Biomedical subjects

J Fischer

Publications and source records attributed to J Fischer.

At least 163 records · Page 9Linked to original sources

PubMed1998

Advantages of patellar resurfacing in total knee arthroplasty. Two-year results of a prospective randomized study.

Complications of patellar resurfacing in total knee arthroplasty have rekindled the interest of many surgeons in patellar retention. In a prospective study 20 randomly selected patients of 40 underwent patellar resurfacing in combination with their total knee arthroplasty. The other 20 patients were left with an unresurfaced patella. Within 24 months of follow-up, the advantages of patellar resurfacing could be seen according to the Knee Society Score. Especially in advanced osteoarthritis of the knee joint, the patients achieved better scores in climbing stairs and in function. The superior functional results are arguments for patellar resurfacing, at least in knees with advanced osteoarthritis.

Aged↗

PubMed1998

Microsurgical management of a complicated aneurysmal endovascular embolisation with GDC coil: a case report.

We present a case involving a microsurgical approach to solving the problem of a medial cerebral artery (MCA) occlusion occurring after GDC coiling of an internal cerebral artery (ICA) bifurcation aneurysm in a 40 year old woman. We describe the clinical course of the case and discuss technical possibilities and risks of clipping a coiled aneurysm. One key to success is awareness of changes in the aneurysm's properties after coiling. With loss of elasticity the aneurysm had the effect of a tumor fixed on the vessel. The apposition of the aneurysm to the wall of the vessel, as well as the aneurysm's rigidity and increase of intracranial pressure after subarachnoideal hemorrhage (SAH), may lead to occlusion of the vessel. In cases of an mandatory operation due to the occlusion of a main arterial stem after coiling, it is primarily crucial to perforate the aneurysm's fundus, remove the coils, and, finally, to clip the slack neck of the aneurysm. An attempt to precisely prepare and clip the aneurysmal neck without removing the coils could result in the rupture of the aneurysm's neck.

Adult↗

PubMed1998

Genetic linkage of progressive pseudorheumatoid dysplasia to a 3-cM interval of chromosome 6q22.

Progressive pseudorheumatoid dysplasia (PPD), MIM 208230, is an autosomal-recessive disorder, clinically characterized by spondyloepiphyseal dysplasia and progressive arthropathy. Linkage analysis of three families of different geographic and ethnic origin, including 11 affected individuals, showed strong evidence for localization of a gene for progressive pseudorheumatoid dysplasia to chromosome 6q with a maximum two-point lod score for D6S1647 of 8.34 at theta=0. Analysis of regions of homozygosity placed the gene in a 3-cM interval between D6S 1594 and D6S432. No significant shared haplotype was found for markers of the linked interval in the three families analyzed. Five genes encoding collagen and one encoding a specific procollagen-processing enzyme that map near this interval represent good candidates for the PPD gene.

Arthritis, Rheumatoid↗

PubMed1998

Nonvagal origin of galanin-containing nerve terminals innervating striated muscle fibers of the rat esophagus.

We investigated the origin of galanin-positive nerve fibers on motor endplates in rat esophagus using anterograde 1,1'-dioleyl-3,3,3', 3'-tetramethylindocarbocyanine methane sulfonate (DiI) tracing from the nucleus ambiguus combined with galanin immunocytochemistry and calcitonin gene-related peptide immunocytochemistry. To demonstrate spatial relationships of galanin-positive nerve fibers to vagal and enteric nerve fibers on motor endplates, we combined galanin immunocytochemistry with calcitonin gene-related peptide immunostaining for labeling of vagal terminals, and vasoactive intestinal peptide immunoreactivity and NADPH-diaphorase histochemistry for demonstration of enteric nerve fibers. Within fine varicose nerve fibers, galanin was colocalized with vasoactive intestinal peptide and NADPH-diaphorase to a high degree and turned out to be completely separated from calcitonin gene-related peptide-positive or anterogradely DiI-labeled vagal motor terminals. These results indicate that the enteric nervous system is the most important and possibly the only source of galanin-positive nerve terminals on motor endplates in rat esophagus. Galanin may be, in addition to nitric oxide and vasoactive intestinal peptide, a mediator of the enteric coinnervation of striated muscle in this organ.

Animals↗

PubMed1998

Multifocal neoplasia involving the colon and appendix in ulcerative colitis: pathological and molecular features.

A patient with ulcerative colitis, extensive dysplasia, multifocal colon cancer, and an appendiceal cystadenoma is described. A 48-year-old man with a 26-year history of ulcerative colitis (UC) had extensive dysplasia involving nearly the entire colon and four dysplasia-associated mass lesions (DALMs). Four invasive adenocarcinomas were present. This case is the first documentation of a DALM (mucinous cystadenoma) arising in the appendix in the setting of UC. The genetic alterations present in the various lesions were analyzed. The molecular profiles of the neoplastic lesions differed. Mutations were found in p53 and ras genes, and one site showed microsatellite instability in a single genetic locus. These molecular abnormalities develop before invasive cancer develops, and may undergo clonal expansion to create large mucosal patches containing certain cells with genetic alterations. The diversity of the early changes suggests that the recurrent inflammation characteristic of long-standing UC randomly damages genes known to participate in colon carcinogenesis and that it affects multiple target genes. The findings also support a multiclonal origin of synchronous tumors because the molecular phenotypes of the preinvasive lesions differed at various sites.

Appendiceal Neoplasms↗

PubMed1998

Fusion of macrophages on an implant surface is associated with down-regulated expression of ligands for galectin-1 and -3 in the rat.

Galectins have a wide range of biological activities which are elicited by binding to appropriate glycoligands. Besides regulation of the expression of the galectins the extent of the presence of suitable binding sites will be relevant to infer the cellular responsiveness to this class of sugar receptors. Thus ligand presentation requires monitoring by the tissue lectin. We demonstrate the expression of galectin-3 by macrophages and foreign-body giant multinucleate cells colonizing a cellophane implant in the rat by the A1D6 monoclonal antibody. The extents of ligand presence are visualized in the same cells by biotinylated galectin-3 and also by galectin-1 which is produced by diverse mammalian cell types and widely distributed. Labeled mistletoe (VAA) and tomato (LEA) lectins are used as tools to assess the degree of similarity of the binding profile between endogenous and exogenous proteins. The presentation of alpha-galactosides is monitored with a natural immunoglobulin G subfraction obtained by two consecutive affinity chromatography steps. The binding of labeled galectins and plant lectins was significantly lower to foreign-body giant multinucleate cells than to mononuclear macrophages. The application of the alpha-galactoside-specific probe yielded no significant staining. The potential problem of epitope accessibility could be excluded by the concomitant positivity obtained with an IgG subfraction with selectivity to beta-galactosides also obtained by affinity chromatography. These results provide no evidence for a role of alpha-galactosides for the binding of galectins in the rat macrophages colonizing the implant. The reduced level of expression of glycoligands for galectin-1 and -3 in foreign-body giant multinucleate cells in contrast with the mononuclear macrophages suggests an inhibitory influence of macrophage fusion on the expression of galectin-reactive molecules.

Animals↗

PubMed1998

The rat dermorphin-like immunoreactivity is supported by an aminopeptidase resistant peptide.

Site-directed antibodies against synthetic related dermorphin peptides were previously produced and characterized. One of them, which specifically recognizes the crucial 'opioid message' (the N-terminal part of the dermorphin molecule (i.e. Tyr-D-Ala-Phe-Gly) was selected in order to detect and locate endogenous dermorphin-like molecules in rat, mouse and guinea pig tissues. Dermorphin-like peptides were found to be present in tissues known to contain peptides such as neurons in the central nervous system, nerve fibers in the gut and B and T immune cells. With all the tissues assayed, the HPLC profile obtained on the immunoreactive material showed the same main peak eluted at a retention time of 32 +/- 1 min. The results of biochemical experiments in which enzymatic treatments were performed on the dermorphin-like immunoreactivity indicate the immunoreactivity is a peptide resistant to aminopeptidase hydrolysis. This finding suggests the presence of a residue conferring resistance to proteolytic processes of this kind, which is likely to be a D-amino acid residue.

Aminopeptidases↗

PubMed1998

Substance P receptor immunodetection in the spinal cord: comparative use of direct anti-receptor antibody and anti-complementary peptide antibody.

The immunolocalization of substance P (SP) receptors was compared in the rat spinal cord using either a direct anti-substance P NK1-receptor antibody (anti-SPR) or an anti-complementary peptide antibody (anti-CP). The first antibody recognizes an intracellular epitope, the C-terminal tail of the NK1-receptor. The second antibody recognizes an extracellular epitope located at or near the ligand-binding domain because anti-CP antibody and SP were previously shown to compete for binding to the receptor. At the light microscope level, it was observed that anti-CP antibody labels both laminae I and II of the dorsal horn, while anti-SPR antibody labels exclusively lamina I, except at the lumbar level. This could suggest that spinal NK1 receptors are heterogeneous. Anti-SPR antibodies may recognize an NK1 receptor subclass confined to lamina I. Conversely, anti-CP antibody may recognize either another receptor subclass or two different subclasses present in laminae I and II. At the electron microscope level, labeling was localized either on the intracellular or the extracellular face of the plasma membrane depending on the location of the epitope recognized by both antibodies on the transmembrane receptor. However, using either antibody, the ultrastructural labeling was found at non-junctional sites, suggesting that SP may act in a non-synaptic manner on all putative receptor subclasses.

Animals↗

PubMed1998

Time course of the tilorone-induced lysosomal accumulation of sulphated glycosaminoglycans in cultured fibroblasts.

Dicationic amphiphilic drugs such as the immunomodulator tilorone [2,7-bis-[2-(diethylamino)ethoxy]fluoren-9-one] are accumulated in lysosomes and disturb the degradation of sulphated glycosaminoglycans (GAGs) thus leading to generalized lysosomal GAG storage (mainly dermatan sulphate) in vivo and in cultured cells. In the present study, the time course of the tilorone-induced GAG storage was determined in cultured bovine corneal fibroblasts by a radiochemical approach and by morphological examination. In contrast to the rapid lysosomal accumulation of the drug as reported previously, it took approximately 42 h to reach 50% of the GAG storage obtained after 96 h. This is thought to be due to the fact that the temporal development of storage of undigested GAGs depends on the natural delivery of GAGs towards the lysosomal apparatus.

Adjuvants, Immunologic↗

PubMed1998

The effect of different thawing methods, growth factor combinations and media on the ex vivo expansion of umbilical cord blood primitive and committed progenitors.

Assuming a threshold of 2 x 10(7) nucleated cells (NC)/kg body weight required for transplantation and 10 +/- 5 x 10(8) NC per cord blood (CB) unit (n = 1828, July 1997), 100%, 65% and 25% of the CB units stored in the CB Bank Düsseldorf contain sufficient NC to engraft patients of 10 kg, 35 kg and 50-70 kg, respectively. Thus, there is a potential limitation for the use of CB in adults which, however, may be overcome by ex vivo expansion of cells important in the different phases of engraftment. Therefore, four combinations of SCF, Flt3-L, IL-3, erythropoietin and GM-CSF as well as three media were evaluated for their capacity to amplify hematopoietic progenitors. A prerequisite for expansion was the significantly higher recovery of CD34+ cells, colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC) by thawing cryopreserved CB units with an isotonic albumin/dextran solution. When CD34+ CB cells were cultured with the four cytokine combinations in H5100 medium, all combinations promoted an expansion of total cells (43 to 356-fold) and CFC (49 to 462-fold) within 7 days, however, early progenitors as defined by mixed-colony formation (CFU-GEMM) were substantially amplified only with SCF, Flt3-L plus IL-3 (94.3 +/- 62.4-fold). H5100 medium or a serum-free medium supplemented with SCF, Flt3-L plus IL-3 were superior to 20% FCS/RPMI-1640 medium in the expansion of all progenitor cell types and were similarly effective in supporting the amplification of total cells, CFC, CFU-GM, BFU-E/CFU-E and LTC-IC (maximum at day 7: 6.7 +/- 3.4-fold and 5.5 +/- 0.5-fold, respectively). However, the serum-free medium promoted a significantly higher expansion of CFU-GEMM (176.9 +/- 81.7-fold) than H5100 medium (83.5 +/- 26.2-fold) at day 7 and only under serum-free conditions, CFU-GEMM were maintained over 14 days in tissue culture. These results demonstrate that committed progenitors as well as the more immature CFU-GEMM and LTC-IC can be substantially amplified at the same time without exhausting the proliferative potential.

Adult↗

PubMed1998

The effect of cisapride on dysmotility-like functional dyspepsia: reduction of the fasting and postprandial area, but not of the postprandial antral expansion.

OBJECTIVE: To test the effect of cisapride on symptom score and on fasting and postprandial antral area in patients with dysmotility-like functional dyspepsia compared with controls. METHODS: Nineteen consecutive patients with dysmotility-like functional dyspepsia (13 females, six males, aged 18-79 y) and 12 control subjects (six females, six males, aged 19-68 y) were investigated. A symptom score including six upper digestive symptoms rated from 0 to 3 was applied. The patients received in a randomized order cisapride 10 mg t.i.d. (n = 10), or placebo (n = 9) for 3 days. The controls also received cisapride (n = 6) or placebo (n = 6) in the same way. The antral area in fasting condition and immediately after a semiliquid test meal (250 ml, 342 kcal) was assessed by real-time ultrasonography in front of the aorta and mesenteric vein. The measurements were carried out before starting and after finishing the trials with cisapride and placebo. RESULTS: The symptom score (mean +/- SD) was 7.1 +/- 2.4 in dysmotility-like functional dyspepsia vs 0.5 +/- 0.2 in controls (P < 0.0001). The fasting antral area was 4.5 +/- 0.9 cm2 in dysmotility-like functional dyspepsia vs 2.2 +/- 0.2 cm2 in controls (P < 0.0001). Postprandial antral area was also larger in dysmotility-like dyspepsia than in controls (6.2 +/- 1.0 vs 3.0 +/- 0.3 cm2, Pb= 0.0001). Symptom score correlated with fasting antral area in dysmotility-like functional dyspepsia (rb= 0.38, Pb= 0.05). Cisapride decreased the symptom score to 4.5 +/- 2.5 (P = 0.0009) and placebo to 5.3 +/- 2.4 (P = 0.02). Cisapride significantly reduced the fasting antral area and the postprandial antral area in the dyspeptic group, but not in the control group. Postprandial antral expansion was not influenced by cisapride. Placebo did not change the sonographic parameters in both groups. CONCLUSIONS: In dysmotility-like functional dyspepsia, fasting and postprandial antral areas are wider than in controls. Despite a good placebo response, cisapride is effective in improving the symptoms in dysmotility-like functional dyspepsia, associated with the reduction of fasting and postprandial antral areas.

Adolescent↗

PubMed1998

PET and CBF studies of chronic hydrocephalus: a contribution to surgical indication and prognosis.

The authors investigate whether measurement of cerebral blood flow (CBF) in chronic hydrocephalus is a reliable indicator in selecting patients to undergo ventriculoperitoneal shunting. Global and regional CBF is quantified (Kety-Schmidt one-compartment model) by positron emission tomography in 21 patients. CBF is determined following injection of 15O-H2O at three time points: 1 week before, 7 days after, and 7 months after shunting. The neurological status of these patients is classified, and cerebrospinal fluid (CSF) dynamics continuous intracranial pressure [ICP] monitoring and CSF infusion tests) were assessed prior to surgery. Preoperative global CBF values correlate well with clinical outcome. Patients with a significantly lower global CBF value show clinical improvement after 7 months, whereas patients with higher CBF values do not (mean, 33 vs. 45 ml/100 ml per minute; p < 0.05). In contrast to conventional methods, including long-term ICP measurement and CSF infusion tests, preoperative global CBF values are discriminating in terms of clinical outcome. Thus, measurement of CBF may be helpful in evaluating the ultimate utility of shunt therapy in chronic hydrocephalus.

Aged↗

PubMed1998

Effect of a recombinant lectin, Viscum album agglutinin on the secretion of interleukin-12 in cultured human peripheral blood mononuclear cells and on NK-cell-mediated cytotoxicity of rat splenocytes in vitro and in vivo.

A plant lectin, Viscum album agglutinin-I (VAA-I) has been shown to increase the number and cytotoxic activity of natural killer (NK) cells in animal models, but the mechanisms underlying these effects are poorly understood. We investigated the effects of the recombinant form of this lectin (rVAA) on secretion of interleukin (IL)-12 and on NK-mediated cytotoxicity against K562 target cells in cultures of human peripheral blood mononuclear cells (PBMC) as well as against YAC-1 target cells in cultured rat spleen cells. In 24-hour cultures of PBMC, 10 ng/ml plant VAA-I and 50 ng/ml rVAA induced significant increases in the secretion of total IL-12. Its biologically active heterodimeric form, p70, was also significantly induced by rVAA. Preincubation of PBMC or splenocytes for 48 h with rVAA in concentrations ranging between 10 pg/ml and 100 pg/ml resulted in moderate enhancements of NK-mediated cytotoxicity. However, coincubation of a low dose of rVAA (100 pg/ml) together with IL-2 and IL-12 (60 U/ml and 2 U/ml, respectively) led to additive stimulation of NK activity. In in vivo experiments, rVAA showed an enhancing effect on NK activity with a bell-shaped curve of efficacy. Forty-eight hours after a single intravenous injection of its most effective doses, 0.5 and 1 ng/kg, into Wistar rats, the NK cytotoxicity of splenocytes against YAC-1 targets doubled, and the frequency of large granular lymphocytes in peripheral blood showed 2.1- and 3-fold increases as compared to control animals. Twenty-four hours following these low lectin doses, the number of large granular lymphocytes was also significantly elevated. After 48 h, 0.5 ng/kg rVAA induced a significant augmentation in the percentage of peripheral Mac-1+ mononuclear cells, including activated monocytes and NK cells. The present results suggest that rVAA augments the secretion of an active form of IL-12 and potentiates the cytokine-induced NK activation. These effects of rVAA may be related to its stimulatory effects on MHC-unrestricted cytotoxicity in vivo.

Adjuvants, Immunologic↗

PubMed1998

Efficacy and safety of acarbose in metformin-treated patients with type 2 diabetes.

OBJECTIVE: To demonstrate the efficacy, tolerability, and safety of acarbose compared with placebo in patients with type 2 diabetes inadequately controlled with diet and metformin (2,000 or 2,500 mg/day in divided doses). RESEARCH DESIGN AND METHODS: This study had a multicenter randomized double-blind placebo-controlled parallel-group comparison design. The trial lasted 31 weeks and consisted of a 1-week screening period, a 6-week placebo pretreatment period, and a 24-week period of acarbose or placebo, with a forced titration from 25-50 mg t.i.d. and a titration of 50-100 mg tid that was based on glucose control. The primary efficacy variable was the mean change from baseline in HbA1c. Secondary efficacy variables included mean changes from baseline in fasting and postprandial plasma glucose, serum insulin, and triglyceride levels. RESULTS: The addition of acarbose to patients on background metformin and diet therapy showed a statistically significant reduction in mean HbA1c of 0.65%. There were statistically significant reductions in fasting and postprandial plasma glucose and serum insulin levels compared with placebo. Gastrointestinal side effects were more frequently reported in the acarbose-treated patients. No significant differences in liver transaminase elevations were observed between patients treated with acarbose and those treated with placebo. CONCLUSIONS: The results of this study demonstrate that the addition of acarbose to patients with type 2 diabetes who are inadequately controlled with metformin and diet is safe and generally well tolerated and that it significantly lowers HbA1c and fasting and postprandial glucose and insulin levels.

Acarbose↗

PubMed1998

[North Rhine-Westphalia Scientific Rehabilitation Group--"future strategies for rehabilitation"].

This Northrine-Westfalian integrated research system in rehabilitation aims at the development of future strategies for medical rehabilitation. The well known deficits of rehabilitation have led to different complementary projects. These comprise research on the lack of evidence in efficacy, predictors for outcomes, international cooperation, university related curricula in training, implementation of health economics and disease management, and finally the need for an actual adaptation of social legislation. The research topics have been transformed into key themes which will be coherently integrated by additional external expert knowledge acquired in workshops organized by a task force group for the development of future strategies.

Forecasting↗

PubMed1998

[The changing clinical picture of gastroduodenal ulcer disease].

OBJECTIVE: The authors evaluate the changing clinical picture of gastroduodenal ulceration in recent years. METHOD: They analysed their own clinical material from January 1994 till April 1998 when at the Second Surgical Clinic in Olomouc 188 patients were hospitalised on account of gastroduodenal ulceration. RESULTS: The group of patients comprised a high proportion of patients above 60 years of age (102, i.e. 55%) and twice as many cases of duodenal ulcers as compared with gastric ones. In 4% ulcers were present at both sites. In 92% (173 patients) acute admissions were involved and only in 8% (15 patients a planned admission for elective treatment was involved. As to complications haemorrhage was most frequent (84%), perforations in 13% and pylorostenosis in 3%. Of the acute admissions 56 patients were operated, i.e. 32%, the rest were treated by conservative methods. The surgical lethality was 12%, the lethality of the conservatively treated patients 5%. CONCLUSION: Gastroduodenal ulceration is at present characterised by a predominance of conservative treatment, a decline of elective operations, a high percentage of complications in particular in advanced age, more frequent affection of the duodenum and late indication for surgery, when conservative treatment is not very successful.

Adolescent↗

PubMed1998

[Significance of alpha 2,6-specific sialyltransferase ST6N and alpha 2,3-specific sialyltransferase ST3N in stomach carcinoma].

The objective of this prospective study was to investigate the role of sialytransferase activities in patients with gastric cancer. In patients with gastric cancer we observed a significant correlation between sialyltransferase ST6N levels and survival after a median follow up of one year. High ST6N levels in the tumor and the surrounding normal mucosa were associated with poor prognosis. The results of this pilot study encourage further evaluation of sialyltransferase in patients with gastric cancer.

Biopsy↗

PubMed1998

[Comparison of adjuvant chemotherapy in breast carcinoma with a combination of cyclophosphamide, methotrexate, 5-fluorouracil (CMF) and AC (doxorubicin, cyclophosphamide). Initial results of a national cooperative study].

The aim of this multicentric, prospective randomized trial is to evaluate and to compare, effects and toxicities of two chemotherapeutic combinations (AC and CMF) in adjuvant treatment of breast cancer. Both combinations were given in equitoxic doses and number of cycles was only four. There are 106 women treated for breast cancer T1c-3a, N0-1, M0 in the study. After surgery the patients were randomized, 54 for AC combination and 52 for CMF. We evaluate toxicity of this treatment in all patients in the study. Hematological and nonhematological side effects were comparable in both groups except alopecia (in the group AC was 100%). The study is not finished yet. Preliminary analysis does not show any difference between these two groups.

Antineoplastic Combined Chemotherapy Protocols↗