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E Richter

Publications and source records attributed to E Richter.

At least 127 records · Page 7Linked to original sources
PubMed1996

Symptom reporting in cancer patients: the role of negative affect and experienced social stigma.

BACKGROUND: Recent research suggests that patients' appraisal of somatic symptoms is more closely related to emotional variables (particularly negative affect) than to their actual health as determined by external criteria. METHODS: Sixty surgical cancer patients who at the time of a routine follow-up examination filled out the European Organization for Research and Treatment of Cancer (EORTC) quality of life questionnaire-C30, which included a positive/negative affect scale and a scale tapping into experienced social stigma. Patients' health status was determined in two ways: the examining physician gave a global judgement on a standardized scale at the end of the examination, and an additional two external physicians later rated the patients based on the findings listed in the medical record. RESULTS: Patients' reports of somatic symptoms were strongly correlated with two measures of negative affect (r = 0.75 and r = 0.65, respectively) and with experienced social stigma (r = 0.51). In contrast, the correlations between reported symptoms and the examining or external physicians' ratings were considerably weaker (r = 0.31 and r = 0.19). According to a multiple linear regression with 6 predictors, negative affect was the best single predictor of symptom reporting (beta = 0.68; P < 0.001) and global quality of life (beta = 0.48; P < 0.001). Factor analysis yielded a dimension of somatopsychosocial distress that accounted for 44.1% of the variance and is comprised of reported symptoms (factor loading = 0.86), negative affect (0.90 and 0.82), experienced social stigma (0.74), and global quality of life (0.70). Physicians' ratings and positive affect constituted two additional separate factors. CONCLUSIONS: Cancer patients' reporting of somatic symptoms by means of a standardized quality of life questionnaire is closely related to emotional and social distress and is not equivalent to health status as determined from a clinical perspective. Researchers and practitioners have to be aware of this fact when interpreting quality of life data. Furthermore, negative affect deserves attention as an important signal for intervention in tumor follow-up programs.

Abdominal Neoplasms↗
PubMed1996

Metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by hamster, mouse and rat intestine: relevance of species differences.

We recently demonstrated the metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in rat intestinal segments, as well as the inducibility of intestinal NNK metabolism by starvation or acetone treatment. To improve our understanding of intestinal NNK turnover we have additionally investigated NNK metabolism in isolated perfused jejunal segments from NMRI mice and Syrian golden hamsters. [14C]NNK (1 micromol/l) was metabolized extensively by jejunal segments from female NMRI mice (88.5%) and female Syrian hamsters (86.4%), whereas in male NMRI mouse segments a slightly lower metabolism (68.8%) was observed. Alpha-Hydroxylation was the predominant metabolic pathway in mice (58% of total metabolism), whereas in female Syrian hamsters N-oxidation accounted for >50% of the metabolites [4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanol 27%, 4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanone 22% of total radioactivity]. Formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) was low in both species. Total NNK metabolism in male NMRI mice was increased by starvation to 84.4% and by acetone treatment to 90.0% of the absorbed radioactivity. This increase was due to an increase in N-oxidation, whereas the amounts of alpha-hydroxides and NNAL remained unchanged. In female Syrian hamsters acetone treatment had only minimal effects upon the metabolite composition. Acetone-treated NMRI mice and Syrian hamsters were additionally gavaged with the chemopreventive agent phenethylisothiocyanate (PEITC). In mice this treatment slightly decreased keto acid formation (0.6-fold, P<0.05), whereas in hamsters PEITC had no effect. In summary, intestinal metabolism of NNK in rats, mice and hamsters differs in both the extent of total metabolism (hamsters > or = mice > rats) and the metabolite composition, indicating major species differences.

Animals↗
PubMed1996

Plasma pyrimethamine concentrations during long-term treatment for cerebral toxoplasmosis in patients with AIDS.

Steady-state plasma pyrimethamine levels were measured by gas chromatography. The specimens were taken from 74 adults with advanced human immunodeficiency virus infection receiving pyrimethamine-containing drugs for prophylaxis or curative therapy of reactivated cerebral toxoplasmosis. During an overall treatment period of 1,049 months, 1,012 plasma samples were investigated. Pyrimethamine concentrations could be evaluated in 904 plasma samples. The weekly dosage of pyrimethamine ranged from 25 to 1,400 mg; one patient with severe diarrhea received 2,100 mg/week. Steady-state plasma pyrimethamine concentrations were achieved after 12 to 20 days. Pyrimethamine concentrations evidently increased with the weekly dosage given. Mean concentrations were 253 +/- 151 ng/ml with 50 mg of pyrimethamine per week, 471 +/- 214 ng/ml with 100 mg of pyrimethamine per week, 1,893 +/- 1,182 ng/ml with 350 mg of pyrimethamine per week and 3,369 +/- 1,726 ng/ml with 1,050 mg of pyrimethamine per week. A widespread interpatient range was found for every dosage. With the simultaneous use of enzyme-inducing comedication, the plasma pyrimethamine levels decreased in several patients. Mild chronic liver disease did not influence plasma pyrimethamine concentrations. To avoid ineffective therapy or severe side effects, monitoring of pyrimethamine could be useful in patients receiving enzyme-inducing comedications and in patients with severe diarrhea or poor compliance.

AIDS-Related Opportunistic Infections↗
PubMed1996

Viral hepatitis.

Explore the source record for details and available documents.

Hepatitis A↗
PubMed1996

Assessment of mycobacterial DNA in cells and tissues of mycobacterial and sarcoid lesions.

In this study we applied a polymerase chain reaction (PCR) assay for the detection and species-specific identification of mycobacteria to samples from patients with sarcoidosis and mycobacterial infections and from control patients. The PCR-technique is based on the amplification of mycobacterial DNA coding for 16S rRNA, which is present in all mycobacterial species, and on the additional sequencing of the PCR fragment to determine the species. Mycobacterial DNA could be detected in lung tissues and bronchoalveolar lavage cells from cases of tuberculosis and infections with atypical mycobacteria. On the other hand, mycobacterial DNA was amplified only in lung tissue from one patient with sarcoidosis. Twenty-three samples from patients with sarcoidosis were negative for mycobacterial DNA. From our results we conclude that the granulomatous lesions in sarcoidosis may not be due to mycobacterial infections.

Base Sequence↗
PubMed1996

Bacterial reduction of N-oxides of tobacco-specific nitrosamines (TSNA).

1. Contrary to established metabolic pattern, a recent investigation of NNK metabolism produced in rat urine higher levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) than their N-oxides, suggesting that reconversion of N-oxides could occur after urine formation. 2. To verify the possible role of bacteria in the reduction of NNK-N-oxide and NNAL-N-oxide to their respective parent compounds, NNK and NNAL, in smokers with urinary tract infection (UTI), the N-oxides were isolated from the urine of rats treated with [5-3H]NNK and individually incubated at 37 degrees C with ten bacterial species in sterile human urine under different pH regimens. After incubation with the bacteria, aliquots of culture media were analyzed by high pressure liquid chromatography (HPLC) with radiochemical detection. 3. Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae and Proteus mirabilis possessed varying capacity to regenerate NNK and NNAL from their N-oxides while others showed no detectable reductive capability within 24 h. 4. This result constitutes the first experimental evidence that in tobacco users with concomitant UTI, bacterial regeneration of the procarcinogenic NNK and NNAL from their N-oxides could occur in the bladder leading to increased carcinogen burden in these individuals.

Animals↗
PubMed1996

[Coincidence of Pneumocystis carinii pneumonia and lung carcinoma in AIDS].

In a formerly drug-dependent patient of 35 years of age suffering from an advanced HIV infection there was a development within a period of a few months of rapid weight loss amounting to 12 kg, persistent subfebrile temperatures and progressive dyspnoea on exercise. The histological pattern obtained via bronchoscopy revealed not only pneumocystis carinii pneumonia, which had already been suspected clinically, but also a not very differentiated adenocarcinoma of the lung with lymphangiosis carcinomatosa. The patient died three months after tis diagnosis was established, which had been followed by the usual pneumocystosis therapy and palliative treatment with glucocorticoids.

AIDS-Related Opportunistic Infections↗
PubMed1995

Characterisation of cell movement by impedance measurement on fibroblasts grown on perforated Si-membranes.

Mouse fibroblasts grown on perforated Si-membranes (pore diameter approximately 10 microns have been studied to clarify cell locomotive ability. The cell motility was microscopically monitored by a time-lapse video system and, simultaneously, the impedance of the growing cells was measured every 5 s. The correlations between observed cell activities and measured impedance events are discussed and classified. The method is sensitive and allows discrimination between signals arising from translocation of single cells and those arising from filopodia activities. Both cell and filopodia motion could be detected. Designs of microdevices fabricated in semiconductor technology are presented.

3T3 Cells↗
PubMed1995

Synthesis, pharmacologic activity, and structure-activity relationships of a series of propafenone-related modulators of multidrug resistance.

A series of [(o-acylaryl)oxy]propanolamines have been prepared and evaluated for multidrug resistance-reverting activity in a human tumor cell model. Structure-activity relationship studies indicate that the phenylpropiophenone moiety as well as the substitution pattern at the nitrogen atom is crucial for activity of the compounds. Incorporation of the ether oxygen into a benzofuran substructure, which renders the compound an arylethanolamine, decreased biologic activity. Highest activity could be observed with the arylpiparazines 4f-h, which not only completely restored daunomycin sensitivity but also showed moderate activity in restoring etoposide toxicity.

Daunorubicin↗
PubMed1995

An improved method for the species-specific assessment of mycobacteria in routinely formalin-fixed and paraffin-embedded tissues.

A polymerase chain reaction (PCR) assay for the rapid and species-specific diagnosis of mycobacterial infections in paraffin-embedded clinical specimens was developed using oligonucleotide primers to amplify a fragment of the DNA coding for the ribosomal 16S RNA of mycobacteria. The oligonucleotide primers amplified DNA from all 14 species of mycobacteria tested. By means of a reamplification protocol, as few as one to two mycobacteria could be detected in the presence of human DNA. The method of DNA isolation and amplification was applied on sections of routinely formalin-fixed and paraffin-embedded tissues. PCR for the beta-actin gene served as a control for successful DNA isolation. Mycobacterial DNA could be detected in cases of mycobacterial infections. The mycobacterial species was determined by additional sequencing of the PCR fragment. This PCR method may be a powerful tool for the diagnosis of mycobacterial infections from histopathological material and for the assessment of those mycobacteria that cannot readily be cultured, such as Mycobacterium leprae.

Base Sequence↗
PubMed1995

Intestinal metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in rats: Sex difference, inducibility and inhibition by phenethylisothiocyanate.

The intestinal metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was investigated in male and female Sprague-Dawley (SD) rats and male F344 rats, using isolated perfused intestinal segments. [1(-14)C]-NNK at 1 microM was metabolized by alpha-hydroxylation, pyridine N-oxidation and carbonyl reduction. Jejunal segments from control female rats metabolized 26.2% of the NNK during transepithelial transfer to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL, 12.2%), 4-(methylnitrosamino)-1-3-pyridyl-N-oxide)-1-butanone (NNK-N-oxide, 7.7%), 4-oxo-4-(3-pyridyl)-butanol (KAlc, 2.7%), 4-(methylnitrosamino)-1-(3-pyridyl-N-oxide)-1-butanol (NNAL-N-oxide, 1.8%), 4-oxo-4-(3-pyridyl)butyric acid (KA, 1.1%) and 4-hydroxy-4-(3-pyridyl)butyric acid (HA, 0.7%). Ileal segments metabolized 20.8% of the NNK during absorption, with no difference in metabolite distribution as compared to jejunal segments. In control male SD and F344 rats, jejunal presystemic metabolism was 2.3-fold higher (56.4% and 60.8% respectively), mainly because of a 4-fold increase in NNAL formation (44.1% and 48.5%)> total NNK metabolism was also induced in female rats by starvation (84.4% metabolites), acetone (89.3%), phenobarbital PB, 75.3%) and Clophen A50 (61%). PB and Clophen A50 induced N-oxidation to 38.9% (4 x) and 27.8% (3 x), and to a lesser extent NNAL formation and alpha-hydroxylation (2 x), Starvation mainly increased N-oxidation with a time-dependent increase from 1 day to 3 days of starvation (4 x and 8 x versus controls), whereas alpha-hydroxylation and NNAL formation was elevated only after 1 day starvation. Acetone pretreatment (3 days) stimulated all three pathways (NNAL 2 x, N-oxidation 4 x, alpha-hydroxylation 4 x). In male F344 rats, starvation and acetone induced N-oxidation (5 x and 7 x) and alpha-hydroxylation (3 x and 5 x), and decreased NNAL formation by 40%, probably due to substrate competition or further metabolism of NNAL. In acetone-induced female SD rats, NNK metabolism was inhibited by in vivo pretreatment with phenethylisothiocyanate (PEITC) or in vitro addition of 1% ethanol to the perfusate. Both inhibition experiments reduced total metabolism by 20%; N-oxidation and alpha-dhyroxylation were reduced to values found in control rats, whereas NNAL formation increased from 31% to 51%.Inhibition of NNK metabolism by PEITC im male F344 rats was less pronounced compared to female SD rats; again a decrease in alpha-hydroxylation (6.7% to 3.3%) and N-oxidation (73.6% to 35.3) was accompanied by increased NNAL formation (9.8% to 41.0%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acetone↗
PubMed1995

Localization of thioredoxin in the rat brain and functional implications.

The immunoreactivity for thioredoxin, which catalyzes protein disulfide reductions, has previously been shown to exist in nerve cells and their axons. Here we demonstrate the localization of thioredoxin mRNA as revealed by in situ hybridization in the rat brain. The gene is expressed in nerve cells of a variety of brain regions, for example, the cerebral cortex, the piriform cortex, the medial preoptic area, the CA3/CA4 region of the hippocampal formation, the dentate gyrus, the paraventricular nucleus of the hypothalamus, the arcuate nucleus, the substantia nigra pars compacta, the locus coeruleus, the ependyma of the 4th ventricle, and the epithelial cells of the choroid plexus. This distribution implicates an important function in nerve cell metabolism, especially in regions with high energy demands and indicates a role of the choroid plexus in nerve cell protection from environmental influences. It was found that after mechanical injury induced by partial unilateral hemitransection the thioredoxin mRNA expression is upregulated in the lesioned area and spreads to the cortical hemispheres at the lesioned level. This induction suggests a function of thioredoxin in the regeneration machinery of the brain following mechanical injury and oxidative stress.

Animals↗
PubMed1995

CD26 expression in leprosy and other granulomatous diseases correlates with the production of interferon-gamma.

BACKGROUND: Leprosy represents a spectrum of clinical manifestations that reflect the immune response to antigens of Mycobacterium leprae. The tuberculoid form of leprosy, which is characterized by an organized development of granulomas, has recently been correlated with a Th1-like immune response. The lepromatous form of leprosy, with a characteristic lack of cellular immunity, has been correlated with a Th2-like immune response to mycobacterial antigens. Dipeptidylpeptidase IV (CD26) is an ectopeptidase that is expressed in various tissues; in the hemopoietic system, it is predominantly expressed by T cells. EXPERIMENTAL DESIGN: We stained frozen sections of skin biopsies obtained from patients with different forms of leprosy, sarcoidosis, and Piringer's lymphadenitis. Sections were stained for interferon-gamma (IFN-gamma) and CD26 with the alkaline phosphatase anti-alkaline phosphatase technique and in two-color stainings by immunofluorescence. RESULTS: We found strong signals for IFN-gamma and for CD26 in all investigated cases of tuberculoid leprosy. In contrast, in all biopsies taken from patients with lepromatous leprosy, we found no or very weak signals for these antigens. By immunofluorescence double-labeling, we could show that IFN-gamma and CD26 were expressed by the identical cell population. We confirmed this correlation of CD26 expression and IFN-gamma production in other granulomatous inflammatory reactions such as sarcoidosis and Piringer's lymphadenitis. CONCLUSIONS: From our results, we conclude that a high expression of CD26 may be suggestive of Th1-like immune reactions.

Dipeptidyl Peptidase 4↗