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Biomedical subjects

C Fischer

Publications and source records attributed to C Fischer.

At least 307 records · Page 17Linked to original sources

Young children's comprehension of montage.

2 studies examined children's comprehension of brief stop-animation televised segments incorporating elements of cinematic montage such as pans, zooms, and cuts. Children reconstructed the action and dialogue in these segments using the same dolls and settings depicted. In Study 1, there was no effect of cinematic techniques on reconstruction performance of 3- and 5-year-olds as compared to control segments filmed without these techniques. The results challenged the assumption that the use of such techniques per se contributes to young children's poor comprehension of television shows. In Study 2, 12 new segments were produced in which comprehending the montage required inferences of character perspective, implied action sequences, spatial relationships, and simultaneity of different actions. Averaging across all segments, 62% of the 4-year-olds and 88% of the 7-year-olds demonstrated clear comprehension of the montage. Inferences concerning implied action sequences were easiest for both ages. Inferences of simultaneity were most difficult for 4-year-olds, whereas inferences of character perspective were most difficult for 7-year-olds. Preschool children are thus capable of understanding cinematic events conveyed through camera techniques and film editing, despite previous assertions to the contrary. This ability nevertheless substantially increases with age.

Child↗

A PGE2-derivative for quantitative gas chromatographic mass spectrometric measurement in the selected ion monitoring mode.

The quantification of prostaglandin PGE2 by gas chromatography mass spectrometry in the form of an easily prepared derivative is described. After extraction and purification of biological samples the compound was derivatized in two steps to 9-enol-PGE2- methylester - trimethylsilylether , 9-enol-PGE2-Me- TMS3 . The molecular ion at m/z 582 with 40% relative abundance and the fragment ion at m/z 492 with 100% relative abundance permit a specific and sensitive evaluation in the selected ion monitoring mode. The high masses selected lie above the biological background. The calibration curve produced by adding known amounts (10-200 ng) of PGE2 to blank human urine and with (2H4)-deuterated PGE2 as internal standard gave a linear correlation. The separation from biological impurities was obtained on a 50 m glass capillary column and resulted in sharp and symmetrical peaks.

Adult↗

A stable isotope method for the quantification of N-acetyl-5-aminosalicylic acid in plasma and urine.

The synthesis of a number of N-acyl-5-aminosalicylic acids and their derivatives is described. These compounds allow the sensitive and specific mass spectrometric determination of unlabelled or deuterium-labelled N-acetyl-5-aminosalicylic acid in biological samples. An in vivo study shows that the labelled compound, administered to rats, is excreted isotopically unchanged to at least 97%, and that no significant deacetylation/acetylation mechanism exists for this metabolite N-acetyl-5-aminosalicylic acid of salicylazosulphapyridine.

Aminosalicylic Acids↗

Renal function was not impaired by treatment with 5-aminosalicylic acid in rats and man.

In rat experiments and a clinical trial we have examined the suspected nephrotoxic potential of 5-aminosalicylic acid (5-ASA), the biological active metabolite of sulfasalazine (SZ). Male Wistar rats were treated orally for 4 weeks daily with 30 and 200 mg 5-ASA/kg and 75 and 500 mg SZ/kg. The two renal marker enzymes N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30), alanineaminopeptidase (AAP; EC 3.4.11.2) and creatinine were monitored in urine. At the end of the experiment rats were sacrificed, the removed kidneys histologically examined and drugs, their metabolites and creatinine measured in plasma and urine. In 9 patients treated chronically for their Crohn's disease with 3 X 0.5 g 5-ASA daily in form of suppositories and an oral preparation urinary excretions of NAG, AAP and serum creatinine were also monitored before and during therapy. Neither the animal experiments nor the observations in patients gave any evidence of nephrotoxic lesions induced by 5-ASA. Thus, our data show that in the doses applied, 5-ASA was devoid of altering renal excretion in rats and man.

Aminosalicylic Acids↗

[Treatment of partial motor status epilepticus in adults with intravenous diphenylhydantoin (DPH). Prospective study of 50 cases].

Fifty adult patients with partial motor status epilepticus were treated with a single intravenous (i.v.) injection of diphenylhydantoin (DPH), 20 mg/kg body weight at a rate of 1 mg/kg/min. Seizures were controlled in 32 patients (64%) during the injection or within the following hour; in 13 of them previous (i.v.) injections out of benzodiazepines had been ineffective. DPH was effective in 10 patients of 11 with a previous history of epileptic seizures and without problems of consciousness during their epileptic status. In contrast, 13 failures out of 18 concern occasional status in patients deeply comatose because of head trauma, neurosurgical operation or intracerebral hemorrhage. Total plasmatic levels of DPH, when measured 24 h after the injection, were found between 38 mumol/l in all patients, and were in the range of 40 mumol/l-100 mumol/l in 77% of cases. Adverse effects were: pain at the injection site (6 cases), horizontal nystagmus during injection (5 cases), transient cerebellar symptoms (3 cases). This study confirms that single loading doses of DPH can maintain DPH plasmatic levels within the therapeutic range during 24 h, with minor or transient side effects, provided that cardiovascular contra-indications are respected.

Adult↗

Is N-acetylation of 5-aminosalicylic acid reversible in man?

In two healthy male subjects the disposition of deuterated N-(2H3) acetyl-5-aminosalicylic acid (d3-ac-5-AS) was investigated after a single rectal dose of 500 mg d3-ac-5-AS. Urine and plasma were analysed by h.p.l.c. and gas chromatography mass-spectrometry. Peak concentrations of around 0.5 microgram/ml occurred within 6 h and plasma concentrations declined thereafter with a half-life (t1/2) of about 6 h which was confirmed by urinary excretion data. Renal clearance of d3-ac-5-AS ranged between 200 and 300 ml/min and only 4.4-11.2% of the dose could be recovered in the 48 h urine. Since no undeuterated ac-5-AS could be detected in any of the plasma and urine samples an irreversible acetylation of 5-AS is assumed in man.

Acetylation↗

Effect of dexamethasone on in vivo prostanoid production in the rabbit.

To investigate the effects of antiinflammatory steroids on in vivo prostaglandin production, urinary excretion rates of six different cyclo-oxygenase products were determined before, during, and after the administration of dexamethasone (1 mg/kg per d). Urine was collected in metabolism cages and was analyzed for prostaglandins E2 and F2 alpha (PGE2 and PGF2 alpha) by radioimmunoassay after open-column chromatography; 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2) were determined by radioimmunoassay after organic solvent extraction and reversed-phase high performance liquid chromatography; 7 alpha-hydroxy-5,11-di-keto-tetranorprostane-1,16-dioic acid (PGE-M) and 5 alpha,7 alpha-dihydroxy-11-keto-tetranorprostane-1,16-dioic-acid (PGF-M), the major urinary metabolites of prostaglandins E and F, were determined by gas chromatography-mass spectrometry and by radioimmunoassay, respectively. Dexamethasone failed to cause a statistically significant change in the excretion rate of PGE2 (control, 250.4 +/- 40.8; dexamethasone, 297.6 +/- 78.7 ng/kg per d). In contrast, PGF2 alpha excretion decreased during administration of dexamethasone (from 1,036 +/- 228 to 449 +/- 158 ng/kg per d; P less than 0.05). The urinary excretion rates of 6-keto-PGF1 alpha, TxB2, PGE-M, and PGF-M were not significantly altered by dexamethasone. (Control and dexamethasone values were, respectively, 63.6 +/- 7.9 and 103.5 +/- 17.9 ng/kg per d for 6-keto-PGF1 alpha; 13.0 +/- 3.0 and 14.8 +/- 2.1 ng/kg per d for TxB2; 1,251 +/- 217 and 1,905 +/- 573 ng/kg per d for PGE-M; and 4,131 +/- 611 and 4,793 +/- 600 ng/kg per d for PGF-M). Urine flow was significantly higher during dexamethasone administration (control, 159 +/- 24; dexamethasone, 305 +/- 29 ml/24 h; P less than 0.01). However, no correlation could be detected between changes in urine flow and changes in the excretion rate of any of the prostanoids investigated. It is concluded that the administration of pharmacological doses of glucocorticoids does not affect the basal rate of total body prostanoid synthesis.

Animals↗

A human beta-endorphin pituitary adenoma.

A beta-endorphin (beta END)-containing pituitary adenoma was demonstrated by immunocytochemical, biochemical, and ultrastructural methods in a 43-yr-old man who had impotence, slight testicular atrophy, and an enlarged sella turcica (grade II0), but no manifestations of Cushing's disease. Preoperative hormone data revealed hyperprolactinemia (97 ng/ml), low plasma cortisol levels without circadian rhythm, undetectable plasma ACTH, and normal plasma FSH and LH levels, with an impaired response to LRH. After hypophysectomy, these hormone levels normalized and responded normally to dynamic tests. Immunocytochemically, 30% of the tumor cells reacted only with beta END antiserum. beta END immunoreactivity was the only component revealed by RIA and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A characteristic ultrastructural aspect is also described. These findings demonstrate dissociation in the secretion of the proopiomelanocortin-derived peptides and suggest a relationship between hyperprolactinemia and tumor secretion of beta END.

Adenoma↗

[Deafness and tinnitus in flare-ups in 10 cases of multiple sclerosis].

Deafness in multiple sclerosis is rare, being reported in less than 1 p. 100 of the cases. Ten cases of deafness associated with tinnitus during acute episodes of multiple sclerosis are presented, the diagnosis being definite in 9 patients and probable, according to McAlpine's criteria, in the tenth case. These were not cases where routine examinations demonstrated a latent hearing defect, but were all patients with sudden, often unilateral, incapacitating deafness during an acute episode of the disease, with regression usually after less than 3 months. Deafness recurred in 3 patients and was the initial symptom in 5 cases. Serial audiometric examinations were performed in most cases together with recordings of various evoked potentials, including early auditory evoked potentials during or after the onset of deafness in all 10 patients. BAEPs abnormalities were noted in 8 and appeared to be correlated more with brain stem demyelinization, as it has been established for a few years, than with the deafness itself. Severe anomalies of auditory evoked potentials regressed after the acute episode in only 1 patient. Lesions of the auditory pathways within the brain stem appear to be the cause of the deafness, as shown by results of auditory tests, which pointed to a central origin. The onset of deafness did not indicate a particular progression of multiple sclerosis.

Adult↗

Metabolic disposition of prostaglandin E1 in man.

Metabolism of [17, 18-3H]prostaglandin E1 was investigated in three healthy male volunteers during intravenous infusion. The infusion rate was 5.0 ng/kg per min. Blood samples were obtained before the end of the infusion as well as 5, 10, 20, 40, 90 and 180 min afterwards; urine and feces were collected until 96 and 72 h, respectively, after the experiment. All samples were analyzed for radioactivity. Urine was further chromatographed, including by high-pressure liquid chromatography, and subsequently analyzed by gas chromatography-mass spectrometry. Radioactivity in plasma rapidly declined during the first 10 min after termination of the infusion, and then was eliminated exponentially with a mean half-life of 181 min, probably reflecting slow excretion of one or more metabolite. 12% of the administered radioactivity could be recovered from feces and 88% from urine. From the radioactive material obtained from urine the following metabolites could be identified (each number represents data of one volunteer): 7 alpha-hydroxy-5,11-diketotetranor-prostane-1,16-dioic acid (10.4, 20.4 and 30.1%), 7 alpha-hydroxy-5,11-diketotetranor-prostanoic acid (8.2, 6.9 and 9.3%), 5 alpha, 7 alpha-dihydroxy-11-ketotetranor-prostane-1,16-dioic acid and its delta-lactone (together accounting for 4.1, 2.1 and 3.8%).

Adult↗

Disposition of 5-aminosalicylic acid, the active metabolite of sulphasalazine, in man.

The disposition of 5-aminosalicylic acid (5-AS), the therapeutically active metabolite of sulphasalazine (SZ), has been studied in patients with active inflammatory bowel disease, in patients with biliary tract disease and post-operative T-tube drainage, and in healthy volunteers. Subjects were treated 3 times a day either with 5-AS 0.5 g suppositories and a slow-release preparation or with SZ 1 g tid (equivalent to 5-AS 1.14 g/day). Plasma and urine concentrations of 5-AS and its acetylated major metabolite (AcAS) were monitored during one dosing interval. In a cross-over trial in 5 patients with ulcerative colitis no difference, was found in the dose-corrected mean (+/- SD) steady state plasma levels (Css) of 5-AS and AcAS between treatment with 5-AS suppositories (0.10 +/- 0.07 and 0.50 +/- 0.20 micrograms/ml, respectively) and SZ (0.12 +/- 0.14 and 0.67 +/- 0.14 micrograms/ml, respectively). Urinary excretion of total AS (5-AS + AcAS), too, was similar (192 +/- 70 and 179 +/- 79 mg/day) with both forms of treatment. The oral slow-release form of 5-AS produced slightly higher Css in 5 patients with Crohn's disease (5-AS 0.21 +/- 0.22 micrograms/ml; AcAS 0.83 +/- 0.40 micrograms/ml) and in 5 healthy volunteers (5-AS 0.28 +/- 0.14 micrograms/ml; AcAS 1.10 +/- 0.43 micrograms/ml). Urinary recovery of total AS averaged 20 +/- 6% (patients) and 27 +/- 10% (volunteers).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Plasma levels of sulfinpyrazone and of two of its metabolites after a single dose and during the steady state.

The pharmacokinetics of sulfinpyrazone, and the plasma levels of its sulfide and sulfone metabolites, have been determined after a single oral dose (400 mg) and during steady-state conditions (4 x 200 mg daily for 6 days) in healthy female volunteers. The plasma half-lives of sulfinpyrazone, the sulfone and the sulfide were 3.7, 3.2 and 14.7 h, respectively, during steady-state. After a single dose and during steady state conditions the half-lives of sulfinpyrazone and the sulfone did not differ significantly. The trough plasma levels of the sulfide metabolite exceeded those of the parent compound in four of the six volunteers on the last day of the study. The data suggest that in man the most likely candidate for the prolonged inhibition of platelet aggregation observed after treatment with sulfinpyrazone is its sulfide metabolite, because of its prolonged elimination.

Adult↗

Treatment of Crohn's disease with peroral 5-aminosalicylic acid.

Eighteen patients with active Crohn's disease entered an open trial with 5-aminosalicylic acid in a slow-release preparation. All had lesions of the small bowel. Ten of them also had Crohn's disease of the colon. 5-Aminosalicylic acid, 500 mg three times daily, was administered for 6 wk. Even with meticulous monitoring, no side effects of any kind were observed, particularly no cases of renal affection, which could have been expected from animal studies. The clinical course was estimated as improved in 13 patients (72%), unchanged in 2 patients (11%), and aggravated in 3 patients (17%); 2 of these 3 were withdrawn from the study and switched to alternative treatment. The Crohn's disease activity index decreased from a median of 226 points to 99 points. On the basis of these results, large-scale controlled therapeutic trails seem warranted in order to establish clinical evidence for the benefit of peroral treatment with 5-aminosalicylic acid in patients with Crohn's disease.

Administration, Oral↗

A tool for assessing compliance with a diet for diabetes.

In summary, criteria to define good, acceptable, and unacceptable compliance with a CONTROL or HCF diabetic diet were established. With the use of these criteria, a simplified system for the evaluation of compliance was developed. The compliance system used an interview approach and a checklist on which patients recorded their food intake in terms of the number of food exchanges consumed throughout the day. The results of this study suggest that (a) research subjects will keep accurate food records using a checklist system for up to 30 weeks; (b) the described compliance system is a valuable educational tool and can assist in the interpretation of clinical data used in diabetes management; and (c) the assigned compliance grades correlate with quantitative parameters of diabetic control.

Adult↗

[Neurophysiologic study of 2 cases of hemianesthesia as a result of subcortical lesions. Results of recording far-field somatosensory evoked potentials].

The volume-conducted responses of the lemniscal pathways to median nerve stimulation at wrist may be recorded on the scalp (far-field potentials). These positive far-field SEPs components are widely distributed on the scalp and their peaking latencies vary between 9 and 15 milliseconds. In normal adults a maximum of 4 far-field potentials (P9, P11, P13 and P14) may be individualized; two of them (P9 and P14) are constant. These SEPs were studied in two patients with lateralized somatosensory loss; one with a cervico-medullary traumatic lesion, the other with a thalamic infarct. These observations allow the following conclusions 1) the P9 component takes origin in the proximal part of the brachial plexus roots; 2) the P14 potential has a brainstem origin; 3) the contralateral N20 potential is generated in (or close to) the primary somato-sensory cortex (SI). Thus it is possible with a single channel to record the activity of the somatosensory pathways from dorsal roots up the parietal cortex.

Adult↗

[5-Aminosalicylic acid in ulcerative colitis and Crohn's disease (author's transl)].

5-Aminosalicylic acid (5-ASA, 0.5 g t.i.d. as suppository) was administered to 10 patients with ulcerative colitis and 4 patients with Crohn's disease. Both diseases were active despite out-patient pretreatment in 9 cases for at least 6 weeks with sulfasalazine (1.5-3.0 g/d) and corticosteroids. Prior to 5-ASA treatment the activity index according to Best was 241 +/- 85 for the ulcerative colitis patients and 263 +/- 83 for the Crohn's disease patients. After an admission of 4 to 6 weeks treatment with 5-ASA led to a significant decrease (P less than 0.0001) to 43 +/- 38 in the ulcerative colitis patients whereas the decrease in the Crohn group was markedly less to 165 +/- 129 (P less than 0.035). Apart from two patients with Crohn's disease the antiphlogistic effect of 5-ASA could be proven by endoscopy, histomorphology and (or) radiography with an 86% remission rate and by the improved faecal quality (n = 12). The results show that 5-ASA leads to improvement in part only of patients with Crohn's disease, however that all patients with ulcerative colitis respond to this biologically active metabolite. Particularly due to absence of undesirable side effects 5-ASA represents an advantageous possibility for treatment.

Adolescent↗