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S Kessler

Publications and source records attributed to S Kessler.

At least 37 records · Page 2Linked to original sources
PubMed2001

BMP-4 of Xenopus laevis stimulates differentiation of human primary osteoblast-like cells.

Since bone morphogenetic proteins (BMPs) are highly homologous, we investigated the hypothesis that recombinant BMP-4 of the genome of Xenopus laevis (rxBMP-4) may influence the proliferation or differentiation of human primary osteoblast-like cells (HPOC), as occurs with recombinant human BMP (rhBMP-2). HPOC were incubated in the presence of either rxBMP-4, rhBMP-2 or basic fibroblast growth factor (rh-bFGF). The last two were used as positive controls and are known to induce differentiation or proliferation of HPOC, respectively. rxBMP-4 (50 ng/ml and 100 ng/ml) induced a differentiation of HPOC to almost the same extent as rhBMP-2, whereas the addition of rh-bFGF, applied in the same concentration, failed to have any influence on cell differentiation. rh-bFGF however, provoked an increase in cell proliferation of up to 150% when compared with non-stimulated HPOC, while rhBMP-2 and rxBMP-4 had no such effect. Our results indicate an equipotent effect of rhBMP-2 and rxBMP-4 obtained from Xenopus laevis on the differentiation and proliferation of human primary osteoblast-like cells.

Adult↗
PubMed2001

[Activity and cost analysis in surgical pathology. Experience of a French university laboratory using the activity-based costing method].

Good self-knowledge enables us to have a well- reasoned adaptation to our environment. Starting from this precept based on simple common sense, activity and cost analysis, when applied to medical departments in a university hospital setting, represents a necessary phase in their scientific progression and in the continuation of their university vocation. This is all the more true given the present climate of economic and organizational restructuring of medical facilities. This paper relates the experience of a French surgical pathology department which was assessed for cost effectiveness using the Activity-Based Costing (ABC) method in 1999. This method, which originated in the business world and of which the general concepts are presented here, has given us a keener understanding of the diverse processes involved, their costs and how these costs are arrived at. Moreover, this method has identified the proportion of costs imputable to diagnostic work and of those linked to work specific to a university hospital, in particular teaching and research and development. The results can then be used for a clearer analysis of the figures required by prescribers and health care funding agencies, and, within the department, to enhance perception of work carried out by the entire staff in order to initiate a new type of management centered on activity (Activity-Based Management). Adaptable to any medical department, whatever its organizational structure, independent of the significance of any given code letter and regardless of the rating method used to grade activities, the ABC method also allows for comparisons between structures of a similar nature. The thoughts it inspires on economic performance must take into account the rules of good medical practice, the imperatives of quality assurance, the need for "breathing space" which are indispensable to research and a humanist conception of working relations.

Costs and Cost Analysis↗
PubMed2000

[Stimulation of primary osteoblast cultures with rh-TGF-beta, rh-bFGF, rh-BMP 2 and rx-BMP 4 in an in vitro model].

Bone metabolism is influenced by systemic and local acting hormons. Bone morphogenetic proteins (BMPs) as representatives of the latter substances are known to have the ability for ectopic bone formation. Within this study, we investigated the influence of different growth factors on the proliferation- and differentiation rate of osteoblast-like cells. For that purpose, human osteoblast-like cells (HPOC) were incubated in the presence of either recombinant BMP-4 of the genome of xenopus laevis (rxBMP-4), recombinant human BMP 2 (rhBMP-2), transforming growth factor-beta (TGF-beta) or basic fibroblast growth factor (rh-bFGF) in two different concentrations each (10 ng/ml and 50 ng/ml). Cell proliferation was measured within a MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromid] assay, the amount of cell differentiation by the activity of alcaline phosphatase. Rx-BMP-4 induced a differentiation of HPOC to almost the same extent as rhBMP-2, whereas the addition of rh-bFGF, applied at the same concentration, failed to have any influence on cell differentiation. However, rh-bFGF provoked an increase in cell proliferation when compared with unstimulated HPOC, while rhBMP-2 and rxBMP-4 showed no effect on proliferation. TGF-beta influenced bone proliferation as well as differentiation significantly. The equipotent effect of recombinant human BMP-2 and recombinant BMP-4 obtained from Xenopus laevis with regard to differentiation and proliferation of human primary osteoblast-like cells originates either in the fact that target cells have receptors for BMP 2 as well as BMP 4, or that both BMP's link to the same receptor with almost the same affinity.

Adult↗
PubMed2000

[A case report: suppurative pericardial effusion].

We present the case of a 67 year old woman who was resuscitated due to cardiac tamponade. Examination of the pus fluid showed a bacterial infection with streptococcus milleri. Four days before resuscitation the patient experienced weakness, dyspnoea, increased temperature (39 degrees C), swelling of the neck, and pain on swallowing. Using computed tomography, examination revealed an infection extending from the right tonsil to the mediastinum and into the pericardium. After surgery to remove the retropharyngeal abscess, the patient healed well. Therefore, on presentation of a cardiac tamponade, possible hematogenous or lymphogenous causes or per continuitatem infections should always be considered. In this case the germs in the fluid and the typical patient history indicated an oropharyngeal reason.

Aged↗
PubMed2000

Assessing the prevalence of hand osteoarthritis in epidemiological studies. The reliability of a radiological hand scale.

OBJECTIVE: The hands are often involved in the osteoarthritic disease process. A radiological grading scale is presented, derived from a published atlas, to assess the prevalence of hand osteoarthritis (OA) involvement in clinical and epidemiological studies and its reproducibility is studied. METHODS: This hand scale is based on the radiological feature "joint space narrowing", which represents the macromorphological process of cartilage loss. Osteophytes and sclerosis are less important unless seen in conjuction with joint space narrowing. Nine individual joints per hand (four proximal interphalangeal joints (PIP), four distal interphalangeal joints (DIP), first carpometacarpal joint (CMC-1)) are scored dichotomously for the presence of OA. To save time and to increase reliability a severity grading of radiological features is not performed. To determine inter-rater and intra-rater reliability of the individual joints and the presence of OA in two separate joint groups (>/= 2 PIP or DIP and at least one CMC-1, used to define "generalised OA" in the ongoing Ulm Osteoarthritis Study) 50 pairs of anteroposterior hand radiographs were read by two investigators twice within one month. The kappa coefficient was calculated to quantify the strength of associations. RESULTS: On average five minutes were needed to score one hand radiograph. Both raters were able to reproduce their own readings in all individual joints and for the presence of OA in two separate joint groups after one month. Reliability was highest for the PIP joints (kappa: 0.56-1. 00) it was slightly lower for the DIP joints (0.38-0.87), for the CMC-1 joints (0.58-0.69) and for OA in two separate joint groups (0. 54). The values for inter-rater agreement were good as well, kappa coefficients ranged from 0.52 to 0.92. CONCLUSION: This grading scale was shown to be reliable within and between readers for all the individual joints as well as for the presence of OA in two separate joint groups. Scoring a limited number of joints dichotomously makes this scale efficient and therefore useful for clinical and epidemiological trials, when dealing with large patient samples.

Aged↗
PubMed2000

A kiss.

Explore the source record for details and available documents.

Adaptation, Psychological↗
PubMed1999

Genetic, molecular, and morphological analysis of compound leaf development.

Leaves, the plant organs responsible for capturing and converting most of the 170 billion metric tons of carbon fixed globally each year, can be broadly grouped into two morphological categories: simple and compound. Although simple-leaved species such as corn and Arabidopsis have traditionally been favored model systems for studying leaf development, recent years have seen an increase in genetic and molecular studies of compound leaf development. Two compound-leaved species in particular have emerged as model systems: tomato and pea. A variety of mutations which alter leaf morphology in these species have been described, and analyses of these mutations have allowed the construction of testable models of leaf development. Also, the knotted-like homeobox (KNOX) genes, which were originally discovered as regulators of meristem function, now appear to have a role in compound leaf development. In addition to the recent genetic and molecular analyses of tomato and pea, insight into the nature of compound leaf development may be gained through the study of (a) heteroblasty and heterophylly, phenomena in which a range of leaf forms can be produced by a single shoot, and (b) the evolutionary origins of compound leaves.

Biological Evolution↗
PubMed1999

[Dynamic 31-phosphorus magnetic resonance spectroscopy of the m. quadriceps: the effect of sex and age on the spectroscopic parameters].

PURPOSE: 31P-MRS is used to assess the influence of sex und age on quadriceps muscle metabolism before and after exercise. MATERIALS AND METHODS: 32 healthy volunteers (15 women, 17 men, mean age: 38 +/- 17 yrs.) were examined by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric und an isotonic form of exercise until exhaustion, respectively. RESULTS: Resting conditions: With increasing subjects' age, the ratio beta-adenosine triphosphate/total phosphate decreased (r = -0.37; p = 0.02). With increasing subjects' age, the ratios inorganic phosphate/phosphocreatine (r = 0.79; p = 5 x 10(-8), phosphomonoester/beta-adenosine triphosphate (r = 0.74; p = 10(-6) and phosphodiester/beta-adenosine triphosphate (r = 0.62; p = 10(-4) increased. The pH was the only one of the evaluated spectroscopic parameters which showed a sex-dependence: Female subjects had a significantly lower pH (7.03 +/- 0.02) than male subjects (7.05 +/- 0.03; p = 0.01). Exercise: With increasing age, the maxima of inorganic phosphate/phosphocreatine were less extreme during both of the exercises (r = -0.42; p = 0.0005). Likewise, the exercise-induced acidosis was less severe with increasing age (r = 0.53; p = 6 x 10(-6). After the end of the exercise, the times of half recovery of inorganic phosphate/phosphocreatine and the pH correlated neither with the subjects' age nor with sex or cross-sectional areas of the quadriceps muscle. CONCLUSION: Sex and age of volunteers affect spectroscopic results. This influence had to be considered in the interpretation of spectroscopic studies.

Adult↗
PubMed1999

Antiplatelet therapy: glycoprotein IIb/IIIa receptor antagonists.

The glycoprotein IIb/IIIa antagonists are potent drugs that inhibit platelet aggregation. They are formulated as monoclonal antibodies and synthetic peptides for intravenous use in patients undergoing high-risk angioplasty procedures and in patients with unstable coronary syndromes. Orally active agents are now being evaluated in clinical trials.

Journal Article↗
PubMed1998

Iron release is reduced by mutations of lysines 206 and 296 in recombinant N-terminal half-transferrin.

Human serum transferrin consists of two iron-binding lobes connected by a short peptide linker. While the high homology and structural similarity between the two halves of the molecule would suggest similar characteristics, it has been shown that the pH-dependent rate of release of iron from the N-terminal lobe is quite different from that of its C-terminal counterpart. This suggests that the N-lobe of human serum transferrin has a specific, pH-dependent, molecular mechanism for releasing iron. Sacchettini and co-workers using structural information have hypothesized that two lysines in the N-terminal lobe of ovotransferrin create a dilysine interaction and suggest that this is the trigger for pH-dependent iron release. To investigate this hypothesis, we used a Pichia pastoris expression system to produce large amounts of wild-type nTf, the single point mutants, nTfK206A (Lys 206 to alanine) and nTfK296A (Lys 296 to alanine), and the double mutant, nTfK206/296A. The purified recombinant proteins were then used to measure rates of iron release to pyrophosphate. It was found that the rate of iron release from all three mutant proteins at pH 5.7 (the pH at which nTf would normally release iron) was too slow to measure. Only when the pH was reduced to 5.0 could the rates of iron release from the mutant proteins be reliably determined. Although this precludes a direct comparison to wild-type nTf (the rate of iron release from nTf at pH 5.0 is too fast to measure), it implicates lysines 206 and 296 in the pH-dependent release of iron from nTf.

Alanine↗
PubMed1998

Scoring prevalence and severity in gonarthritis: the suitability of the Kellgren & Lawrence scale.

In clinical and epidemiological studies the Kellgren & Lawrence (K&L) scale was mainly used in the past to determine the radiological prevalence and severity of gonarthritis. The dependency of this scoring system on the presence of osteophytes has been criticised, and owing to its varying reliability, its appropriateness in cross-sectional and longitudinal studies is questioned. It was the purpose of this study to test whether the dependency of the K&L scale on the presence of osteophytes is reflected in a higher correlation of the overall score with a separate scoring of 'osteophytes' than with other radiological features. Furthermore we compared the inter- and intrarater reliability with the reliability of individual radiological features. Knee radiographs of 40 patients were graded according to the K&L scale and for the presence and severity of five separate radiological features of osteoarthritis. We found a moderate correlation of the K&L scale with the radiological features of 'osteophytes', 'joint space narrowing' and 'flattening of condyles'. The intra- and inter-rater reliability of the K&L scale was higher than the reliability of the individual radiological features. The K&L scale seems not to be strongly dependent on the presence of osteophytes, i.e. there is not a higher correlation of the overall score with that feature than with other radiological features.

Aged↗
PubMed1998

[Bone regeneration stimulated by bone substitute materials].

Prompted by severe problems in autogeneic and allogeneic bone transplantation, intensive efforts were made to find sufficient substitutes. A main demand on these materials, especially in healing of osseous defects, is to achieve results comparable to those of auto- or allografts. These must be related to their biomechanical and particularly to their biological properties, i.e. the ability to form new bone, osseous integration and physiological remodeling. Within different trials in the tibiae of sheep we investigated bone substitutes like hydroxyapatite ceramics (HA) or partially demineralized bone matrix (pDBM) and compared them to the gold standards of autogeneic and allogeneic bone transplantation. Therefore we used two different models: the drill hole model with small size defects of 6 mm in diameter and the shaft defect model as a true-to-life defect with a 5 cm large diaphyseal defect. Evaluation was done by X-rays, histology, microradiography, fluorescent microscopy and morphometry of the small size defects. HA showed only small effects on new bone formation and works merely as an osteoconductor. However, excellent new bone formation was regularly achieved by pDBM in the small defects, whereas it was limited in the large size defects. But considering their mechanism of action, it is possible to bridge large bone defects by pDBM.

Bone Demineralization, Pathologic↗
PubMed1998

[Osteomyelitis--imaging methods and their value].

Various imaging modalities are used in diagnosis of acute and chronic infectious endogenous osteomyelitis and exogenous ostitis. The pathophysiological changes of osteomyelitis/ostitis in the bone and surrounding soft tissue are known. Findings in plain film radiography show these changes only in relatively advanced stages of disease. Hence, plain film radiographs are useful as a basic imaging modality by excluding other differentials and as a follow-up modality under therapy. Ultrasound-using advanced technology--offers diagnostic help in acute osteomyelitis, especially in infants. The various techniques of nuclear medicine show much higher sensitivity for detecting osteomyelitis than plain film radiography, but do not permit good separation for bone involvement and infectious changes in the surrounding soft tissue. While computed tomography offers the ability to display bone and soft tissue separately, it has been widely replaced by magnetic resonance imaging using fat-suppressed sequences and paramagnetic contrast media which show the spread of the infectious changes with higher sensitivity and accuracy.

Adolescent↗
PubMed1998

[Spondarthritis hyperostotica pustulo-psoriatica: nosologic study with clinical and radiologic presentation in relation to the SAPHO syndrome].

Spondarthritis hyperostotica pustulo-psoriatica (Spond.hyp.pp-Schilling), corresponding nosologically to pustulotic arthroosteitis, is a dermato-skeletal "double system" disease of adults. It consists of the triad (a) palmo-plantar pustulosis (Ppp) or, alternatively, Königsbeck-Barber-type psoriasis, (b) sternocostoclavicular hyperostosis (SCCH), and (c) truncal-skeletal changes with syndesmophite-like, hyperostotic and/or parasyndesmophite-like ossifications of layers of the anterior vertebral ligament taken together in the sense of a desmophytal hyperostosis. There is also a potential for sclerosing inflammatory arthritis of the sacro-iliac joints and "dry" inflammatory arthritis of peripheral joints. Thus, the pustulo-psoriatic terrain seems to have a decisive influence on osseous pathology. A total of 38 cases from a study during the years 1982 to 1992 is analysed with regard to morphological characteristics. Rare cases with diaphyseal and pelvic hyperostotic lesions subsequent to bland sclerosing osteomyelitis constitute an overlapping region to chronic recurrent multifocal osteomyelitis (CRMO) and illustrate the relationship between hyperostotic spondarthritis and CRMO. The syndromes of "acquired hyperostosis" and "SAPHO", the former more radiologically oriented and the latter more clinically oriented, together with mainly CRMO and hyperostotic spondarthritis and its forms, constitute the "Spond.hyp.pp.". Although hyperostosis is a guidepost for the radiologist and SAPHO symptoms are one for the clinician, the syndrome does not represent a diagnosis by itself and requires further differentiation. In this report the entity "Spond.hyp. pp." is considered and required contributions from rheumatologically and osteologically oriented radiologist.

Acquired Hyperostosis Syndrome↗