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Biomedical subjects

H Berthold

Publications and source records attributed to H Berthold.

At least 55 records · Page 3Linked to original sources

Human thyroid peroxidase: autoantibody recognition depends on the natural conformation.

Thyroid peroxidase (TPO) purified from human thyroid glands was used to study the correlation relation between natural conformation and its ability for binding of autoantibodies in sera from patients with autoimmune lymphocytic thyroiditis (Hashimoto's thyroiditis). Treatment with heat (60 degrees C), urea, sodium dodecylsulfate (SDS), and dithiothreitol (DTT) decreased the autoantigenicity of TPO on average by 73.3%, 74.1%, 86.3%, and 91.8% measured by enzyme-linked immunosorbent assay (ELISA), respectively. These data demonstrate, that the binding of the majority of autoantibodies to human TPO depends on its natural conformation and modification.

Autoantibodies↗

Frequency of hepatitis C in acute post-transfusion hepatitis after open-heart surgery: a prospective study in 1,476 patients.

Post-transfusion hepatitis was studied prospectively in 1,476 patients undergoing open-heart surgery between 1985 and 1988. Thirty-three (2.2%) patients suffered from post-transfusion hepatitis. Acute post-transfusion hepatitis was attributed to hepatitis B in one case and to hepatitis C in ten patients (0.7%). Four additional patients had preexisting serologic markers of hepatitis C. In 22 (1.5%) patients, hepatitis B or C was excluded as a cause of liver disease. Seroconversion for hepatitis C virus occurred from 3 weeks to more than 6 months after infection. Chronic hepatitis C developed in four patients. In addition, seroconversion to anti-HCV was observed in four patients with moderately elevated aminotransferases. In the control patients anti-HCV antibodies were found in 0.5%. The characteristics of acute hepatitis C after blood transfusion are shown and compared to 22 patients with acute hepatitis non-A, non-B, non-C. The etiology of these 22 cases is discussed.

Aged↗

Baculovirus-mediated expression of human 65 kDa and 67 kDa glutamic acid decarboxylases in SF9 insect cells and their relevance in diagnosis of insulin-dependent diabetes mellitus.

cDNAs coding for the full-length human 65 and 67 kDa glutamic acid decarboxylases (GAD65 and GAD67) were amplified from pancreas and hippocampus cDNA libraries by polymerase chain reaction, respectively. Both cDNAs were inserted into a baculovirus vector which mediated highly efficient expression of the human GAD65 and GAD67 with histidine-hexapeptides as affinity ligands at their C-termini in Spodoptera frugiperda (Sf9) cells. The recombinant GAD proteins were purified to homogeneity by affinity chromatography using a metal-chelating matrix. The infected Sf9 insect cells expressed the recombinant human GAD65 and GAD67 with natural-like conformations, as confirmed by measurement of their enzyme activities as well as their fully restored autoantigenicities. Immunoprecipitation of metabolically labeled infected Sf9 cells demonstrated the autoantigenic potential of the recombinant GAD proteins. The practicability of using recombinant GAD65 and GAD67 derived from the baculovirus expression system for the development of an immunoassay for the diagnosis of insulin-dependent diabetes mellitus is discussed.

Animals↗

Geriatric nursing assessment--the use of a standardized assessment instrument in a clinical setting.

The purpose of the present study was to investigate the content and focus of nursing assessment when using a well-known Swedish, commercially available, standardized structured multidimensional instrument in the assessment of nursing needs/problems in a geriatric rehabilitation department. Two hundred and fifty-six assessment forms were quantitatively and qualitatively analysed. In 113 cases the corresponding nursing care plans were also analysed. Although a few important areas, such as communication and I-ADL, were missing, the instrument enabled the nurses to make a fairly comprehensive nursing assessment. However, the data collected with the instrument were only partly used in the nursing care plans, and relevant nursing diagnosis could be formulated in only 36 cases. The conclusions are that the data collection must be more goal-oriented and that education in diagnostic reasoning should be meaningful. To choose wide assessment areas could probably also facilitate holistic nursing care.

Aged↗

Expression of recombinant human thyroid peroxidase by the baculovirus system and its use in ELISA screening for diagnosis of autoimmune thyroid disease.

The cDNAs coding for human full-length and soluble thyroid peroxidase (TPO) were constructed, cloned into a baculovirus transfer vector and used for infection of Spodoptera frugiperda (Sf9) cells. The soluble TPO lacking 87 amino acids of the C-terminal transmembrane and intracisternal domains was designed as a fusion protein with a histidine-hexapeptide as an affinity ligand at its C-terminus. Whereas the recombinant full-length TPO was expressed mainly in an insoluble form in Sf9 cells, the recombinant soluble TPO was almost completely secreted into the culture medium. Both the full-length and the soluble TPO were purified by conventional methods and by a specific affinity chromatography using metal chelating matrix respectively, and tested for their autoantigenicity towards anti-TPO autoantibodies. The ELISA established with the purified recombinant soluble TPO as antigen demonstrated its specificity, practicability and reproducibility in screening of anti-TPO autoantibodies in sera of autoimmune thyroid patients. High correlation (r = 0.89, n = 175) was obtained between the soluble TPO and natural TPO prepared from human thyroid glands. Pathological sera (n = 200) were positively assayed with a significance of 91%.

Animals↗

Localized ridge augmentation using guided bone regeneration. 1. Surgical procedure in the maxilla.

A new surgical technique for localized ridge augmentation prior to the placement of dental implants has been developed. The technique is based on the principle of guided bone regeneration utilizing barrier membranes. In the present article, the currently used surgical procedure is presented through two case reports. In addition, the different aspects of the surgical technique needed to achieve a predictable success are discussed.

Adolescent↗

Cause and frequency of posttransfusion hepatitis after open-heart surgery.

A total of 1476 patients who underwent open-heart surgery between 1986 and 1988 participated in a prospective study examining posttransfusion hepatitis. They received a total of 8327 units of whole blood, packed erythrocytes, or fresh frozen plasma. The aminotransferase activities were measured preoperatively and 1, 2, 3, 4, 6, 9, 12, and 24 weeks after the operation. Thirty-four patients in all (2.3% of the transfused patients) developed posttransfusion hepatitis, which could be identified as hepatitis B in 1 patient and hepatitis C in 14 patients. No cause for posttransfusion hepatitis could be found in 19 cases (hepatitis of unknown origin). Hepatitis C became chronic in 5 patients. In contrast to hepatitis C, the 19 patients with hepatitis of unknown origin all showed a milder clinical course with lower maximal aminotransferase activities and a shorter duration of the hepatitis. A chronic course was not observed among them. The cause of hepatitis of unknown origin is discussed.

Adult↗

Hepatitis A as an occupational hazard.

Few studies have been carried out to evaluate the role of hepatitis A virus (HAV) as an occupational hazard. Our analysis of data on occupational diseases in Germany showed that hepatitis A ranks as third among infectious occupational diseases. Morbidity based on the frequency of compensation (15.2%) was in the same range as that observed for hepatitis B (19.7%). In another study, data were collected on anti-HAV prevalence among 2293 hospital workers in southwest Germany. Anti-HAV prevalence of hospital staff responsible for patient care and that of the general population were comparable, while food-handlers under the age of 30 years had a higher degree of anti-HAV prevalence. When an evaluation of anti-HAV prevalence data was carried out on persons younger than 30 years who comprised subsets of the medical staff, the relative risk was: charwomen 4.2, food-handlers 2.49, and paediatric nurses 1.84, showing that they had higher prevalence rates than nurses 1.25, physicians 1.09 and laboratory assistants 0.93. Vaccinations for the prevention of hepatitis A should therefore reach individuals that have an increased occupational risk: food-handlers, health care workers in infectious diseases and paediatrics, medical staff in laboratories handling stool samples, medical charwomen and, according to previously published work, staff of day care centres and sewerage workers.

Food Handling↗

Purification of recombinant antigenic epitopes of the human 68-kDa (U1) ribonucleoprotein antigen using the expression system pH6EX3 followed by metal chelating affinity chromatography.

A novel plasmid expression vector (pH6EX3) that directs the synthesis of a fusion protein with a histidine hexapeptide at its N-terminus and a foreign protein at its C-terminus was constructed. The fusion gene is controlled by a strong tac promoter, leading to high-level expression of recombinant protein in several bacterial strains; the protein is deposited mainly as an insoluble mass in inclusion bodies. The fusion protein can be purified from the insoluble cell fraction by one-step affinity chromatography based on the selective interaction between the histidine hexapeptide and a metal chelating matrix charged with Ni2+ ions. The principle of this new system was tested by expressing and purifying antigenic epitopes of the human 68-kDa (U1) ribonucleoprotein autoantigen. With the use of column chromatography and pH gradient elution, about 25 micrograms recombinant protein/ml of bacterial culture was obtained.

Base Sequence↗

Mapping of a linear autoantigenic epitope within the human thyroid peroxidase using recombinant DNA techniques.

Autoantibodies directed against the thyroid peroxidase (TPO), the thyroid microsomal antigen, are widely used to diagnose human autoimmune thyroid disease. A cloned 3.088 kb cDNA coding for the entire mature human TPO was isolated from a cDNA library derived from a pathological thyroid gland of a Graves' disease patient and used further to generate a so-called TPO epitope cDNA library in order to map linear autoantigenic epitopes involving a recombinant molecular biology approach. The TPO epitope cDNA library consisting of randomly fragmented cDNA sequences inserted in the expression vector pGEX-2T was expressed in Escherichia coli and screened with characterized anti-TPO autoantisera from Hashimoto's disease patients. All the sera were positively tested with a purified thyroid microsomal antigen fraction (TMA/TPO). Only about 1% of examined autoantisera were able to recognize bacterial expressed recombinant TPO representing sequential antigenic determinants. A corresponding autoantigenic epitope with 61 amino acids in length was located at the C-terminus of human TPO.

Autoantibodies↗

Production of recombinant rat interleukin-6 in Escherichia coli using a novel highly efficient expression vector pGEX-3T.

Interleukin-6 (IL-6) is one of the most important mediators of the acute phase reaction in liver. For the production of recombinant rat IL-6 in Escherichia coli, a previously isolated cDNA coding for the rat IL-6 was cloned into the modified novel expression vector pGEX-3T. The IL-6 cDNA was highly expressed as a fusion protein with the glutathione S-transferase (GST) at its C-terminus and rat IL-6 at its N-terminus. The GST-IL-6 fusion protein was controlled by a tac-promoter and could be induced very efficiently by isopropyl-beta-D-thiogalactopyranoside. The synthesized GST-IL-6 fusion protein was insoluble and precipitated intracellularly in E. coli. Using an advanced technique, the insoluble protein was solubilized and purified to homogeneity by affinity chromatography using immobilized glutathione in a one-step procedure.

Amino Acid Sequence↗

Intermittent care and caregivers at home.

The role of the caregivers of 22 patients treated in an intermittent nursing home programme was studied. Intermittent care was effective and often led to improvements in the patients. Because of their pronounced feeling of responsibility for these often very demanding patients, the main objection of the caregivers was that they wanted longer or more frequent nursing home periods than were currently offered. Half of the patients were regarded by the formal caregivers as more demanding than other clients in the home help service. In some cases the home helpers considered the patients more dependent in various activities of daily living than did the patients themselves. Meeting other people at the nursing home stimulated the patients and positively influenced the relationship between them and the home helpers. The most important aspect of intermittent care was its potential for variety, medical treatment and nursing care. The caregivers felt secure with it, which was necessary in order for them to relax when being relieved.

Aged↗