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Biomedical subjects

R Wahl

Publications and source records attributed to R Wahl.

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

Direct effect of protirelin (TRH) on PB[123I] in autonomous thyroid adenoma.

In a retrospective study of 27 cases of iodine deficiency and/or latent primary hypothyroidism and in 16 cases of thyroid adenoma with hyperthyreosis the routine radioiodine uptake test was combined with a protirelin (TRH) test. After TRH infusion, [PB*I] and TSH increased significantly in all of these 27 patients who served as controls for the hyperthyroid patients. At the same time, the conversion rate Q rose in 14 of the control patients, but it dropped in 13 cases, thus indicating a TSH-induced discharge from the thyroid of radioiodine containing substances that were not bound to serum proteins. In nine of the 16 patients with autonomous adenoma, PB[*I] rose slightly, but Q did not increase significantly. In seven of the 16 adenoma patients, both PB[*I] and Q even dropped slightly in the absence of measurable serum TSH, thus indicating a negative direct effect of TRH on thyroid hormone metabolism.

Adenoma↗
PubMed1992

[Immediate allergic reaction to natural latex with special reference to surgical gloves].

There is an increasing incidence of contact urticaria (CU) and systemic reactions to rubber products. 34 patients are presented: Most were atopic (22/34) and women (29/34). 24 worked in the medical field. 13 patients showed signs of hand dermatitis. In 31 patients, rub and/or pricktests with liquid latex in different dilutions and with latex gloves led to positive reactions. The allergen(s) appear in part to be watersoluble: 23 of 31 patients revealed positive test reactions to an aqueous glove extract. In two patients, urticarial test reactions to TMTD, Mercapto-Mix, and PPD-mix were considered as possible contributing factor of CU. Scratch tests with corn-starch were negative in all patients. 17 of 29 sera showed RAST (radioallergosorbent test) class 0 using latex allergen disks. SDS-PAGE (sodiumdodecylsulfate-polyacrylamide-electrophoresis) determined protein bands of less than or equal to 14 kD (not allergen specific) and approximately 28 kD. The Western Blot detected the 28 kD protein as allergen in the sera of three patients. Isoelectric focusing (IEF) proved no protein bands. Immunoprinting performed with sera of five patients presented allergen bands in an pH range between 3.8 and 4.55. This shows that radiostaining (immunoprint) is more sensitive than the Coomassie Blue staining. Although three sera showed RAST class 0, immunoblotting detected allergen bands. In these cases the immunoblot appears to be more sensitive than the RAST. A cross reactivity between latex and banana could not be established. Alternative gloves are Neolon (neoprene) or Elastyren (styrene-butadiene polymer).

Adult↗
PubMed1992

Compilation of DNA sequences of Escherichia coli (update 1992).

We have compiled the DNA sequence data for E. coli available from the GENBANK and EMBL data libraries and over a period of several years independently from the literature. This is the fourth listing replacing and increasing the former listings substantially. However, in order to save space this printed version contains DNA sequence information only, if they are publically available in electronic form. The complete compilation including a full set of genetic map data and the E. coli protein index can be obtained in machine readable form from the EMBL data library (ECD release 10) or from the CD-ROM version of this supplement issue directly. After deletion of all detected overlaps a total of 1,820,237 individual bp is found to be determined till the beginning of 1992. This corresponds to a total of 38.56% of the entire E. coli chromosome consisting of about 4,720 kbp. This number may actually be higher by some extra 2.5% derived from lysogenic bacteriophage lambda and various DNA sequences already received for other strains of E. coli.

Bacterial Proteins↗
PubMed1992

Direct effects of protirelin (TRH) on cultured porcine thyrocytes.

In several cases of thyroid adenoma in which no TSH was detectable in the serum, a paradoxical decrease of PB123I and its conversion rate Q (PB123I/serum total radioactivity) was observed after infusion of protirelin (TRH). The possibile direct effect of TRH on thyrocytes was therefore studied in vitro. Porcine thyroid cells were cultured in NCTC-135 medium supplemented with a serum substitute and insulin. TRH and some of its analogs enhanced the incorporation of [3H]thymidine into DNA and the uptake of radioiodide into thyrocytes. In the presence of TSH, TRH did not stimulate radioiodine uptake, whereas incorporation of [3H]thymidine into DNA was not antagonized by TSH. Thus, in this culture system, TRH had a direct effect on both growth and metabolism of thyrocytes. TSH can modulate these effects.

Analysis of Variance↗
PubMed1992

Comparison of the residual allergenic activity of six different hydrolyzed protein formulas.

The residual allergenic activity of protein hydrolysates contained in marketed "hypoallergenic" infant formulas can be determined both by in vivo methods (skin prick tests, provocation tests) and by in vitro methods (radioallergosorbent test, radioallergosorbent inhibition, crossed radioimmunoelectrophoresis, basophil histamine release). In general, whey hydrolysates containing a high percentage of larger peptides have the highest capacity to induce positive skin test and provocation test results, and to bind to human serum IgE antibodies of cow milk-sensitive children. Casein hydrolysates appear to have very little residual allergenic activity. Before hypoallergenic formulas are prescribed for cow milk-sensitive children, individual testing (e.g., skin test, challenge tests) is recommended.

Child↗
PubMed1992

How allergenic are hypoallergenic infant formulae?

In a comparative study six different protein hydrolysates, marketed as 'hypoallergenic' infant formulae were investigated by skin prick tests, RAST, RAST inhibition and titrated provocation tests. When hydrolysates containing a high percentage of larger peptides were found to have the highest capacity to induce positive skin tests, provocation tests and to bind to human serum IgE antibodies of cow's milk allergic children. Casein hydrolysates appeared to have the least residual allergenic activity. We recommend that 'hypoallergenic' formulae should be tested in each case, before being prescribed to cow's milk sensitive children.

Allergens↗
PubMed1992

Respiratory allergies (bronchial asthma and rhinitis) due to sensitization of type I allergy to red spider mite (Panonychus ulmi KOCH).

The inhabitants of a fruit growing area often report spontaneously of sensitization to the red spider mite (RSM) (Panonychus ulmi KOCH). These are for the most part sensitizations with low clinical symptoms (rhinitis, conjunctivitis and erythema). Severe clinical developments with bronchial asthma have been observed. We investigated six patients working in a fruit growing area sensitized by RSM. The sensitizations corresponded to a Type I allergy. Skin tests and provocation tests (nasal as well as bronchial) with RSM showed immediate reactions and RAST positive results were obtained using RSM allergen disks. RAST measurements of sera from nine house-dust mite Dermatophagoides pteronyssinus allergic patients using RSM allergen disks showed RAST-class > 1 for eight patients. RAST inhibition and immunoprint suggest a possible cross-reaction between RSM and D. pteronyssinus.

Adult↗
PubMed1992

Clinical and immunological effects of immunotherapy with alum-absorbed grass allergoid in grass-pollen-induced hay fever.

A double-blind, placebo-controlled study of immunotherapy was conducted in 19 patients with grass-pollen hay fever to evaluate the efficacy and safety of a formalinized depot grass allergoid. The patients were assessed before and during IT by clinical (symptom-medication scores during the grass- pollen season, specific nasal and skin reactivity) and immunological (specific IgE, IgG, IgG1 and IgG4 antibodies) parameters. High doses of grass allergoid, corresponding to a cumulative pre-seasonal dosage of 46,050 PNU, were administered, with only one systemic reaction. The actively treated patients had significantly lower symptom-medication scores than placebo (p less than 0.01) during the month of May and showed a significant decrease in specific skin (p less than 0.01) and nasal (p less than 0.05) reactivity, and a significant early increase in specific IgE (p less than 0.01), IgG (p less than 0.0005), IgG1 (p less than 0.001) and IgG4 (p less than 0.05), with a subsequent decrease of IgE and IgG1. No differences were detected in any of these parameters in the placebo group. A correlation was found between high IgG4/IgG1 ratio and the specific skin reactivity decrease (r = 0.691, p less than 0.05), whereas a high IgG4/IgG1 ratio was associated with higher symptom-medication scores (r = 0.654, p less than 0.05). Possible explanations of these apparent discrepancies are proposed.

Adolescent↗
PubMed1992

Influence of diet and carnitine palmitoyltransferase I inhibition on myosin and sarcoplasmic reticulum.

To examine the role of metabolic signals for ventricular myosin expression and activity of the sarcoplasmic reticulum Ca2+ pump, Wistar rats were treated for 7-8 wk with 5 or 50 mg/kg etomoxir, which inhibits fatty acid utilization. The proportion of myosin V1 was increased (P less than 0.05) with 50 mg/kg etomoxir (75 +/- 5% vs. 62 +/- 6% of control rats), whereas both doses increased the rate of Ca2+ uptake. A carbohydrate-rich fat-free diet or 8% sucrose drinking solutions, however, had no effect on myosin and sarcoplasmic reticulum. When rats were fed diets with an increased content (10 or 20%) of sunflower oil, the calorie intake and myosin V1 increased (56 +/- 8 or 64 +/- 8% vs. 44 +/- 6% of control rats). Isocaloric 10% fat diets of varying fatty acid composition (coconut fat, olive oil, or mackerel oil) also induced a higher calorie intake and increased V1 (64 +/- 6, 60 +/- 9, or 65 +/- 8% for the respective oils vs. 44 +/- 6% of control rats) but did not significantly increase rate of Ca2+ uptake. We concluded that calorie-rich diets changed the myosin expression not by affecting the ratio of fatty acid to glucose utilization but via the increased calorie intake.

Animals↗
PubMed1992

Isoelectric focussing of human thyroxine binding globulin (thyropexin) and human prealbumin (transthyretin).

Two batches of the highly purified thyroid hormone-binding plasma proteins, human thyropexin and transthyretin, which were prepared in gram quantities for use in animal experiments, were subjected to analysis by isoelectric focussing. Under these conditions, it was observed that human transthyretin was composed of two components. This was presumably due to the use of 8 mol/l urea. The preparations of both human transthyretin and human thyropexin contained some products of decomposition which probably arose in the course of the purification processes and, in addition, possibly also contained some normal genetic variants of human thyropexin. In spite of the alterations, both protein preparations largely retained their thyroid hormone-binding capacity, which is essential for in vivo studies on the re-entry of thyroid hormones from the extravascular space into the circulation. For therapeutic use in thyrotoxicosis, human transthyretin seems to be preferable to human thyropexin.

Blotting, Western↗
PubMed1992

Radiolabeled monoclonal antibodies (for the radiology administrator).

Cheaper, faster, safer, these are not the attributes of 1993 automobiles, but criteria for new diagnostic tests in medicine. To achieve these characteristics, medicine is increasingly looking to biotechnology for answers. And the mother of all biotechnology is monoclonal antibody research. In past issues, Administrative Radiology published articles discussing the role of biotechnology in the development of radiopharmaceuticals used in nuclear medicine. In this issue, Richard Wahl, M.D., reviews, in plain talk, the current status and prospects for diagnostic imaging with radiolabeled monoclonal antibodies. Are there any such procedures of value today? Are there any that are FDA approved? Will there ever be such agents that are either useful or approved? If so, will any insurance carrier pay for them? For the answers to these and other "hot" questions, the reader is encouraged to continue on and read this month's Technology Review section.

Antibodies, Monoclonal↗
PubMed1991

Compilation of DNA sequences of Escherichia coli (update 1991).

We have compiled the DNA sequence data for E. coli available from the GENBANK and EMBL data libraries and over a period of several years independently from the literature. This is the third listing replacing and increasing the former listing roughly by one fifth. However, in order to save space this printed version contains DNA sequence information only. The complete compilation is now available in machine readable form from the EMBL data library (ECD release 6). After deletion of all detected overlaps a total of 1 492,282 individual bp is found to be determined till the beginning of 1991. This corresponds to a total of 31.62% of the entire E. coli chromosome consisting of about 4,720 kbp. This number may actually be higher by some extra 2.5% derived from lysogenic bacteriophage lambda and various DNA sequences already received for statistical purposes only.

Base Sequence↗
PubMed1991

Occupational wood-dust sensitivity from Euonymus europaeus (spindle tree) and investigation of cross reactivity between E.e. wood and Artemisia vulgaris pollen (mugwort).

A 44-year-old goldsmith suffered from rhinitis and conjunctivitis after having worked with wood dust from Euonymus europaeus (E.e.) for 15 years. The material was used for drying pieces of jewelry. Very strong reactions could be seen after friction test, scratch test and nasal challenge using wood dust of E.e. RAST-class 3 could be measured with the serum of this patient using E.e. wood and Artemisia vulgaris (A.v. pollen) allergen disks. RAST-inhibition, western-blot (WB) and immunoprint (IP) indicated common allergens in extracts of E.e. wood and A.v. pollen of different degree. In addition this study indicated that subjects suffering from A.v. pollen allergy also show sensitization to E.e. wood since in 22 of 37 A.v. pollen allergies A.v. (RAST class 2-4) IgE-antibodies could be seen. The present case probably demonstrates for the first time an IgE-mediated type I allergy to E.e. wood.

Adult↗
PubMed1991

Tribolium confusum (confused flour beetle, rice flour beetle)--an occupational allergen in bakers: demonstration of IgE antibodies.

Specific IgE to proteins from Tribolium confusum (TC), a flour beetle, was detected in 9/125 sera of subjects exposed to rye and wheat flour. TC RAST was not inhibited by Dermatophagoides pteronyssinus, rye or wheat flour. Immunoblot experiments showed specific binding to three proteins from adult TC or pupae, not present in rye or wheat flour. These findings suggest that TC might act as an occupational allergen in a proportion of bakers.

Allergens↗
PubMed1991

Investigation of house dust mite (Dermatophagoides pteronyssinus) allergen extracts prepared from purified mite bodies and whole mite culture.

Allergen extracts prepared from purified mite bodies (PMB) and whole mite culture (WMC) were investigated by using in vivo and in vitro methods. PMB showed a more complex allergen pattern than WMC. In PMB, 6 out of 16 allergens could be detected as major allergens. In WMC, 5 out of 10 allergens could be detected as major allergens. Both extracts contained the same amount of the major allergen Der p I. By skin prick testing comparable results were obtained with both extracts. Investigation of the reproducibility showed that 15 production lots of PMB could be produced in a high conformity according to their allergenic potency and their protein and allergen composition.

Allergens↗
PubMed1991

IgE-mediated inhalant allergy against human corticotropin-releasing hormone.

A 25-year-old female developed IgE-mediated sensitization against human recombinant corticotropin-releasing hormone (CRH) with symptoms of allergic rhinoconjunctivitis and bronchial asthma. The occupational allergy was proved by positive skin prick test, bronchial provocation, dose-dependent histamine release, RAST measurements with CRH allergen (RAST class 3) and RAST inhibition. Using the immunoblot technique, a single allergen band with a molecular weight of less than 14.4 kD in the range between the isoelectric point 5.2 and 5.7 was detected for the CRH extract. Since no endocrinological and behavioral disorders were found, increased CRH-specific IgE was not able to influence the regulatory control of this neuropeptide. After 18 months of avoiding the occupational CRH exposure allergen-specific histamine release and RAST were negative.

Adult↗
PubMed1991

Comparison of fifteen production batches of house dust mite extract (Dermatophagoides pteronyssinus).

An important measurement of quality of allergenic extracts is the batch to batch uniformity. Using different methods of protein and immunobiochemical analysis, we could demonstrate, that 15 production batches of house dust mite Dermatophagoides pteronyssinus extract prepared during the course of 4 years from different lots of the source material, (purified whole mite bodies) showed reproducible data.

Allergens↗