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Biomedical subjects

B Möller

Publications and source records attributed to B Möller.

At least 37 records · Page 2Linked to original sources
PubMed1999

Sinus floor augmentation with simultaneous placement of dental implants using a combination of deproteinized bone xenografts and recombinant human osteogenic protein-1. A histometric study in miniature pigs.

Maxillary sinus floor augmentation with autogenous bone has become a widely accepted procedure in implant dentistry. The use of osteoconductive bone substitutes in this indication is controversial, since their use can lead to a prolonged healing time, inhomogenous ossification, foreign body reaction, migration of particles and low bone-implant contact (BIC). The purpose of this study was to examine whether the combination of an osteoinductive protein (recombinant human osteogenic protein-1 (rhOP-1 = bone morphogenetic protein-7) with natural bovine bone mineral (BioOss) would improve ossification and the bone-implant contact (BIC) in a sinus floor augmentation with simultaneous placement of implants. In this study, the maxillary sinus floors in 5 miniature pigs were augmented with 3 ml BioOss containing 420 micrograms rhOP-1 on the test side and 3 ml BioOss alone on the control side. At the time of augmentation a titanium implant (ITI) was inserted from a laterocaudal direction. After 6 months of healing the sites of augmentation were removed and examined in non-decalcified sections by microradiography, fluorescence microscopy of sequentially labelled specimens and by histometry. On both sides, significant amounts of newly-formed bone were observed. However, on the test sites, the percentage of BIC in the augmented area was 80.0% versus 38.6% on control sites. It can be concluded that the application of bone morphogenetic proteins caused a more rapid and enhanced osseointegration of simultaneously placed implants when compared to the bone substitute alone. Therefore recombinant human osteogenic protein-1 delivered by natural bone mineral has the potential to become a clinical alternative for autogenous bone grafts in sinus floor augmentation.

Animals↗
PubMed1999

Association of (Q)R/KRAA positive HLA-DRB1 alleles with disease progression in early active and severe rheumatoid arthritis.

OBJECTIVE: We have shown that HLA-DRB1 alleles influence inflammatory activity in patients with early active and severe rheumatoid arthritis (RA). Therefore, we analyzed the effect of HLA-DRB1 alleles on disease progression in patients with early RA during a clinical followup period of 18 months. METHODS: Disease progression was defined by the Larsen Score, the Ritchie Index (RI), and the Health Assessment Questionnaire (HAQ) score. RESULTS: Patients carrying arthritogenic HLA-DRB1 alleles on one or both haplotypes are characterized by increased radiological joint destruction (Larsen Score). Further, (Q)R/KRAA homozygous patients were characterized by worse overall disease course (higher RI and HAQ). However, analysis of changes in joint effects (delta-RI) and personal disability (delta-HAQ) did not reveal significant differences between patients with or without disease associated HLA-DRB1 alleles. CONCLUSION: The predisposing genetic pattern with disease associated HLA-DRB1 alleles did not profoundly influence the therapeutic outcome. Our data support the role of the HLA-DRB1 gene locus in disease modulation of RA. The genetic predisposition due to HLA-DRB1, however, may have only a limited influence on the therapeutic outcome in clinically severe cases of RA.

Adult↗
PubMed1998

Extraamniotic saline infusion is promising in preparing the cervix for induction of labor.

BACKGROUND: The application of local prostaglandins before induction of labor in women with an unripe cervix is standard procedure in Sweden. Side effects include uterine hypertonus and occasionally fetal heart rate abnormalities. Failed ripening is reported in up to 25% of cases. A previous report of ripening of the cervix by use of extraamniotic physiologic saline infusion through a Foley catheter applied in the cervix claimed results superior to topical prostaglandins. OBJECTIVE: To conduct a prospective randomized trial of extraamniotic saline infusion and intracervical application of dinoprost 0.5 mg on cervical ripening and outcome of labor. METHODS: Eighty-five term singleton pregnant women with unripe cervices where induction of labor was indicated were randomized to prostaglandin or saline infusion after obtaining informed consent. Outcome variables were improvement of cervical score, induction delivery time and mode of delivery. RESULTS: The 42 women in the saline infusion group obtained significantly (p < or = 0.001) higher cervical scores and shorter induction delivery intervals (p < or = 0.005) than the 43 women in the prostaglandin group. Cases of unripe cervix after 24 hours were significantly (p < or = 0.01) fewer in the saline group. There were more Cesarean sections in the saline group, but this difference was not significant. Saline infusion did not induce uterine activity and oxytocin was given in every case after the expulsion of the catheter. CONCLUSIONS: In this study extraamniotic saline infusion was a more efficacious method for ripening of the cervix than intracervical prostaglandin. The absence of early painful contractions is an advantage, but effective stimulation of labor is required to effect delivery after maturation of the cervix.

Adolescent↗
PubMed1997

Amperometric lactate oxidase catheter for real-time lactate monitoring based on thin film technology.

An amperometric lactate oxidase catheter has been developed for in vivo application to real-time lactate monitoring. The electrochemical behaviour of the 1 x 3 mm Pt-Ag/AgCl thin film electrode is not significantly influenced by lactate oxidase-polyurethane covering. Gamma-irradiation (25 kGy) is suitable for the sterilization procedure. The final lactate catheter is characterized by a linear concentration range between 0.5 and 20 mmol/l lactate with a sensitivity around 2 nA mmol-1 l-1 lactate. The accuracy is demonstrated by the measurement of control sera. Both physiological and pathological materials correlate well with the declared values. The dry stored lactate catheter needs about 10 min for hydration and is characterized by response times t98% of less than 2 min. Ex vivo whole blood measurements using the lactate catheter (y) give a correlation with the BIOSEN Med L (x) of y = (1.010x + 0.513) mmol/l (r = 0.9748). Lactate values obtained by continuous catheter operation ex vivo correlate well with those obtained by BIOSEN Med L. First subcutaneous implantation (dog) underlines the characteristics obtained ex vivo: after 30 min hydration the lactate catheter follows the lactate concentration measured ex vivo with samples from the leg vein by BIOSEN Med L.

Animals↗
PubMed1997

Ultrasensitive bienzyme sensor for adrenaline.

A biosensor consisting of an analyte-recycling two-enzyme system using laccase (Coriolus hirsutus) and PQQ-dependent glucose dehydrogenase in combination with the electrochemical detection of oxygen depletion at a platinum electrode was used for adrenaline determination in the nano- and subnanomolar concentration range. Measurements were performed in a flow cell providing excellent baseline stability and fast recovery of the sensor. Improved design of the polymer matrix resulted in a lower detection limit of 200 pmol/l for adrenaline. The sensor has successfully been applied to the analysis of adrenaline in effluate of isolated rabbit hearts.

Animals↗
PubMed1997

HLA-DR/DQ/DP interactions in rheumatoid arthritis.

Rheumatoid arthritis (RA) is associated with the presence of particular HLA-DRB1 alleles. In order to characterize HLA-DQB1 and/or-DPB1 alleles that contribute to disease susceptibility besides HLA-DRB1 alleles, we have analysed the HLA-DRB1, -DQB1 and -DPB1 polymorphism in 84 RA patients and 135 controls. HLA typing for HLA-DRB1 and -DQB1 alleles was performed using sequence-specific primers in combination with sequence-based typing. HLA-DPB1 alleles were characterized by reverse dot-blot hybridization. Our data confirm the predominant role of the (Q)R/KRAA sequence from AA position 70-74 of the HLA-DRB chain for disease susceptibility. In particular, the lysine (K) substitution at position 71 was highly significantly associated with RA. Analysis of the DQB1 locus revealed no association with RA when linkage disequilibrium between HLA-DRB1 and -DQB1 alleles was considered. In contrast, we observed an increased frequency of HLA-DPB1*0401 among (Q)R/KRAA-positive patients. (Q)R/KRAA-negative RA patients exhibited an overrepresentation of HLA-DPB1*0201 and HLA-DPB1*0601. Rheumatoid factor (RF) production correlated with the presence of the disease-associated (Q)R/KRAA amino acid cassette of the HLA-DRB chain. When HLA-DPB1 allele frequencies were compared between RF-positive and RF-negative RA patients, we observed an increased frequency of HLA-DPB1*0401 among RF-positive RA patients and HLA-DPB1*0201 among RF-negative patients. These results suggest that besides the predominent role of HLA-DR molecules in RA, HLA-DP molecules may have an influence on disease susceptibility and could modulate disease progression. HLA-DPB1*0401 may function in addition to HLA-DRB1*04, whereas HLA-DPB1*0201 and -DPB1*0601 may represent additional risk factors among (Q)R/KRAA-negative RA patients.

Adult↗
PubMed1997

HLA-DRB1*04 subtypes are associated with increased inflammatory activity in early rheumatoid arthritis.

The sequence polymorphism of HLA-DRB1 molecules in 84 rheumatoid arthritis (RA) patients with early RA has been analysed to evaluate whether particular HLA-DR alleles influence disease progression in the early stage of the disease. Clinical data were analysed by grouping the patients according to disease-associated haplotype combinations (DRB1*04,04/DRB1*04,01/DRB1*04,X/DRB1*01,X) in comparison to patients who did not carry these haplotypes (DRB1*X,X). Our results indicate that patients with early RA who are homozygous for DRB1*04 exhibit an elevated inflammatory activity and an increase of joint affections. In addition, the amino acid polymorphism (QR/KRAA) at position 70-74 seems to affect the production of rheumatoid factors. These results support the role of HLA-DRB1 alleles in the pathogenesis of RA and indicate that patients with particular HLA-DRB1*04 haplotype combinations may require intensified therapeutic interventions in the early stage of the disease to prevent disease progression.

Adult↗
PubMed1996

Soluble tumor necrosis factor (TNF) receptors conserve TNF bioactivity in meningitis patient spinal fluid.

The content of tumor necrosis factor (TNF)-alpha antigen and the bioactivity of soluble TNF receptor type II (sTNF-RII) in cerebrospinal fluid (CSF) from 29 patients with meningeal symptoms and fever were examined. Immunoreactive TNF was demonstrated in CSF from 4 of 7 patients with bacterial meningitis. In 3 of 8 patients with aseptic meningitis, CSF also contained TNF, but TNF bioactivity was confined to samples from patients with bacterial meningitis. Bioactive TNF was exclusively in high-performance liquid chromatography fractions containing 30- to 60-kDa proteins. Lipopolysaccharide induced down-regulation, possibly after shedding of granulocyte surface membrane TNF-RII. Consistently, there was a statistically significant correlation between sTNF-RII and CSF leukocyte counts. Bioactive TNF was found only in CSF containing >1 ng of sTNF-RII/mL; samples without TNF bioactivity contained less sTNF-RII. Thus, a stabilizing effect of sTNF-RII on the oligomeric cytokine in vivo is plausible.

Cells, Cultured↗
PubMed1996

A simple method for preoperative assessment of the best fitting electrode length in single lead VDD pacing.

For single lead VDD pacing, electrodes with various distances between the lead tip and the floating atrial dipole (AV distance) are available. Using different AV distances allows positioning of the atrial dipole in the mid- to high right atrium, regardless of the size of the right heart. In this position, reliable atrial sensing and rejection of ventricular far-field potentials can be expected. A simple test for the preoperative assessment of the best fitting AV distance in the individual patient was tested. We studied 24 consecutive patients prior to implantation of a VDD pacemaker. With the patient in supine position, a test electrode with an AV distance of 13 cm was taped onto the thorax. Under fluoroscopic control, it was moved until its course and projection onto the heart was equal to that of a ventricular lead. If fluoroscopy then showed a projection of the atrial dipole onto the mid- to high right atrium, a lead with a similar AV distance of 13 or 13.5 cm was used for implantation. If the atrial dipole projected itself too high or too low, a shorter or longer lead had to be implanted. The maximum time for the test was 2 minutes, and the maximum fluoroscopy time was 15 seconds. According to the test, a lead with an AV distance of 13 or 13.5 cm was implanted in 18 of 24 patients, and a lead with an AV distance of 15.5 or 16 cm was implanted in 6 of 24 patients. The atrial dipole could easily be positioned in the mid- to high right atrium in all patients, demonstrating a correct preoperative assessment of the best fitting AV distance. Intraoperatively, a P wave amplitude of 3.5 +/- 3.0 mV was measured. The described test allows a fast and reliable assessment of the best fitting electrode length in single lead VDD pacing.

Adult↗
PubMed1995

Sodium and dopamine excretion in prehypertensive Dahl rats during severe hypervolaemia.

As opposed to the salt-resistant Dahl-R rat the salt-sensitive Dahl-S has a defective renal dopamine DA1 receptor that may be involved in its susceptibility to develop hypertension during a high salt diet. To compare the ability of prehypertensive Dahl-R and Dahl-S to respond to a severe isotonic sodium load, renal function was monitored during a severe form of acute isotonic volume expansion (10% VE). Mean arterial blood pressure before VE was similar in Dahl-R and Dahl-S and decreased in both strains by 6% during VE. The accumulated sodium excretion during VE in Dahl-R was 411 +/- 64 micromol 100 min(-1) g(-1) kidney wt (kw) which was not different from that in Dahl-S (420 +/- 95 micromol 100 min(-1) g(-1) kw). The accumulated dopamine excretion (a mirror of renal dopamine synthesis) during VE was also similar in Dahl-R (134 +/- 13 ng 100 min(-1) g(-1) kw) and Dahl-S (126 +/- 16 ng 100 min(-1) g(-1) kw). The excretion of DOPAC, the main metabolite of Dahl-S, glomerular filtration rate and systemic haematocrit did not differ between the strains before, during or after VE. To conclude, in spite of a defective renal DA1 receptor prehypertensive Dahl-S do not respond with an attenuated natriuretic or dopamine excretory response when subjected to a severe isotonic sodium load. The results do not support a sodium retaining role over a defective DA1 receptor in the salt-sensitive hypertension in Dahl-S.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Effect on human teeth of renal transplantation: a postmortem study.

Extracted teeth from five deceased patients treated by renal transplantation were examined radiographically and histologically, and compared with teeth from healthy persons of approximately the same age. In three of the patients with a renal transplant, the radiographs showed normal pulp chamber sizes, but histologic examination revealed a widened predentin zone, approximately four times greater than in the controls. In two of the patients the radiographs showed marked reduction of the pulp chamber size. The histologic changes of these teeth were mainly an extensive amount of secondary dentin along the pulp chamber walls and the root canals, with a markedly reduced pulp space. One explanation for the difference between the patients was that patients with extensive pulp calcifications were given a higher total amount of corticosteroids than patients with a widened predentin zone.

Adult↗
PubMed1993

[Promoting competence in a model trial of a complementary course of study in health sciences/public health at the Berlin Technical University in cooperation with the Free University and other science and general practice institutions].

Since October 1992 (winter semester 92/93) graduates are being educated in Public Health at Berlin Technical University in cooperation with the Free University of Berlin as well as with the Humboldt University of Berlin and other institutions of science and practice in Berlin and Brandenburg. For the time being the course of studies is a pilot project for 4 years. The aim of the postgraduate studies is the creation of permanent structures and therefore institutionalisation. It is open to graduates and college graduates of public-health relevant subject areas of specialisation are "Health Promotion in the community and at the workplace" and "Planning and Management in Health Services". The course of studies takes 4 semesters and is divided into basic studies, studies of main points of emphasis and project studies. Social medicine and especially epidemiology are part of the basic disciplines, which are indispensable for finding the way of looking at problems concerning public health. The reason for the peculiarity with regard to establishing public health at other German universities are the main topics representing the interaction between the technical and ecological development of health. The graduate degree is "Magister of Public Health". During the time of the pilot project the course of studies is subjected to external and internal surveillance regarding quality assurance and quality optimisation of teaching and organisation of the studies. On the one hand this is done by an external advisory committee and on the other hand by internal and external evaluation.

Community Medicine↗
PubMed1992

Optical evaluation of red blood cell geometry using micropipette aspiration.

Although red blood cell (RBC) geometry has been extensively studied by micropipette aspiration, the small size of RBC and pipettes vs. the optical resolution of light microscopy suggests the need to consider potential errors. The present study addressed such difficulties and investigated four specific problems: (1) use of exact equations to calculate RBC membrane area and volume; (2) calibration of the pipette internal diameter (PID); (3) correction for a noncylindrical pipette barrel; (4) diffraction distortion of the RBC image. The observed PID represents a cylinder lens enlargement that can be theoretically derived from the glass/buffer refractive index ratio (1.49/1.33 = 1.12). This enlargement was experimentally confirmed by: (1) studying pipettes bent to allow measurement through the barrel (horizontal) and at the orifice (vertical), with a resulting diameter ratio of 1.12 +/- 0.01; (2) and by replacing the surrounding buffer with immersion oil and hence abolishing the lens phenomenon (ratio = 1.12 +/- 0.02). In addition, use of aspirated oil droplets demonstrated a 3.2 +/- 0.2% error when the PID is focused at a sharp, maximum diameter. The average pipette cone angle was 1.49 +/- 0.09 degrees and varied considerably with pipette pulling procedures; calculated tongue geometry inside the pipette was affected by the noncylindrical pipette barrel. The RBC diffraction error, demonstrated by touching two aspirated cells held by opposing pipettes, was 0.091 +/- 0.002 microns. The PID, cone angle, and diffraction artifacts significantly (p < 0.001) affected calculated RBC geometry (average errors up to 5.4% for area and 9.6% for volume). Two new methods to calculate, rather than directly measure, the PID from images of a single RBC, during either osmotic or pressure manipulation, were evaluated; the osmotic method closely predicted the PID, whereas the pressure method markedly underestimated the PID. Our results thus confirm the need to consider the above-mentioned phenomena when determining RBC geometric parameters via micropipette aspiration.

Algorithms↗
PubMed1991

High level expression of functional full length human thyroid hormone receptor beta 1 in insect cells using a recombinant baculovirus.

We have cloned the human thyroid hormone receptor beta 1 (hThR beta) from the human breast cancer cell line T47D using the PCR technique. A recombinant baculovirus transfer vector pVL1392/hThR beta was constructed and the full length receptor was expressed in the insect cell line Spodoptera frugiperda (Sf9). Approx. 10-15 x 10(6) receptors are expressed/cell which implies a production level of 2.5-4.0 mg hThR beta/l of cell culture. The expressed hThR beta displayed a single class of binding sites for T3 with high affinity. Western blot analysis using a polyclonal antibody indicated that the molecular weight of the baculovirus expressed receptor is approx. 50 kDa. Crude nuclear extract of hThR beta labeled with [125I]T3 sedimented as a 4 S peak on a glycerol gradient. No receptor could be detected in the cytoplasm indicating its proper translocation to the nuclear compartment. An oligonucleotide containing a palindromic thyroid hormone response element is specifically recognized and retarded in a gel-mobility-shift assay in the presence of nuclear extract of Sf9 cells expressing hThR beta. These data suggest that hThR beta expressed in Sf9 cells is functional and displays characteristics virtually indistinguishable from those of the thyroid hormone receptor (ThR) extracted from mammalian cells. Furthermore, the data indicate that the baculovirus expression system is adequate for large-scale production of receptor for detailed structural and functional studies.

Animals↗