Biomedical subjects

F Müller

Publications and source records attributed to F Müller.

At least 217 records · Page 12Linked to original sources

PubMed1994

Age-related satisfaction with complete dentures, desire for improvement and attitudes to implant treatment.

In the edentulous lower jaw implant stabilised dentures have proved clinically so successful that the indication for this treatment is now being discussed more often with geriatric patients. The aim of this study of edentate subjects was to determine the age-relation of the demand for denture improvement, the risks and feasibility of implant treatment. Sixty four complete denture wearers aged from 42 to 84 years took part in the study. A questionnaire was used to determine the subjective demand for denture improvement. For 33 subjects implants seemed possible. For these patients fear and scepticism concerning implant treatment were specified and quantified. Impaired general health was the most frequent absolute contra-indication for implants; the local oral prerequisites tended to be slightly less favourable in elderly. Older patients were more satisfied with poorly fitting dentures and were less prepared to take trouble to achieve denture improvement. Although scepticism concerning implant treatment was not age-related, patients who were keen for an improvement of their dentures were significantly younger and less sceptical about implants.

Adaptation, Psychological↗

PubMed1994

[Sigmoid diverticulitis in immunosuppressive drug therapy].

In a retrospective study we evaluated the data of 92 patients (41 women, 51 men, age median: 63 years) with diverticulitis of the sigma who were treated surgically in our clinic from January 1986 till December 1992. Twelve patients (13%) suffered from suppression of the immune system due to a corticoid therapy (n = 3), chemotherapy (n = 1), combination of corticoid therapy and chemotherapy (n = 1), combination of chemotherapy and azathioprine, leucopenia due to carbimazole therapy as a side effect (n = 1) and immunosuppression with prednisone, azathioprine and cyclosporine after renal and heart transplantations (n = 5). The therapy was Hartmann's procedure in 5 patients, drainage and loop colostomy in one patient, sigma resection with primary anastomosis without a protective enterostomy in 5 patients and with a loop ileostomy in one patient. One patient died in the early postoperative course. Sigma diverticulitis in immunosuppressed patients is a well-known problem especially in large clinics with organ transplantation units. In contrast to reports from up to the eighties we found no significant difference in the postoperative morbidity and mortality after surgical treatment of acute sigma diverticulitis in immunosuppressed patients compared to non immunosuppressed patients.

Adult↗

PubMed1994

[Hereditary defects in artificially-inseminated breeds].

Since it is possible to analyse genes directly and thus decipher the genome, animal hereditary diseases are in the centre of attention again. This publication presents some selected genetically determined illnesses and points out to the significance of monogene disorders with recessive genetic pathway particularly. By using genetic engineering, e.g. PCR, significant progress can be made in the diagnosis of genetic defects. But it is necessary to find ways of dealing with them.

Animals↗

PubMed1994

Elevated serum calprotectin levels in HIV-infected patients: the calprotectin response during ZDV treatment is associated with clinical events.

The calcium-binding myelomonocytic protein calprotectin (L1 protein) was quantified in serum from 51 patients with HIV infection and in 20 HIV-seronegative blood donors. Significantly elevated levels were found both in asymptomatic patients and in people with AIDS compared with controls. The calprotectin level was not related to ongoing or recent opportunistic infections. For patients with CD4+ counts above 50 x 10(6)/L, a significant negative correlation was found between serum calprotectin levels and the CD4+ counts. Serial samples from 24 patients during their first year of zidovudine (ZDV) treatment showed a further elevation of serum calprotectin during the first months of ZDV treatment, with a subsequent decline to pretreatment levels. A low calprotectin response during the first 6 months, determined as area under the curve, was associated with the occurrence of at least one AIDS-defining infection during the first year of antiviral treatment. Also, a low calprotectin maximal response during ZDV therapy was associated with short survival. Similar associations were not found for neopterin, beta 2-microglobulin, HIV p24 antigen, or CD4+ or CD8+ lymphocytes in blood. Our findings in a limited number of patients suggest that calprotectin levels may reflect immune activation and other immune mechanisms correlated with enhanced antimicrobial defense induced at least transiently by antiviral treatment.

AIDS-Related Opportunistic Infections↗

PubMed1994

Occipitocervical segmentation in staged human embryos.

Serial sections of 108 human embryos from stage 11 to stage 23 were investigated, and 33 reconstructions were prepared. The existence of 4 occipital somites was confirmed. The important developmental distinction between axial (central) and lateral components obtains in the occipital as well as in the vertebral region. The lateral occipital components begin to show dense areas as the cervical region is approached. The lateral occipital and vertebral components arise in registration with the initial sclerotomes. In both the occipital and the vertebral region the related nerves and intersegmental arteries traverse the loose areas of the sclerotomes. The axial occipital region is not segmented, whereas the cervical components develop from perinotochordal loose areas. Three complete centra (known as XYZ) develop in the atlanto-axial region, although they are related to only 2 1/2 sclerotomes and only 2 neural arches. The height of the XYZ complex equals that of 3 centra elsewhere, and not 2 1/2, as previously maintained. The experimental findings in the occipitocervical region of the chick embryo show both similarities to, as well as differences from, the data for the human embryo. A scheme showing the early development of the entire vertebral column is included.

Atlanto-Occipital Joint↗

PubMed1994

[Current status of magnetic resonance tomography in diagnosis of the ankle joint--a critical evaluation].

Anatomical preparations of the ankle were examined by T1-weighted SE-sequences in three planes to identify normal topography. The current status of magnetic resonance imaging (MRI) was assessed and illustrated by image examples. Together with conventional radiography, MRI yields relevant information for therapy planning. This technique allows accurate staging of traumatic and degenerative involving the soft tissues of the joint, including tendons and ligaments. MRI clearly delineates joint fluid, osteochondral abnormalities, and is helpful in the diagnosis of inflammatory changes of the synovia and bone marrow. Furthermore, it is the modality of choice for evaluating tissue neoplasma. Its advantages are not only the detection of the process and definition of its extent, but also the determination of local soft-tissue infiltration.

Ankle Injuries↗

PubMed1994

The influence of desipramine on thyroid hormone metabolism in rat brain.

The effect of the antidepressant desipramine (DMI) on the activities of the three iodothyronine deiodinase isoenzymes involved in the central metabolism of thyroid hormones were investigated in 11 brain regions and 3 peripheral tissues in the rat. The investigations were carried out at three different times during the light/dark cycle: 5 A.M., 1 P.M. and 11 P.M. Interest is focused on changes in the two enzymes that catalyze: i) the 5'deiodination of T4 to the biologically active T3, i.e., type II 5'deiodinase (5'D-II), and ii) the 5 (or inner-ring) deiodination of T3 to the biologically inactive 3,3'T2, i.e., type III 5 deiodinase (5D-III). Fourteen days' treatment with 20 mg/kg DMI, but not with 5 mg/kg DMI, induced significant increases in 5'D-II in eight different areas of the CNS. The regions affected were identical to those that receive noradrenergic input from the locus coeruleus. Even control animals showed a circadian rhythm of 5'D-II activity in some brain regions, and the effects of DMI also depended on the time of death within the 24-hr rhythm. 5D-III was not affected. Serum T4 were lower after administration of DMI, most probably because of enhanced tissue uptake of T4. This is in line with the corresponding finding in depressed patients, indicating that similar changes in both central and peripheral thyroid hormone metabolism may occur after antidepressant pharmacotherapy in both humans and rats. These data support the hypothesis that interactions with the CNS metabolism of the thyroid hormones may be involved in the mechanisms of action of DMI.

Animals↗

PubMed1993

The influence of sleep deprivation on thyroid hormone metabolism in rat frontal cortex.

The effects of 24 h sleep deprivation (SD) on central thyroid hormone metabolism were investigated in rat frontal cortex. SD induced a significant rise in the activity of iodothyronine type II 5'-deiodinase (5'D-II), which catalyzes the conversion of thyroxine (T4) to triiodothyronine (T3) in the rat central nervous system (CNS). Tissue concentrations of T4 remained unchanged, whereas levels of T3 increased to more than 150% of the corresponding levels measured in control rats. Serum concentrations of T4 and T3 were also significantly enhanced by SD--an effect that has previously been described in depressed patients having undergone the same procedure. These results suggest that SD can dramatically increase T3 concentrations (and possibly function) in rat CNS. Whether or not these findings are of relevance in regard to the well-known antidepressant effect of SD in psychiatric patients with major depressive disorders remains to be established.

Animals↗

PubMed1993

Efficient transient expression system based on square pulse electroporation and in vivo luciferase assay of fertilized fish eggs.

Electroporation mediated DNA transfer into fish eggs has been improved by using a train of square pulses. Fertilized eggs of African catfish (Clarias gariepinus), zebrafish (Brachydanio rerio) and rosy barb (Barbus conchonius) were dechorionated enzymatically followed by application of pulses. Efficiency of plasmid DNA delivery was significantly increased by applying multiple pulses on dechorionated eggs. Optimization of physical parameters such as field strength, pulse width and pulse numbers resulted in reproducible transient expression in 25-50% of embryos and larvae by using the firefly luciferase and the E. coli beta-galactosidase (lacZ) genes both driven by CMV IE1 promoter. Temporal luciferase expression was assayed using both qualitative (sheet film) and quantitative (scintillation counting) methods in developing embryos and fry in vivo. Spatial expression of lacZ was assayed by histochemical staining. A number of embryos revealed foreign gene product also localised in the vegetal pole of the embryo.

Animals↗

PubMed1993

Bovine papilloma virus (BPV)-encoded E2 protein enhances binding of E1 protein to the BPV replication origin.

The replication of bovine papilloma virus (BPV) DNA in vivo requires two viral-encoded proteins, E1 and E2, while all other proteins are derived from the host. We described previously the isolation of the E1 protein and showed that it contains multiple functions required for BPV DNA replication. The BPV transcription factor E2 was shown by others to stimulate BPV DNA replication in vitro. Here, we present results that account for the role of the E2 protein. The E1 protein bound selectively to the BPV minimal origin of replication. This process required MgCl2 and ATP for maximal efficiency. The E1 protein also catalyzed a BPV origin-dependent DNA unwinding reaction. In this report, we show that at low levels of E1 protein, origin binding could be stimulated up to 40-fold by the E2 protein, provided that the DNA contained an E2 binding site. Consistent with this result, the E2 protein stimulated the origin-specific unwinding reaction catalyzed by E1, but it had no effect on the nonspecific E1-catalyzed helicase activity. In the absence of an E2 binding site, both origin-dependent binding and unwinding reactions with the E1 protein were unaffected by the E2 protein. These results suggest that E2 participates in the initiation of BPV DNA replication by enhancing E1 binding to the BPV origin via DNA-protein and protein-protein interactions.

Animals↗

PubMed1993

Homonuclear and heteronuclear NMR studies of oxidized Desulfovibrio vulgaris flavodoxin. Sequential assignments and identification of secondary structure elements.

Recombinant Desulfovibrio vulgaris flavodoxin (molecular mass 16.3 kDa) was produced in Escherichia coli. The oxidized protein has been investigated with a combination of homonuclear and heteronuclear two-dimensional and heteronuclear three-dimensional NMR spectroscopy. Sequence-specific assignment of all backbone and most of the side chain 1H and 15N resonances has been obtained. The secondary structure has been inferred from the pattern of sequential, medium-, and long-range NOEs, together with information about slowly exchanging amide hydrogens and HN-H alpha spin-spin coupling constants. In solution, flavodoxin consists of a five-stranded parallel beta-sheet and four alpha-helices. Residues 3-9, 32-36, 52-58, 87-96, and 123-128 are involved in the beta-sheet whereas the a-helical regions comprise residues 13-28, 69-76, 104-114, and 134-148. Several proton resonances of the bound flavin mononucleotide cofactor have been assigned. NOE contacts between the prosthetic group and the apoprotein have been detected.

Amino Acid Sequence↗

PubMed1993

Bovine papilloma virus (BPV)-encoded E1 protein contains multiple activities required for BPV DNA replication.

Replication of bovine papilloma virus (BPV) DNA requires two virus-encoded proteins, E1 and E2, while all other proteins are supplied by the host cell. Here, we describe the isolation of the E1 protein and show that it is a multifunctional protein. Purified E1 protein was required for the in vitro replication of BPV origin-containing DNA by extracts of mouse cells, as reported [Yang, L., Li, R., Mohr, I. J., Clark, R. & Botchan, M. R. (1991) Nature (London) 353, 628-632]. In addition, the E1 protein cosedimented with a number of other activities including (i) DNA helicase activity, (ii) BPV origin-containing DNA-specific binding activity, (iii) DNA-dependent ATPase activity, and (iv) BPV origin-specific unwinding of superhelical DNA. The E1 protein, acting as a helicase, moved in the 3'-->5' direction, like simian virus 40 (SV40) large tumor antigen, which plays a pivotal role in SV40 DNA replication. However, unlike the SV40 large tumor antigen, the helicase activity of E1 was stimulated 5-fold by the presence of a fork structure at the junction between single-stranded and double-stranded DNA and was supported efficiently by all eight nucleoside triphosphates. The E1-catalyzed ATPase activity required the presence of single-stranded or double-stranded DNAs.

Adenosine Triphosphatases↗

PubMed1993

Treatment of anovaginal fistulas with an anocutaneous flap in patients with Crohn's disease.

We report on a new and simple operative technique for closure of anovaginal fistulas with an anocutaneous flap in patients with Crohn's disease. From January 1989 till December 1990 this operation was performed in 10 women with Crohn's disease. Seven of the ten patients suffered from Crohn's proctitis. In these patients a protective enterostomy was applied before the operative closure of the fistula. All fistulas healed primarily. Within a median follow up of 18 months (7-24 months) a relapse occurred in 3 patients; two of these were treated successfully with fibrin injection in one case and a further operative closure of the fistula using the same procedure in the second case. In the third patient a seton was placed into the recurrent fistula track, which is still present after 4 weeks.

Adult↗

PubMed1993

Rod and cone photoreceptor cells express distinct genes for cGMP-gated channels.

Signal transduction in vertebrate rod and cone photoreceptor cells involves ion channels that are directly gated by the internal messenger cGMP. Rods and each type of cones express genetically related yet different forms of photopigments. Enzymes that control the light-stimulated hydrolysis of cGMP in rods and cones are also the product of distinct genes. Two different cDNA clones encoding cGMP-gated channels have been characterized from the chicken retina. Expression of cDNAs in Xenopus oocytes gives rise to cGMP-stimulated channel activity. Antibodies against a synthetic peptide specific for the C-terminal amino acid sequence derived from one clone stain outer segments of cone but not rod photoreceptors. Therefore chicken rod and cone cells each express different forms of cGMP-gated channels that are genetically related to each other. Expression in COS-1 cells produces the complete form of both channel polypeptides, whereas Western blot analysis indicates that channels in outer segment membranes are present in a processed form that is significantly shorter than the full-length polypeptide.

Amino Acid Sequence↗

PubMed1993

Effects of selenium and iodine deficiency on type I, type II and type III iodothyronine deiodinases and circulating thyroid hormones in the rat.

The effects of nutritional selenium (Se) deficiency over a period of three generations and of a combined selenium and iodine deficiency on hepatic and cerebrocortical iodothyronine deiodinases and on circulating thyroid hormone levels were examined in the rat. Se deficiency strongly decreased hepatic type I iodothyronine 5'- and 5-deiodinase to 6-13% of that in controls. Iodine depletion had only a marginal decreasing effect on the type I activity. Cerebrocortical type II 5'-deiodinase was decreased in Se-deficient, iodine-replete rats. Its 5-6-fold elevation in iodine-deficient rats was not reversed by additional selenium deficiency. Cortex type III 5-deiodinase was modestly decreased in all groups with insufficient trace element supply. Long-term Se deficiency has only limited effects on serum T4 and T3 levels. Two months of iodine deficiency decreased serum T4 to less than 10% of that in controls, but did not significantly affect serum T3 levels. The strong decrease of hepatic outer- and inner-ring deiodination of T4 in Se deficiency obviously reflects the reduced tissue concentration of the type I deiodinase which was recently identified as a selenoenzyme. The maintenance of increased cerebrocortical type II deiodinase in iodine-depleted animals irrespective of adequate or deficient selenium supply suggests that the type II isoenzyme does not contain selenium in its catalytic site. Further studies are necessary to clarify whether the weak, but repeatedly confirmed decrease of cortex type III deiodinase is the direct effect of Se deficiency or the indirect consequence of the multilevel change in thyroid hormone metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

In vivo assessment of insulin binding in different organs of growing and adult glutamate-induced obese rats.

Injection of Na-L-glutamate into neonate Wistar-rats (2 mg/g body mass s.c.; day 1-5 of life) induces hypothalamic lesions, which are followed by hypoplastic-hypertrophic obesity despite normophagia. In contrast to other animal models of obesity, these rats develop obesity under peripheral normoinsulinemic conditions. However, beginning at an age of 2 months (growing rats), peripheral insulin concentration rises gradually and at an age of 6 months (adults rats) hyperinsulinemia becomes manifest. Surprisingly, adult rats show normoglycemia, pointing to alterations in insulin sensitivity. In continuation to previous work, insulin binding of different organs of growing and adult rats was investigated using the in vivo radioreceptor assay described by Whitcomb et al. in 1985. In contrast to in vitro methods, this assay works under real metabolic and hormonal conditions in plasma of lean and obese rats. Insulin binding of liver, pancreas, adrenals, stomach, duodenum, spleen, and heart muscles was found to be not statistically different between lean and obese rats of both age groups. Thus, liver insulin binding was 6323 +/- 458 pg/g wet organ in growing, and 7586 +/- 959 pg/g in adult lean rats. Corresponding values for obese rats were 5755 +/- 445 pg/g and 7830 +/- 526 pg/g, respectively. Organ specific down regulation of insulin binding in obese rats was not detected, suggesting unalterated insulin sensitivity. It is concluded that hyperinsulinemia of adult glutamate-induced obese rats cannot be explained by diminished insulin binding and reduced organ specific insulin clearance.

Aging↗

PubMed1993

Oral candidiasis is associated with low levels of parotid calprotectin in individuals with infection due to human immunodeficiency virus.

The level of the antifungal leukocyte protein calprotectin was determined in parotid saliva from 44 individuals with infection due to human immunodeficiency virus (HIV) and 19 healthy HIV-seronegative controls. Nine of the HIV-infected subjects suffered from oral candidiasis. Similar calprotectin levels were found in subjects with HIV infection as a whole group and in controls. When HIV-infected individuals with or without oral candidiasis were compared, the calprotectin level was significantly lower in the former group (67 micrograms/L vs. 216 micrograms/L). We suggest that calprotectin may play a role in the defense against oral candidal infections in HIV-infected patients, although several other antimicrobial factors also are probably operative.

AIDS-Related Opportunistic Infections↗

PubMed1993

Duodenal intraepithelial gamma/delta T cells and soluble CD8, neopterin, and beta 2-microglobulin in serum of IgA-deficient subjects with or without IgG subclass deficiency.

Expression of the gamma/delta T cell receptor (TCR) on CD3+ intraepithelial lymphocytes (IELs) was studied by two-colour immunofluorescence in duodenal tissue sections from healthy (n = 6) or infection-prone (n = 7) subjects with selective IgA deficiency (IgAD), and subjects (n = 4) with combined IgAD and IgG subclass deficiency. TCR gamma/delta+ IEL proportions in selective IgAD subjects (median 6.3%, range 1.0-41%) and in those with combined deficiency (median 4.5%, range 1.2-33%) were well within the range (0.3-38%) for histologically normal controls (n = 11), but the healthy IgAD subgroup tended to show raised TCR gamma/delta+ IEL proportions (median 13.6%) compared with the other two subgroups. Also the number of TCR gamma/delta+ IELs per intestinal length unit was relatively high (median 13.9/mm) in the healthy IgAD subjects, and significantly raised (P < 0.03) compared with controls (median 3.2/mm). Paired staining revealed that most TCR gamma/delta+ IELs in both selective IgAD (98%) and combined deficiency (99%) were CD8-, and a large fraction (median 84% and 63%, respectively) expressed the V delta 1/J delta 1-encoded epitope. The total number of CD3+ IELs (mostly CD8+) was similar to controls. IgAD subjects, and especially the healthy subgroup, had significantly increased serum concentrations of soluble CD8 (P < 0.0002), neopterin (P < 0.005), and beta 2-microglobulin (P < 0.007), which was similar to our previous observations in common variable immunodeficiency, and probably reflected stimulation of cell-mediated immunity. In addition, the increased TCR gamma/delta+ IELs might reflect a component of compensatory surface protection in the healthy IgAD subgroup.

Adolescent↗