Determination of toxic α-dicarbonyl compounds, glyoxal, methylglyoxal, and diacetyl, released to the headspace of lipid commodities upon heat treatment.

Toxic α-dicarbonyl compounds, glyoxal, 2-methylglyoxal, and diacetyl, released from the headspace from butter, margarine, safflower oil, beef fat, and cheese heated at 100 and 200 °C were analyzed by gas chromatography as quinoxaline derivatives. Total amounts of α-dicarbonyl compounds ranged from 40.5 ng/g (butter) to 331.2 ng/g (beef fat) at 100 °C and from 302.4 ng/g (safflower oil) to 4521.5 ng/g (margarine) at 200 °C. The total amount of α-dicarbonyl compounds increased approximately 55- and 15-fold in the headspace of heated butter and margarine, respectively, when the temperature was increased from 100 to 200 °C. However, only slight differences associated with temperature variation were observed in the cases of safflower oil and beef fat (1.3- and 1.1-fold, respectively). Diacetyl was found in the highest amounts among all samples, ranging from 13.9 ± 0.3 ng/g (butter) to 2835.7 ng/g (cheese) at 100 °C and from 112.5 ± 102 ng/g (safflower oil) to 2274.5 ± 442.6 ng/g (margarine) at 200 °C, followed by methylglyoxal, ranging from 13.0 ± 0.5 to 112.7 ± 10.1 ng/g (cheese) at 100 °C and from 34.7 ± 5.0 ng/g (safflower oil) to 1790 ± 372.3 ng/g (margarine) at 200 °C. Much less glyoxal formed, in amounts ranging from 13.6 ± 0.7 ng/g (butter) to 53.4 ± 11.2 ng/g (beef fat) at both temperatures. The amounts of α-dicarbonyl compounds released into the vapor phase from lipid commodities during heating were satisfactorily analyzed.

Glucose autoxidation induces functional damage to proteins via modification of critical arginine residues.

Nonenzymatic modification of proteins in hyperglycemia is a major mechanism causing diabetic complications. These modifications can have pathogenic consequences when they target active site residues, thus affecting protein function. In the present study, we examined the role of glucose autoxidation in functional protein damage using lysozyme and RGD-α3NC1 domain of collagen IV as model proteins in vitro. We demonstrated that glucose autoxidation induced inhibition of lysozyme activity as well as NC1 domain binding to α(V)ß(3) integrin receptor via modification of critical arginine residues by reactive carbonyl species (RCS) glyoxal (GO) and methylglyoxal while nonoxidative glucose adduction to the protein did not affect protein function. The role of RCS in protein damage was confirmed using pyridoxamine which blocked glucose autoxidation and RCS production, thus protecting protein function, even in the presence of high concentrations of glucose. Glucose autoxidation may cause protein damage in vivo since increased levels of GO-derived modifications of arginine residues were detected within the assembly interface of collagen IV NC1 domains isolated from renal ECM of diabetic rats. Since arginine residues are frequently present within protein active sites, glucose autoxidation may be a common mechanism contributing to ECM protein functional damage in hyperglycemia and oxidative environment. Our data also point out the pitfalls in functional studies, particularly in cell culture experiments, that involve glucose treatment but do not take into account toxic effects of RCS derived from glucose autoxidation.

Impact of first- and second-line treatment for Hodgkin's lymphoma on the incidence of AML/MDS and NHL--experience of the German Hodgkin's Lymphoma Study Group analyzed by a parametric model of carcinogenesis.

BACKGROUND: Using a parametric carcinogenesis model, we disentangle the superimposing effects of primary and relapse therapies of Hodgkin's disease on secondary neoplasias. PATIENTS AND METHODS: We analyze eight randomized trials of the German Hodgkin's lymphoma study group [5357 individuals, 67 secondary acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and 97 secondary non-Hodgkin's lymphoma (NHL)]. Primary therapies were divided into four groups: radiotherapy alone, moderately dosed COPP/ABVD-like chemotherapies for intermediate and advanced stages and BEACOPP escalated. RESULTS: For secondary AML/MDS, the hazards after primary therapies are proportional (maximum at 3.4 years), while the hazard after relapse therapy is more peaked (maximum at 1.8 years). Intermediate and advanced stage chemotherapy resulted in a cumulative risk of 1.5%, while the risk after BEACOPP escalated is higher (4.4%, P = 0.004) and comparable with that after relapse therapy (4.5%). For secondary NHL, there are no differences in cumulative risk between the primary therapies (2.9%), while the risk after relapse therapy is increased (6.6%, P = 0.002). CONCLUSIONS: BEACOPP escalated moderately increases the risk of secondary AML/MDS but not NHL. No differences were found between other chemotherapies of advanced stages and intermediate stages. Secondary AML/MDS occurs faster after relapse treatment than after primary treatment.

Occupational contact allergy to glyoxal.

Glyoxal is a dialdehyde that is used as a disinfectant in health care and dentistry work. Allergic contact dermatitis from glyoxal has been described in these occupations. We analysed our patient data from 1998 to 2004 for allergic reactions to glyoxal. 20 patients had allergic reactions to glyoxal on patch testing. 5 of these patients worked in dentistry and 4 of them had present exposure to glyoxal. 9 patients were machinists without obvious exposure to glyoxal. A grinder with work-related facial dermatitis is described in detail. The chemical analysis of air samples from his workplace revealed 9.4-21 microg/m3 glyoxal. Glyoxal was also present in the used metal-working fluid, and apparently it had been formed during grinding. The remaining 6 patients worked in miscellaneous occupations and had no present exposure to glyoxal. Glyoxal is irritant on patch testing. Especially, solitary reactions to glyoxal 10% in aq. may be false-positive irritant reactions. 9 (45%) of our patients reacted to formaldehyde or glutaraldehyde. Glyoxal is an important allergen in dentistry and medical care, and we recommend it to be added to the antimicrobial patch test series. It also seems to be a 'hidden' allergen in the metal industry.

Low acute hematological toxicity during chemotherapy predicts reduced disease control in advanced Hodgkin's disease.

Chemotherapy-treated patients with advanced Hodgkin's disease (HD) differ considerably in acute hematotoxicity. Hematotoxicity may be indicative of pharmacological and metabolic heterogeneity. We hypothesized that low hematotoxicity might correlate with reduced systemic dose and thus reduced disease control. A total of 266 patients with advanced HD treated with cyclophosphamide, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine, and dacarbazine (COPP-ABVD) were analyzed (HD6 trial of the German Hodgkin's Lymphoma Study Group). The reported WHO grade of leukocytopenia was averaged over chemotherapy cycles given and weighted with the reciprocal dose intensity of the corresponding cycle. The low and high toxicity groups were defined in retrospect as having had an averaged WHO grade of leukocytopenia 2.1, respectively. The independent impact of low hematological toxicity on freedom from treatment failure (FFTF) was assessed multivariately adjusting for the international prognostic score for advanced HD. The results were validated in two independent cohorts [181 patients treated with COPP-ABVD (HD9-trial) and 250 patients treated with COPP-ABV-ifosfamide, methotrexate, etoposide, and prednisone (IMEP) (HD6 trial)]. The 5-year FFTF rates were 68% for patients with high toxicity vs 47% for patients with low toxicity [multivariate relative risk (RR) 2.0, 95% confidence interval (CI) 1.4-3.0, p=0.0002]. Patients with low toxicity received significantly higher nominal dose ( p=0.02) and dose intensity ( p<0.0001). This finding was confirmed in both validation cohorts (multivariate RR 2.1, 95% CI 1.2-3.8, p=0.01 and RR 1.5, 95% CI 1.01-2.26, p=0.04, respectively). Patients with low hematotoxicity have significantly higher failure rates despite higher doses and dose intensity. Hematotoxicity is an independent prognostic factor for treatment outcome. This observation suggests a strategy of individualized dosing adapted to hematotoxicity.

Glyoxal is an important allergen for (medical care) cleaning staff.

While disinfection is essential in medical practice, it carries the risk of serious adverse effects, including allergic contact dermatitis. To assess the current importance of glyoxal [CAS 107-22-2] as occupational allergen, a retrospective descriptive analysis of records of an occupational dermatitis clinic in Osnabrück and of national surveillance data of the Information Network of Departments of Dermatology (IVDK) in Germany and Austria was performed. Of 189 highly selected patients with occupational dermatitis tested with glyoxal (1% in water or, as trimer, 1% in petrolatum) in Osnabrück, 11 had positive reactions to glyoxal, which were occupationally relevant in 9 cases. Causative occupations included mainly nursing and room cleaning. In a less selected population of 2626 additional patients tested in other centres of the IVDK, 40 further positive reactions to glyoxal were observed. Concomitant sensitisation to glutardialdehyde and formaldehyde, respectively, was frequently observed. In conclusion, glyoxal should be tested in all patients with contact dermatitis working in occupations with possible exposure to respective disinfecting/cleaning agents.

Analysis of the risk of solid tumor following Hodgkin's disease.

BACKGROUND AND OBJECTIVE: This study examines the occurrence of solid tumor (ST) in relation to the different types of therapy (radiotherapy, chemotherapy and radiochemotherapy; splenectomy or splenic irradiation vs no splenectomy-no splenic irradiation) received by patients treated for Hodgkin's disease (HD). METHODS: The study included 1,045 HD patients treated at the Department of Radiation Oncology, the Institute of Radiology and the Department of Human Biopathology, Hematology Section, University of Rome, "La Sapienza", from 1972 to 1992. For 23% of the patients the follow-up period was longer than 10 years. The average follow-up period was 72 months. For a more accurate calculation of the risk of ST occurrence, the patients were first divided into 3 subgroups according to initial treatment and then according to the total treatment they had received. Moreover, to establish a probable connection between solid tumor and splenic treatment the patients were also divided into 3 subgroups (splenectomy, splenic irradiation and no splenectomy/no splenic irradiation). RESULTS: We recorded twenty-four cases of ST after initial treatment. Secondary solid tumor showed a cumulative risk of 0.2% and 13.4% at 5 and 20 years, respectively. After initial treatment with radiotherapy (RT) alone, the cumulative risk was 1.7% and 5.2% at 10 and 20 years, respectively; in the chemotherapy (CT) group, it was 2.4% and 18.1%; in the CT(+)RT group, it was 1.7% and 9%. No statistically significant differences were observed among the different types of treatment (splenectomy, splenic irradiation or no splenectomy/no splenic irradiation) as regards the occurrence of ST. According to multivariate analysis, the most important factor in the risk of ST was age (> 40). Relative risk was 5.2, p = 0.0001. INTERPRETATION AND CONCLUSIONS: We conclude that an age of over 40 at diagnosis and treatment with CT alone greatly increase the risk of solid tumor occurrence.