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Biomedical subjects

H Müller

Publications and source records attributed to H Müller.

At least 505 records · Page 28Linked to original sources
PubMed1988

Changes in dental blood flow following electrical tooth pulp stimulation--influences of capsaicin and guanethidine.

The responses of rat incisors microcirculation to electrical pulp stimulation was examined. A fast initial decrease was followed by a long lasting increase in blood flow due to activation of sympathetic efferents and nociceptive afferents, respectively. Both constituents of the response could be abolished differentially by the use of guanethidine (sympathectomy) and capsaicin (C-deafferentiation), respectively. The results point to a role of both C-efferents and peptidergic C-afferents in the control of tooth pulp circulation.

Animals↗
PubMed1988

Further evaluation of the effects of laminin, testosterone, ganglioside GM 1, and catalase on early growth in rat nerve regeneration chambers.

We present here the results of an extended series of experiments on the effects of exogenous biochemical agents on nerve regeneration. They were applied by multiple injection into in vivo nerve regeneration chambers developed in this laboratory for rat sciatic nerve. Previously, a mixture of laminin, testosterone, ganglioside GM 1, and catalase at a defined concentration was shown to substantially advance the progress and maturation of regeneration in 16-day chambers, out of a variety of numerous other agents screened. In this study, an attempt is made to further clarify the contribution of the single ingredients used in combination. None of the agents proved to be able to mimic the previously observed effects by themselves (to their full extent). The best results were obtained by application of laminin; catalase treatment revealed results apparently worse than those in controls. Therefore, a redefined combination of the described agents, catalase now being omitted, was also tested. These results appeared to be grossly similar to those we recently reported.

Animals↗
PubMed1988

Acute adrenocortical stimulation by recombinant gamma interferon in human controls.

We examined the effect of 20 micrograms recombinant gamma-interferon (rec-gamma-IFN) upon corticotropin (ACTH) and cortisol secretion in 10 healthy male controls. We observed that rec-gamma-IFN enhances cortisol secretion with maxima around 3 hours after injection of the test dose. This effect was suppressible by a single dose of 1.5 mg dexamethasone and was not associated with increased ACTH secretion. Rec-gamma-IFN also failed to enhance ACTH secretion from a pituitary cell culture. From these data we conclude that rec-gamma-IFN acts on lymphoid cells which in turn release a yet unidentified substance that directly activates the adrenocortex in a feedback controlled manner.

Adrenal Cortex↗
PubMed1988

The genome of budgerigar fledgling disease virus, an avian polyomavirus.

Budgerigar fledgling disease virus (BFDV) represents the first avian member of the Polyomavirus family. In contrast to mammalian polyomaviruses BFDV exhibits unique biological properties, in particular it is able to cause an acute disease with distinct organ manifestations in affected birds. Here we present the complete nucleotide sequence of the BFDV genome, consisting of 4980 bp. When compared to published nucleotide sequences of other polyomaviruses, the BFDV genome exposes a number of very similar structural features, and undoubtedly qualifies as a member of that family of viruses. The most important differences include a large T antigen remarkably reduced in size, and an origin of replication region with fundamental deviations from the origin structure of all other polyomaviruses. The specific characteristics of the BFDV genome may be used to place this virus into a distinct subgroup within the Polyomavirus family and may give a clue to the elucidation of its extraordinary biological properties.

Amino Acid Sequence↗
PubMed1988

Androgens inhibit proliferation of human peripheral blood lymphocytes in vitro.

The effect of sex hormones on human lymphocytes was examined in vitro on cell cultures of human peripheral blood mononuclear cells (HPBM). Cells were stimulated using T- and B-cell mitogens, and hormones in physiological (nM) or pharmacological (microM) concentrations were added. Proliferation was determined by measuring the incorporation of tritiated thymidine. It was found that both testosterone and dihydrotestosterone, in physiological concentrations, can attenuate DNA synthesis. The effect was dose dependent in that pharmacological concentrations of both testosterone and dihydrotestosterone caused a strong inhibitory effect on proliferation of in vitro cultured HPBM. However, cell cultures of a few individuals were insensitive to the androgens even at pharmacological concentrations. Also, no difference could be detected in the response between cultured cells of females and males. Although a slight reduction in antibody production was evident in pokeweed mitogen-stimulated cultures, in the presence of both testosterone and dihydrotestosterone, it was, however, not statistically significant.

Adult↗
PubMed1988

The spleen in acquired immunodeficiency syndrome (AIDS).

72 spleens from AIDS patients were studied by histologic and immunohistochemical methods. Apart from the opportunistic infections and malignancies typically occurring in AIDS patients (malignant lymphomas, Kaposi's sarcoma, mycobacterial infections, cryptococcosis, cytomegalovirus infections) morphological changes probably directly attributable to HIV infection were noted that progressed from follicular hyperplasia with nearly normal periarteriolar lymphoid sheaths to atrophy of follicles and severe cellular depletion of T cell areas with concomitant plasmacytosis and occurrence of small giant cells. At the same time the number of Protein S-100 positive cells markedly increased; in some cases almost all pulp cord macrophages expressed the antigen. In addition, the sinus endothelia strongly expressed protease inhibitors.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Tattooing in maxillo-facial surgery.

A patient is described who had a discoloration of the skin caused by too deep tattooing of the oral mucosa. To avoid this complication a safe tattoo technique is described.

Animals↗
PubMed1988

Influence of dextran on the absorption of adrenaline-containing lignocaine solutions: a protective mechanism in local anaesthesia.

The effect of adding 6% dextran to a lignocaine solution containing adrenaline was studied in 27 neurosurgical patients during modified neuroleptanaesthesia. Before trepanation they received infiltration anaesthesia of the scalp at the site of the proposed operation. For a period of 1 h following injection plasma concentrations of adrenaline were measured by high pressure liquid chromatography and serum concentrations of lignocaine by gas chromatography. The addition of dextran caused a significant reduction in the absorption of both adrenaline and lignocaine from the injection site. It is concluded that the dextran adjuvant constitutes a protective mechanism against toxic systemic side effects in local anaesthesia using adrenaline-containing anaesthetic solutions. This effect is particularly significant in patients with pre-existing cardiovascular disease and when local anaesthetic solutions are used in combination with volatile anaesthetics.

Absorption↗
PubMed1988

Comparative studies on structural and antigenic properties of two serotypes of infectious bursal disease virus.

The electrophoretic mobilities of the two genome segments and the structural polypeptides of the chicken strain Cu-1 (serotype I) and the turkey isolate 23/82 (serotype II) of infectious bursal disease virus were compared. There is a close antigenic relationship between the smaller of the two major structural proteins (32K) of both strains. Neutralizing monoclonal antibodies are induced by the larger protein (40K in Cu-1) which differentiates between the two serotypes. The 40K structural protein also has epitopes which do not induce neutralizing antibodies and which are common to both strains. There is evidence that the antigenic region responsible for the production of neutralizing antibodies is highly conformation-dependent. Passively administered neutralizing antibodies directed against the 40K structural polypeptide of Cu-1 confer protective immunity to susceptible chickens, whereas antibodies directed against the 32K structural protein do not have any protective effect.

Animals↗
PubMed1988

The spleen in Hodgkin's disease. An immunohistochemical study of lymphocyte subpopulations and macrophages.

Lymphocyte subpopulations and macrophages in 16 spleens from patients with Hodgkin's disease were analysed immunohistochemically using monoclonal antibodies of the Leu and the Ki M series. In non-involved splenic tissue there is an increase of T-lymphocytes with an increased T-helper/T-suppressor cell ratio, while Ki M-1, -2, -3 and -5-positive, i.e. phenotypically different macrophages, are reduced. These results indicate that involvement of the spleen in Hodgkin's disease is accompanied by changes with respect not only to lymphocyte subpopulations but also to cells of the mononuclear phagocyte system. The immunodeficiency associated with Hodgkin's disease is probably not solely due to lymphocyte dysfunction, since the disease may lead, at least in the spleen, to alterations in macrophages and accessory cells and this may contribute to the impairment of cell-mediated immunity.

Adolescent↗
PubMed1988

Tetanus toxin and botulinum A and C neurotoxins inhibit noradrenaline release from cultured mouse brain.

Primary nerve cell cultures from the brainstem of embryonic mice take up [3H]noradrenaline. Release can be evoked by high K+ or sea anemone toxin II and depends on Ca2+. The cultures allow neurochemical studies on the long-term actions of clostridial neurotoxins. Tetanus and botulinum A and C neurotoxins partially inhibit the absolute and fractional release evoked by high K+, as well as the fractional basal release. The detection limit for the toxins is below 5 pM. Total radioactivity is higher in the poisoned cultures, although the initial velocity of uptake is not measurably influenced by tetanus or botulinum A toxin. Pretreatment with neuraminidase prevents the effects of botulinum A toxin and diminishes those of botulinum C and tetanus toxins. Within 6 days, the cultures partially recover from tetanus toxin poisoning. Antitoxin prevents the actions of the toxin, but only slightly promotes recovery. The data indicate close pharmacological analogies between the clostridial neurotoxins.

Animals↗
PubMed1988

Dual effect of dihydroergotamine at vascular 5-hydroxytryptamine receptors in pithed rats.

Dihydroergotamine (DHE), administered intravenously to pithed normotensive rats, increased the mean arterial blood pressure dose-dependently. This pressor effect was noncompetitively inhibited by the 5-hydroxytryptamine (5-HT) receptor antagonists pizotifen and cyproheptadine (0.1 mg/kg each). The alpha 1-adrenoceptor blocker prazosin (1 mg/kg) had no influence on the DHE effect whereas the alpha 2-adrenoceptor blocker yohimbine, at the same dose, proved to be a noncompetitive inhibitor of this pressor effect. The results indicate that both the 5-HT receptors and alpha 2-adrenoceptors are involved in the DHE-induced vasoconstriction. On the other hand, in pithed normotensive rats, DHE proved to be a potent inhibitor of the pressor response to 5-HT but it did not inhibit that to noradrenaline. The results obtained characterize DHE as a noncompetitive dualist at vascular 5-HT receptors.

Adrenergic alpha-Antagonists↗
PubMed1988

Formation of double-walled microtubules and multilayered tubulin sheets by basic proteins.

Some basic proteins enable microtubule protein to form special assembly products in vitro, known as double-walled microtubules. Using histones (H1, core histones) as well as the human encephalitogenic protein to induce the formation of double-walled microtubules, we made the following electron microscopic observations: (1) Double-walled microtubules consist of an "inner" microtubule which is covered by electron-dense material, apparently formed from the basic protein, and by a second tubulin wall. (2) The tubulin of the second wall seems to be arranged as protofilaments, surrounding the inner microtubule in a helical or ring-like manner. (3) The surface of double-walled microtubules lacks the projections of microtubule-associated proteins, usually found on microtubules. (4) In the case of protofilament ribbons (incomplete microtubules), H1 binds exclusively to their convex sides that correspond to the surface of microtubules. Zn2+-induced tubulin sheets, consisting in contrast to microtubules of alternately arranged protofilaments, are covered by H1 on both surfaces. Furthermore, multilayered sheet aggregates appeared. The results indicate that the basic proteins used interact only with that protofilament side which represents the microtubule surface. In accordance with this general principle, models on the structure of double-walled microtubules and multilayered tubulin sheets were derived.

Animals↗
PubMed1988

[Effect of acebutolol on plasma catecholamines and perioperative endocrine stress parameters].

In order to investigate the effect of intraoperative beta-blockade with acebutolol on the endocrine stress response during modified neuroleptanesthesia, 20 patients for major abdominal or thoracic surgery from ASA groups I-III were randomly allocated to the following groups: (1) control group without acebutolol treatment; or (2) treatment group, administration of 0.2 mg/kg acebutolol 5 min after induction of anesthesia. During a period of 30 min before operation, intraoperatively, and 30 min after the end of operation plasma levels of norepinephrine and epinephrine (by HPLC) and ADH, ACTH, and cortisol (by RIA) were measured. In addition, mean arterial pressure (MAP), HR, and plasma concentrations of glucose, lactate, and free glycerol were determined. Statistical evaluation was undertaken by analysis of variance with repeated measures on one factor, considering P values of less than 0.05 as significant. The administration of acebutolol had no influence on plasma catecholamine concentrations during the preoperative rest period. There was no evidence of any interaction between beta-blockade and plasma catecholamines. After induction of anesthesia, the levels of all hormones decreased. During the operation, there was a significant increase in all endocrine parameters measured. No differences were found between the treatment and control groups. All endocrine parameters reached their highest levels 30 min after the end of the operation. The differences in MAP, HR, glucose, lactate, and free glycerol between the groups failed to reach statistical significance.

Acebutolol↗
PubMed1988

[Effect of nimodipine on plasma catecholamines and perioperative endocrine stress parameters].

The influence of nimodipine on plasma-catecholamines, ADH, ACTH and cortisol during standardized, modified neurolept-anaesthesia was investigated in 20 patients for major abdominal and thoracic surgery. The application of nimodipine led to an intra- and postoperative increase in both adrenaline and noradrenaline. No influence could be demonstrated on ADH, ACTH or cortisol. Group-levels of MAP were lower in the nimodipine-group. No statistical differences became obvious for HR, glucose, lactate and free glycerol. The increases in adrenaline and noradrenaline can be attributed to a cardiocirculatory rebound-phenomenon due to the vasodilative properties of the substance. Under the conditions of adequate fentanylanalgesia, no influence of nimodipine on ADH, ACTH or cortisol was found.

Adolescent↗
PubMed1988

Establishment of two Epstein-Barr virus negative Burkitt cell lines from a patient with AIDS and B-cell lymphoma.

To analyze the pathogenesis of B-cell lymphomas in patients with acquired immunodeficiency syndrome (AIDS), we studied two cell lines, Es I and Es III, established from one such lymphoma for the presence of sequences of the Epstein-Barr virus (EBV) and the human immunodeficiency virus [HIV; lymphadenopathy-associated virus (LAV/HTLV-III)] as well as for the presence of cytogenetic abnormalities and monoclonal rearrangements of immunoglobulin and T-cell receptor genes. Both cell lines expressed the same IgM, kappa phenotype as the original lymphoma. The karyotype of Es I was 46, XY, t(8;14), 2 p+, inv (6p), 17p-, and the cells of Es III had an additional i(7q). Immunoglobulin gene studies demonstrated the identical monoclonal rearrangements in both cell lines. Neither EBV nor HIV sequences were detectable in the malignant B cells at the genomic level, leading to the conclusion that mechanisms other than transformation by EBV or HIV may have contributed to the B-cell lymphoma in this patient and possibly also to the generally increased frequency in patients with AIDS.

Acquired Immunodeficiency Syndrome↗