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Biomedical subjects

W Fritz

Publications and source records attributed to W Fritz.

At least 37 records · Page 2Linked to original sources
PubMed1983

[Formation and occurrence of cancer-producing hydrocarbons in cereals and possibilities for their reduction].

According to the authors' investigations every inhabitant of the GDR takes between 0.2 and 1.0 mg BaP. per year by food consumption including amounts of 0.03 to 0.17 mg on account of cereals and mill products. For the contamination of cereals the following sources are in consideration: environmental contamination on account of industry dust (distant from industry 0.1 to 0.6, near to industry 0.3 to 4.2 micrograms BaP/kg), passing over from soil to plant (with model experiments with soils more than 10 000 micrograms BaP/kg up to 22.3 micrograms BaP/kg dry matter) as well as technologically caused contamination for instance by direct fume-and-gas drying (with the use of raw lignite up to 10 micrograms BaP/kg). As it can be concluded from model experiments BaP passes to flour at milling in dependence of the extraction rate. By separating the husks prior to milling more than 50% of BaP can be removed from the stock.

Air Pollutants↗
PubMed1983

[Analysis and evaluation of carcinogenic polycyclic aromatic hydrocarbons from the view of food hygiene and toxicology--a survey].

The contamination of foods is technologically induced by smoke gases (smoking, grilling, drying) and also due to environmental factors such as air and soil, soil conditioners, migration from plastics etc. The author presents and discusses the major problems concerning the accurate analysis of smallest amounts (micrograms/kg of food) of polycyclic aromatic hydrocarbons (PAH). Such problems occur in the separation from he matrix and the clean-up of the PAH, as well as in their identification and determination. Benzo[a]pyrene - under certain preconditions internationally accepted as the reference standard of PAH - is ingested by the GDR citizens in an order of magnitude ranging from 0.2 to 1.0 mg per annum; this corresponds to a daily intake varying within 0.5 and 2.5 micrograms. It is particularly difficult and as yet not possible to establish scientifically founded maximum tolerances for cancerogenic substances in foods which exclude a risk to man. The establishment of tolerances in the sense of a "socially acceptable level of risk" (which does not mean physiological safety) is recommended. Controlled tolerances would enable the legislator to aim at the optimum reduction or exclusion of the cancerogenic noxious agent in the framework of technical and economic possibilities.

Benzo(a)pyrene↗
PubMed1983

[Behavior of benzo(a)pyrene in the soil and passage from soil to crops].

The behaviour of Benzo[a]pyren (BaP) in the soil and its passage from the soil into the crops has been investigated by means of model tests. In situ fluorescence spectroscopy enables a detection of 0.01 micrograms/BaP/kg with recoveries ranged from 75 to 99.6% and an average variation coefficient of 15%. A decomposition of BaP in test soils within 18 months from 30 mg/kg to 1.5 mg/kg could be attributed to decomposition by soil bacteria. After addition of bactericidal substances to the soil there was no decomposition for several years. In soils with concentrations below 1000 micrograms BaP/kg no passage of BaP into the crops can be detected. Contrary to the opinion of several authors that BaP does not pass from the soil into the crops, model tests conducted for a few years show that a relevant passage into crops such as carrots and radish, as well as into lettuce, spinach and parsley, is possible. The passage into potatoes, tomatoes, peas, and beans is less significant. The degree of contamination of crops is in a certain relation to the degree of the contamination of the soils, but this has only been found with a BaP content of more than 1000 micrograms/kg. Sandy soils which significantly exceed the BaP content of about 1000 micrograms/kg, as they may occur in industrial areas, above all near emittents, are not suitable for the cultivation of some vegetables, such as lettuce and carrots, for human nutrition.

Benzo(a)pyrene↗
PubMed1982

[Treatment of postoperative pulmonary insufficiency in newborn with congenital diaphragmatic hernia].

Treatment of postoperative pulmonary insufficiency in congenital diaphragmatic hernia has two aims: on the one hand, it serves to assist in achieving full pulmonary development, whereas on the other hand it aims at lowering pulmonary hypertension. Full development of the hypoplastic lung is the decisively important factor with regard to improving ventilation and perfusion. The same degree of importance is attached to correcting hypoxia as well as acidosis. The different performance of the lungs in respect of mechanics of breathing can be influenced most effectively by a well-balanced application of several measures exercising an influence on pulmonary pressure, such as positive ventilatory pressure and thoracic suction drainage. If these measures are unsuccessful and in case of a clinically relevant ductal right-left shunt, it is recommended to administer vasodilators; in exceptional cases, ductal ligature can be the procedure of choice. These therapeutic problems are discussed on the basis of an evaluation of the authors' own patients treated between 1976 and 1980 (10 cases).

Diaphragmatic Eventration↗
PubMed1982

Comparisons: Indian and non-Indian use of psychiatric services.

Major differences were found between the Saskatchewan Indian and non-Indian populations in regard to the prevalence of psychiatric disorders, their rates of treatment and the mix of inpatient and outpatient services they receive. Diagnostic and treatment differences between the two populations were more pronounced in the "private" in relation to demographic, socioeconomic and cultural differences between Indian and non-Indian populations and to size and organizational differences between the "public" and "private" treatment sectors.

Ambulatory Care↗
PubMed1981

[Environmentally induced contamination of foods by carcinogenic hydrocarbons in the GDR and the Hungarian People's Republic].

In the GDR the benzo[a]pyrene (BaP) contents of vegetables grown in areas far from industrial plants range from 0.01 to 2.3 microgram/kg of fresh weight with a mean of 0.43 microgram/kg; and in the Hungarian People's Republic the BaP contents of such vegetables lie between 0.05 and 3.85 microgram/kg with a mean of 0.6 microgram/kg. The BaP contents of vegetables from areas near industrial plants or in the immediate proximity of emitters range from 0.15 to 12.4 microgram/kg (in the GDR) and from 0.05 to 19.6 microgram/kg (in the Hungarian People's Republic), being markedly superior to the values obtained with comparable vegetables from areas far from industrial plants. The BaP contents of samples from the Hungarian People's Republic collected near a relatively new petrochemical plant were 3.5 times as high as those of samples collected in areas far from industrial plants; and the BaP contents obtained with samples collected in the proximity of an old petrochemical plant were 8 times as high as those observed with samples collected in areas far from industrial plants. The contamination depends strongly upon the type of emitter. Samples collected in the GDR in the immediate proximity of coal-preparation plants (such as tar extraction, coking or carbon black plants) contained BaP contents 10 to 100 times as high as those found in samples collected in areas far from industrial plants. Targeted measures aiming at diminishing air pollution will widely reduce the contamination of harvested crops with cancerogenic hydrocarbons.

Carcinogens↗
PubMed1981

Survey of selected mycotoxins in food.

The contamination of a variety of foods with the mycotoxins aflatoxins B1, B2, G1, M1, ochratoxin A, patulin, and byssochlamic acid was investigated. With the developed methods, the identification was made possible by in situ fluorescence spectral analysis with a far reaching exclusion of substances which simulate sycotoxins. Aflatoxin B1 was detected in 2 samples of 105 spontaneously moulded food specimens and only in 1 of a group of 198 food samples that were obviously not moulded. Aflatoxin M1 was identified in 4 of 60 samples of the so-called wintermilk. Investigated dairy products did not contain aflatoxin M1. Ochratoxin A could be detected twice in 49 spontaneously moulded corn samples, aflatoxin, however, was not found. Further investigations of 50 samples of moulded food revealed ochratoxin A in 2 samples of raw coffee. Food samples obviously not moulded did not contain ochratoxin A. Patulin was detected in 19 of 110 samples of fruit and fruit products, especially in commercial apple juice, in rotten parts of apples, and in moulded fruit products. Byssochlamic acid was not detected in fruit juices or in fruit. The toxicological consequences of mycotoxins in food and possibilities to reduce mycotoxins are discussed.

Aflatoxins↗
PubMed1981

[Comparative studies on the contamination of foods by cancerogenic hydrocarbons in the Soviet Union and in the GDR. Part 2. Contribution to the method (author's transl)].

The principle of the method used in the Central Institute of Nutrition of the Academy of Sciences of the GDR, in the Oncological-Scientific Centre in Moscow, and in the Petrov Institute of Oncology in Leningrad, for the determination of cancerogenic hydrocarbons including the reference substance benzo[a]pyrene in foods is described and compared with other methods. The results of a comparative study among the institutes mentioned are in a good agreement. The coefficients of variation range between 3.5 and 18.9 percent, depending of the samples. These methodical presumptions enable an international cooperation to recognize the sources and the amounts of food contamination by benzo[a]pyrene.

Benzopyrenes↗
PubMed1980

[Analysis of volatile nitrosamines in food of animal origin].

A method is described for the fluorescence-spectrophotometric densitometric determination of nitrosamines. For this purpose, foods of animal origin are vacuum-distilled, the distilled-over nitrosamines are extracted with methylene chloride from an acid medium and, after cleavage by hydrogen bromide, the corresponding amines are reacted with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole. The purificaton of the extract and the resolution of the corresponding fluorescent amine derivatives are effected simultaneously by two-dimensional thin-layer chromatography. The determination is achieved by in situ fluorescence spectrophotometry against test substances on the same slab. This method seems useful for investigations into the formation of nitrosamines in foods of animal origin because it permits to detect nitrosamine concentrations as low as 0.1 microgram/kg of food.

Animals↗
PubMed1980

Smoked food and cancer.

Smoking is a well-known source of food contaminated caused by carcinogenic polycyclic aromatic hydrocarbons. Epidemiological studies indicates a statistical correlation between the increased occurrence of cancer of the intestinal tract and the frequent intake of smoked foods. As observed during the last 10 years in a certain district of Hungary with a Slovenian population, the percentage of stomach cancer among all types of cancer is nearly twice as high (47-50%) as in Hungary altogether (29.9%). In this special district, predominantly home-smoked meat products are consumed. Using identical techniques, the authors investigated the contamination of smoked foodstuffs by carcinogenic, cocarcinogenic and other polyaromatic hydrocarbons in the German Democratic Republic and in Hungary. No significant differences have been found either in the average values or in the ranges of the benzo(a)pyrene (BaP) contents in meats smoked by industrial processes used in the GDR and in Hungary. In the GDR, industrially smoked foods contain on average 0.43 micrograms/kg, products smoked in handicraft workshops 0.76 micrograms/kg, home-smoked products 0.74 micrograms/kg. The mean BaP content of all smoked meat and sausage products amounts of 0.55 micrograms/kg. In Hungary, the following average values have been found: 0.6 micrograms/kg for industrially smoked products, 0.74 micrograms/kg for home-smoked products, the total being 0.7 micrograms/kg. The average BaP value of home-smoked (softwood) products of the Slovenian population in Hungary is as high as 4.16 micrograms/kg. Apart from this particular case, the techniques used in both countries permit the production of smoked meat and sausages with a BaP content of less than 1 microgram/kg.

Benzopyrenes↗