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Biomedical subjects

M Felder

Publications and source records attributed to M Felder.

At least 19 recordsLinked to original sources
PubMed1996

Extracorporeal shock wave lithotripsy (ESWL) of gallbladder stones: experience in Bolzano.

During a period of 24 months, 115 patients with symptomatic gallbladder stones (77 females, 38 males; median age 46 years, range 22-87) were treated by extracorporeal shock wave lithotripsy with a Lithostar Plus. Concomitant bile acid dissolution therapy (ursodeoxycholic acid + chenodeoxycholic acid 7.5 mg/kg/day each or tauroursodesoxycholic acid 5-10mg/kg/day) was administered until 3 months after total fragment clearance. Complete clearance of all fragments was obtained after 6, 9, 12, 18 and 24 months in, respectively, 30, 45, 51, 62 and 72%. Life table analysis of the subgroups showed significantly better clearance results in patients with fragments < 5mm at the first extracorporeal shock wave lithotripsy session (67%) than in patients with larger fragments (39%) (p < 0.01). Patients with solitary stones < 20mm cleared their fragments better (58%) at 12 months than those with multiple stones (49%), but the differences were not statistically significant. Stone recurrence was 6% at 1 year and was lower in patients with solitary stones (3%) than in those with multiple stones (12%). Major side effects consisted in 2 cases of mild acute pancreatits and 19% of biliary colics.

Cholelithiasis↗
PubMed1994

Characterisation of plasmids from diketogluconic acid producing strains of Gluconobacter oxydans.

Gluconobacter oxydans ATCC 9937, which produces 2,5-diketogluconic acid, an intermediate in vitamin C synthesis, has three plasmids of sizes 27.7 kb (pVJ1), 12.3 kb (pVJ2) and 18 kb (pVJ4). A restriction map was constructed of pVJ1. A potential glucose dehydrogenase gene was located on pVJ1 using the polymerase chain reaction with heterologous primers. Two other G. oxydans strains had no detectable plasmid DNA (IFO 12258) and a plasmid (pVJ3) of 9.4 kb (IFO 3293), respectively.

Base Sequence↗
PubMed1994

Turning of nerve growth cones induced by neurotransmitters.

Pathfinding by growing nerve processes in the developing nervous system depends on the turning response of the growing tip, the growth cone, to extracellular guidance cues. There is evidence in vivo and in cell culture that some growth cones exhibit chemotropic behaviour, but the identity of endogenous chemoattractants remains elusive. Neurotransmitters appear early in the developing embryo and may have morphogenic roles in development. In cell culture a number of neurotransmitters were found to induce growth inhibition or retraction of neurites. Here we report positive turning responses of the nerve growth cone in a defined extracellular gradient of the neurotransmitter acetylcholine (ACh). The growth cone response depends on the activation of neuronal nicotinic ACh receptors, requires the presence of extracellular Ca2+, and appears to be mediated by Ca(2+)-calmodulin-dependent protein kinase II. Fluorescence imaging of cytosolic Ca2+ concentration ([Ca2+]i) at the growth cone showed a small but significant evaluation of [Ca2+]i within minutes of the onset of ACh application and before the turning of the growth cone. These findings suggest that neurotransmitters may serve as specific chemoattractants for growth cone guidance and that cytosolic Ca2+ may act as a second messenger in the cytoplasm of the growth cone to initiate the turning response.

Acetylcholine↗
PubMed1994

[Problems with bone densitometry].

Today, bone density can be measured by different technical methods which show variations in terms of reproducibility, accuracy and sensibility. A crucial parameter is the reproducibility, which differs considerably from method to method. With densitometric methods it is possible not only to evaluate patients at risk getting an osteoporosis but also to establish an individual prophylaxis and therapy by means of highly precise quantitative methods, based on the parameters 'bone density' and 'loss of bone density'. A high bone turnover leads to fast bone loss and, vice versa, fast bone loss, measured by densitometry, is correlated with high bone turnover in postmenopausal women. This allows to establish an individual therapy with antiresorption resp. bone-stimulating agents and the knowledge about a tailored, individual treatment increases patients' compliance and reduces the rate of 'non-responders'.

Aged↗
PubMed1994

[Osteoporosis therapy, current status].

Treatment of osteoporosis includes various possibilities with drugs. Furthermore, approaches with physiotherapy and adequate diet are also important. As to drugs substances like calcium, estrogens, bisphosphonates, calcitonin, fluoride and vitamin D have to be mentioned. Anabolic steroids have some beneficial effects on bone, but there are problems with side effects. Strontium and ibriflavone show interesting potentials, but they need to be studied in more detail.

Aged↗
PubMed1993

Efficacy and safety of radiation synovectomy with Yttrium-90: a retrospective long-term analysis of 164 applications in 82 patients.

In this long term retrospective study of radiation synovectomy with Yttrium-90 (Y90), we evaluated the results of 164 applications in 82 patients with RA, OA with synovitis, ankylosing spondylitis and psoriatic arthritis. Radiation synovectomy with Y90 has an overall success rate of approximately 50% and is therefore an effective alternative to surgical synovectomy in chronic synovitis which fails to respond to conservative treatment. Elbow and knee responded significantly better than shoulder and ankle joints. Patients with radiological stages from 0 to 2 showed a significantly better success rate than those with stage 3 changes. In responders, repeat therapy for recurrence of symptoms or treatment of a symptomatic corresponding symmetrical joint is advisable. Repeat therapy in a previous non-responder is associated with an unacceptably high failure rate. Therefore, when a joint fails to respond after 6 months, arthroscopy should be performed to evaluate further treatment procedures. A successful result was found in only 11 of 25 joints treated with arthroscopic synovectomy followed by radiation synovectomy within 2 weeks, indicating no benefit of this combination.

Adult↗
PubMed1991

[Drug therapy of ankylosing spondylitis].

Ankylosing spondylitis has to be treated with NSAID's in order to influence the inflammatory process and thus reducing pain and slowing down the stiffening of the vertebral column. For this purpose, apart from the NSAID's Sulphasalazine is used. As a symptomatic treatment of pain and muscle spasm simple analgesics and muscle relaxants can be used. In peripheral arthritis a local treatment with intraarticular steroids can be useful, and sometimes a radiosynoviorthesis can stop the inflammation for a longer period. In case of osteoporotic fractures prescription of calcitonin may be considered.

Adrenal Cortex Hormones↗
PubMed1991

Bone loss in patients with rheumatoid arthritis--effect of steroids measured by low dose quantitative computed tomography.

For 2 years bone density changes in patients with rheumatoid arthritis were monitored to determine the effect of low dose corticosteroid treatment. Sixteen perimenopausal females were studied. Of these nine were treated with 5 to 20 mg prednisone per day and seven had no steroids. The differential effects on trabecular bone density and on cortical bone in the radius and the tibia were examined with high precision peripheral quantitative computed tomography (QCT). Steroid therapy did not influence cortical bone loss and had only a minor influence on trabecular bone density. Of greater importance was the influence of estrogen depletion. Corticosteroids and estrogen depletion, however, cannot explain fully the yearly loss of 5.7% in the trabecular and 4% in the cortical bone of the radius.

Adult↗
PubMed1990

[Assessment of the course of chronic polyarthritis].

In the following review the classical clinical and radiological parameters of rheumatoid arthritis are discussed. In our own study we made a prospective follow up of 29 patients with rheumatoid arthritis (104 years of disease) comparing the clinical and laboratory data with the radiological findings. Finally we investigated in another population with rheumatoid arthritis (315 patients) the question of quality of life using a structured questionnaire.

Arthritis, Rheumatoid↗
PubMed1990

Effect of salmon calcitonin on the infiltration of T lymphocytes in a synovium-like membrane of a rat inflammatory model.

The effect of salmon calcitonin (SCT) on the number of T lymphocytes accumulating in air pouch lining membranes produced on the back of Wistar rats was studied. SCT was given from day 0 through day seven following the air cavitation by daily injections of 2.5-20 micrograms/kg directly into the air cavity. Compared with saline controls, treatment with SCT caused a clear reduction in percentage of T lymphocytes, T helper cells and T non-helper subset in the synovial-like air pouch lining as revealed by FITC-labeled monoclonal antibodies and quantified by flow cytophotometric measurements. This effect may be due to a reduction in local vascular permeability caused by SCT.

Air↗
PubMed1988

Impaired mitogen-induced interferon-gamma production in rheumatoid arthritis and related diseases.

Peripheral blood lymphocytes from patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS), Reiter's disease, osteoarthritis, and from healthy volunteers were investigated for interferon-gamma (IFN-gamma) production after mitogen activation. Phytohaemagglutinin stimulation revealed an impaired IFN-gamma production in RA, SLE, and PSS but normal levels in Reiter's disease and osteoarthritis. In RA this deficiency was also seen after pokeweed mitogen, OKT3, and concanavalin A activation. No major differences were found in interleukin 2 (IL-2) production and cell proliferation. The IL-2 receptor expression was reduced on stimulated RA lymphocytes. The deficient IFN-gamma production was compensated in RA by co-stimulation of PHA or OKT3 with phorbol myristic acetate (PMA). In addition, the combination of the calcium ionophore A 23187 and PMA induced a strong IFN-gamma secretion in all patient groups and in the controls.

Adolescent↗
PubMed1988

Quantitative computed tomography of the rheumatic knee.

A good noninvasive means to quantitate the extent and course of bone loss in rheumatoid arthritis (RA) is currently not available. We report on ways of assessing arthritic bone changes by means of quantitative computed tomography (QCT). The visualization of lesions and the quantitation of bone density diminutions are based on a stack of forty thin computed tomograms and 3D reconstructions. A pilot study shows that QCT may be a useful tool in the noninvasive assessment of the progression of RA and that it may help to evaluate the efficacy of therapeutic procedures.

Adult↗