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Biomedical subjects

J Jankowski

Publications and source records attributed to J Jankowski.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Evaluation of protective properties of sunglasses commonly available in the marketplace].

The optical properties of sunglasses common on the market were tested for UV radiation and visible light. Out of a large variety of sunglasses offered to customers, four types of sunglasses visually diversified, so they could suit mostly different tastes and requirements of customers, had been selected randomly. It was found that even not branded sunglasses satisfy the requirements of protective glasses. None of the sunglasses tested transmitted UV-B radiation (280-315 nm) and considerably limited UV-A radiation (315-400 nm). Moreover, radiation permeability in the visible range was good. UV-A transmission occurred mostly in the wavelength range above 380 nm. In order to evaluate the properties of protective sunglasses the ocular sun protective factor (OSPF) was defined and proposed.

Environmental Exposure↗
PubMed1996

[Problems evaluating the risk of occupational neoplasms in persons exposed to ionizing radiation].

The author presents basic physical processes of interaction between ionizing radiation and matter as well as biological effects induced by radiation. On this basis of the rich literature on epidemiological studies of main groups of persons with past exposure to considerable radiation doses, most common types of postradiation neoplasms are discussed together with the cause-effect relationship of occupational radiation.

Adult↗
PubMed1996

The consequences of the Chernobyl accident one decade after the disaster.

An international conference organised by the European Commission, the International Agency of Atomic Energy and the World Health Organization took place in Vienna, Austria on 8-12 April 1996. The EC/IAEA/WHO International Conference: One Decade after Chernobyl, was aimed at summing up the consequences of the accident. This article has been prepared on the basis of the Conference proceedings, discussions held during individual sessions and original publications devoted to this subject. All the materials are in the author's possession and can be made available to those interested.

Adult↗
PubMed1995

Morphological analysis of gastro-esophageal diseases by molecular cell techniques.

The molecular cell sciences have had a great impact in the analysis of the genetic and epigenetic events of esophageal and gastric tumorigenesis. In other regions of the alimentary tract such as the colon, the serial identification of the molecular events in the corresponding morphological lesions is perhaps most advanced. This is, in part, due to the relative ease of the histological characterisation of the premalignant lesions. In this regard the analysis of morphological and molecular adaptation in the alimentary tract is inextricable. This review aims, therefore, to judiciously assess the relative applications of contemporary techniques in investigative histopathology.

Adenocarcinoma↗
PubMed1995

Association of transforming growth factor alpha (TGFA) and its precursors with malignant change in Barrett's epithelium: biological and clinical variables.

Adenocarcinomas of the gastro-esophageal junction (GEJ) and those arising in Barrett's esophagus (BE) are increasing in the West and have a poorer prognosis than distal stomach cancers. This has been attributed mainly to anatomical location, but biological factors such as growth-regulatory molecules have been implicated. We have investigated the expression of one of these factors, TGF alpha, and its precursor prepro TGF alpha in 82 adenocarcinomas of GEJ (32 resected specimens and 50 biopsies) as well as in 48 BE biopsies without tumor, by immunohistochemistry and by Western-blot analysis. TGF alpha staining was shown in the cytoplasm and membrane of cells. Western blot confirmed that most immunoreactivity was against mature TGF alpha (5.6 kDa), but higher-molecular-weight bands were also identifiable, suggesting some reactivity with prepro protein. TGF alpha expression was more extense and intense in intestinal metaplasia and cancer. The tubular histological type of adenocarcinoma was more often positive than the signet-ring type. Primary tumors with lymph-node metastases also had increased TGF alpha expression. We conclude, therefore, that there is differential regulation of the expression of TGF alpha and its precursors during esophageal tumorigenesis.

Adenocarcinoma↗
PubMed1995

Expression of transforming growth factor alpha, epidermal growth factor receptor and epidermal growth factor in precursor lesions to gastric carcinoma.

Epidermal growth factor (EGF), its related peptide transforming growth factor (TGF-alpha) and their common receptor (EGFR) have been implicated in the control of cell proliferation and differentiation in the gastrointestinal epithelium and may play an important role in gastric carcinogenesis. We compared the immunohistochemical expression and topographic distribution of these peptides using Western blot analysis in gastric carcinoma precursor lesions and in non-cancer tissue. We observed: (i) increased and extended expression of TGF-alpha in normal mucosa and hyperplasia in carcinoma fields compared with non-cancer controls; (ii) increased expression of EGFR in intestinal metaplasia (IM) from carcinoma fields compared with controls; (iii) EGF expression was not detected in normal mucosa and only weakly in IM; (iv) coexpression of TGF-alpha/EGFR and EGF/EGFR was higher in intestinal metaplasia in carcinoma fields than in non-cancer controls. We conclude that altered expression of TGF-alpha/EGFR is associated with morphological changes during gastric carcinogenesis. In this regard increased expression of TGF-alpha is a very early event which is subsequently followed by up-regulation of EGFR and this has important biological and clinical implications.

Epidermal Growth Factor↗
PubMed1995

[Analysis of diagnostic X-Ray units in Poland in view of patients' exposure to ionizing radiation].

An analysis of diagnostic X-ray units in Poland is presented. The air-kerma on the X-ray table was measured for X-ray parameters used routinely during lumbo-sacral spine radiography in a standard patient. The measurements were performed using TLD made of lithium-fluoride. The dose received by patients in different X-ray departments is sometimes higher than two orders of magnitude from 0.14 mGy to 72.11 mGy for the same examination. The dose can be significantly reduced if the cassettes with amplyfying foils, made from rare earth components, are used.

Air Pollutants, Radioactive↗
PubMed1995

[Assessment of ultraviolet radiation penetration into human skin. I. Theoretical analysis].

This is one of the two articles under the same title "Assessment of ultraviolet radiation penetrating into human skin" which are aimed at presenting a part of broader studies in this area. They drive at identifying biophysical aspects of the effects of ultraviolet radiation on human skin. In order to characterise such parameters as UV reflectance from the skin surface of UV absorption and dispersion coefficients, it is necessary to develop appropriate methods. In Part I--"Theoretical analysis", theoretical principles for interpreting measurements of radiation dispersed in different geometrical configurations are presented. They can serve as a basis for estimating the values of UV linear absorption and dispersion coefficients in skin tissues.

Biophysical Phenomena↗
PubMed1995

[Evaluation of ultraviolet radiation reflectance for human skin].

In a group of 20 males aged 19-20 years ultraviolet radiation reflectance of different wavelength (250-400 nm) from skin surface was measured. It was found that the reflectance increased monotonically with the decrease of wavelength. The reflectance values were compared with the coefficient of relative spectral biological effectiveness and significance of both values for evaluation of human exposure to ultraviolet radiation was discussed.

Adult↗
PubMed1994

Secretory and absorptive activity of oesophageal epithelium: evidence of circulating mucosubstances.

The space between the oesophageal basal and prickle epithelial cells appears empty by standard ultrastructural preparative techniques. Fixation of human oesophageal biopsies with a variety of agents, including tannic acid, glutaraldehyde-lysine, cetylpyridinium chloride and Ruthenium Red shows that this space is filled with mucosubstances, some free, some attached to the cells as a glycocalyx. There is evidence that this material is secreted constitutively by the basal and prickle cells. This secretion may be changed or blocked by incubating oesophageal biopsies in the presence of colchicine or dinitrophenol. Incubation at 16 degrees C has the same effect. Absorption from the intercellular space may be followed using the fluid phase marker, horseradish peroxidase. Early endosomes may also be shown by their acid phosphatase activity. Incubation of biopsies at 20-22 degrees C allows early endosomes to accumulate material, but not pass it on the late endosomes.

Absorption↗
PubMed1994

[Safer radiologic examinations].

The paper presents a short survey of reasons why high doses are used in diagnostic X-ray examinations and methods for their reduction. Special attention is paid to the use of cassettes with rare-earth intensifying screens. The results of dose measurements made for several combinations of cassette-film are also presented. Patients can receive the lowest doses if it would be possible to use DuPont cassettes with FOTON films.

Equipment Safety↗
PubMed1994

[Ultraviolet radiation in selected computer monitoring].

Bearing in mind that computer monitors have become quite popular nowadays among both professionals and hobbyists, the authors analysed the UV radiation emitted by them. Chromatic and monochromatic monitors were used in the study. The ultraviolet radiation of monitors was compared with the UV emission of sterilamps and fluorescent lamps. The same order of radiation intensity was found in all sources under study. In addition, the effectiveness of two popular screen filters in suppressing the UV emission of computer monitors was studied. The suppression of radiation was observed together with a parallel absorption of the visible part of radiation.

Computer Terminals↗
PubMed1993

The administration of supplementary oxygen to prevent hypoxia during upper alimentary endoscopy.

A prospective, randomized, controlled trial was conducted in 200 consecutive patients undergoing endoscopy of the upper alimentary tract. One hundred patients received supplementary oxygen at 4 liters/minute through nasal cannulae, while 100 patients received no additional oxygen. Within each of these two groups, 50 patients were sedated with midazolam and 50 patients with diazepam suspension ("Diazemuls"). The patients' weights were recorded and correlated with their height to assess whether they were over or under their ideal weight. Oxygen saturation was recorded at baseline and throughout the endoscopic procedure. The principal finding of this study was that hypoxia (oxygen saturation less than 93%) was prevented in all cases by the administration of 4 liters/minute of oxygen, whereas 48 of the 100 patients who did not receive oxygen exhibited falls in oxygen saturation to less than 93% (p < 0.0001). Those with the highest risk were the obese patients (p < 0.01). There was no significant difference between the two sedative drug groups in either frequency or severity of associated hypoxia (p = 0.77, patients not given oxygen; p = 0.31, patients receiving oxygen). The cost of administering oxygen during upper gastrointestinal endoscopy would be an average of 95 pence ($1.60) per patient. In conclusion, the administration of oxygen during endoscopy is a worthwhile prophylactic measure to prevent hypoxia and its potential adverse effects.

Costs and Cost Analysis↗