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H J Koch

Publications and source records attributed to H J Koch.

At least 37 records · Page 2Linked to original sources
PubMed2002

Uniform decrease of alpha-global field power induced by intermittent photic stimulation of healthy subjects.

Nineteen-channel EEGs were recorded from the scalp surface of 30 healthy subjects (16 males and 14 females, mean age: 34 years, SD: 11.7 years) at rest and under trains of intermittent photic stimulation (IPS) at rates of 5, 10 and 20 Hz. Digitalized data were submitted to spectral analysis with fast fourier transformation providing the basis for the computation of global field power (GFP). For quantification, GFP values in the frequency ranges of 5, 10 and 20 Hz at rest were divided by the corresponding data obtained under IPS. All subjects showed a photic driving effect at each rate of stimulation. GFP data were normally distributed, whereas ratios from photic driving effect data showed no uniform behavior due to high interindividual variability. Suppression of alpha-power after IPS with 10 Hz was observed in about 70% of the volunteers. In contrast, ratios of alpha-power were unequivocal in all subjects: IPS at 20 Hz always led to a suppression of alpha-power. Dividing alpha-GFP with 20-Hz IPS by alpha-GFP at rest (R = alpha-GFP(IPS)/alpha-GFP(rest)) thus resulted in ratios lower than 1. We conclude that ratios from GFP data with 20-Hz IPS may provide a suitable paradigm for further investigations.

Adult↗
PubMed2002

Anthropometric data and acetylsalicylic acid pharmacokinetics.

The relationship between anthropometric data and pharmacokinetic characteristics of acetylsalicylic acid (ASA) after administration of a single oral dose of 500 mg ASA, an oral and intravenous dose of 500 mg D,L-lysine-mono-acetylsalicylate (Lys-ASA) and an oral dose of 1,000 mg Lys-ASA were evaluated. Individual data from an open, randomized crossover trial in 13 healthy volunteers (age 18-50 years, 6 female, 7 male, height 158-189 cm, weight 45-118 kg) were re-analyzed using a non-compartmental approach. The influence of body weight, height, body surface area and age on pharmacokinetic characteristics (Cmax, Tmax, AUClast, MRTlast, t 1/2, Cl, Vd) was assessed using the multiple regression method and pairwise multiple correlations were calculated. Multiple regression analysis showed significant multiple correlation coefficients of approximately 0.86 for Cmax (500 mg Lys-ASA i.v., 1,000 mg Lys-ASA per os and 500 mg ASA per os), Cl and AUClast (1,000 mg Lys-ASA per os). Standardized regression values (beta) reflected a major contribution for height, weight and body surface area, but age was not a relevant factor. Pairwise comparisons confirmed negative correlations between anthropometric characteristics and Cmax, AUClast and MRTlast and positive correlations between anthropometric data, Cl and Vd. In conclusion, apart from Tmax and t 1/2, all pharmacokinetic characteristics were influenced by body weight, height and body surface area. Whereas repeated administration of high doses in patients with low body weights may give rise to toxic effects, acute single dose administration would not lead to significant under-dosing in tall or stout patients.

Adult↗
PubMed2001

Treatment of stage II cutaneous T-cell lymphoma with interferon alfa-2a and extracorporeal photochemotherapy: a prospective controlled trial.

BACKGROUND: Both interferon alpha and extracorporeal photochemotherapy have been shown to be effective in primary cutaneous T-cell lymphomas (CTCLs). However, no prospective trial has been published on the combination of both treatments, although retrospective investigations suggested a better efficacy than for either interferon or extracorporeal photochemotherapy. OBJECTIVE: Our purpose was to evaluate the efficacy and toxicity of combined interferon alfa-2a with extracorporeal photochemotherapy in a prospective controlled trial. METHODS: A prospective controlled study was performed. Fourteen patients (all male) aged 38 to 72 years with CTCL of the mycosis fungoides type, stage IIa/IIb, and a 72-year-old male patient with a Ki-1 lymphoma were treated twice a month for 6 months with extracorporeal photochemotherapy using oral 8-methoxypsoralen as photosensitizer in combination with interferon alfa-2a subcutaneously 3 times a week in the maximal tolerable dosage (ie, up to 18 x 10(6) U). The effects were investigated by a skin score, staging, histologic score (density of the T-cell infiltrate; from 0 = absent to 3 = heavy), immunohistology, and laboratory investigations including total peripheral T-cell count, CD4/CD8 ratio, and soluble interleukin 2 receptor (sIL-2R). RESULTS: After 6 months, best response was a complete response (CR) in 4 patients, a partial response (PR) in 3, and a stable disease (SD) in 7 of 14 patients (overall response rate [CR + PR] 50%). In responders the time to best response was 4.3 +/- 1.4 months. The skin score decreased from 22.5 +/- 8.1 to 15.1 +/- 11.0 (P <.001), the histologic score decreased from 2.57 +/- 0.51 to 1.21 +/- 0.80 (P <.001). In the lesional skin the percentage of CD4 cells decreased from 75% to 51% (P =.038) and Ki-67-positive cells decreased from 6.7% to 2.4% (P =.001). The total T-cell count/microL decreased from 1018.9 +/- 557.1 to 667.9 +/- 417.9 (P =.012), and the CD4/CD8 ratio also decreased from 1.88 +/- 0.92 to 1.51 +/- 0.67 (P =.038). The sIL-2R levels did not change significantly during the first 4 months of treatment. Among patients of stage IIa the response rate was 60% in contrast to only 25% of those in stage IIb. Side effects were seen temporarily, ranging from grade 0 to grade 3. There was no need for additional therapy, but interferon dose was decreased because of side effects. After 1 year of follow-up the total response rate was 46.2% (6 of 13 patients): 5 of 9 with stage IIa(55.6%) and 1 of 4 with stage IIb (25.0%). CONCLUSION: These results indicate that patients with CTCL stage IIa can achieve a total response rate of 56% with combined interferon alfa-2a and extracorporeal photochemotherapy. Responders seem to experience their best response within the first 6 months of treatment. The treatment is well tolerated and does not cause severe side effects.

Administration, Oral↗
PubMed2001

Intermittent 20-HZ-photic stimulation leads to a uniform reduction of alpha-global field power in healthy volunteers.

19-channel-EEGs were recorded from scalp surface of 30 healthy subjects (16m, 14f, mean age: 34 ys, SD: 11.7 ys) at rest and under IPS (Intermittent Photic Stimulation) at rates of 5, 10 and 20 Hertz (Hz). Digitalized data underwent spectral analysis with fast fourier transfomation (FFT) yielding the basis for the computation of global field power (GFP). For quantification GFP values in the frequency ranges of 5, 10 and 20 Hz at rest were divided by the corresponding data gained under IPS. While ratios from PDE data showed no stable parameter due to high interindividual variability, ratios of alpha-power turned out to be uniform in all subjects: IPS at 20 Hz always led to a suppression of alpha-power. Dividing alpha-GFP at rest by alpha-GFP under 20-Hz IPS thus resulted in a ratio < 1. We conclude that ratios from GFP data are a stable diagnostic paradigma.

Adult↗
PubMed2001

Severe bradyarrhythmia in a patient with Alzheimer's disease and a patient with cerebral ischaemia, both induced by acute distension of the bladder.

Two case reports are presented of bradycardia in two elderly patients, which was resistant to atropine but which resolved immediately the acute bladder distension was treated. Generally, a sympathetic cardiac response is expected, and this paradoxical response may be due not only to lesions of the reflex loop involving both the vagal and the sympathetic nerves, but also to endocrinological factors. As acute urinary distension is not uncommon on geriatric wards, bradyarrhythmia due to bladder distension should be considered in elderly patients.

Acute Disease↗