatic (AS), excretory-secretory (ES), and microfilarial (MF) antigens were highest during the patent phase of infection in dogs with either form of dirofilariasis. Patent sera from dogs destined for occult infections contained anti-AS and anti-MF antibody concentrations of 1,572 and 1,004 micrograms/ml, respectively, while microfilaremic-bound dogs contained 1,044 and 906 micrograms/ml, respectively. Chronic sera (430 days post infection) from occult dogs contained anti-AS and anti-MF antibody levels of 982 and 600 micrograms/ml, respectively, which were higher than in microfilaremic dogs. The antibody response to ES antigen was generally 10-fold less in absolute antibody concentrations at all time points tested. Immunoperoxidase staining of antigens transferred to nitrocellulose revealed the presence of several antigenic proteins which were recognized by occult, and to a lesser extent or not at all, by microfilaremic dogs. Sera drawn from occult-bound dogs 280 days post-infection, a time corresponding to microfilarial clearance (transition phase), contained higher antibody activity to microfilarial proteins weighing 47.5, 42.0, 34.2, and 22.4 kilodaltons compared to the microfilaremic dogs. This difference in antigen recognition became more apparent during the chronic phase of infection.

Animals↗
PubMed1984

Production and testing of an international reference standard of short ragweed pollen extract.

A lyophilized candidate International Reference Standard of short ragweed pollen extract was prepared by use of defined source material. In preliminary experiments, this extract was demonstrated by RAST inhibition and crossed radioimmunoelectrophoresis assays to contain several well-characterized ragweed allergens and to contain multiple antigenic bands by crossed immunoelectrophoresis analysis. In a subsequent multinational collaborative study involving 12 laboratories in five countries, the candidate extract was compared with existing national reference or commercial ragweed extracts by a variety of immunochemical, biochemical, and physicochemical procedures. The candidate extract could be used to assign relative orders of potency to the comparison-test extracts. In separate studies, the candidate extract was demonstrated to be stable when it was stored at either -20 degrees C or +5 degrees C for at least 2 yr. The candidate extract has been accepted as an International Reference Standard with an assigned arbitrary potency of 100,000 units per ampule .

Humans↗
PubMed1984

Development of a chemotherapeutic model for microfilaricidal drugs to Dirofilaria immitis.

Microfilariae obtained from in vitro culture of adult Dirofilaria immitis were inoculated into naive dogs and used to test the in vivo efficacy of the antimicrofilarial drug Dizan. Injection of 33 million microfilariae into a 3-month-old male beagle pup over a 5-day period resulted in a microfilaremia that peaked at 863 microfilariae per ml on day 30. Treatment with Dizan resulted in a rapid clearance of microfilariae from the peripheral circulation. Four additional male beagle pups that were each given a total of 31 million microfilariae over 100 days maintained an average of 25 microfilariae per ml for 2 months. Microfilaremias were monitored by ELISA, a modified Knott's method and selected blood chemistry tests. It was shown that after residing in the peripheral circulation the microfilariae were able to develop into infective larvae in mosquitoes; therefore, the system may be a reasonable model of the natural microfilaremic state.

Aedes↗
PubMed1984

Antigens of Dirofilaria immitis which are immunogenic in the canine host: detection by immuno-staining of protein blots with the antibodies of occult dogs.

We describe here the profiles of antigens of Dirofilaria immitis that are immunogenic in dogs. Purebred beagle dogs were inoculated with a standard number of the infective third-stage larvae of the heartworm. Microfilaremia and anti-heartworm antibody levels were monitored by the Knott's test and by ELISA, respectively. Antibody-binding polypeptides were detected by immunoperoxidase staining of protein blots of detergent extracts of adult parasites from SDS-PAGE gels. Densitometric scans of these blots revealed considerable variation in the profiles of dirofilarial antigens detected by the sera obtained at different stages of the infection. Sera obtained during the prepatent phase, i.e., 3 mo post-infection (titer 1:2000), detected antigens of Mr 75, 80, 100, 130, and 200 kilodaltons. In addition to these antigens, sera obtained at the onset of microfilaremia, 6 mo post-infection (titer 1:30,000), detected antigens of Mr 15, 16, 18, 34, and 38 kilodaltons. Protein blots stained with sera from dogs, which subsequently cleared the microfilaremia and in which the infection became occult, showed that most of the antibody reactivities were directed at antigens of Mr 15, 21, and 38 kilodaltons. The variations in the species of molecules detected in sera obtained during the course of an infection seem to reflect fluctuations in the levels of specific antibodies directed at the individual heartworm antigens. We discuss the apparent role that the metamorphic differentiation of the parasite may play in determining the levels of reactivities of these antibodies at specific stages of the infection.

Animals↗