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Biomedical subjects

K Hoffmann

Publications and source records attributed to K Hoffmann.

At least 145 records · Page 8Linked to original sources
PubMed1999

[Short assessment of subjective quality of life. Application and results of a short form of the Berliner Lebensqualitätprofil (BELP-KF)].

The concurrent validity between the Berliner Lebensqualitätsprofil (BELP) and a new developed short form (BELP-KF) was tested in a sample of schizophrenia outpatients (N = 36) and turned out to be very high. The restriction to subjective quality of life questions did not lead to a greater halo-effect in the sense of an increasing similarity of single item values. Correlations with psychopathological symptoms were almost identical for both interview-versions. The same is true concerning the factorial structure of the satisfaction items which was nearly congruent. Two optional items on satisfaction with sexual life and with psychopharmacological treatment, which had been included into the short interview version, were attributable to an underlying general satisfaction dimension. Among 14 variables satisfaction with psychopharmacological treatment had the second highest factor-loading on the resulting general satisfaction factor.

Antipsychotic Agents↗
PubMed1999

Megakaryocytic growth in patients with refractory anemia is suppressed by treatment with interferon alpha.

IFN alpha alone or in combination with retinoids or haematopoietic growth factors has been used to treat patients with early MDS because of its properties as a differentiation inducing agent. We investigated whether treatment of patients with refractory anemia (RA) with IFN alpha (1.5x10(6) IU twice a week) and intermittent all-trans retinoic acid (ATRA, 25 mg/m2/d) influences in-vitro megakaryocytic (MK) proliferation and differentiation stimulated by PEG-rHuMGDF. Low-density non-adherent bone marrow (BM) cells from 8 patients with RA were assayed prior to any treatment other than supportive and after a period of 6 months of treatment. MK development was assayed in suspension cultures in the presence of PEG-rHuMGDF and SCF for 7 d using morphological criteria and flow cytometric analysis of CD42b (GP1b) positive cells. BM-cells from 10 healthy individuals served as control. Following stimulation with PEG-rHuMGDF 23+/-7% and 16+/-4% of control cells were CD42b positive after 5 and 7 d of cultures, respectively. In cultures of cells from MDS patients prior to treatment 8+/-2% and 7+/-3% of cells were CD42b+ on days 5 and 7. In the course of IFN alpha treatment cultures of all BM samples from these MDS patients revealed a significant reduction of MK precursor cells (3+/-2%, CD42b+, p=0.03 and 0.04). In conclusion, treatment with TFN alpha and ATRA did not result in improved megakaryocytopoiesis as assessed by in-vitro cultures. On the contrary, low-dose IFN alpha appears to suppress cell proliferation as well as MK development.

Administration, Oral↗
PubMed1999

Therapeutic relationships and quality of life: association of two subjective constructs in schizophrenia patients.

Subjective quality of life is an important criterion in outcome evaluation that has been well-researched in psychiatry. By comparison, the therapeutic relationship which may also be subjectively assessed has been relatively neglected as an outcome criterion although it has predictive power in relation to outcome. This exploratory study investigated subjective quality of life and therapeutic relationships in first-admission (N = 90) and long-term (N = 168) schizophrenia patients, each at two points of time. The follow-up period was 9 months for the first-admission sample and 1.5 years for the long-term sample. A significant relationship was found between global assessments of quality of life and therapeutic relationships in long-term, but not in first-admission patients. This finding was consistent at both assessments, suggesting that therapeutic relationships may become more central to quality of life in long-term care situations and that patients' views of this relationship are increasingly embedded in their overall appraisal of life.

Adult↗
PubMed1999

[Discharge in inpatient care. Results of a survey. Postscript to part III of the Berlin Deinstitutionalization Study].

PURPOSE: 42 percent long-term patients from the Berlin Deinstitutionalization Study sample have been discharged to full-time institutional settings. METHODS: The questionnaires of a mail-survey covered features of 58 different non-hospital full-time institutional settings and care for a group of 125 long-term mental patients. RESULTS: The return rate was more than 70 percent. For 78 percent of the discharged former long-term inpatients the political goal of complete psychiatric care in the patient's home area has been reached, but only 20 percent live in smaller institutions of up to 40 places. CONCLUSIONS: The significance of other data of the survey does not exceed that of stock-taking and certain indications because of the selective data and the limitations of the method. There is an urgent need for further research in examining the quality of non-hospital institutional care for psychiatric long-term patients.

Adult↗
PubMed1999

Femtosecond two-photon excited fluorescence of melanin.

Fluorescence of synthetic melanin in dimethyl sulfoxide has been excited by two-photon absorption at 800 nm, using 120 fs pulses with photon flux densities > or = 10(27) cm-2 s-1. The shortest main component of the three-exponential decay of fluorescence is 200 +/- 2 ps. The overall spectral shape is red-shifted with respect to the 400 nm excited fluorescence. Two-photon excited melanin fluorescence also has been measured from excised samples of healthy human skin tissue. Because of the selectivity of melanin excitation via resonant two-photon absorption, it is hypothesized that fluorescence excited in this way may yield information on malignant transformation.

Humans↗
PubMed1998

Remote suturing for percutaneous closure of popliteal artery access.

We present a case of balloon angioplasty of the superficial femoral artery via a popliteal artery access with successful percutaneous vascular closure of the vascular access site (6-F Techstar). A femoral arterial approach had not been feasible due to previous aorto-femoral and femoro-femoral bypass operations. Clinical and ultrasound follow-up showed no complications up to 3 months after remote suturing.

Aged↗
PubMed1998

[Sun protection by optimally designed fabrics].

A rising incidence worldwide of skin cancer has been observed for years. A high cumulative exposure to UV radiation is a major factor in the development of such neoplasms. Suitable protective measures are therefore becoming increasingly important. Textiles provide simple, effective and medically safe protection against UV radiation. At present, however, in Europe--in contrast to Australia--the UV protection factor (UPF) for summer textiles is not stated. It is a largely unknown fact that by far not all textiles offer sufficient protection. Our goal was to study the factors which determine the UV transmission of fabrics and, based on these findings, to design materials which provide enhanced protection. A spectrophotometric method was used to determine the UV transmission by fabrics made of cotton, silk, polyester and viscose. The UV protection factors of the fabrics were computed on the basis of the transmission data. The UV protection factor is dependent on the type of fibre, yarn and surface design, weight per square metre, moisture content, colour, finishing method and degree of wear. To optimize the UV protection via textiles, a viscose yarn with a low UV transmission was used. This yarn makes it possible to design light-weight summer fabrics with optimized UV protection. This development will make it possible to offer clothing with high UV protection on the European marked. This clothing will not be more expensive than normal products, so that effective prevention should be more available.

Clothing↗
PubMed1998

[Mometasone and calcipotriol optimize the initial therapeutic effect of dithranol in chronic persistent psoriasis].

In a randomized study 30 patients with chronic stationary psoriasis were treated with 3 different topical schemes. Group 1 (n = 10) received monotherapy (dithranol (D) twice a day, D/D), group 2 (n = 10) calcipotriol mornings/dithranol evenings (calcipotriol (C)/dithranol (D) C/D) and 3 (mometasone (M) mornings/dithranol (D) evenings, M/D). During the therapy period of 4 weeks we documented the PASI-Score as well as infiltration, erythema and desquamation weekly. The M/D group revealed in the first week a significantly faster reduction of the PASI-score (5.3) than in the D/D group (PASI 13.22). The C/D group (PASI 10.5) show a not significantly faster reduction. After 4 weeks of treatment and after a follow period of 6 weeks there were similar PASI-Scores in all groups. There were less side-effects in the M/D group than in the others. The beginning, more anti-psoriatic effectiveness was achieved by the mometasone/dithranol combination than the other schemes. In the long term, the effects were similar.

Administration, Topical↗
PubMed1998

Identification of the stimulated hemiretinae using a reduced number of PVEP trials.

Left and right hemifield pattern-reversal visual evoked potentials (PVEP) at P100 latency are characterised by typical field distributions of potential and the spectral parameter instantaneous frequency (IF). Both parameters can be utilised for the correct identification of the stimulated hemiretina in healthy volunteers (Hoffmann, K. et al. Electroenceph. clin. Neurophysiol., 100, 1996: 569-578). The aim of this study was the investigation of the robustness of instantaneous frequency for reduced numbers of averages. Hemifield PVEP of 15 volunteers (20 channel records) were analysed. The number of averages was reduced step-by-step (64-32-16-8-4-1). For each average, the time of P100 latency was determined by the Global field power maximum between 90 and 125 ms. The stimulated hemifield was identified using the potential or instantaneous frequency values at the occipital electrode positions O1 and O2: by maximal potential and instantaneous frequency on the stimulus-contralateral side. In summary, by reduced numbers of averages (as well as by single trials) the stimulated hemiretina was correctly identified more frequently on the basis of instantaneous frequency than of potential distribution. A number of 8 averages seems to be sufficient for the correct identification of the stimulus condition. Consequently, for the identification of left and right hemifield stimulations the recording time could be reduced immensely. Instantaneous frequency is suggested as an additional and robust parameter for the selective averaging of artefact-free trials during the recording of hemifield PVEP.

Adult↗
PubMed1998

Identification of a co-repressor binding site in catabolite control protein CcpA.

The catabolite control protein CcpA is the central regulator of carbon catabolite repression in Bacilli and other Gram-positive bacteria. A comparison of 12 CcpA-like sequences with regulators from the LacI/GalR family defines a CcpA subfamily based on extensive similarities found among CcpAs and not in 32 other members of the family. These amino acids are clustered in three blocks in the CcpA sequence. Their interpretation, assuming a PurR-like fold, reveals that almost all of them are surface exposed and form a continuous patch on the N-terminal subdomain of the protein core extending into the DNA reading head. We introduced nine single amino acid exchanges in the subfamily specific residues of CcpA from Bacillus megaterium. Six mutants, namely CcpA47RS, 79AE, 89YE, 295YR, 299YE and 303RD, are inactive or severely impaired in catabolite repression, underlining their relevance for CcpA function. They are negatively transdominant over wild-type CcpA demonstrating their ability to correctly fold for dimerization. Five of them are unable or impaired in binding HPr-Ser-46-P in vitro, establishing a correlation between catabolite repression efficiency and HPr-Ser-46-P binding. These results support the hypothesis that the conserved region in CcpA is the HPr-Ser-46-P binding site.

Amino Acid Sequence↗
PubMed1998

[100 MHz ultrasound of psoriasis vulgaris plaque].

PURPOSE: 20 MHz sonography of inflammatory diseases has concentrated on the evaluation of the echo-poor area in the upper dermis. With regard to higher resolution, this study focuses on the alterations of the epidermis and upper dermis skin using 100 MHz sonography. METHOD: 70 fully developed psoriasis vulgaris plaques of 20 patients were examined using our 100 MHz ultrasound equipment after application of salicylic acid in petrolatum for 24 h. After informing the patient about the aims of the study, a small knife biopsy was taken from 11 plaques. RESULTS: All psoriasis plaques exhibited, in comparison with normal skin, a significant widening of the skin entry echo (p < 0.001). Focally, this echo-rich line broke up into two thinner lines. Correlating histology exhibited in these areas an orthohyperkeratosis and focal parakeratosis. The upper dermis showed an echo-poor, band-shaped area which corresponded histologically to an acanthosis, elongation of rete ridges, and widening of the stratum papillare. The mean grey level of the echo-poor area and of the dermis beneath was significantly lower (p < 0.001) than the normal adjacent dermis. The thickness of the echo-poor area correlated with the thickness of the sum of the acanthosis and the inflammatory infiltrate in the histological sections (r = 0.94). CONCLUSION: Using 100 MHz sonography changes of the skin entry echo and the upper dermis can be visualized and quantified.

Adult↗
PubMed1998

Rhythmical variations of haemoglobin oxygenation in cutaneous capillaries.

The consequences of rhythmical arteriolar vasomotion for nutrition and the tissue oxygen supply to human skin are largely unknown. In the study presented here, the periodic variations of haemoglobin oxygenation in the small cutaneous vessels have been evaluated with a new reflection spectrophotometer. For the assessment of spatial variations, we examined 24 different sites in 20 healthy volunteers. For quantification of the relatively long duration of periodic variations, a Digital Fourier Transformation with a specially programmed filter was used. In 265 out of 480 spectra (55.2%), periodic variations of the haemoglobin oxygenation were found. The average of the main frequency of waves was 7.0 +/- 2.5 cycles per minute. The occurrence of variations of haemoglobin oxygenation depended on the measuring site. In the gluteal region, variations were observed in 17 out of 20 subjects, on the palms in 16 out of 20, at the foot plantar in 18 out of 20 in comparison to the cheek (8/20), the lip (5/20) and the eyelid (6/20). On the head we observed significantly more variations per minute than in the lower extremities. Because these variations, with duration of up to 30 s, have a relatively slow dynamic compared with heart rate and breathing frequency, consequences for the cutaneous diffusion and metabolism of other substrates are very likely.

Adult↗
PubMed1998

Multimodal time-variant signal analysis of neonatal EEG burst patterns.

It can be shown that dominant rhythmic signal components of neonatal EEG burst patterns (discontinuous EEG in quiet sleep) are characterized by a quadratic phase coupling (bispectral analysis), i.e. a multiplicative interaction (connection) between the underlying electrophysiological processes can be assumed. By means of pattern recognition algorithms as well as time-variant spectral and coherence analysis, a so-called "initial wave" (narrow band rhythm within a frequency range of 3-12 Hz) can be demonstrated within the first part of the burst pattern. The detection of this signal component and of the quadratic phase coupling is more successful in the frontal region. By means of amplitude demodulation of the "initial wave" the phase coupling can be attributed to an amplitude modulation. The results were derived from 6 neonates (20 burst patterns for each neonate; 8-channel recordings). A 16-channel EEG-recording was analyzed for one neonate.

Electroencephalography↗
PubMed1998

[Pyrethroids in house dust of the German housing population--results of 2 nationwide cross-sectional studies].

As a part of the German Environmental Surveys performed in 1985/86 (West Germany), 1990/91 (West Germany) and 1991/92 (East Germany), dust samples were collected in the households of about 1600 randomly selected adults (25 to 69 years) and an analysis of these samples was performed in respect of their content of 8 different pyrethroids and of the synergist piperonyl butoxide (PBO). In the 1990-92 survey about 90% of the samples contained permethrin in concentrations above the limit of quantification. This showed permethrin to be the most widespread of the 8 compounds investigated. The geometric mean of the permethrin content in domestic dust was 0.22 mg/kg. Only about 8% of the samples contained one or more of the other investigated substances (cyfluthrin, lambda-cyhalothrin, cypermethrin, alpha-cypermethrin, deltamethrin, empenthrin, d-phenothrin) in quantifiable amounts. About 76% of the samples contained quantifiable amounts of PBO. In East Germany the geometric mean of the PBO content (0.21 mg/kg) was significantly higher than in West Germany (0.07 mg/kg), but no difference for permethrin was found. Significant associations could be shown for the permethrin content and the application of biocides as well as for the PBO content and regional factors (size of community, type of dwelling area). Samples collected in 1985/86 (West Germany) showed a geometric mean for permethrin of 0.06 mg/kg and for PBO of 0.07 mg/kg. Comparing the values of 1985/86 and 1990/91, a significant increase can be observed for permethrin, whereas the PBO concentration remained constant.

Adult↗