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Biomedical subjects

M Herrmann

Publications and source records attributed to M Herrmann.

At least 73 records · Page 4Linked to original sources

Monoclonal antibodies directed against the rev protein of human immunodeficiency virus type 1.

The rev (art/trs) protein of human immunodeficiency virus type 1 (HIV-1), a phosphoprotein of 20 K apparent molecular weight, is essential to target the mRNA for virion polypeptides into the cytoplasm. The rev protein was expressed in Escherichia coli as a beta-galactosidase fusion protein with a cleavage site for proteinase factor Xa. The rev-specific fragment was isolated to immunize mice. Five stable hybridoma cell lines were obtained producing monoclonal antibodies that reacted with rev protein in Western blot and ELISA. Using the monoclonal antibodies in indirect immunofluorescence, the rev protein could be localized in the nucleus, mostly in the nucleoli, of Hela cells that were transfected with a eukaryotic rev expression plasmid.

Animals

Treatment of experimental foreign body infection caused by methicillin-resistant Staphylococcus aureus.

A novel model of experimental foreign body infection was developed in rats: four perforated Teflon tissue cages per animal were implanted subcutaneously and 3 to 4 weeks later were infected with 0.5 x 10(5) to 2 x 10(5) CFU of methicillin-resistant Staphylococcus aureus. After 2 weeks, the number of CFU in the cage fluid was determined [day 1 mean, (7.25 +/- 0.79) log10 CFU/ml], and treatment with vancomycin (50 mg/kg twice a day [BID]), fleroxacin (50 mg/kg BID), or fifampin (25 mg/kg BID), alone and in combination, was initiated for a duration of 6 days. Concentrations of antibiotics in cage fluids were in the range of those encountered in clinical conditions. Eighteen hours after the last injection (day 7), the number of CFU in the cage fluid was determined and the difference between day 1 and day 7 values was calculated. Rifampin, alone and in combination with fleroxacin or vancomycin, was the most effective regimen in reducing the bacterial counts in the tissue cage fluids [(1.87 +/- 1.44, 2.18 +/- 1.02, and 2.55 +/- 1.09 log10) CFU/ml, P less than 0.001, respectively]. After treatment, cage fluids and cages were analyzed for resistant bacteria. Resistance to rifampin occurred in 15 of 19 cages in animals treated with rifampin alone and in 4 of 25 in animals treated with rifampin plus vancomycin. We detected no development of resistance to rifampin in animals treated with rifampin plus fleroxacin or to fleroxacin in animals treated with this antimicrobial agent. In conclusion, regimens including rifampin alone or in combination with vancomycin or fleroxacin were an effective treatment of foreign body infection due to methicillin-resistant S. aureus in reducing bacteria counts, but rifampin monotherapy was compromised by significant emergence of resistance. The combined therapy of fleroxacin with rifampin prevent development of resistance to rifampin.

Animals

[Emotional experience and subjective illness perception in chronic aphasia--a comparison of patients with their family members].

The results of a pilot study are demonstrated. 10 chronically aphasic patients and their relatives were interviewed by a semi-structured questionnaire. Main themes are the subjective perception and the emotional experience of psychosocial changes, psychological disturbances, communicative and neuropsychological impairments, as well as the perception of restraints caused by symptoms of disease. Methodological difficulties which arise from linguistic and communicative restrictions of aphasic patients are discussed. Data show clear emotional restraints of aphasics and their relatives in occupational, social, psychological and communicative areas. The results indicate independence of subjectively perceived alteration and its emotional experience. The differences of the emotional experience of aphasics and their relatives are discussed. While aphasics are more burdened by restrictions of independence, their relatives gave more importance to emotional changes and familiar problems.

Activities of Daily Living

[The effect of selected output parameters on the flushing results of MOET (Multiple Ovulation and Embryo Transfer)].

Superovulation responses from 299 Hessian donors were used to analyse the influence of selected traits and ovulation-parameters. The effects of the age of life were similar to those of other authors. Fat yield (phenotypic) showed a small positive influence on the number of collected embryos. Genetic value of the sire had no effect and using sperm of one or two bulls made no difference. A prediction of an individual MOET-response by a selected parameter is not possible.

Age Factors

C3-containing serum immune complexes in patients with systemic lupus erythematosus: correlation to disease activity and comparison with other rheumatic diseases.

Although testing for circulating immune complexes (CIC) is regarded as a useful, complementary, laboratory parameter in the differential diagnosis and management of immune complex-induced vasculitis syndromes, there is still an uncertainty with regard to assay systems used for the demonstrated of soluble immune complexes. This is partly due to difficulties in the reproducibility, handling and principle limitations of available test systems for the assessment of soluble immune complexes in body fluids. In the present communication a modification of the anti-C3 test for the determination of CIC was developed using nitrocellulose as a solid phase matrix. IgG-, IgA- and IgM-containing CIC were determined and quantified using standard immune complex preparations. When 39 sera of SLE patients, 12 sera of patients with vasculitis syndromes, 10 sera of rheumatoid arthritis patients and 11 sera of patients with ankylosing spondylitis were tested, predominantly IgG-containing CIC could be demonstrated. Only in SLE patients was a significant amount of other immunoglobulin isotypes detected in CIC. In these patients a significant difference of IgG-containing CIC levels was found with regard to patients with high and low disease activity (P less than 0.0001). A significant correlation was also established between IgG-containing CIC and anti-dsDNA antibodies (P less than 0.001). In a longitudinal study the isotypes in the isolated CIC were found to be constant.

Antigen-Antibody Complex

Are retroviruses involved in the pathogenesis of SLE? Evidence demonstrated by molecular analysis of nucleic acids from SLE patients' plasma.

High molecular weight DNA of up to 20 kbp and, additionally, an RNase-insensitive RNA of more than 60 b were isolated from plasmapheresis fluids taken from patients with active systemic lupus erythematosus (SLE). Similar nucleic acids could not be demonstrated in the plasma samples from patients with Waldenstroem's disease, rheumatoid arthritis, myasthenia gravis, and other diseases including active systemic disorders. The purified nucleic acids were analyzed in several ways; they proved to be immunogenic by inducing polyclonal and monoclonal antibodies to natural DNA as well as to synthetic polynucleotides (e.g. polyguanylic acid) after injection into experimental animals (rabbits or mice respectively). Biochemical and molecular cloning analysis of the DNA revealed features like high levels of CpG-dinucleotides, usually not observed in common human DNA. A possible exogenous origin was substantiated by comparative sequence studies of cloned plasma DNA, which showed homologies to human retroviruses, e.g. PL1 (85%/60 b) and the sequences of the gag and pol genes of human immunodeficiency virus type I (85%/157 b). Experiments applying isolated plasma nucleic acids in transfection experiments showed the induction of morphological changes in an EBV-immortalized B-cell line drawn from a healthy human donor, such as vacuolization and syncitia formation. Northern blot analysis demonstrated, exclusively in the transfected cell line, the expression of mRNA homologous to the cloned plasma DNA. Using this clone as a probe, homologous sequences could be demonstrated by Northern blot analysis in EBV-immortalized cell lines from SLE patients only and, by means of DNA amplification, in peripheral blood lymphocytes from SLE and AIDS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Communicative skills in chronic and severe nonfluent aphasia.

A diagnostic tool was developed for the investigation of communicative skills in nonfluent aphasic patients suffering from moderate or severe language deficits. Communicative skills and neurolinguistic deficits were assessed in 20 patients suffering from Broca's or global aphasia. Comparative data analysis revealed remarkably low correlations between communicative and neurolinguistic deficits. In nonfluent aphasic patients with severe linguistic impairment communicative abilities and non- and paralinguistic compensatory efforts and skills accounted for their efficient performance.

Adult

Longitudinal study of progestins, mineralocorticoids, and glucocorticoids throughout human pregnancy.

The maternal adrenal cortex seems to be involved in the adaptation to pregnancy. To study in detail adrenocortical secretion during pregnancy, we measured plasma aldosterone, corticosterone, 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, and cortisone simultaneously by RIA after extraction and automated Sephadex LH-20 chromatography of 10 normal pregnant women longitudinally throughout pregnancy at weeks 8-10, 14-17, 21-24, 28-32, and 38 as well as at the time of admission to the delivery room. The mean plasma progesterone and 17-hydroxy-progesterone concentrations increased from 37.2 +/- 6.5 (+/- SE) and 8.2 +/- 1.0 nmol/L, respectively, in early gestation to maximum levels of 138.0 +/- 25.7 and 22.8 +/- 2.2 nmol/L at week 38 (P less than 0.01). Plasma glucocorticoid levels rose 2- to 3-fold (P less than 0.01) from weeks 8-10 (corticosterone, 18.5 +/- 5.4; 11-deoxycortisol, 1.9 +/- 0.2; cortisone, 24.2 +/- 4.2; cortisol, 195.5 +/- 37.6 nmol/L) to week 38 (corticosterone, 42.9 +/- 11.2; 11-deoxycortisol, 4.6 +/- 0.5; cortisone, 71.5 +/- 13.6; cortisol, 420 +/- 63 nmol/L). Similarly, plasma mineralocorticoid levels increased 5- to 7-fold (P less than 0.01) from weeks 8-10 (11-deoxycorticosterone, 0.69 +/- 0.12; aldosterone, 0.41 +/- 0.08 nmol/L) to maximum levels at week 38 (5.3 +/- 0.9 and 2.1 +/- 0.3 nmol/L, respectively). At the time of admission to the delivery room, plasma 11-deoxycortisol, corticosterone, and cortisol concentrations were higher (P less than 0.02) than at 38 weeks, but plasma progestin and mineralocorticoid concentrations were not. We conclude that the source of the elevated maternal corticosteroid levels in pregnancy in addition to the estrogen-mediated rise in corticosteroid-binding globulin is the maternal adrenal cortex itself. The peak glucocorticoid levels at admission to the delivery room reflect increased maternal and fetal stress with the onset of labor.

17-alpha-Hydroxyprogesterone

Antibody binding of macromolecular DNA and RNA in the plasma of SLE patients.

Plasmapheresis fluids from 20 patients with clinically active SLE, from three patients with Waldenstrom's disease, from three patients with rheumatoid arthritis, two patients with myasthenia gravis and other diseases including active systemic disorders were precipitated using polyethylene glycol 6000 (PEG). By applying ethidium bromide staining, plasma nucleic acids (PNA) could be demonstrated in PEG-precipitates of SLE patients exclusively. Purified immunoglobulins of SLE plasma precipitates were shown to form antigen-antibody complexes with PNA as demonstrated by electronmicroscopy. Further characterization of PNA by agarose gel electrophoresis revealed a molecular weight up to 20 kbp. Cesium chloride buoyant density gradients showed non-homogeneous molecules, excluding pure microbial origin. In spite of RNase digestion, the PNA contained RNA with 30-70% riboguanosine as shown by nucleoside analysis. The high amount of guanosine-rich RNA was further supported by similarities between PNA and polyriboguanylic acid in hyperchrome shifting due to thermic denaturation. HPLC analysis showed a molecular weight of ribonucleic acids of more than 60 b thus excluding mere oligonucleotides. In contrast to B-type dsDNA, PNA from SLE patients were immunogenic. Antibodies against PNA could be induced in rabbits by subcutaneous injection. The antisera thus obtained showed crossreactivity with polyriboguanylic acid and dsDNA preparations.

Antibodies, Antinuclear

[Measuring chemiluminescence during blood preservation. 1. Spontaneous chemiluminescence].

A device for the measurement of spontaneous chemiluminescence (SCL) of biological fluids and cell suspensions according to Vladimirov (1966) description with using of contemporary equipment was constructed. Its dark impulse rate at room temperature of the photomultiplier was 1.5 s-1. The volume of measuring cell was 2 ml. An application of the device to investigate the blood during its conservation (21 days at 4 degrees C) showed an absence of the SCL of whole blood. The mean values of plasma SCL were in agreement with literature data. There were no regular changes of plasma SCL during the storage of blood indicating unsuitability of SCL for the detection of blood injury during its conservation.

Blood Preservation

Nonverbal communication as a compensative strategy for severely nonfluent aphasics? A quantitative approach.

Seven severely nonfluent aphasics and one relative or close friend were investigated in an interview situation. The conversation was videotaped and analyzed for the use of nonverbal communication between aphasic and partner. The results indicate that the group of aphasics used significantly more frequently and for a significantly longer period of time nonverbal channels of communication than their healthy partners. The aphasic patients also used significantly fewer speech-focused movements and significantly more codified gestures. Nonverbal elements were more frequently used as speech substitutes by the group of aphasics.

Adult

Fibronectin, fibrinogen, and laminin act as mediators of adherence of clinical staphylococcal isolates to foreign material.

Bacterial adherence to polymer surfaces is a required early step in intravenous (iv) device infection. We collected eight strains of Staphylococcus aureus and 19 of coagulase-negative staphylococci from patients with proven iv device bacteremia and studied the role of plasma or connective-tissue proteins in promoting bacterial adherence to polymethylmethacrylate (PMMA) coverslips. Although only a negligible percentage of organisms adhered to albumin-coated PMMA, surface-bound fibronectin significantly promoted adherence of all isolates. Fibrinogen markedly promoted adherence of all S. aureus strains but of only four coagulase-negative strains. Thus, coagulase-negative staphylococci revealed a marked heterogeneity in adherence to fibrinogen-coated surfaces, a result suggesting the existence of heretofore unknown receptors for fibrinogen. Laminin promoted adherence of staphylococci to a much lower extent. Although strain specific, adherence of clinical staphylococcal isolates to foreign surfaces is significantly increased by fibronectin, fibrinogen, and laminin, an observation suggesting the possible contribution of these proteins to the pathogenesis of iv device infection.

Bacterial Adhesion

Adjustment of the myelin sheath to axonal atrophy in the rat spinal root by the formation of infolded myelin loops.

Atrophy of the L4 dorsal and ventral spinal roots was experimentally induced by unilateral sciatic neurectomy in groups of young (2 and 4 months) and older (12 months) albino rats. During the 4 months following neurectomy, the occurrence of infolded myelin loops (IMLs) was quantitatively examined in transverse sections prepared using perfusion fixation with glutaraldehyde and embedding in epoxy resin. The number of IMLs was higher on the operated side and increased with the time of survival and the age of the animals. The formation of IMLs is a characteristic early response of a large-caliber myelin sheath to axonal atrophy, probably reflecting the presence of redundant myelin.

Aging