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Biomedical subjects

M Felder

Publications and source records attributed to M Felder.

At least 55 records · Page 3Linked to original sources

[Drug therapy of arthroses].

Osteoarthritis (OA) is one of the most common diseases requiring treatment. A clear clinical and pathophysiological understanding of the disease is required before treating a patient with OA. Drug therapy of patients with OA is mainly divided into two groups: a group receiving symptomatic therapy and a group receiving drugs intended to modify or improve the disease. Symptomatic therapy includes pure analgesics as well as non-steroidal antirheumatic drugs and muscle relaxants. Their use depends on the activity as well as on the form of clinical manifestation (activated/decompensated disease). If there are signs of severe activation, intra-articular steroids, orgotein or even synoviorthesis with yttrium are administered as local therapy. All of these therapies are used in the sense of trouble shooters, as they cannot alter the course of the disease in the long run. The disease-modifying substances have well been investigated in vitro and in animal models. Furthermore, some clinical trials have shown evidence for the usefulness of these substances in the therapy of OA.

Administration, Topical↗

The effects of calcitonin on central neurons in the rat.

The effects of salmon calcitonin on central neurons were studied in anesthetized rats. Calcitonin applied iontophoretically consistently inhibited spontaneous activity in half of the neurons tested in the anterior hypothalamic nucleus and subthalamus but had virtually no effect on cortical and thalamic neurons. Calcitonin also inhibited glutamate-evoked activity in the neurons tested. Calcitonin administered into the brain ventricular system led to a marked decrease in spontaneous discharge of hypothalamic cells in the majority of cells tested. The onset of this response began within 20 and 30 min of calcitonin application.

Animals↗

[Acute drug-induced pancreatitis].

93 publications concerning drug-induced pancreatitis are reviewed. A confirmed causal relationship between drug and acute pancreatitis so far exists only for 8 compounds: azathioprine, chlorothiazide, furosemide, sulfonamides, tetracycline, estrogens, valproic acid and L-asparaginase. There is less convincing, but still suggestive, evidence for a causal relationship with 5 other drugs, namely: corticosteroids, chlorthalidone, ethacrynic acid, phenformin and iatrogenic hypercalcemia. Due to inadequate or contradictory evidence, the link between a number of additional drugs and acute pancreatitis is considered possible, conditional or doubtful. Finally, the scant literature concerning the pathogenesis and histological lesions of drug-induced pancreatitis is briefly reviewed.

Acute Disease↗

In vitro stimulation of lymphocytes from patients with rheumatoid arthritis.

Peripheral blood lymphocytes from patients with rheumatoid arthritis (RA) and from normal controls were compared in 20 microliters droplet cultures following stimulation with phytohemagglutinin or concanavalin A. The dynamics of proliferation were significantly changed in RA. Higher numbers of cells in culture were needed to achieve the same response. This may explain the low proliferative responses of lymphocytes from some patients with RA, and apparent changes of in vitro suppressor effects, reported by other authors. Diurnal variations of lymphocytes in RA patients were also studied. No differences in the response to mitogen of lymphocytes taken at 7 AM and 7 PM were found.

Adult↗

Properties of rat and mouse beta-glucuronidase mRNA and cDNA, including evidence for sequence polymorphism and genetic regulation of mRNA levels.

cDNA clones containing partial sequences for beta-glucuronidase (beta G) were constructed from rat preputial gland RNA and identified by their ability to selectively hybridize beta G mRNA. One such rat clone was used to isolate several cross-hybridizing clones from a mouse-cDNA library prepared from kidney RNA from androgen-treated animals. Together, the set of mouse clones spans about 2.0 kb of the 2.6-kb beta G mRNA. Using these cDNA clones as probes, a genomic polymorphism for DNA restriction fragment size was found that proved to be genetically linked to the beta G gene complex. A fragment of beta G cDNA was subcloned into a vector carrying an SP6 polymerase promoter to provide a template for the in vitro synthesis of single-stranded RNA complementary to beta G mRNA. This provided an extremely sensitive probe for the assay of beta G mRNA sequences. Using either nick-translated cDNA or transcribed RNA as a hybridization probe, we found that mouse beta G RNA levels are strongly induced by testosterone, and that induction by testosterone is pituitary-dependent. During the lag period preceding induction, during the induction period itself, and during deinduction following removal of testosterone, beta G mRNA levels paralleled rates of beta G synthesis previously measured by in vivo pulse-labelling experiments. Genetic variation in the extent of induction affected either the level of beta G mRNA or its efficiency of translation depending on the strain of mice tested.

Amino Acid Sequence↗

Changes in the populations of lymphoid cells in human peripheral blood following physical exercise.

Marked lymphocytosis occurs after exercise. In a study of healthy volunteers this was dominated by one population lacking T cell and B cell determinants and another expressing the Leu 2a phenotype (cytotoxic/suppressor). Lymphocytes from two individuals were characterised further and a near five-fold increase in cells expressing antigens associated with natural killer (NK) cells (Leu 7 and Leu 11) was noted. In addition, these emergent lymphocytes, unlike most T cells, lacked acid alpha-naphthyl esterase activity. In functional studies, exercise led to significantly greater NK activity but, in spite of altering the distribution of lymphocyte subpopulations, there was no detectable change in the proliferative response to the T cell mitogen, concanavalin A, over a wide range of cell concentration, mitogen dose and time. The numbers of low density macrophages and dendritic cells increased concomitantly with the increase in total lymphocytes. We conclude that exercise increases the proportion of circulating NK cells and cells expressing the Leu 2a phenotype.

Cell Separation↗

Serum immunoreactive cationic trypsinogen response to secretin in normal subjects.

Serum immunoreactive cationic trypsinogen (ICT) response to bolus injection of secretin (1 Clinical Units/kg of body weight) has been evaluated in 123 normal controls and related to sex, age, smoking habit, and alcohol and coffee consumption. A 100% increase of serum immunoreactive cationic trypsinogen levels after secretin has been considered as a positive response (R+). When the population was considered as a whole, 55% of subjects proved to be R+ and the remaining were R-. In the R+ group the serum immunoreactive cationic trypsinogen response was appreciated as early as 5 min after secretin and even after 2 min in the few cases in which it was evaluated. It is suggested that this direct leakage of the proenzyme from the pancreas may be due to an increased sensitivity of the pancreas to secretin. Coffee consumption and age of subjects did not affect the test. Male sex, smoking habit, and alcohol intake were associated with a significantly higher percentage of R+. Therefore, we suggest that alcohol and smoking might result in the development of biochemical abnormalities in pancreatic function before the appearance of clinical evidence of pancreatic disease.

Adult↗

[Non-steroidal antirheumatics: side-effects and interactions].

Side effects of non-steroidal antirheumatic drugs (NSAD) may occur in any organ system, since the prostaglandins, the synthesis of which is inhibited by NSAD, play a role in numerous adverse cellular processes throughout the body. Besides these physiologic regulations there are adverse effects of NSAD, such as bone marrow aplasia, of unexplained etiology. The interactions of NSAD are of clinical relevance in drug types such as the salicylates, pyrazolons and fenamic acids (e.g. interactions with cumarin derivatives). The clinically relevant interactions of NSAD are discussed in detail.

Anemia, Aplastic↗

Circulating trypsin-like immunoreactivity in chronic pancreatitis.

The present study has been designed to work out the factors regulating the fasting serum levels of trypsin-like immunoreactivity in chronic pancreatitis. One hundred patients with chronic pancreatitis have been included and studied during a painless phase of the disease. No relationships have been observed between serum trypsin-like immunoreactivity and the presence of pancreatic calcifications. Serum immunoreactive trypsin levels showed a gradual decline parallel to the progressive impairment of bicarbonate and enzyme (trypsin and chymotrypsin) outputs in duodenal aspirates during pancreatic secretory studies. Therefore, serum trypsin-like immunoreactivity levels are thought to reflect the functional capacity of the exocrine pancreas. Reduced levels of trypsin-like immunoreactivity were detected in almost all patients with diabetes and steatorrhea. However, the finding of low levels also in a minority of chronic pancreatitis patients with normal endoscopic retrograde cholangiopancreatography or pancreatic secretory tests points to other factors which, in addition to the atrophy of the pancreatic parenchyma, may influence the circulating levels of trypsin-like immunoreactivity in chronic pancreatitis.

Antigens↗

Endoscopic double-blind controlled trial of ranitidine vs placebo in the short-term treatment of duodenal ulcer.

The aim of the present study was to investigate the effectiveness of ranitidine in the treatment of duodenal ulcer. Fourty patients with endoscopically proven pyloric or duodenal ulcer were treated with ranitidine 40 mg t.d. with meals and 80 mg nocte, or identical placebo tablets under double-blind conditions. Endoscopy after four weeks of treatment revealed complete healing in 15 out of 18 (83.3%) ranitidine-treated patients and in 5 out of 17 (29.4%) of the placebo patients (P less than 0.01). Ulcer symptoms were significantly less in ranitidine-treated patients, while the difference in antacid consumption between the two groups was found to be only arithmetical. No side effects or significant hematological or biochemical abnormalities were found. Four-week treatment with 200 mg of ranitidine daily seems to correspond to that of 6-8 weeks with 1-1, 6 g of cimetidine.

Adult↗

Placebo controlled studies with ranitidine in duodenal ulcer.

171 duodenal ulcer patients were treated for four weeks with either ranitidine or placebo under double-blind conditions. 40 patients (monocentre study) received ranitidine (40 mg), or placebo t.d.s. with meals and 80 mg at bedtime. 131 patients (multicentre study) received ranitidine (150 mg), or placebo b.d. In the monocentre study endoscopy after 4 weeks of treatment showed complete healing in 83.3% of the ranitidine patients and 30.4% of those on placebo (P less than 0.01%). In the multicentre study the healing percentages were 79.4% and 30.4%, respectively (P less than 0.001). In both trials pain and antacid consumption decreased in patients taking ranitidine more than in patients on placebo. After 4 weeks in the double blind studies 13 of the 15 patients with unhealed ulcer in the monocentre study and 51 of 54 patients in the multicentre study received open treatment with ranitidine for another 4 week period. The overall healing percentages by the 8th week of treatment with ranitidine were 94.4% and 93.6% respectively. No serious side effects, or haematological changes were observed during the treatment with ranitidine.

Administration, Oral↗

[2 cases of multiple myeloma with osteosclerosis].

A report on two patients with osteoclerotic myeloma is presented (myeloma with osteoblastic lesions). In case one, metastatic bone tumor of unknown origin was wrongly diagnosed initially. Because of increasing neurological symptoms laminectomy was performed. Biopsy led to the correct diagnosis of multiple myeloma of IgA-type. Patient also had a very severe peripheral neuropathy. The second patient had pancytopenia and osteosclerotic lesions of the pelvis. Bone marrow aspiration revealed so-called "empty marrow". Based on these findings, myelofibrosis was wrongly diagnosed at another hospital. Bone marrow aspiration, paper- and immunoelectrophoresis subsequently produced the correct diagnosis of multiple myeloma of IgG-type. Multiple myeloma usually is characterized by osteolytic lesions of the bones. However, the literature contains some 50 cases with osteosclerotic multiple myeloma, three different forms of which are described. In a fairly large percentage osteosclerotic multiple myeloma is combined with periphereal polyneuropathy. It would appear that in IgE-myeloma the incidence of sclerotic lesions is higher. Osteosclerotic multiple myeloma is very rare. It should however be considered if the differential diagnosis of osteosclerotic bone lesions is established.

Aged↗