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W Becker

Publications and source records attributed to W Becker.

At least 361 records · Page 20Linked to original sources
PubMed1990

Dietary linoleate supplementation modulates formyl-peptide receptor expression and functional responses of rat neutrophils.

We studied effects of dietary supplementation with the essential fatty acid (EFA) linoleic acid (LA) to see if neutrophil responses would be modulated. Neutrophils from rats maintained on a diet supplemented with EFA to 10% of the energy content--the high EFA (HEFA) group--showed a significantly higher LA concentration (but similar arachidonic acid content) compared with neutrophils from control rats maintained on a standard diet with 3% of the energy content as EFA. The HEFA group showed a significantly higher neutrophil oxidative metabolism compared with controls in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP), but this response was equal to control values when stimulated by ionophore A23187, sodium fluoride, or phorbol myristate acetate. Similarly, FMLP conferred a more pronounced increase of intracellular Ca2+ in HEFA neutrophils, whereas this response to ionomycin was equal to that in controls. In contrast, HEFA rat neutrophil migration was decreased to 71% of the value in controls in response to FMLP. Similar results were observed for aggregation responses. On A23187 stimulation, HEFA and control neutrophils generated equal amounts of leukotriene B4 and other 5-lipoxygenase products as well as thromboxane B2 and 6-keto-prostaglandin F1 alpha. However, assessment of binding of FMLP labeled with tritium revealed an increase of the low affinity state of the FMLP receptor population. Thus an increased intake of one unsaturated fatty acid, LA, leading to its accumulation in neutrophils, conferred alterations in formyl-peptide-elicited responses, not associated with the formation of the assessed arachidonate-derived mediators, but most likely through the observed modulation of FMLP receptor subpopulations.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

The relationship of retrobulbar hematomas to vision in cynomolgus monkeys.

An experimental model has been developed to measure the effect of retrobulbar hematomas on functional vision in cynomolgus monkeys. In this model, functional vision was quantitated using flashed evoked visual potentials in five monkeys following creation of retrobulbar hematomas. In one monkey used as a control, functional vision remained impaired for 180 minutes following induction of retinal ischemia by increased intraorbital pressure. In two monkeys in which increased intraorbital pressure was relieved by anterior chamber paracentesis following 15 minutes of retinal ischemia, flashed evoked visual potential promptly returned to baseline level. In two additional monkeys in which increased intraorbital pressure was relieved following 30 minutes of retinal ischemia, flashed evoked visual potentials improved but never returned to baseline levels. This study demonstrates the usefulness of flashed evoked visual potentials in measuring functional vision in cynomolgus monkeys. This experimental model should prove useful in evaluating the effects of increased intraorbital pressure on functional vision and the effect of intervention on impaired vision due to retrobulbar hematomas. Further studies with larger numbers of animals are needed to clarify these preliminary studies and document longer-term effects of retinal ischemia secondary to retrobulbar hematomas.

Animals↗
PubMed1990

99mTc-labelled polyclonal human immunoglobulin for localization of inflammatory sites--early in vitro-results.

99mTc-labelled polyclonal human immunoglobulin (HIG) has been shown to be able to localize inflammatory sites. Hypothetically these immunoglobulins bind directly to bacteria, HIG binds directly to Fc-receptors on the surface membrane of leucocytes or HIG simply passes vessels of increased permeability. To collect further information experiments were carried out in vitro with the blood of human volunteers. 0.5 mg 99mTc-HIG, 2 mg 99mTc-human albumin and 0.5 mg 99mTc-labelled murine monoclonal antigranulocyte antibodies were added to in vitro isolated human "mixed" leucocyte pellets and to 30 ml whole blood of 6 healthy volunteers. The whole blood and the directly labelled leucocyte pellet were layered and separated on a discontinuous Percoll/plasma gradient. The activity distribution was measured within the gradient. The 99mTc-HIG labelled gradients showed a significant uptake of the activity within the monocyte band whereas the 99mTc-albumin gradients showed no specific albumin uptake in any cellular band. The 99mTc-antibody labelled gradients showed a significantly increased uptake on granulocytes. It is concluded that in man a specific monocyte-associated uptake and binding mechanism of 99mTc-HIG plays an important role in the localisation of inflamed sites.

Granulocytes↗
PubMed1990

Clinical and microbiologic findings that may contribute to dental implant failure.

Clinical and DNA probe analysis were used to evaluate 36 failing implant sites in 13 patients. Failing implants showed evidence of increased mobility and a high incidence of peri-implant radiolucencies in radiographs. The probing depth was greater than 6 mm in 58% of the sites measured. Moderate levels of Actinobacillus actinomycetemcomitans, Bacteroides intermedius, and Bacteroides gingivalis were detected with DNA probe analysis.

Actinobacillus↗
PubMed1989

Tc-99m-HMPAO labelled human platelets: in vitro and in vivo results.

The lipophilic 99mTc-HMPAO complex can be used for labelling platelets as well as granulocytes. Platelets were isolated according to standard isolation procedures for the evaluation of the optimal labelling parameters. The labelling efficiency (%) depends on incubation temperature (22 degrees C: 40%: 37 degrees C: 50%), incubation time (3 min: 20%, 25 min: 55%) and the incubation medium (plasma: 40%; saline 50%). The 60 min 99mTc elution out of the platelets ranged around 8%. The platelet recovery used as a quality control parameter is around 25% +/- 4% and is stable for at least 240 min. The high elution rate out of the platelets leads to renal excretion of the label and hence to significant kidney and bladder activity. Intestinal excretion of the label can also be frequently demonstrated. Fresh thrombotic lesions can normally be detected 4 h after reinjection of the labelled platelets, and in some patients as early as 1 h after reinjection. In conclusion, 99mTc-HMPAO seems to be a promising platelet label for imaging thrombotic lesions but not for platelet survival studies, because of the short physical half life of 99mTc.

Blood Platelets↗
PubMed1989

Kinetic data of in-vivo labeled granulocytes in humans with a murine Tc-99m-labelled monoclonal antibody.

Twenty-five patients were examined in vivo with 99mTc labelled monoclonal antibodies; 15 with suspected infections with an antigranulocyte antibody (BW 250/183), 10 with suspected recurrence of a colorectal carcinoma with an anti CEA antibody (BW 431/26). Both antibodies were IgG1 isotypes. In the patients with suspected infections no change of the peripheral leukocyte count could be observed after the antibody injection (1 mg, n = 9; 0.5 mg, n = 1; 0.25 mg, n = 6). In 2 patients examined with the anti CEA antibody (2 mg), a significant decrease of the peripheral leukocyte count could be observed. The recovery rate of the 99mTc antibody labelled granulocytes was calculated to be about 10%. The increase of the antibody-antigen binding was calculated to be 0.2%/min. In vivo the organ distribution curves demonstrated an increase of 99mTc activity over spleen and bone marrow of 1.1%/min, which was interpreted as antigen-antibody reactivity. The organ distribution curves of the anti granulocyte antibody over spleen and bone marrow showed typical binding characteristics to the local granulocyte epitopes. The curves over other organs showed a simple perfusion pattern. The curves of the anti CEA antibody showed a perfusion pattern over all the examined organs. A sham dialysis model in one patient with renal insufficiency undergoing regular dialysis treatment demonstrated the viability of 99mTc antibody labelled granulocytes in vivo. The kinetic patterns of the 99mTc antibody in patients with Crohn's disease were interpreted as CEA binding of the antibody in the bowel wall.

Animals↗
PubMed1989

The role of nasal secretions in allergic disease of the nose.

Findings in recent years have stressed the importance of research on the target organ in IgE-mediated allergies of the respiratory tract. In this review we have focussed on the nasal secretions (NS) as a contract medium between allergens and the respiratory mucosa. Our findings have demonstrated that NS show different allergen extraction activities in relation to different conditions. Whereas NS of allergic and inflamed noses extracted allergens very rapidly, NS of normal noses showed no extraction activity. Furthermore, it could be demonstrated that the IgE specificities in NS are comparable with those in the serum of individual patients not indicating a local IgE synthesis. The presence and function of basophilic cells and eosinophils and their mediators are discussed in the light of recent studies.

Humans↗
PubMed1989

Alterations in hemolymph components in Biomphalaria glabrata during long-term infection with Schistosoma mansoni.

Total protein, hemoglobin, glucose, and urea concentrations in hemolymph of Biomphalaria glabrata were studied during a 12-week infection of the snails with Schistosoma mansoni. The results suggest an equilibrium between host and parasite metabolism, which is reached after about 6 weeks of infection. During the period studied, the protein spectrum of infected snails showed no difference in quality compared with that of noninfected snails; all fractions were present, and no additional fractions appeared. Only the lipoprotein fraction increased fourfold in the 1st week of infection, decreasing during the 2nd week to concentrations that were also found in noninfected individuals. No further significant alterations could be detected until week 12 postinfection (PI).

Animals↗
PubMed1989

[Initial experiences with hysterosalpingoscintigraphy in normal and pathologic fallopian tube passage].

A prospective study in 38 patients was designed to evaluate the efficacy and reliability of radionuclide hysterosalpingoscintigraphy (HSS) using 99mTc labelled human albumin macroaggregates (HAMA). Following application in the posterior vaginal fornix at the time of ovulation, HAMA normally migrate spontaneously through the uterus and tubes and may be identified after 20 min (range 5-90 min) in the uterine cavity and after 2 hrs (range 40 min - 3 hrs) in the free pelvis, using a gamma camera. When correlated with the findings of conventional contrast hysterosalpingography (HSG), the radionuclide procedure yielded comparable results in females with patent or clearly obstructed tubes. Using 8-10 MBq 99mTc, radiation exposure was estimated to be 0.75 cGy per ovary, which is considerably less than the mean dose absorbed with HSG. As the HSS procedure imitates the migration of spermatozoa by the means of an inert tracer, it allows a direct insight in the mechanisms of passive transport taking place in the uterus and tubes at the period of ovulation. Thus, it reflects the physiological state of the female reproductive tract. On the basis of the scintigraphic findings, equivocal results on HSG have to be re-evaluated, as tubes, which are anatomically patent under high pressure, may be functionally deficient.

Adult↗
PubMed1989

[The role of radiotherapy in endocrine orbitopathy].

The treatment of Graves' ophthalmopathy is symptomatic because the etiology remains unknown though evidence supports an aberrant immune response. Orbital radiotherapy, combined with corticosteroids, is indicated for rapidly progressive ophthalmopathy and troublesome soft tissue symptoms. In case of sight-threatening manifestations operative decompression is the method of choice. However, radiotherapy seems to be a safe and effective method as a good to excellent response in 60-70% of patients can be expected. The treatment results of 15 patients with a long term follow-up are presented.

Adult↗