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Biomedical subjects

W Lutz

Publications and source records attributed to W Lutz.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Arteriosclerosis and cancer--fats or carbohydrates?].

The big field studies failed to yield the results expected from the lipid theory of arteriosclerosis. By only lowering the intake of animal fats and cholesterol (MRFIT) the death rate from cardiovascular disease was not significantly decreased whilst the use of strong drugs to lower the cholesterol level (LRC, Helsinki Heart) did not influence total mortality. The carbohydrate theory of arteriosclerosis according to epidemiological studies explains the results on the basis of evolutionary concepts through the different time spans a population had to adapt to the new foodstuff, carbohydrate appearing in the Neolithic Age. Studies on the effect of carbohydrates in humans are proposed.

Arteriosclerosis↗
PubMed1989

[The use of markers for determination of the activity of microsomal enzymes connected with cytochrome p-450].

The mixed-function oxidases, among them cytochrome P-450, are participating in the metabolism of many xenobiotics. Using marker drugs it is possible to assess the induction or inhibition of these oxidases. The paper described the usefulness of use of certain drugs metabolised by this system in various liver diseases. Data from the literature are presented concerning the use of marker drugs labelled with C14 and determination of the effectiveness of the mixed-function oxidases by measurement of 14CO2 activity in exhaled air.

Breath Tests↗
PubMed1989

Randomisation by cluster and the problem of social class bias.

For randomised population trials the unit of randomisation is normally the individual person. In some situations, however, investigators take other groups as basic unit and one such design is cluster randomisation. Considerable attention has been given to this design recently in statistical and epidemiological literature. The Edinburgh randomised trial of breast cancer screening is an example which takes general practices as clusters of patients. The experience of this trial is reported here. Mortality from all causes, cardiovascular disease and lung cancer over the first 5 year period of follow up are examined. We found that spurious mortality differences were present in the analyses, which do not allow for socio-economic status. From examination of methods of adjusting for this, we conclude that allowance can be made at the analysis stage, and it is intended that this approach will be adopted when breast cancer mortality is analysed in the Edinburgh trial. Nevertheless, we recommend that for future studies with outcome related to socio-economic status, randomisations which use this design be stratified by socio-economic criteria where this is feasible.

Bias↗
PubMed1989

Comparative analysis of completed parity distributions: a global WFS perspective.

This paper studies completed parity distributions for all the industrialized and developing countries that participated in the World Fertility Survey. This is done by means of a table based on parity calculated for all ever-married women above age 40 by educational and residential subcategories. The information is also used to compare mean family and mean sibship sizes and to study changes in the concentration of reproduction independent of the level of fertility. The cross- section of countries considered implies that, as fertility declines, the transition from high to low fertility is associated with an increase in the concentration; i.e., a smaller proportion of women having 1/2 the children. The big exception is China, where fertility declined steeply without an increase in concentration.

Birth Rate↗
PubMed1989

[Bioactivation of xenobiotics by cytochrome P-448 and its role in the process of carcinogenesis].

The paper presents the general data concerning cytochrome P-448, as well as its participation in the formation of oxygen radicals and active metabolic intermediates, originated during xenobiotics' oxidation. Also, induction of synthesis of cytochrome P-448 (aromatic hydrocarbons hydroxylase), along with the role this phenomenon plays in the initiation of neoplastic process, are discussed.

Acetaminophen↗
PubMed1989

[Usefulness of biological tumor markers for early detection of neoplastic changes in the bladder of persons exposed to aromatic amines].

Industrial exposure to aromatic amines may result in bladder cancer, especially in persons characterized by a slow acetylation phenotype. What is particularly important in neoplastics therapies is an early detection of neoplastic changes. Prophylactic and prognostic examination suggest that determination of neoplastic markers may contribute to an early detection of these changes. From the results gathered it emerges that carcinoembryonal antigen (CEA) and tissue polypeptide antigen (TPA) are most useful for an early detection of bladder cancer. It seems reasonable to examine the most seriously exposed ones using methods for CEA and TPA determination. Such an examination performed twice or three times in this group should help to early detect hyperplasia of urinary bladder epithelium.

Adult↗
PubMed1988

A system for stereotactic radiosurgery with a linear accelerator.

A small field irradiation technique to deliver high doses of single fraction photon radiation to small, precisely located volumes (0.5 to 8 cm3) within the brain has been developed. Our method uses a modified Brown-Roberts-Wells (BRS), CT-guided, stereotactic system and a 6 MV linear accelerator equipped with a special collimator (diameters of 12.5 mm to 30.0 mm projected to isocenter) located 23 cm from isocenter. Target localization via planar angiography has been added. Treatment consists of a series of arcing beams using both gantry and couch rotations. During treatment, the patient's head is immobilized independently of the radiotherapy couch and is precisely positioned without reference to room lasers or light field. A precise verification of alignment precedes each treatment. Extensive performance tests have shown that a target, localized by CT, can be irradiated with a positional accuracy of 2.4 mm in any direction with 95% confidence. If angiography is used for localization, the results are better. The dose 1.0 cm outside the target volume is less than 20% of the prescribed dose for a medium sized collimator.

Brain Neoplasms↗
PubMed1988

Linear accelerator as a neurosurgical tool for stereotactic radiosurgery.

A new system has been developed for stereotactically delivering prescribed high doses of radiation to precisely located volumes of approximately 0.6 to 10.0 ml within the brain. A Brown-Roberts-Wells stereotactic apparatus and a 6-MeV linear accelerator equipped with a special collimator (12.5 to 30 mm in diameter) have been adapted. The 20-mm collimator allows treatment of a nearly spherical volume of 2.1 ml. Outside the treatment field, the dosage declines to 80% of the dose prescribed for the periphery of the lesion over a distance of 1.8 mm and to 50% over the next 3.4 mm. Localization can be accomplished via computed tomography or cerebral angiography. Treatment is accomplished with an arcing beam of photon radiation with the turntable (couch) in each of four positions. The entire system has been extensively tested for accuracy in alignment and distribution of radiation. Errors have been measured for the alignment of the apparatus and for the process of localization. Safety of operation was emphasized throughout the design and testing phase.

Brain Diseases↗
PubMed1988

Effect of the application of an anionic detergent combined with FABRY's tincture and its components on human skin resident flora. Part 1: Dermofug solution combined with either FABRY's tincture or 50 v/v% isopropanol.

The aim of the study was to investigate the antimicrobial longterm efficacy of the combined application of an anionic detergent (Dermofug) either with 50 v/v% isopropanol or FABRY's tincture (3 w/v% salicylic acid, 1 v/v% liquefied phenol containing 50 v/v% isopropanol) on the resident flora of the human forehead skin after repeated applications using the forehead skin test. The test results show that both combinations tested are able to penetrate the infrainfundibulum of the sebaceous glands. The combined application of 10 v/v% Dermofug solution (D) and FABRY's tincture (F) showed better antibacterial efficacy than the combination of D and 50 v/v% isopropanol (I) against the coagulase-negative-staphylococci in the stratum corneum/acroinfundibulum as well as in the infrainfundibulum of the sebaceous glands. Against Propionibacterium spp., D and F showed better efficacy than D and I in the stratum corneum/acroinfundibulum, and equal efficacy in the infrainfundibulum of the sebaceous glands. It remains to be clarified in further investigations, which of the components of FABRY's tincture leads to the better antibacterial efficacy of the combined application of D and F in comparison to D and I, the salicylic acid or the phenol acid component.

1-Propanol↗
PubMed1987

Culture, religion, and fertility: a global view.

This study tries to assess the effects of culture and religion on fertility after accounting for a country's socioeconomic standing. Analysis of covariance models are estimated for 128 countries with time-series covering the period 1950-1975. The dependent variable is the gross reproduction rate; independent variables are the infant mortality rate, an aggregate indicator of female educational standing, and gross domestic product per person as well as categorical variables for religion and cultural region. It turns out that the European countries have generally lower fertility than could be expected from their socioeconomic standing. In the Arab countries, culture and religion tend to have strong positive effects on fertility. Across cultures, Catholicism has a fertility-increasing effect but it--like the effect of all religions except Islam--is diminishing over time. In contrast, the effect of culture (as measured by a regional variable) on the level of national fertility has been increasing at the expense of socioeconomic effects.

Birth Rate↗
PubMed1987

[Evaluation of the functional status of hepatic microsomal enzymes in workers exposed to carbon dioxide and vinyl chloride by using the antipyrine test].

Examined were 42 CS2-exposed subjects, 34 CV-exposed subjects and 14 healthy people (control group) with no exposure to chemicals that might change the hepatic microsomal enzymes activity. All the subjects underwent antipyrine test (clearance and plasma half-time). The activities of AspAT and AlAT aminotransferases, alkaline phosphatase, gamma-glutamyl-transferase, and the value of thymol test and BSP were determined. Furthermore, in CV-exposed subjects, the organic clearance for N 2,4-dimethyl-acetanilide-iminodiacetic acid was determined. It was demonstrated that the mean value of antipyrine clearance was significantly reduced in CS2-exposed group, whereas in CV-exposed subjects the mean clearance value differed significantly from the control group value. The pathological values of antipyrine clearance were found in 12 CS2-exposed and only in 3 CV-exposed subjects. Pathological findings of the Hepida test were found in 3 CV-exposed subjects who exhibited normal antipyrine clearance values. This would imply that the Hepida test detects disturbances of different type in hepatic cells functioning, as compared to the antipyrine test. The studies confirmed that the antipyrine test performed in a simplified version (a single biological sampling) bears the same reference value for the detection of disturbances in hepatic microsomal enzymes as the traditional version of the test calling for repeated collection of blood or saliva.

Adult↗