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Biomedical subjects

H P Müller

Publications and source records attributed to H P Müller.

At least 19 recordsLinked to original sources

[Does chronic periodontitis play a role in the pathogenesis of cardiovascular and cerebrovascular diseases?].

The role of chronic infections in the initiation of atherosclerotic lesions has been vividly discussed in recent years. A possible causal relationship between cardiovascular diseases and infections with, e. g., Chlamydia pneumoniae, Helicobacter pylori, or herpes viruses had also been established for chronic periodontitis, in particular after discovery of DNA of typical periodontal pathogens in atheromatous plaques. Especially in longitudinal epidemiologic studies, a low or moderate association between existing periodontitis and the development of, e. g., coronary heart disease or non-haemorrhagic stroke had been observed. In this article the respective literature is critically reviewed. In particular, the influence of incomplete or inappropriate adjustment for common risk factors for both diseases, i. e., cardiovascular disease and periodontitis should be analysed. In metaanalyses of prospective studies, in which the respective endpoint occurred after the investigation had commenced, relative risks of periodontitis of 1.12 (95 % confidence interval 0.95-1.33) for coronary heart disease and 1.73 (0.89-3.34) for ischaemic stroke were calculated. Whether chronic periodontitis actually represents an important risk for the development of cardiovascular diseases remains questionable. Already planned intervention studies appear to be premature and ethically highly problematic.

Cerebral Infarction↗

[Quality management: internal guidelines and critical pathways for patients].

BACKGROUND: The construction and implementation of "Practice Guidelines" was one of the most important developments in American medicine of the last 15 years. There is ongoing controversy about the effectiveness of these guidelines to get introduced into practice. It has been proved, however, that guidelines developed by care organizations themselves, will show a higher effectiveness and acceptance and will achieve more positive results (Internal Guidelines, "Locally Owned" Standards). "Mipp": Internal Guidelines are also the starting point for the patient pathways of the model of integrated patient pathways "mipp", developed at the Kantonsspital Aarau in the last 7 years. The model is presented with its main features: Construction and Implementation of Pathways, Path-Controlling, Path-Benchmarking and Path-Visualization. "Mipp" Pathways share with Clinical Pathways the interdisciplinary perspectives for an efficient quality management. The description of processes is combined with an integrated calculation of costs, which is the basis of standard cost accounting and even activity based-costing. CONCLUSION: In the field of upcoming prospective payment systems (PPS) like ARDRG, APDRG etc. it is of utmost importance for care organizations to have a clear view regarding the treatment processes and the possibilities of their improvement.

Benchmarking↗

Magnetocardiographic mapping of QRS fragmentation in patients with a history of malignant tachyarrhythmias.

BACKGROUND: The identification of patients at increased risk for ventricular tachycardia or ventricular fibrillation (VT/VF) and sudden cardiac death has consequences for therapeutic options and thus may reduce mortality in patients with coronary artery disease (CAD). HYPOTHESIS: We hypothesized that the intra-QRS fragmentation in magnetocardiographic recordings is increased in patients with CAD and with a history of VT/VF. METHODS: Multichannel magnetocardiography (MCG) was carried out in 34 healthy controls, 42 patients with CAD without a history of VT/VF, and 43 patients with CAD and with a history of VT/VF. The intra-QRS fragmentation was quantified by a new fragmentation score. Its spatial distribution was investigated using two-dimensional (2-D) contour maps according to the sensor position of the 49-channel magnetogradiometer. RESULTS: Patients with CAD and with a history of VT/VF had significantly increased QRS fragmentation compared with patients with CAD without VT/VF or controls (72.9+/-37.5, 48.5+/-14.3, and 42.5+/-7.8, respectively: p <0.05). The area of high fragmentation in 2-D contour maps was twice as large in patients with than in those without a history of VT/VF (represented by the number of MCG channels with high fragmentation: 26.3+/-15.5 vs. 12.4+/-9.9, p<0.0001). Patients prone to VT/VF could be identified with a sensitivity of 64% and a specificity of 90%. CONCLUSION: In patients with CAD and with a history of VT/VF, intra-QRS fragmentation is increased and the area of high fragmentation in 2-D contour maps is enlarged. These findings may be helpful in identifying patients with CAD at risk for malignant tachyarrhythmias.

Adult↗

Gingivitis in young adults with Actinobacillus actinomycetemcomitans.

High intraoral load of A. actinomycetemcomitans in subjects with no or minimal periodontal disease may induce subtle changes in clinical periodontal conditions. The aim of the present study was to compare, at a site level, clinical conditions in two groups of young adults with plaque-induced gingivitis. In one group, more than 20% subgingival sites harboured cultivable A. actinomycetemcomitans (n=9), whereas in the other group, the organism was present in 20% or fewer subgingival plaque samples (n=8). Whereas no overt differences in clinical conditions could be ascertained, on average, the association between the presence of subgingival plaque and bleeding upon probing was considerably stronger (Mantel-Haenszel's common odds ratio RMH and 95% confidence interval 3.903, 2.951-5.165, P<0.001) in subjects with only a few subgingival sites harbouring A. actinomycetemcomitans as compared to subjects with a widespread intraoral distribution of the organism (R(MH)=1.637, 1.226-2.184, P<0.001). Since the proportion of sites not bleeding upon probing in the presence of supragingival plaque was slightly elevated in these subjects, the present findings may suggest a suppressed inflammatory reaction on supragingival plaque in the presence of a pronounced intraoral load of A. actinomycetemcomitans.

Adolescent↗

Bleeding on probing in smokers and non-smokers in a steady state plaque environment.

An altered gingival inflammatory response to supragingival plaque in smokers had been claimed by several authors. Relatively limited information exists with regard to the consistency of naturally occurring plaque and bleeding upon probing within the oral cavity under usual oral hygiene measures. The aims of the present study were to describe the distribution of tooth surfaces covered by supragingival plaque and gingival units bleeding upon probing in a steady state environment of no dental intervention. In addition relative consistency of plaque and bleeding was investigated. 65 volunteers, 14 women and 51 men in the age range of 19 to 30 years, participated. 33 volunteers were heavy smokers and 32 non-smokers. Clinical examinations revealed mild, plaque-induced gingivitis with no overt destructive periodontitis. Within a 6-month period. presence and amount of plaque, calculus and gingival bleeding was site-specifically assessed four times, i.e., every 8 weeks. Well-defined, symmetric and consistent patterns of plaque and calculus distribution within the oral cavity were observed, which were rather identical in smokers and non-smokers. Smokers had evenly more plaque in all regions of the oral cavity. In contrast, there was no obvious pattern of bleeding upon probing. Consistency of observations was considerably lower than for plaque scores. This was particularly true for smokers, where the association between bleeding scores was generally smaller than in non-smokers. A large portion of the variation of gingival bleeding may be due to presently unknown factors other than plaque and calculus with considerable consequences for preventive programmes.

Adult↗

Intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minimal periodontal disease.

The aim of the present study was to investigate the intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minor signs of periodontal disease but harboring the organisms in the oral cavity. 17 healthy volunteers, 20 to 27 years of age, participated. Samples from mucosal surfaces of the oro-pharyngeal cavity and saliva (n = 221) as well as subgingival plaque from every tooth (n =477) were selectively cultivated for A. actinomycetemcomitans. Species identity and presence of the leukotoxin encoding gene, ltxA, were checked by multiplex polymerase chain reaction. Moreover, the leukotoxin promoter region was analyzed. No isolate harbored a 530 bp deletion in the promoter region of the leukotoxin gene, signaling minimally toxic strains. 42.1 +/- 30.4% extracrevicular and 34.4 +/- 29.5% subgingival samples were culture-positive. In extracrevicular samples, the organism could easily be recovered from cheek mucosa (62%), saliva (59%) and the palatal tonsils (41%). Mean log-transformed numbers of A. actinomycetecomitans colony forming units (CFU/ml) in culture-positive material ranged between 1.8 from the hard palate and 2.3 from 10 microl saliva. The highest prevalence in subgingival plaque was observed at maxillary 3rd molars (55%) followed by maxillary lateral incisors (50%) and mandibular 3rd molars (41%). Mean log-transformed counts of CFU/ml ranged between 2.2 at maxillary 3rd molars and 3.4 at upper central incisors. When adjusted for jaw, site and tooth type, the odds of isolating higher numbers of the organism were increased with every mm probing depth by a factor of 1.35 (p <0.05). The odds ratio for bleeding on probing was 1.38. Thus, in this young adult population with minor periodontal disease, A. actinomyetemcomitans was mainly associated with some deviation from gingival health. Of concern might be a minority of subjects (29%) with an extremely wide distribution of the organism in the oral cavity.

Adolescent↗

ApoE-containing high density lipoproteins and phospholipid transfer protein activity increase in patients with a systemic inflammatory response.

High density lipoproteins (HDL) mediate reverse cholesterol transport as well as the clearance of oxidation products or inflammatory mediators, thereby contributing to tissue integrity. The decrease in HDL in inflammation has been attributed to decreased lecithin:cholesterol acyltransferase activity, whereas the role of phospholipid transfer protein (PLTP) and cholesteryl ester transfer protein has not been analyzed in detail. We have studied the activities of HDL-modifying proteins and the heterogeneity of HDL in healthy control subjects and three groups of postsurgery patients: no bacterial infection (group 1), bacterial focus and systemic inflammatory response (group 2), and severe sepsis (group 3). For all patients, a decrease in total HDL could be demonstrated, with a loss of mainly large, apolipoprotein A-I (apoA-I) HDL particles, an almost total loss of apoC-I, and an increase in apoE HDL (200-500 kDa), which did not contain significant amounts of apoA-I, apoA-II, or apoC-I. PLTP activity was increased in patients of groups 2 and 3, paralleled by a redistribution of PLTP into a population of small (120- to 200-kDa) particles, probably representing PLTP homodimers or lipid-complexed PLTP. In summary, the increase in apoE HDL and PLTP activity may improve the delivery of energy substrates and phospholipids to tissues that must maintain cellular membrane homeostasis under conditions of inflammatory stress.

Adult↗

Failure of root coverage of shallow gingival recessions employing GTR and a bioresorbable membrane.

The aim of the present study was to compare the postsurgical outcome of two different modes of surgical root coverage of predominantly shallow, Class I or II, gingival recessions. Fourteen facial recessions in nine patients were subjected to a coronally repositioned flap in combination with a bioresorbable membrane, and 14 sites in 13 patients were treated with a connective tissue graft employing an envelope technique. Immediately before surgery and after 6 and 12 months, gingival dimensions as well as root coverage and attachment gain were assessed. At baseline, mean recession depths amounted to 2.77+/-1.67 mm and 2.49+/-1.07 mm for patients treated with a bioresorbable membrane and a free connective tissue graft, respectively. Acceptable and stable root coverage of 81% to 82% of baseline recession depth and 78% of its width was achieved by grafting. In contrast, guided tissue regeneration (GTR) resulted in only 50% coverage of recession depth and, after 12 months, only 11% of its width (P < 0.01). Logistic regression revealed that the odds of obtaining success, ie, at least 80% root coverage, were 3.3 times greater in cases treated with a connective tissue graft (P < 0.05). In addition, the odds ratio was 2.3 in cases of recessions below 2.5 mm compared to deeper recessions and 2 at canines compared to premolars. It was concluded that shallow recessions in the 1.5 to 3.5 mm range should not be treated with GTR. In these situations, predictable results are achieved with free connective tissue grafts employing an envelope technique.

Absorbable Implants↗

Site-specific association between supragingival plaque and bleeding upon probing in young adults.

The aim of the present study was to consider supragingival plaque as a risk factor for gingivitis in a group of young adults without destructive periodontal disease. A total of 127 subjects, 17 to 30 years of age, participated. Periodontal probing depth, clinical attachment level as well as bleeding upon probing and supragingival plaque was assessed at 6 sites of every tooth present. The individual odds ratios between plaque and bleeding ranged between 0.237 and 66.6. 23% volunteers had an odds ratio of below 1.2. Only 15% individuals presented with an attributable risk of supragingival plaque for bleeding upon probing of 50% or more. Overall, the odds of bleeding, adjusted for periodontal probing depth, was increased by 67% in the presence of plaque. Large differences were observed at different teeth with the highest odds ratio at mandibular premolars with 2.557 (95% confidence interval 2.033-3.216) and the lowest at maxillary molars with 1.355 (1.161-1.732). It was concluded that there was high interindividual and intraindividual variation of the relative risk for bleeding in the presence of plaque. The observed low overall relative risk has important consequences in educational and health care programmes since the risk of supragingival plaque which is actually attributable for the observed bleeding on probing may be rather small.

Adolescent↗

Dynamics of mucosal dimensions after root coverage with a bioresorbable membrane.

BACKGROUND: So far, the clinical effects of the placement of a resorbable membrane for guided tissue regeneration have not been studied in humans in great detail. The dynamics of the resorptive processes, in particular, appear to be rather speculative. In the present longitudinal study, specific alterations of the dimensions of the dentogingival mucosa were explored after surgical root coverage by using a bioresorbable membrane and a coronally-repositioned flap. METHODS: The study population consisted of 14 patients with a total of 31 predominantly shallow, Miller class I, II or III recessions. The thickness of the masticatory and lining mucosa before and after surgical intervention was measured with an ultrasonic device. RESULTS: Mean (+/-sd) recession depth and width were 2.85+/-1.29 and 4.46+/-1.14 mm, respectively. After 12 months, 51+/-29% of the recession depth (p<0.001) and 13+/-35% of its width (n.s.) were covered. Root coverage seems to be rather defect-type sensitive with best results obtained at canines with relatively shallow recessions. Mucosal thickness was considerably increased after surgery with a gradual decrease during the following 9 months. Thus, thickness of the marginal tissue rose from 0.82+/-0.27 mm to 1.49+/-0.54 mm 3 months after placement of the membrane (p<0.001). After 12 months, a mean thickness of 1.03+/-0.40 mm was observed (p<0.001). Even more pronounced alterations were noted for the alveolar lining mucosa with a threefold increase of thickness 3 months after surgery and a gradual decrease to about 1 mm after 12 months. CONCLUSIONS: The present results point to the considerable space making capacity of the bioresorbable membrane which probably allows for the ingrowth of a granulation tissue derived from the underlying structures. The gradual decline in mucosal thickness between months 6 and 9 after surgery may be paralleled by the maturation of the granulation tissue while complete resorption of the membrane had been accomplished.

Absorbable Implants↗

Thickness of masticatory mucosa.

BACKGROUND: The aim of the present study was to assess thickness of all parts of the masticatory mucosa by using an ultrasonic measuring device. METHODS: A total of 40 periodontally healthy subjects, 19 to 30 years old, took part. Thickness of masticatory mucosa was measured at a maximum of 149 sites in each proband. RESULTS: Female volunteers had significantly thinner mean masticatory mucosa than males (p<0.01). Mean thickness of facial gingiva ranged between 0.7 mm at canines in the maxilla and central incisors in the mandible and 2.3 mm at 3rd molars in the mandible. In the mandible, thickness of lingual gingiva ranged between 0.9 mm at lateral incisors and 2.3 mm at 3rd molars. Interdental gingiva ranged between 1.0 mm 2.1 mm. With 3 mm or more, on average, palatal masticatory mucosa was thickest in the 3rd molar region and at 2nd premolars at more central locations. 2 regions with comparatively thin palatal mucosa of about 2 mm were identified, namely (i) at central and lateral incisors and (ii) at the prominence of the palatal roots of 1st and 2nd molars. The thickest tissue with more than 4 mm, on average, was observed in the tuberosity and retromolar regions. CONCLUSIONS: Considerable intra- as well as interindividual variation of thickness of masticatory mucosa could be observed. According to differences in thickness of facial and interdental gingiva, it appears that lining is also an important function of the gingiva in reducing and smoothing the pronounced convexities of the dentoalveolar, i.e., skeletal, complex.

Adult↗

Masticatory mucosa in subjects with different periodontal phenotypes.

AIMS: The aim of the present investigation was to study thickness of masticatory mucosa and gingival width in subjects with different periodontal phenotypes. METHODS: Periodontal phenotypes were defined with the aid of cluster analysis of standardised parameters including mean gingival thickness and width as well as ratio of crown width to its length at maxillary canines, lateral and central incisors of 40 young adults with healthy periodontal conditions. RESULTS: 3 groupings could be observed. Clusters A1 and A2 comprised 75% of all subjects. They were characterised by thin gingiva and a slender tooth form. Clusters A1 and A2 were differentiated by gingival width. Cluster B comprised 11 subjects with relatively thick and wide gingiva and a quadratic tooth shape. In general, characteristics of the frontal sextant in the maxilla were also found in other parts of the dentition. Thus, mean thickness of masticatory mucosa as well as gingival width and crown form differed significantly among clusters. In addition, cluster B subjects had a significantly greater mean periodontal probing depth. Multiple linear regression analysis was employed to identify significant factors influencing palatal mucosal thickness. Women had considerably thinner palatal mucosa than men. Furthermore, cluster affiliation had a significant influence on thickness of palatal mucosa. Thickest tissue was found in the premolar region, whereas the mucosa over the root prominence of the first molar represented an anatomical barrier for graft harvesting. CONCLUSIONS: Thickness of masticatory mucosa strongly depends on gender and the periodontal phenotype.

Adult↗

[Smoking and periodontal health].

The causal agents of destructive periodontal disease are several gram-negative bacteria. The mere presence, however, in the dental biofilm does not guarantee onset of the disease. The immunological and inflammatory host response as well as connective tissue and bone metabolism are strongly influenced by genetic, acquired and behavioural risk factors. Among the last, tobacco consumption holds a primary position. Prevalence, extent and severity of periodontitis as well as tooth loss and edentulism are influenced by tobacco consumption in a dose-dependent manner. About 50% of periodontal disease in young adults is attributable to cigarette smoking. Postoperative results in periodontally diseased smokers are considerably poorer than those achieved in non-smokers. As a consequence smoking cessation has to be in corporated in traditional treatment concepts for inflammatory periodontal disease.

Adult↗

Acute fascioliasis with multiple liver abscesses.

Human fascioliasis is distributed worldwide with several foci of high endemicity. Being a rare disease in Europe, we describe here a case in the initial hepatic phase of the disease. Therapeutic and, with reference to the 2 distinct stages of disease, diagnostic standards are discussed.

Acute Disease↗

Protection induced in mice vaccinated with recombinant collagen-binding protein (CnBP) and alpha-toxoid against intramammary infection with Staphylococcus aureus.

Mice vaccinated with a combination of two Staphylococcus aureus antigens consisting of a recombinant collagen-binding protein (CnBP) and alpha-toxoid (alpha-toxoid) were significantly protected from intramammary challenge infection with S. aureus. The average number of bacteria recovered from the glands of mice vaccinated with the combination of CnBP/alpha-toxoid was significantly lower compared to the average number of bacteria recovered from the glands of mice vaccinated with only CnBP or alpha-toxoid or controls (P< or =0.01). Histopathological examination of mammary glands of mice vaccinated with CnBP together with alpha-toxoid showed no pathological changes, whereas glands of mice vaccinated with CnBP or alpha-toxoid alone developed severe mastitis and showed both focal and disseminated necrosis.

Animals↗

Protein GRAB of streptococcus pyogenes regulates proteolysis at the bacterial surface by binding alpha2-macroglobulin.

In the molecular interplay between pathogenic microorganisms and their host, proteolytic mechanisms are believed to play a crucial role. Here we find that the important human pathogen Streptococcus pyogenes (group A Streptococcus) expresses a surface protein with high affinity (Ka = 2.0 x 10(8) M-1) for alpha2-macroglobulin (alpha2M), the dominating proteinase inhibitor of human plasma. The immunoglobulin-binding protein G of group C and G streptococci also contains an alpha2M-binding domain and a gene encoding protein GRAB (protein G-related alpha2M-binding protein) was identified in the S. pyogenes Genome Sequencing data base. The grab gene is present in most S. pyogenes strains and is well conserved. Protein GRAB has typical features of a surface-attached protein of Gram-positive bacteria. It also contains a region homologous to parts of the alpha2M-binding domain of protein G and a variable number of a unique 28-amino acid-long repeat. Using Escherichia coli-produced protein GRAB and synthetic GRAB peptides, the alpha2M-binding region was mapped to the NH2-terminal part of protein GRAB, which is the region with homology to protein G. An isogenic S. pyogenes mutant lacking surface-associated protein GRAB showed no alpha2M binding activity and was attenuated in virulence when injected intraperitoneally in mice. Finally, alpha2M bound to the bacterial surface via protein GRAB was found to entrap and inhibit the activity of both S. pyogenes and host proteinases, thereby protecting important virulence determinants from proteolytic degradation. This regulation of proteolytic activity at the bacterial surface should affect the host-microbe relation during S. pyogenes infections.

Amino Acid Sequence↗

Absence of an especially toxic clone among isolates of Actinobacillus actinomycetemcomitans recovered from army recruits.

Actinobacillus actinomycetemcomitans is a major periodontal pathogen which is associated with early-onset and adult periodontitis. The organism has been shown to be widely distributed among dentate, healthy individuals as well. It has been demonstrated that A. actinomycetemcomitans shows great genetic diversity. An especially virulent clone of the organism (JP2-like) with a specific 530-base pair (bp) deletion in the promoter region of the leukotoxin gene has been isolated from localized juvenile periodontitis patients and related subjects of African and African-American origin. The aim of the present study was to examine the presence of this specific clone employing specific oligonucleotide primers in a polymerase chain reaction among 51 isolates of A. actinomycetemcomitans recovered from 201, 18- to 25-year-old recruits with no or minor periodontal disease. In addition, clinical isolates from 37 periodontitis patients were analyzed as well as reference strains ATCC 29524, NCTC 9710, Y4 and JP2. Primers amplifying a specific 285-bp amplification product in the ltxA region of the leukotoxin gene and a specific 547-bp amplification product of 16 S rRNA were used to genetically confirm identification of the organisms. Primers amplifying sequences in the leukotoxin promoter region were used to identify the deletion. Species specific primers definitively identified all A. actinomycetemcomitans isolates. No isolates from army recruits or the reference strains displayed the deletion in the leukotoxin promoter region. However, in the periodontitis group, a 24-year-old individual from Ghana with localized juvenile periodontitis was identified with an intraoral infection with highly toxic A. actinomycetemcomitans (JP2-like). Present results confirm previous observations of absence of a highly toxic clone of A. actinomycetemcomitans among periodontally healthy and diseased Caucasians as well as a possible presence in localized juvenile periodontitis in individuals of African origin.

Adolescent↗