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Biomedical subjects

A Boehm

Publications and source records attributed to A Boehm.

13 recordsLinked to original sources
PubMed2006

Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potential.

BACKGROUND: The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. METHODS: An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. RESULTS: In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. CONCLUSION: Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein.

Allergens↗
PubMed2003

Cross-modal plasticity for sensory and motor activation patterns in blind subjects.

Experimental data on cortical reorganization in blind subjects using H(2)(15)O positron emission tomography and functional magnetic resonance imaging (fMRI) showed activation of the visual cortex related to Braille reading and tactile discrimination tasks in congenitally and early blind subjects. The purpose of our study was to differentiate whether occipital activation of blind subjects during Braille reading is task specific or only triggered by sensory or motor area activation. Twelve congenitally and early-onset blind subjects were studied with fMRI during Braille reading, discriminating nonsense dots, sensory stimulation with electromagnetic pulses, and finger tapping. All experiments were performed utilizing a block design with 6 active epochs alternating with 6 rest conditions lasting 34 s each. Echo-planar imaging sequences with 34 transversal slices were performed on a 1.5-T MR scanner. All blind individuals reading Braille and discriminating nonsense dots showed robust activation of the primary, secondary, and higher visual cortex. Application of peripheral electrical stimuli to the reading hand revealed expected sensory activation of the primary somatosensory cortex, but no activation in the visual cortex. Pure motor activation during finger tapping with the reading hand showed expected precentral activation and no activation of visual cortex. In conclusion, occipital activation during Braille reading and discrimination tasks is not due to plasticity of sensory or motor function; pure motor or sensory tasks do not lead to an activation of striate cortex. The brain learns to differentiate between "finger touching" and "finger reading." Our results suggest that activation of the visual cortex in blind subjects is related to higher and more complex brain functions.

Adult↗
PubMed1997

The influence of organizational and personal characteristics on community planning activity.

The authors identify the influence of organizational and personal characteristics on the tendencies of community organizational workers in Israel to implement planning activities. The research examines these factors in relation to two planning styles, rational and organizational-political, and also distinguishes among factors influencing the tendency for implementation of each style. The principal findings indicate that the tendency of workers to implement rational activities is influenced by mechanical characteristics of the organization. On the other hand, the tendency of the workers to implement organizational-political activities is influenced significantly by organic characteristics--variety and conflict--with the organization. The frequency of use of both styles is influenced by professional education in community organization.

Community Health Planning↗
PubMed1992

Therapy of alopecia areata with diphencyprone.

The properties of diphencyprone (DPC), its possible mechanism of action in the therapy of alopecia areata (AA), and its side-effects are summarized. The results of our own study of treatment in 45 patients with AA, with a mean treatment duration of 72 (15-146) weeks, are presented, and compared with the results of previous studies. We suggest that, in future, therapy protocols should define entry criteria and therapy results more precisely, and include follow-up assessments to establish the length of remission. In view of the low response rates and short lengths of remission, the indications for DPC therapy should be set more rigorously.

Adolescent↗
PubMed1992

Studies on cultured fibroblasts from patients with cutaneous malignant melanoma.

Cultured fibroblasts from patients with cutaneous malignant melanoma (CMM) were tested for chromosomal instability by determination of micronuclei (MN) and sister chromatide exchange (SCE). The constitutive as well as the UV-induced level of MN was increased in CMM patients, being most pronounced in the familial cases. There was an increased UV sensitivity in CMM by using SCE, but no spontaneously enhanced SCE value. The enhanced UV sensitivity in CMM patients was in a comparable range as those of XP heterozygotes. We thus conclude that chromosomal instability is a concurrent feature of a genetic predisposition for CMM.

Cells, Cultured↗
PubMed1990

Analysis of gunshot residue test results in 112 suicides.

The results of gunshot residue (GSR) tests in 112 suicide cases investigated by the U.S. Army Criminal Investigation Command over a ten-year period are described. Only suicide cases in which there was certainty that the victim fired a weapon were examined in an effort to reduce ambiguous results. Previous case work research by Rudzitis indicated that positive GSR test results were encountered in suicides 62% of the time using various combinations of neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS). Threshold values of 0.2-micrograms antimony and 0.3-micrograms barium (0.2-micrograms antimony and 0.5-micrograms barium after 1985) used by the U.S. Army Criminal Investigation Laboratory resulted in positive GSR results in suicide cases 38% of the time. The effects of time, location of body, handling of the body, weapon type, caliber, and condition of the hands on GSR results are examined. Case studies involving suicides by unit armorers are discussed.

Firearms↗
PubMed1988

The affinities of prostaglandin H2 and thromboxane A2 for their receptor are similar in washed human platelets.

Both thromboxane A2 (TXA2) and its precursor prostaglandin H2 (PGH2) are labile and share a common receptor. The affinities of these two compounds for their putative common receptor are unknown. We compared the potencies of TXA2 and PGH2 to aggregate human platelets and bind to the TXA2/PGH2 receptor. TXA2 was more potent than PGH2 in initiating aggregation in platelet-rich plasma, EC50 of 66 +/- 15 nM and 2.5 +/- 1.3 microM, respectively. In washed platelets, however, PGH2 was more potent than TXA2 with EC50 values of 45 +/- 2 nM and 163 +/- 21 nM, respectively. The affinity of these two compounds in washed platelets was determined in radioligand competition binding assays employing [125I]-PTA-OH. The Kd values for PGH2 and TXA2 were 43 nM and 125 nM, respectively. The results demonstrate that the affinity of PGH2 for the platelet TXA2/PGH2 receptor is greater than previously thought. The data raise the possibility that PGH2 may significantly contribute to the responses attributed to TXA2 in vivo.

Binding, Competitive↗
PubMed1988

Polymyxin B increases TXA2/PGH2 agonist and antagonist affinities in human platelet membranes.

The effects of polymyxin B, a cyclic polycationic peptide antibiotic, on the binding of thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor agonists and antagonists to the putative human platelet TXA2/PGH2 receptor have been determined. Crude membranes were prepared from washed human platelets and the binding of [125I]-PTA-OH, a TXA2/PGH2 receptor antagonist, was used as a ligand to characterize the effects of polymyxin B on agonist and antagonist binding. Polymyxin B produced a concentration-dependent decrease in the IC50 values for the TXA2/PGH2 agonist, U46619, in radioligand competition binding assays. Polymyxin B also decreased the IC50 values of the TXA2/PGH2 agonist ONO 11113 from 75 +/- 11 nM to 38 +/- 2.5 nM and the TXA2/PGH2 receptor antagonist SQ29548 from 60 +/- 14 nM to 20 +/- 2.3 nM. The Kd for [125I]-PTA-OH was also reduced by polymyxin B from 107 +/- 10 nM to 76 +/- 6 nM but it had no effect on the maximum number of binding sites (Bmax). Polymyxin B had no significant effect on the binding affinity of U46619 in intact washed human platelets. These results raise the possibility that polymyxin B can alter the conformational state of the TXA2/PGH2 receptor when it is in a crude membrane fraction but not in intact platelets.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMedDate not supplied

Unique solutions in pediatric critical care.

This pediatric intensive care unit (PICU) functions as a part of a multidisciplinary adult ICU and has evolved into a unique health care setting. The Special Care Unit (SCU), which is the name for our ICU, serves a population of adult and pediatric patients, including trauma, open-heart surgery, medicine, surgery, and neurosurgery. All staff are expected to provide care for adults and children without regard to admitting diagnosis. In addition to meeting the critical care needs of this diverse pediatric population in the SCU, we provide a pediatric critical care ground transport program for critically ill children from outlying hospitals. Competency-based orientation tools were developed and are used to guide the orientation process. The tools identify the required knowledge base necessary for a staff member to adequately care for the adult and pediatric populations and track each staff member's progress through orientation. The model used to deliver care to adults and children in this setting is innovative. This model represents one solution to providing critical care to both the adult and pediatric population in today's era of health care redesign.

Child↗