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1.
Lett Appl Microbiol ; 66(4): 306-312, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29330879

ABSTRACT

This work investigates the potential bioconversion of spent coffee grounds (SCG) into lactic acid (LA). SCG were hydrolysed by a combination of dilute acid treatment and subsequent application of cellulase. The SCG hydrolysate contained a considerable amount of reducing sugars (9·02 ± 0·03 g l-1 , glucose; 26·49 ± 0·10 g l-1 galactose and 2·81 ± 0·07 g l-1 arabinose) and it was used as a substrate for culturing several lactic acid bacteria (LAB) and LA-producing Bacillus coagulans. Among the screened micro-organisms, Lactobacillus rhamnosus CCM 1825 was identified as the most promising producer of LA on a SCG hydrolysate. Despite the inhibitory effect exerted by furfural and phenolic compounds in the medium, reasonably high LA concentrations (25·69 ± 1·45 g l-1 ) and yields (98%) were gained. Therefore, it could be demonstrated that SCG is a promising raw material for the production of LA and could serve as a feedstock for the sustainable large-scale production of LA. SIGNIFICANCE AND IMPACT OF THE STUDY: Spent coffee grounds (SCG) represent solid waste generated in millions of tonnes by coffee-processing industries. Their disposal represents a serious environmental problem; however, SCG could be valorized within a biorefinery concept yielding various valuable products. Herein, we suggest that SCG can be used as a complex carbon source for the lactic acid production.


Subject(s)
Bioreactors/microbiology , Cellulase/metabolism , Coffee/metabolism , Lactic Acid/biosynthesis , Refuse Disposal/methods , Bacillus coagulans/enzymology , Bacillus coagulans/metabolism , Biotechnology , Coffee/chemistry , Fermentation , Hydrolysis , Lacticaseibacillus rhamnosus/enzymology , Lacticaseibacillus rhamnosus/metabolism , Solid Waste
2.
Rehabilitation (Stuttg) ; 51(3): 160-70, 2012 Jun.
Article in German | MEDLINE | ID: mdl-22174099

ABSTRACT

PURPOSE: Prostate cancer patients often suffer from treatment-associated morbidities which lead to severe physical and mental impairments. Nevertheless, only a relatively small percentage of this patient population uses medical rehabilitation services; there is still a lack of evidence concerning possible factors causing use and non-use of services. Therefore, this study exploratively aims at the identification of predictors of the use of rehabilitation services in a cohort of prostate cancer patients. METHOD: In a prospective multicentre study to evaluate outpatient oncological rehabilitation services, n=242 prostate cancer patients who used outpatient or inpatient rehabilitation services ("users") were compared with n=253 prostate cancer patients who did not use rehabilitation ("non-users") at measure point 1. At the beginning of the rehabilitation programme and at the end of primary treatment, respectively, patients completed a self-report questionnaire consisting of standardized instruments designed to assess the following independent variables: autonomy striving (TPF), self-efficacy expectancy (GSE), distress (distress thermometer), anxiety and depression (HADS-D), quality of life (SF-8), social support (SSUK), rehabilitation motivation: readiness to change, knowledge, scepticism regarding rehabilitation services (PAREMO-20). Illness- and treatment-related variables (tumour state, comorbidity, primary therapies) were documented by the attending oncologists. RESULTS: Only few significant and effective differences between rehabilitation users and non-users are observed: Non-users are suffering more often from gastrointestinal comorbidities (18% vs. 2%, w=0.25). Both patient groups report severe quality-of-life impairments, particularly with respect to their physical functioning. Non-users achieve significantly higher scores on the scale "scepticism" (PAREMO-20) than users (eta²=0.19). The scale "scepticism" is also identified as the dominant predictor of utilization of rehabilitation services (R²=0.23). Suffering from comorbid diseases of the digestive system, self-efficacy expectation and employment status emerge as further significant predictors (R²=0.12, and R²=0.02 each). With increasing scepticism and in case of comorbidity the probability of rehabilitation utilization was decreasing. CONCLUSION: Besides illness-related variables prostate cancer patients' expectancies regarding the effectiveness of rehabilitation services to alleviate their medical conditions seem to be more relevant for rehabilitation utilization than sociodemographic variables or psychosocial distress. Further studies should investigate the replicability of these results and should focus on the doctor-patient-communication and the amount of information about goals and concepts of rehabilitation services prostate cancer patients are told. For clinical practice of information-giving about rehabilitation services it can be recommended not only to assess patients' physical and mental conditions but also to explore their expectations and concerns about rehabilitative treatment options in order to remove any doubts and to be able to optimize oncological care.


Subject(s)
Mental Disorders/epidemiology , Mental Disorders/rehabilitation , Prostatic Neoplasms/epidemiology , Prostatic Neoplasms/rehabilitation , Rehabilitation/statistics & numerical data , Adult , Aged , Comorbidity , Germany/epidemiology , Humans , Male , Middle Aged , Prevalence , Prognosis , Psychology , Risk Factors , Utilization Review
3.
Mycotoxin Res ; 23(1): 27-33, 2007 Mar.
Article in English | MEDLINE | ID: mdl-23605813

ABSTRACT

The contamination of animal feed with mycotoxins represents a worldwide problem for the animal industry. The most applied method for protecting animals against aflatoxicosis is the utilization of clay minerals. In the course of a research project adsorption experiments were performed in buffer solutions in order to evaluate the ability to bind Aflatoxin B1 (AfB1) at various pH-values. In order to investigate the strength of binding, the chemisorption index was calculated. Isothermal analysis was used to determine the values for the maximum adsorption capacity. Adsorption experiments in simulated gastrointestinal fluid and real gastric juice were carried out. Furthermore binding capability of the materials regarding selected vitamins was examined. Special attention was paid to the formation of AfB2a during experimental conditions. Based on the obtainedin vitro results, highly promising sorbent materials were ranked for furtherin vivo studies. Some adsorbing bentonites were also analysed mineralogically, but the results did not indicate which smectite property influences the adsorption process for AfB1.

4.
Bioresour Technol ; 92(1): 21-9, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14643982

ABSTRACT

Grass and silage presscakes from various types of raw materials were hydrolyzed with dilute acid at moderate conditions to recover hemicellulose-derived sugars. Extracting the material with cold water prior to hydrolysis significantly increased the yield. The poor performance without extraction was due to the high buffer capacity of the material. The best results were obtained with extracted grass and silage from a permanent pasture and extracted clover/grass silage. The highest observed sugar yield was 16.43 g/100 g dry-matter, which represents approximately 25% of the available sugars and 60% of the hemicellulose fraction. Including the soluble sugar oligomers, the yields were even higher (up to 20 g/100 g dry-matter). A statistical experiment design with extracted clover/grass silage was performed to estimate the effects of temperature, time, and dry-matter concentration. Acid and dry-matter concentration had the highest effect on sugar yield, whereas temperature and acid concentration were mainly responsible for forming sugar degradation products. These findings agree with recent kinetic theories. Yields in this experiment were comparable to those of other lignocellulosic materials.


Subject(s)
Carbohydrates/isolation & purification , Poaceae/chemistry , Polysaccharides/chemistry , Silage/analysis , Hydrogen-Ion Concentration , Hydrolysis , Kinetics , Sulfuric Acids
5.
Anal Bioanal Chem ; 374(4): 654-7, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12397487

ABSTRACT

Variable angle spectroscopic ellipsometry (VASE) and ellipsometric porosimetry (EP) have been used to study the effect of treatment with hexamethyldisilazane (HMDS) on the porosity of silica xerogel films. Chemical modification of the surface with HMDS was found to reduce the porosity by approximately 15%. This reduction was connected with changes which occur in the silica network, with further condensation or the reaction between neighbouring trimethylsilyl (TMS) surface groups being possible causes.

6.
Eur J Med Res ; 3(8): 361-6, 1998 Aug 18.
Article in English | MEDLINE | ID: mdl-9707517

ABSTRACT

OBJECTIVE: The influence of several antipsoriatic therapies on microsomal enzyme activity was assessed by comparing measurements of antipyrine kinetics prior to and two weeks after initiation of therapy. METHODS: Serum and urine analysis was carried out by means of high performance liquid chromatography (HPLC). Each form of therapy was examined separately. 10 patients were treated with etretinate. The groups treated with 8-methoxypsoralene (8-MOP) in combination with UVA irradiation (PUVA), etretinate in combination with PUVA (RePUVA), anthralin, or combined UVA and UVB irradiation (SUP) consisted of 7 patients each. RESULTS: Neither anthralin nor SUP therapy led to any significant changes in antipyrine kinetics. Antipyrine clearance under the other regimens was, however, reduced. It was 23% lower in PUVA-treated patients, 20% lower in those receiving retinoids and 28% lower in those under RePUVA (p<0.05 - 0. 01). CONCLUSIONS: PUVA, etretinate and RePUVA inhibit microsomal enzyme activity in the liver. Possible drug interactions with other P subset450 inducing or inhibiting agents should be considered in the therapy of psoriatic patients.


Subject(s)
Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , PUVA Therapy/adverse effects , Psoriasis/drug therapy , Psoriasis/enzymology , Administration, Topical , Anthralin/adverse effects , Anti-Inflammatory Agents/adverse effects , Antipyrine/pharmacokinetics , Cytochrome P-450 Enzyme Inhibitors , Drug Interactions , Etretinate/adverse effects , Humans , Keratolytic Agents/adverse effects , Metabolic Clearance Rate/drug effects , Metabolic Clearance Rate/radiation effects , Methoxsalen/adverse effects , Microsomes, Liver/radiation effects , Psoriasis/radiotherapy , Ultraviolet Rays/adverse effects
7.
J Clin Oncol ; 12(8): 1685-92, 1994 Aug.
Article in English | MEDLINE | ID: mdl-7518860

ABSTRACT

PURPOSE: To evaluate the feasibility of a sequential high-dose therapy with peripheral-blood progenitor-cell (PBPC) support in patients with follicular lymphoma. PATIENTS AND METHODS: Since July 1991, we have included 30 patients (17 men and 13 women) with a median age of 41 years (range, 26 to 55) in the study. At the time of study entry, 17 patients were in first and six in second or higher remission. Another six patients had relapse of disease and one had tumor progression. PBPC were collected during filgrastim-supported leukocyte recovery following high-dose cytarabine (ara-C)/mitoxantrone (HAM). RESULTS: A median of two leukaphereses (range, one to seven) resulted in a median of 5.7 x 10(6) CD34+ cells/kg (range, 2.9 to 23.7 x 10(6). A distinct population of B-lymphoid progenitors (CD34+/CD19+) was not detectable in the autografts, and the content of CD19+ B cells was remarkably low, comprising a median of 0.07% of the mononuclear cells. Using the polymerase chain reaction (PCR) assay for the major breakpoint regions (MBR) of the bcl-2/immunoglobulin H (IgH) translocation, 22 patients had autografts positive for the t(14;18) translocation, whereas seven patients had PCR-negative transplants. The autograft of one patient could not be assessed. Following myeloablative therapy, hematologic recovery was rapid without cytokine support. The median times to reach a platelet count > or = 20 x 10(9)/L and neutrophil count > or = 0.5 x 10(9)/L were 11 and 13 days, respectively. Nonhematologic toxicity was moderate. Twenty-nine patients were alive in remission after a median follow-up duration of 6 months (range, 1 to 18). Of 22 patients autografted with t(14;18)-positive harvests, 11 had PCR-detectable cells in bone marrow and/or peripheral blood as long as 16 months posttransplantation. In contrast, six patients became PCR-negative between 3 and 16 months after reinfusion. Follow-up examinations with PCR data for the remaining five patients are not yet available. CONCLUSION: Conversion to PCR negativity in patients autografted with PCR-positive harvests suggests that the myeloablative regimen is effective and that any reinfused t(14;18)-positive cells may not be sustained. Because conventional chemotherapy provides no cure, we believe that high-dose therapy including total-body irradiation (TBI) should be explored in these particularly radiosensitive lymphomas.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Hematopoietic Stem Cell Transplantation , Lymphoma, Non-Hodgkin/therapy , Adult , Base Sequence , Chromosomes, Human, Pair 14 , Chromosomes, Human, Pair 18 , Combined Modality Therapy , Cytarabine/administration & dosage , Feasibility Studies , Female , Filgrastim , Flow Cytometry , Fluorescent Antibody Technique , Granulocyte Colony-Stimulating Factor , Humans , Lymphoma, Non-Hodgkin/genetics , Lymphoma, Non-Hodgkin/pathology , Male , Middle Aged , Mitoxantrone/administration & dosage , Molecular Sequence Data , Platelet Transfusion , Polymerase Chain Reaction , Recombinant Proteins , Translocation, Genetic , Transplantation, Autologous , Whole-Body Irradiation
8.
Blood ; 83(12): 3787-94, 1994 Jun 15.
Article in English | MEDLINE | ID: mdl-7515721

ABSTRACT

For patients with advanced-stage or poor-prognosis malignant lymphoma, high-dose therapy with peripheral blood progenitor cell (PBPC) support may become a first-line treatment. The duration of severe cytopenia in this setting is inversely related to the number of PBPCs autografted. In a retrospective analysis, we therefore looked for factors influencing the yield of PBPCs in 61 patients (16 with high-grade and 29 with low-/intermediate-grade non-Hodgkin's lymphoma [NHL], and 16 with Hodgkin's disease) who received cytotoxic chemotherapy and filgrastim (R-metHuG-CSF, 300 micrograms/d; median, 4.2 micrograms/kg/d; range, 2.7 to 6.6 micrograms/kg/d; subcutaneously). Sixteen patients had active disease, while 45 were in partial remission (PR) or complete remission (CR) after conventional therapy. A median of three leukaphereses (range, one to 10) resulted in a median of 5.7 x 10(6) CD34+ cells/kg (range, 0.03 to 31.1 x 10(6)). Previous cytotoxic chemotherapy and irradiation adversely affected the yield of CD34+ cells. Each cycle of chemotherapy is associated with an average decrease of 0.2 x 10(6) CD34+ cells/kg per leukapheresis in nonirradiated patients, while large-field radiotherapy reduces the collection efficiency by an average of 1.8 x 10(6)/kg CD34+ cells. The collection efficiency was also significantly lower in patients with Hodgkin's disease. However, except for one, all had been previously irradiated. In contrast, age, sex, disease status, bone marrow involvement during mobilization, and the time since the last chemotherapy or radiotherapy were not significantly related to the collection efficiency. Following high-dose conditioning therapy, 42 patients were autografted with filgrastim-mobilized PBPCs. Hematological recovery (neutrophils > or = 0.5 x 10(9)/L and an unsupported platelet count > or = 20 x 10(9)/L) within 2 weeks was observed in patients autografted with > or = 2.5 x 10(6) CD34+ cells/kg. In seven patients, the quantity of CD34+ cells reinfused was below this threshold. They required a median of 17 days (range, 11 to 34) and 31 days (range, 13 to 141) for neutrophil and platelet recovery, respectively. If autografting with PBPCs in malignant lymphoma with poor prognosis is being considered, mobilization and harvesting should be planned early after initial diagnosis to avoid exhaustion of hematopoiesis by cumulative toxicity.


Subject(s)
Hematopoietic Stem Cell Transplantation , Lymphoma/therapy , Adolescent , Adult , Antigens, CD/analysis , Antigens, CD34 , Cell Separation , Female , Filgrastim , Granulocyte Colony-Stimulating Factor/pharmacology , Humans , Male , Middle Aged , Recombinant Proteins/pharmacology , Transplantation, Autologous
9.
Cancer Res ; 51(11): 2943-8, 1991 Jun 01.
Article in English | MEDLINE | ID: mdl-2032232

ABSTRACT

DNA protein cross-links (DPC), DNA interstrand cross-links (ISCL), and DNA single strand breaks following treatment of experimental ovarian tumor cells (O-342) with five new metal complexes (three platinum, one titanium, one ruthenium compounds) were investigated at 6, 24, and 48 h after drug exposure and compared with their in vitro growth inhibitory potential. cis-Diamminedichloroplatinum(II) (cisplatin, DDP) served as reference drug. The following new compounds were tested: 18-crown-6-tetracarboxybis-diammineplatinum(II) (CTDP), cis-aminotrismethylenephosphonato-diammineplatinum(II) (AMDP), cis-diamminecyclohexano-aminotrismethylenephosphonato-platin um(II) (DAMP), diethoxybis-(1-phenylbutane-1,3-dionato)-titanium(IV) (budotitane), and trans-indazolium-tetrachlorobisindazole-ruthenate(III) (IndCR). At equimolar concentrations DNA cross-linking activity of the platinum agents decreased in the order cisplatin, CTDP, AMDP, DAMP; this was paralleled by growth inhibition in a cell proliferation assay. CTDP-induced interstrand cross-linking occurred more slowly compared to cisplatin (DDP) (6 h: CTDP, 73 +/- 15 versus DDP, 365 +/- 72 rad equivalents), but reached a peak similar to cisplatin 24 h after exposure (CTDP, 317 +/- 68 versus DDP, 392 +/- 116 rad equivalents). At this time point in contrast to DDP no DNA protein cross-links were observed for CTDP (total cross-links: CTDP 310 +/- 71, DDP 1987 +/- 436 rad equivalents). Thus, at 24 h, CTDP was found to be distinctly less reactive to proteins than DDP, and it is suggested that CTDP might be similar in its toxicity pattern to the structurally related compound carboplatin which was also reported to be less reactive to protein than DDP. By 48 h, CTDP- and DDP-induced interstrand cross-links were 65 +/- 21 and 180 +/- 33 rad equivalents, respectively. Although at a lower level, by 24 h, AMDP showed a ratio of ISCL to total cross-links (179 +/- 39 versus 213 +/- 31 rad equivalents), which was comparable to CTDP. The second biphosphonate complex DAMP was the least active platinum compound in terms of DNA damage, effecting only 16 +/- 7 rad equivalents ISCL and 63 +/- 28 rad equivalents total cross-links; similar to DDP, DAMP displayed a higher DPC fraction at 24 h. The titanium complex diethoxybis-(1-phenylbutane-1,3-dionato)-tita-++ +nium(IV) showed dose-dependent inhibition of cell proliferation, while no significant DNA damage could be detected with the alkaline elution technique. These results, together with observations from other authors, indicating that space-filling planar aromatic ring systems are important for its antitumor activity, suggest as possible mechanism of action of diethoxybis-(1-phenylbutane-1,3-dionato)-titanium(IV) intercalation into the DNA.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Crown Ethers , DNA, Neoplasm/drug effects , Indazoles/pharmacology , Organometallic Compounds/pharmacology , Organophosphorus Compounds/pharmacology , Organoplatinum Compounds/pharmacology , Ovarian Neoplasms/drug therapy , Ruthenium/pharmacology , Titanium/pharmacology , Animals , Drug Screening Assays, Antitumor , Ethers, Cyclic , Ethylnitrosourea , Female , Ovarian Neoplasms/chemically induced , Ovarian Neoplasms/genetics , Rats
10.
Cancer Chemother Pharmacol ; 27(4): 301-7, 1991.
Article in English | MEDLINE | ID: mdl-1998986

ABSTRACT

The antitumor activity of eight new metal complexes (three platinum, one titanium, four ruthenium derivatives) was investigated in a cisplatin (DDP)--sensitive (O-342) and a DDP-resistant (O-342/DDP) ovarian tumor line using the bilayer soft-agar assay. A continuous exposure set up at logarithmically spaced concentrations was used to test the drugs; to uncover possible pharmacokinetic features, a short-term exposure was additionally included for selected compounds. DDP served as the reference drug. The following compounds were investigated: 18-crown-6-tetracarboxybis-diammineplatinum(II) (CTDP), cis-aminotrismethylenephosphonato-diammine-platinum(II) (ADP), cis-diamminecyclohexano-aminotrismethylenephosphonato-platin um(II) (DAP), diethoxybis(1-phenylbutane-1,3-dionato)titanium(IV) (DBT, budotitane), trans-imidazolium-bisimidazoletetrachlororuthenate(III) (ICR), trans-indazolium-tetrachlorobisindazoleruthenate(III) (IndCR), cis-triazolium-tetrachlorobis-triazoleruthenate(III) (TCR) and trans-pyrazolium-tetrachlorobispyrazoleruthenate(III) (PCR). Of the new metal complexes, CTDP was the most active compound in O-342, resulting in a percentage of control plating efficiency (+/- SE) of 1 +/- 1, 12 +/- 8 and 40 +/- 21 following continuous exposure to 10, 1 and 0.1 microM, respectively, and was thus comparable to DDP at equimolar concentrations. In the resistant line, 10 microM CTDP reduced colony growth to 18% +/- 8%, whereas an equimolar concentration of DDP effected a reduction to 26% +/- 9%. During short-term exposure. CTDP was inferior to DDP, which may be ascribed to the stability of the bis-dicarboxylate platinum ring system. The titanium compound DBT, in contrast, showed promising effects at its highest concentration (100 microM) during short-term exposure in both lines; at this concentration the activity in O-342/DDP was higher than that in O-342 (7% +/- 7% vs 34% +/- 17% of control plating efficiency at 100 microM). All ruthenium complexes showed higher activity in the resistant line O-342/DDP than in the sensitive counterpart. ICR was the most active compound. Following continuous exposure of O-342/DDP cells to 10 microM ICR, colony growth was reduced to 18% +/- 4% that of controls. Further studies should concentrate on CTDP and ICR for the following reasons; the activity of CTDP was equal to that of DDP at equimolar concentrations during continuous exposure; considering that the in vivo toxicity of DDP was 3-fold that of CTDP, an increase in the therapeutic index of CTDP would be expected. ICR showed the best effect of all ruthenium complexes; it was superior to DDP in the resistant line.


Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Platinum/pharmacology , Ruthenium/pharmacology , Titanium/pharmacology , Animals , Dose-Response Relationship, Drug , Drug Resistance , Drug Screening Assays, Antitumor , Female , Ovarian Neoplasms/pathology , Rats , Tumor Cells, Cultured/drug effects
11.
Eur J Cancer ; 27(1): 62-7, 1991.
Article in English | MEDLINE | ID: mdl-1826445

ABSTRACT

In a cisplatin resistant subline (O-342/DPP) of an intraperitoneally growing transplantable rat ovarian tumour (O-342), intracellular glutathione (GSH) was approximately doubled (mean [S.E.] 1.5 [0.26] vs. 0.8 [0.2] nmol/10(6) cells). GSH reductase activity was higher (30.64 [4.07] vs. 20 [0.92] nmol/min per mg protein), although no difference was found for GSH-S-transferase. 24 h after exposure to cisplatin, formation of DNA interstrand cross-links was at a maximum in both lines and significantly higher in O-342 (162 [23] vs. 88 [22] rad eq). Combination treatment of O-342/DDP with buthionine sulphoximine plus cisplatin resulted in a marginal increase in survival compared with cisplatin treatment; treatment of this line with 3-aminobenzamide plus cisplatin was also superior to cisplatin alone. In the sensitive line both combinations were likewise superior to cisplatin alone. In vitro, at equimolar concentration, a new platinum complex (CTDP) was at least as active as cisplatin in both lines, which suggests a superior therapeutic index because its LD50 in mice is threefold higher than that of cisplatin. A ruthenium complex (ICR) had a higher activity in the resistant line. A titanium complex (budotitane) was not active.


Subject(s)
Cisplatin/therapeutic use , Drug Resistance/physiology , Ovarian Neoplasms/drug therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Line , Female , Glutathione/metabolism , Glutathione Reductase/metabolism , Glutathione Transferase/metabolism , Metals/pharmacology , Neoplastic Stem Cells/drug effects , Ovarian Neoplasms/metabolism , Rats , Rats, Inbred Strains
12.
Cancer Res ; 49(12): 3267-70, 1989 Jun 15.
Article in English | MEDLINE | ID: mdl-2720679

ABSTRACT

1-Nitroso-1-(2-hydroxyethyl)-3-(2-chloroethyl)urea (Compound I) and 1-nitroso-1-(2-hydroxypropyl)-3-(2-chloroethyl)urea (Compound II) display significantly reduced antitumor activity compared to the corresponding isomeric derivatives 1-nitroso-1-(2-chloroethyl)-3-(2-hydroxyethyl) urea (Compound III) and 1-nitroso-1-(2-chloroethyl)-3-(2-hydroxypropyl) urea (Compound IV). Their low therapeutic activity is paralleled by low toxicity while mutagenicity and carcinogenicity are high. A comparative investigation of the genotoxicity of Compounds I and III using primary cultures of fetal hamster lung cells revealed an about 14-fold higher rate of DNA single-strand breaks following exposure (100 microM, 1 h) to Compound I as compared to Compound III. The rate of DNA interstrand cross-links, on the other hand, was 11-fold higher following Compound III as compared to Compound I. The results underline that the therapeutic activity of chloroethylnitrosoureas is mainly attributable to their cross-linking potential while induction of DNA single-strand breaks plays a decisive role for mutagenicity and carcinogenicity but appears not to be relevant for antineoplastic effectiveness.


Subject(s)
Antineoplastic Agents/therapeutic use , Leukemia L1210/drug therapy , Leukemia, Experimental/drug therapy , Nitrosourea Compounds/therapeutic use , Animals , Drug Evaluation, Preclinical , Female , Mice , Mice, Inbred Strains , Rats , Rats, Inbred Strains , Structure-Activity Relationship
13.
Z Gastroenterol ; 17(5): 318-24, 1979 May.
Article in German | MEDLINE | ID: mdl-463172

ABSTRACT

The possible role of calcium in human bile during the biliary stimulated exocrine pancreatic secretion was investigated in 15 healthy volunteers. Total outputs of trypsin, bicarbonate, bilirubin and volume in the duodenal juice and serum gastrin were measured during a continuous intravenous infusion of secretion (0.5 CHR U/kg/h) for 40 min. The same parameters were determined after a single intraduodenal dose of Ca++ (20 ml 13,5, 135 or 270 mval/l, n = 5 for each dose) and compared with aequivalent intraduodenal dose of Na+ and an intravenous dose of secretion/cholecystokinin (1 CHR and IDU U/kg). Low calcium (13,5 mval/l) had no effect on the output of pancreatic enzymes and bile. However the higher doses led to a significant increases of the outputs of trypsin and bilirubin, which was about 75% of the enhancement seen with secretin/cholecystokinin in the dose used. Serumgastrin secretion was significantly increased only after the higher calcium doses.--Serum insulin in peripheral venous blood venous blood was unchanged after duodenal application of 20 ml 270 mval/l calcium (n = 5). From these data one has to conclude that the Ca++-content of bile has no stimulatory effect on the exocrine pancreas and on serum gastrin and insulin.


Subject(s)
Calcium/pharmacology , Gastrins/blood , Pancreatic Juice/metabolism , Adolescent , Adult , Aged , Bile/analysis , Calcium/analysis , Duodenum , Humans , Insulin/blood , Middle Aged
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