Biomedical subjects

A E Davidson

Publications and source records attributed to A E Davidson.

15 recordsLinked to original sources

PubMed2001

Three-color imaging using fluorescent proteins in living zebrafish embryos.

The zebrafish embryo is especially valuable for cell biological studies because of its optical clarity. In this system, use of an in vivo fluorescent reporter has been limited to green fluorescent protein (GFP). We have examined other fluorescent proteins alone or in conjunction with GFP to investigate their efficacy as markers for multi-labeling purposes in live zebrafish. By injecting plasmid DNA containing fluorescent protein expression cassettes, we generated single-, double-, or triple-labeled embryos using GFP, blue fluorescent protein (BFP, a color-shifted GFP), and red fluorescent protein (DsRed, a wild-type protein structurally related to GFP). Fluorescent imaging demonstrates that GFP and DsRed are highly stable proteins, exhibiting no detectable photoinstability, and a high signal-to-noise ratio. BFP demonstrated detectable photoinstability and a lower signal-to-noise ratio than either GFP or DsRed. Using appropriate filter sets, these fluorescent proteins can be independently detected even when simultaneously expressed in the same cells. Multiple labels in individual zebrafish cells open the door to a number of biological avenues of investigation, including multiple, independent tags of transgenic fish lines, lineage studies of wild-type proteins expressed using polycistronic messages, and the detection of protein-protein interactions at the subcellular level using fluorescent protein fusions.

Animals↗

PubMed1994

Access to care among children visiting the emergency room with acute exacerbations of asthma.

To determine differences in access to continuing and preventive care among pediatric patients utilizing the emergency room for treatment of acute exacerbation of asthma, families of 170 asthma patients aged 2 to 17 years were surveyed prospectively. An interview schedule instrument generated information about socioeconomic factors, source of medical care including maintenance and specialty care, medication use, and plans for management of asthma exacerbations. A primary physician or clinic could be identified by 162 patients (95%). Regular preventive therapy (cromolyn, theophylline, or steroids) was used by 45 patients (27%). Allergy evaluations had been previously performed for 59 patients (35%). "Come to Emergency Room" was part of the asthma management plan for 56 patients (33%) and was the only asthma management plan for 34 patients (20%). Logistic regression analysis found that black and Hispanic patients (odds ratio = 0.38) and patients with Medicaid (odds ratio = 0.43) were less likely to call their MD or clinic prior to reporting to the emergency room. Patients with Medicaid were more likely to have two or more prior emergency room visits compared with a group of patients with private insurance and self-paying patients (odds ratio = 4.17). While the majority of patients in this study could identify a source of primary care, patients on Medicaid were significantly less likely to access continuing and preventive care and more likely to utilize the emergency room.

Adolescent↗

PubMed1992

Internalization of monoclonal antibodies selected for immunotoxin activity against small-cell lung cancer.

Two hybridomas producing MOABs with anti-SCLC activity were selected for immunotoxin activity by an indirect screen and were twice cloned. Binding activity of the MOABs to SCLC cells was demonstrated by immunoperoxidase activity, which could be blocked by streptavidin. The MOABs mediated the internalization of a biotinylated Fab' anti-mouse Ig marker at 37 degrees C. Internalization of the biotinylated marker by the SCLC target cells resulted in protection of the marker from streptavidin-blocking. These results show that MOABs selected for immunotoxin activity against SCLC can mediate internalization of an antibody fragment with a mass about 50% greater than that of the toxin. MOABs selected for immunotoxin activity may be useful for delivering agents other than toxins to the inside of SCLC cells.

Antibodies, Monoclonal↗

PubMed1992

Buckwheat-induced anaphylaxis: a case report.

Buckwheat (Fagopyrum schulentum) is not taxonomically related to wheat and other cereal grains. Buckwheat flour is used as a wheat substitute in breads, biscuits, pancakes, and crepes. Occupational exposure to buckwheat flour has been associated with rhinitis, conjunctivitis, contact urticaria, and occupational asthma. We present a patient who developed urticaria and hypotension after ingestion of buckwheat crepes. Skin testing by the prick technique revealed 3+ positive reaction to buckwheat with negative reactions to other foods including wheat, egg white, and milk. RAST for anti-buckwheat IgE was strongly positive. Buckwheat ingestion is a potential cause of food-related anaphylaxis. There does not appear to be cross-reactivity between buckwheat and wheat allergy.

Adult↗

PubMed1992