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H Müller

Publications and source records attributed to H Müller.

At least 577 records · Page 32Linked to original sources
PubMed1986

Binding of C-reactive protein to human polymorphonuclear leukocytes: evidence for association of binding sites with Fc receptors.

The functional similarities between C-reactive protein (CRP) and IgG raised the question as to whether human phagocytes are stimulated by CRP in the same way as by binding of antigen-complexed or aggregated IgG to their Fc receptors. Studies with the use of highly purified 125I-labeled CRP showed specific and saturable binding to human polymorphonuclear leukocytes (PMN) with a KD of 10.5 +/- 5.7 X 10(-8) M only when carried out in heat-inactivated plasma. The number of specific binding sites per cell was estimated at 1 to 3 X 10(6). Competitive inhibition of CRP binding by antigen-complexed or aggregated IgG suggests CRP binding sites to be associated with PMN Fc receptors. Only when assayed in heat-inactivated plasma did CRP binding induce adherence of cells to tissue culture dishes. However, no metabolic and potentially cytotoxic stimulation of PMN was detected during CRP plasma-dependent attachment to surfaces: induction of aggregation, release of secondary granule constituents, and activation of the hexose monophosphate pathway were not observed. These results imply that CRP-PMN interactions is dependent on an additional factor present in heat-inactivated plasma and is followed only by a complement-independent increase in PMN attachment to surfaces. Because CRP was found to be deposited at sites of tissue injury, the CRP-mediated adherence of PMN may be an important step in localizing an inflammatory focus.

Antigen-Antibody Complex↗
PubMed1986

Replication of infectious bursal disease virus in lymphoid cells.

Replication of infectious bursal disease virus in lymphoid cells from the bursa of Fabricius occurs preferentially in a population of proliferating cells characterized by increased thymidine incorporation and by blast cell formation. This was demonstrated by enrichment of virus producing cells in gradients of bovine serum albumin and by mitogenic stimulation of cells with fetal calf serum or an extract prepared from bursae of susceptible chickens. Susceptibility of lymphoid bursa cells is not correlated with the expression of immunoglobulins on their surface. This conclusion was reached after the enrichment of Ig-bearing cells by rosetting techniques and by separation through a cell sorter.

Animals↗
PubMed1986

[The effect of cellulose on endogenous nitrogen excretion in rats, evaluated using N-15 technics].

Metabolic faecal nitrogen excretion was assessed in 8 young rats (90-100 g body weight) following an oral application of 75 mg 15N-glycine (95 atom-% 15N). Four rats received an experimental diet containing 12% cellulose, while a control diet containing 4% cellulose was fed to the remaining 4 animals. The high cellulose content induced a highly significant reduction of the N balance due to a greatly increased urinary N excretion. The metabolic faecal nitrogen was determined by measuring 15N excretion in faeces and urine from day 5 (3) to day 8 following 15N glycine administration. During this time interval 15N elimination follows an exponential curve. Increasing the dietary cellulose content from 4 to 12% produced a rise in metabolic faecal nitrogen from 13.9 to 15.7 mg/day and in total faecal nitrogen from 21.3 to 24.4 mg/day. From these values a mean true protein digestibility of 98% was calculated for both groups of rats, regardless of the difference in dietary cellulose content. The fraction of endogenous faecal nitrogen which is of bacterial origin was determined through the analysis of 2, 6-diamino-pimelic acid (DAP). The added cellulose in the experimental diet caused a rise in faecal DAP from 0.302 to 0.402 mg/day corresponding to an increase of bacterial nitrogen from 5.2 to 6.4 mg/day. Accordingly the observed rise in endogenous faecal nitrogen is largely due to increased bacterial nitrogen.

Animals↗
PubMed1986

[Heterogeneity of breast cancer].

Breast cancer is in many aspects a heterogeneous disease. This becomes also evident in family studies. The families of 116 women with breast cancer with 50 years and less at diagnosis were compared to than of 161 breast cancer patients with 51 years and more with respect to breast cancer in the relatives. Younger breast cancer patients had more second degree relatives with breast cancer. Probands with a positive family history were on the average 10 years younger than probands with a negative family history. A positive family history increases breast cancer risk by 4.3 times for first degree relatives and by 2.3 times for second degree relatives in comparison to the general population. These results point to an etiological heterogeneity of breast cancer.

Adult↗
PubMed1986

A polyoma-like virus associated with an acute disease of fledgling budgerigars (Melopsittacus undulatus).

A virus previously isolated from fledgling budgerigars (Melopsittacus undulatus) suffering from an acute disease, has been purified and the structural characteristics have been determined. The virions with a buoyant density of 1.34 g/ml are non-enveloped icosahedral particles with a diameter of about 46-48 nm. Their DNA genome has a molecular weight of about 3.3 X 10(6) d, and exists as supericoiled circular, relaxed circular, and linear molecules. There are eight structural proteins, the most abundant of which has a molecular weight of about 42,000 d. Empty capsid shells with buoyant densities of 1.31 g/ml are similar in size and shape, but lack DNA and histone-like polypeptides. Virus replication in chicken embryo cells results in cytopathic changes characterized by rounding and enlargement of the nucleus, and formation of intranuclear inclusion bodies. All these properties justify classification of the virus as polyoma-like.

Animals↗
PubMed1986

Botulinum A neurotoxin unlike tetanus toxin acts via a neuraminidase sensitive structure.

The binding and effects of tetanus and botulinum A neurotoxins were studied on mouse spinal cord cultures treated with neuraminidase. In untreated cultures both neurotoxins blocked synaptic transmission. Treatment of the cell cultures with neuraminidase, 25 mU/ml for 24 hr, decreased the potency of botulinum A neurotoxin. At 7 X 10(-11) M no toxin effect on inhibitory or excitatory synapses was observed, whereas at higher concentrations of the toxin the concentration-response curve was shifted to the right by a factor of about 30. Surprisingly, the action of tetanus toxin over a large concentration range was unaffected by pretreatment of the neurones with the enzyme. Accordingly, neurones treated with neuraminidase failed to bind 125I-botulinum A neurotoxin, whereas labelled tetanus toxin was still fixed by cell bodies, as well as by neurites, as shown by histoautoradiography. Chromatographic extraction of gangliosides from cultures prelabelled with 14C-glucosamine showed a dramatic loss in the contents of polysialogangliosides following treatment with neuraminidase. Our results indicate that neuraminidase-sensitive structures might be important for the action of botulinum A neurotoxin. The effect of tetanus toxin appears to be mediated by a different site which is insensitive to neuraminidase.

Action Potentials↗
PubMed1986

Cloning and characterization of budgerigar fledgling disease virus, an avian polyomavirus.

The DNA of a virus isolated from fledgling budgerigars, designated BFDV, was cloned and analyzed with regard to its relationship to the polyomavirus subgroup of the papovavirus family. Under relaxed conditions, the DNA of BFDV cross-hybridized with the DNAs of members of the polyomavirus subgroup, such as the mouse polyomavirus, the monkey viruses simian virus 40, stump-tailed macaque virus, and lymphotropic papovavirus, and the human viruses JCV and BKV. Under stringent conditions, however, no homologies could be detected. Furthermore, BFDV propagated in chicken embryo cells was antigenically related to the capsid antigen(s) of the other polyomaviruses. The virus was able to transform hamster embryo cells in vitro which is a typical feature of polyomaviruses. These data clearly indicate that BFDV is a new distinct member of the polyomavirus genus representing the first nonmammalian polyomavirus.

Animals↗
PubMed1986

Formation, characterization and interfering capacity of a small plaque mutant and of incomplete virus particles of infectious bursal disease virus.

Serial undiluted passages of infectious bursal disease virus in chick embryo cells were accompanied by a von Magnus type fluctuation of infectivity in viral harvests and a gradual decrease of plaque size. From the 9th undiluted passage on, the whole virus population consisted of small plaque-forming virus. The small plaque size remained constant when subsequent infections were carried out at low multiplicities. Small plaque virus interfered with the replication of large plaque standard virus. The small plaque/low yield mutation favoured the generation of defective particles which could be separated from complete particles by their lower densities in CsCl-gradients, where six fractions became visible and could be analyzed separately. Most of the defective virus particles had lost the larger of their two dsRNA segments and showed an aberrant protein composition. They had a very low residual infectivity and were also able to interfere with the replication of complete virus.

Animals↗
PubMed1986

Impaired DNA-repair synthesis in lymphocytes of breast cancer patients.

UV-C light induced DNA-repair synthesis was studied in unstimulated lymphocytes of 41 female patients (aged 33-83 years) with invasive breast cancer and of 27 healthy women (aged 37-68 years). As a parameter for the determination of the DNA-repair synthesis the incorporation of [3H] thymidine was taken in the presence of 2 mM hydroxyurea (HU). The [3H] thymidine incorporation levels were reduced in 20 of the 41 patients and in only 3 of the 27 controls. This difference between the two groups was significant. An impaired DNA-repair synthesis might be involved in the etiology of breast cancer in some patients.

Adult↗
PubMed1986

Clear cell differentiation in an ameloblastoma.

A multilocular ameloblastoma is described in which, in addition to histologically typical ameloblastomatous structures, clear cell differentiation was found. We concluded that in the differential diagnosis of a jaw tumour in which clear cells are seen, in addition to a muco-epidermoid carcinoma and a metastatic deposit, the clear cell type of ameloblastoma should also be considered.

Adolescent↗
PubMed1986

Condylar hyperplasia. A clinico-pathological analysis of 22 cases.

A series of 22 cases of unilateral condylar hyperplasia is presented with the emphasis on histopathological aspects. It is concluded that there are two types of condylar hyperplasia. The first manifests itself in the adolescent or the young adult and represents an exaggerated, normally proceeding growth and maturation process. The histological structure of the condyle in these cases is age-dependent as is shown by a conversion of hyaline growth cartilage into fibrocartilage occurring at about 20 years of age. The second type of condylar hyperplasia, seen in older people, probably represents reactive growth as a response to an eliciting agent that mostly can be identified. In these cases the histological architecture of the condyle is distorted by large masses of hyaline cartilage while there are concomitant degenerative changes in the form of arthrosis. In contrast to the patients suffering from the first type of condylar hyperplasia, the latter ones complain of additional joint symptoms, mostly pain. Moreover it is concluded that joint scintigraphy does not clearly discriminate between genuine condylar hyperplasia and reactive processes due to arthrosis, which may have clinical implications.

Adolescent↗
PubMed1986

All-trans-retinoic acid inhibits retinol esterification by acyl-CoA: retinol acyltransferase (EC 2.3.1.76) from rat and human small intestinal mucosa.

1. Formation of retinyl esters catalyzed by acyl-CoA:retinol acyltransferase (ARAT; retinol fatty-acyltransferase; EC 2.3.1.76) from intestinal mucosa has been studied in vitro in the presence of all-trans-retinoic acid. 2. The incubation system contained microsomal preparations from the tissue tested, radioactive retinol and palmitoyl-CoA. The product formed was separated from the substrates by chromatography on alumina columns. 3. All-trans-retinoic acid inhibited ARAT both from rat and human intestinal mucosa. 4. Inhibition occurred instantly. At a concentration of retinol of 80 microM, a 50% inhibition was obtained with 50 microM-retinoic acid. 5. The inhibition of ARAT by retinoic acid may be of importance for normal retinol absorption in patients receiving retinoid therapy.

Acyltransferases↗
PubMed1986

Severe hemorrhage from intestinal hemangiomatosis in Klippel-Trenaunay syndrome: pitfalls in diagnosis and management.

A child with Klippel-Trenaunay syndrome (KTS) and severe anemia caused by bleeding from diffuse intestinal hemangiomatosis is presented. Hemangiomas of the bowel should be considered in any child with unexplained anemia and coexisting cutaneous hemangiomas. The diagnostic workup of patients with KTS and symptomatic hemangiomatosis is outlined with respect to indications for surgical management.

Anemia↗