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Biomedical subjects

K Maier

Publications and source records attributed to K Maier.

At least 73 records · Page 4Linked to original sources
PubMed1989

Flumazenil disposition and elimination in cirrhosis.

Flumazenil, a new and specific benzodiazepine antagonist that appears to be free of intrinsic pharmacologic action, is extensively metabolized by oxidative processes and represents a high-clearance drug. Consequently, it could be anticipated that hepatic disease affects the elimination and oral bioavailability of flumazenil. Therefore, the pharmacokinetics of flumazenil was evaluated in eight patients who had moderate cirrhosis and in eight age-matched healthy volunteers after a single oral dose (30 mg) and after an intravenous dose (2 mg). The mean half-life (t1/2) was 0.8 versus 1.4 hours (p = 0.003) and total plasma clearance was 1201 versus 705 ml per minute (p = 0.009) for control subjects versus patients with cirrhosis. Bioavailability increased from the normal 28% to 65% (p = 0.001) in patients with hepatic dysfunction. Routine liver tests did not correlate with the elimination of flumazenil in individual patients. It can be concluded that elimination of flumazenil is impaired in patients who have stable alcoholic cirrhosis. Despite the relative wide margin of safety of flumazenil, somewhat lower doses could be effective in such patients if long-term oral use is anticipated.

Administration, Oral↗
PubMed1989

Liver-derived cytotoxic T cells in hepatitis A virus infection.

An autologous in vitro model was developed to analyze the immunologic cause of liver tissue injury during hepatitis A virus (HAV) infection. Human T lymphocytes infiltrating the livers of two patients with acute HAV infection were isolated from liver biopsy cores, cloned, and expanded in vitro. Procedures using a cell culture system with HAV-infected autologous skin fibroblasts demonstrated that 42% and 53% of the liver-infiltrating CD8+ clones were HAV-specific and that they kill HAV-infected skin fibroblasts in a human leukocyte antigen-restricted manner. Data show virus-specific killing by liver-infiltrating T lymphocytes in man and support the hypothesis that liver cell injury in acute HAV infection is mediated by HAV-specific CD8+ T lymphocytes and is not caused by a cytopathic effect of the virus itself.

Adult↗
PubMed1988

[Ulcerative colitis. Activity index for the clinical and histological classification of inflammatory activity].

According to Truelove and Witts, ulcerative colitis has been rated only by clinical classification without taking into account morphological alterations, and so far (in contrast to Crohn's disease) no activity index has been available for clinical studies. Therefore, we have developed an index during a therapeutic trial with mesalazine (5-aminosalicylic acid) to evaluate the initial state of inflammation and assess therapeutic efficacy. The activity index includes 5 items: stool frequency (score 0 to 3), rectal bleeding (score 0 to 3), endoscopy (score 0 to 3), histology (score 0 to 4), and extension of inflammation (score 0 to 4). In 42 patients with ulcerative colitis treatment with mesalazine (2 suppositories of 250 mg 3 times daily) was monitored for 12 weeks. In 37 patients a clinical improvement was observed, as indicated by a significance decrease in the mean activity index from initially 10.2 to 6.1 (after 6 weeks) and 3.4 (after 12 weeks). The proposed index could be modified by additional parameters.

Adult↗
PubMed1988

Human gamma interferon production by cytotoxic T lymphocytes sensitized during hepatitis A virus infection.

The production of interferon (IFN) during a chromium-51 release assay with hepatitis A virus (HAV)-infected fibroblasts and autologous peripheral blood lymphocytes from patients with acute HAV infection was studied to determine whether IFN plays a role in immunopathogenesis of hepatitis A infection in humans. Skin fibroblasts of eight patients after acute HAV infection and from two control persons without history of current or past HAV infection were infected with HAV. Peripheral blood lymphocytes were collected at different times after the onset of icterus and tested in a chromium-51 release assay against autologous HAV-infected skin fibroblasts for their cytolytic and IFN-producing activity. The IFN produced during the assay was characterized and found to have the properties of human gamma IFN. Cytotoxicity and gamma IFN release were virus specific. The cell types responsible for both functions were characterized and found to be in the HLA-dependent T8+ lymphocyte subset. Considering that gamma IFN has an antiviral effect on persistent HAV infection in vitro and that it probably accounts for stimulation of HLA class I antigen expression on hepatocytes, our experimental results presented here demonstrate that human gamma IFN produced by HAV-specific T cells may participate in pathogenesis of hepatitis A infection in humans.

Cells, Cultured↗
PubMed1988

Differentiation of fibroblast stem cells.

Primary human skin fibroblasts derived from the abdomen of 45 female donors of the four age groups 1-20, 20-40, 40-60, and 60-80 years were studied in primary explant, in primary low-density mass cultures, and in primary clonal populations in vitro. As a function of the age of the donor, primary mitotic and postmitotic fibroblasts in the three primary cell systems analysed represent heterogeneous populations with reproducible changes in the proportions of the mitotic fibroblasts MF I, MF II, MF III, and postmitotic fibroblasts PMF IV, PMF V, PMF VI, and PMF VII. These findings make it very likely that equivalent cell types exist in the connective tissue of skin in vivo, and that these cells undergo reproducible changes in the proportions of the mitotic and postmitotic counterparts in vivo as a function of the age of the donor. Secondary mitotic human skin fibroblast populations of the cell line HH-8 in vitro underwent 53.6 +/- 6.0 cumulative population doublings (CPD) in 302 +/- 27 days. If appropriate methods are applied, mitotic fibroblasts differentiate spontaneously into postmitotic fibroblasts which are kept in stationary cultures for up to 305 +/- 41 additional days. As a function of the CPD level and of the duration of stationary culture, secondary mitotic and postmitotic fibroblast populations are heterogeneous populations with reproducible changes in the proportions of mitotic fibroblasts MF I, MF II, and MF III, and postmitotic fibroblasts PMF IV, PMF V, PMF VI, and PMF VII. The seven secondary fibroblast cell types show differentiation-dependent and cell-type specific patterns of [35S]methionine polypeptides in total soluble cytoplasmic and nuclear proteins, in secreted proteins, and in membrane bound proteins. These findings make it very likely that the morphologically recognizable primary and secondary fibroblasts differentiate spontaneously along a seven stage terminal cell lineage MF I - MF II - MF III - PMF IV - PMF V - PMF VI - PMF VII in three compartments of the fibroblasts stem cell system.

Adolescent↗
PubMed1985

[Successful acute treatment of chronic inflammatory intestinal diseases with oral 5-aminosalicylic acid].

The effectiveness of oral 5-aminosalicylic acid (0.5 g t.i.d.) and of salazosulfapyridine (1.0 g t.i.d.) was compared in a randomized controlled study in two groups with 30 patients each with ulcerative colitis and with Crohn's disease. Persistent complaints within the first 5 days were treated with additional methyl-prednisolone (40 mg/d initially). After treatment for 8 weeks patients with ulcerative colitis showed morphologic remissions in 60% of the 5-aminosalicylic acid group and in 53% of the salazosulfapyridine group. Clinical improvement was achieved in 86% in both groups. Clinical improvement in Crohn's disease was seen in 87% of patients of the 5-aminosalicylic acid group and in 80% of the salazosulfapyridine group. This was evidenced by the significant fall (P = 0,0001) of the mean activity index. Additional steroid medication was nearly equal in both treatment groups. There were no side effects during treatment with 5-aminosalicylic acid. In contrast, salazosulfapyridine had to be withdrawn in four patients due to signs of intolerance. 5-Aminosalicylic acid can thus be considered a valuable alternative to conventional treatment on the basis of equal effectiveness as salazosulfapyridine and lack of undesirable side effects.

Adolescent↗
PubMed1984

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↗
PubMed1984

Purification and characterization of a gamma crystallin from mouse lenses.

A gamma-crystallin has been purified by a two-step column chromatography from an extract of water soluble lens proteins from (101/ E1xC3H /E1)F1 mice. About 17% of the water soluble lens protein in normal mice is represented by this gamma-crystallin. The protein has been shown to be absent in cataractous lenses of Nop /+ mice after isoelectric focusing of water soluble lens proteins. It has a MW of 20,000. Amino acid analysis reveals the occurrence of eight cystein residues, which is considered to be high compared to other crystallins. The protein might play an important role in cataractogenesis.

Amino Acids↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1982

[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↗
PubMed1982

Pteridine-binding alpha 1-acid glycoprotein from blood of patients with neoplastic diseases.

A glycoprotein was selectively enriched in the supernatant (Fraction b) obtained by alcohol and trichloroacetic acid fractionation of digitonin extracts from blood of patients with neoplastic diseases and of control subjects. Subsequent chromatography with concanavalin A:Sepharose separated a concanavalin A-reactive fraction from a concanavalin A-nonreactive one. In sodium dodecyl sulfate gel electrophoresis, the fractions from both malignant origin as well as control subjects appeared as single bands showing the same mobility. They were identical with the band obtained from commercial alpha 1-acid glycoprotein. In Fraction b of malignant origin, greatly increased amounts of the alpha 1-acid glycoprotein from malignant cases (AGPM) were found as compared to alpha 1-acid glycoprotein from controls (AGPC). Furthermore, AGPC had a higher glycine content than did AGPM. The electrofocusing pattern of AGPM showed additional bands between pH 3.7 and 4.4, whereas AGPC and commercial alpha 1-acid glycoprotein focused between pH 3.2 and 3.8. In contrast to AGPC and to a commercial alpha 1-acid glycoprotein, AGPM is characterized by a chromophoric group with maximal absorbance at 400 nm. It could be detached by treatment with 6 M guanidine hydrochloride thus indicating a noncovalent binding. The spectral data on the separated chromophore at pH 0.5 agreed with that of a 6,7-substituted pteridine. After detachment with reducing agents, a pteridine in its 7,8-dihydro form was indicated by spectral analysis.

Amino Acids↗