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Biomedical subjects

J Olszewski

Publications and source records attributed to J Olszewski.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Diagnostic and therapeutic difficulties in tumors of neck and pharynx encountered in clinical cases].

The authors show case of lateral cervical cyst and carcinoma of the tonsil in woman 50 years, paying attention to large diagnostic and therapeutic difficulties. After operation of the lateral cervical cyst on the left side, metastasis of tumor followed, which was operated (after negative result of the thin-needle biopsy method) and histopathological examination of the tumor didn't prove atypical cells. In a few month after operation there followed tumorous infiltration in region angle of mandibula and in tonsillar region on the side and performed the thin-needle biopsy method showed planoepithelial carcinoma of the tonsil with transitional cells, which infiltrated the lingua, fundus of the oris and lymphonodes of the neck. Next the patient was sent to further treatment in the Oncological Hospital in Lodz. In connexion with advanced of the carcinoma, the using treatment (radiotherapy Co--60 and chemotherapy) was only the palliative treatment and prolongated life of the patient about 3 years.

Biopsy, Needle↗
PubMed1993

Analysis of mRNA decay and rRNA processing in Escherichia coli multiple mutants carrying a deletion in RNase III.

RNase III is an endonuclease involved in processing both rRNA and certain mRNAs. To help determine whether RNase III (rnc) is required for general mRNA turnover in Escherichia coli, we have created a deletion-insertion mutation (delta rnc-38) in the structural gene. In addition, a series of multiple mutant strains containing deficiencies in RNase II (rnb-500), polynucleotide phosphorylase (pnp-7 or pnp-200), RNase E (rne-1 or rne-3071), and RNase III (delta rnc-38) were constructed. The delta rnc-38 single mutant was viable and led to the accumulation of 30S rRNA precursors, as has been previously observed with the rnc-105 allele (P. Gegenheimer, N. Watson, and D. Apirion, J. Biol. Chem. 252:3064-3073, 1977). In the multiple mutant strains, the presence of the delta rnc-38 allele resulted in the more rapid decay of pulse-labeled RNA but did not suppress conditional lethality, suggesting that the lethality associated with altered mRNA turnover may be due to the stabilization of specific mRNAs. In addition, these results indicate that RNase III is probably not required for general mRNA decay. Of particular interest was the observation that the delta rnc-38 rne-1 double mutant did not accumulate 30S rRNA precursors at 30 degrees C, while the delta rnc-38 rne-3071 double mutant did. Possible explanations of these results are discussed.

DNA Mutational Analysis↗
PubMed1993

Cooperative vendor selection saves money, helps improve care.

A cooperative effort between physicians and facility administrators with respect to purchase of materials and services can reduce costs dramatically and provide clinical benefits, as well. At Hamot Medical Center in Erie, Pa., orthopaedic physicians and hospital administrators developed a process for selecting a single source of implants used in total joint replacement procedures. As a result, the medical center was able to enter into a volume purchasing contract anticipated to save the medical center about $630,000 over the two-year period of the contract.

Competitive Bidding↗
PubMed1993

Computer-aided methods for evaluating cancer risk in miners due to radiation exposure.

The paper presents some aspects of radiation hazard which occurs in a non-nuclear sector of industry, namely radiation hazard in non-uranium underground mines. The radiation hazard is caused in each type of underground mine by the naturally occurring noble radioactive gas-radon (222Rn) and radioactive products of its decay 218Po, 214Pb, 214Bi/214Po the so-called 'radon daughters' occurring in the mines' air. The paper presents the concept of how to provide a reliable system of assessment of miners' exposure by application of representative individual dosimetry, and also presents principles of computer-aided methods for interpretation of the results of miner's dosimetry useful for conversion of dosimetry data to the term of expected risk of cancer caused by exposure at miner's workplaces. The representative Individual Dosimetry system strengthened by computer-aided methods of analysis of results provided essential information on radiation cancer risk for miners employed in coal mines, metal-ore mines, chemical raw material mines in Poland. The coefficient of annual cancer risk induction is 1.5 x 10(-4) year-1 for coal mines, 1.40 x 10(-4) year-1 for metal ore mines and 1.5 x 10(-4) year-1 for chemical raw material mines. The radiation risk appears to be of the same magnitude as the conventional risk of life loss at work-related accidents. The average Lost Life Expectancy coefficient for both the radiation risk and conventional risk are 0.5 and 0.3 year per each miner, respectively.

Electronic Data Processing↗
PubMed1993

Cellular oxidation of low density lipoprotein is caused by thiol production in media containing transition metal ions.

The oxidation of low density lipoprotein (LDL) may be important in atherosclerosis. LDL can be oxidized by cultured cells, including macrophages and endothelial cells. This cellular oxidation is dependent on transition metal ions in the medium. We now report that LDL oxidation by endothelial cells and macrophages is caused by cell-dependent appearance of thiol in the medium ("thiol production"). Thiol appeared in medium when cells were incubated under standard serum-free culture conditions. L-Cystine in the medium was required for thiol production and also for LDL oxidation. Cell-dependent appearance of thiol was inhibited by glutamate (which blocks cystine uptake) and by diethylmaleate (which reacts with thiols). Both compounds also blocked cellular LDL oxidation, even though neither compound had antioxidant activity. Finally, we designed an enzymatic system, based on glutathione reductase, that mimicked cellular thiol production. This enzymatic system caused LDL oxidation, and showed the same dependency for transition metal ions as did cellular LDL oxidation. We conclude that in media containing transition metal ions, cellular oxidation of LDL can be explained by the cell-dependent appearance of thiol in the medium. A very similar mechanism was proposed in 1987 by Heinecke et al. (J. Biol. Chem. 262: 10098-10103). Under other conditions, however, cellular oxidation of LDL may occur by other mechanisms.

Animals↗
PubMed1993

[Determination of natural ionizing radiation exposure near copper mines in Poland].

The results of preliminary tests of natural ionising radiation performed in the area of mining plants and their surroundings have been presented. The survey included measurements of radon concentration and gamma-ray dose rate in free air at 25 locations, 40K, 226Ra and 228Th determination in 48 samples of ore, ore concentrate, floatation tailings, rock and soil as well as 226Ra determination in 11 samples of mine water and river. It was found that the natural radioactivity of ore, rock, concentrate and tailings from mine is higher than the environmental background. For that reason a technologically enhanced natural radiation may occur at some places of mining plants and surrounding areas. Those places must undergo full dosimetric investigation and be under control. It was impossible to estimate how much the environment is contaminated by radon and water coming from mine. However one can say that generally the gamma ray background and radon concentration in free air of this region are at the level considered as a normal.

Air Pollution, Radioactive↗
PubMed1993

[Diagnostic evaluation of the cervical nystagmus in cervical torsion test].

The aim of this work was comparative evaluation of the cervical nystagmus in cervical torsion test with the Nylen's positional nystagmus and their diagnostic value in correlation from anatomical state of cervical column. The authors examined 40 patients with degeneration of cervical spinal column and with normal radiograph of cervical spinal column. The obtained results showed that the cervical nystagmus in cervical torsion test was more frequent (47.5%) than the Nylen's positional nystagmus (37.5%). The cervical nystagmus in cervical torsion test was observed also in health subjects. The authors think that the above mentioned deviations can be caused by the discreet degeneration of cervical spinal column, unseizable in radiograph. The examinations showed that the cervical nystagmus in cervical torsion test could be used simultaneously with the Nylen's positional nystagmus in diagnostic of vertigo, first at all in patients with degeneration of cervical spinal column.

Adolescent↗
PubMed1992

Cellular oxidative modification of low density lipoprotein does not require lipoxygenases.

The oxidative modification of low density lipoprotein (LDL) may play an important role in the pathogenesis of atherosclerosis. LDL can be oxidatively modified in vitro by endothelial cells, mouse peritoneal macrophages, or copper ions. Studies using lipoxygenase inhibitors have suggested that lipoxygenase(s) is required for the cellular modification of LDL [Rankin, S. M., Parthasarathy, S. & Steinberg, D. (1991) J. Lipid Res. 32, 449-456]. We have reexamined the effect of lipoxygenase inhibitors on cellular modification and found that (i) inhibitors specific for 5-lipoxygenase do not block LDL modification; (ii) inhibitors that block lipoxygenase by donating one electron to the enzyme (reductive inactivation) prevent LDL modification by cells and also modification mediated by copper ions, implying that they act as general antioxidants; (iii) the lipoxygenase inhibitor 5,8,11,14-eicosatetraynoic acid blocks 15-lipoxygenase activity in intact macrophages at concentrations 100 times less than those required to block LDL modification by macrophages; and (iv) 5,8,11,14-eicosatetraynoic acid is cytotoxic at concentrations about twice those required to prevent modification. Furthermore, macrophages and the RECB4 line of endothelial cells modify LDL with similar efficiencies despite dramatic differences in 15-lipoxygenase activity. Thus we conclude that neither 5-lipoxygenase nor 15-lipoxygenase is required for modification of LDL by cultured cells.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1992

Low density lipoprotein is protected from oxidation and the progression of atherosclerosis is slowed in cholesterol-fed rabbits by the antioxidant N,N'-diphenyl-phenylenediamine.

The oxidative modification of low density lipoprotein (LDL) may play an important role in atherosclerosis. We found that the antioxidant N,N'-diphenyl-1,4-phenylenediamine (DPPD) inhibits in vitro LDL oxidation at concentrations much lower than other reported antioxidants. To test whether DPPD could prevent atherosclerosis, New Zealand White rabbits were fed either a diet containing 0.5% cholesterol and 10% corn oil (control group) or the same diet also containing 1% DPPD (DPPD-fed group) for 10 wk. Plasma total cholesterol levels were not different between the two groups, but DPPD feeding increased the levels of triglyceride (73%, P = 0.007) and HDL cholesterol (26%, P = 0.045). Lipoproteins from DPPD-fed rabbits contained DPPD and were much more resistant to oxidation than control lipoproteins. After 10 wk, the DPPD-fed animals had less severe atherosclerosis than did the control animals: thoracic aorta lesion area was decreased by 71% (P = 0.0007), and aortic cholesterol content was decreased by 51% (P = 0.007). Although DPPD cannot be given to humans because it is a mutagen, our results indicate that orally active antioxidants can have antiatherosclerotic activity. This strongly supports the theory that oxidized LDL plays an important role in the pathogenesis of atherosclerosis.

Administration, Oral↗
PubMed1992

[Evaluation of the ear and vestibular apparatus depending on the anatomy of the cervical spine].

Function of the acoustic organ and the vestibular organ in correlation from radiograph of cervical spinal column was examined in 102 patients aged 20-68 years, of both sexes. The obtained results of audiometric and electronystagmographic investigations have shown that the greatest disorders of function of the acoustic organ and the vestibular organ was at the patients with osteophytes and discopathy in cervical spinal column. Impaired hearing and vestibular disorders was observed also at the patients with normal radiograph of cervical spinal column. The authors have thought that the above deviations can be caused by irritation even the discreet degeneration of cervical spinal column, which ones conduct to increased tension of sympathetic system.

Adult↗
PubMed1992

Anatomical basis for selective block of the sympathetic fibers in otolaryngological diseases.

In 40 human adults and 10 fetuses during anatomopathological autopsies, the method of blocking of the sympathetic fibers reaching the internal ear was described. The fibers pass around the vertebral artery. Needle was introduced in the place of decussation of horizontal line passing through superior (females) or inferior (males) margin of the cricoid cartilage with the medial margin of the sternocleidomastoid muscle.

Adrenergic Fibers↗
PubMed1991

Radiological classification of Polish underground mines and recommendations of surveillance.

The paper presents the most recent data, collected 1987-1989, on concentrations of 222Rn products in the air of all Polish underground non-uranium mines, and data on the exposure of the miners employed there. The concentrations and exposure of miners were evaluated by using 'passive' dosimeters, based on the track-etch solid state nuclear track detector, worn as small individual cassettes on helmets of representative groups in every mine for one month, four times a year (once in each season of the year). The paper contains the average annual exposure of miners in coal-, metal-ore-, and chemical raw materials oremines. The paper, also presents expected 'frequency' distributions of individual miners' exposure in particular types of mines, as well as the computer simulations of 'relative frequency' distributions of expected miner's exposure when the Annual Limit of Exposure would be adopted at the level 17, 12, 8.6, 6.9 and 3.4.10(-3) Jhm-3 (5.0, 3.5, 2.5, 2 and 1 WLM). The concept and criteria of classification of mines according to the radiation hazards are presented and discussed. According to that concept, all mines in Poland have been considered and classified into four classes of mines with a different level of radiation hazard. The appropriate radiological surveillance to the respective class of mine is proposed and discussed.

Air Pollutants, Occupational↗
PubMed1990

[Effect of experimental ischemia on the hearing organ of guinea pigs in electron-microscopic studies].

The histologic evaluation of the influence of unilateral stimulation and of the ligation of vertebral artery on the hearing organ in guinea pigs were studied. The material consisted of 20 guinea pigs of both sexes, weight 250-300 g. It was proved that the ligation of the unilateral vertebral artery caused hypoxial lesions in the brainstem and subsequently secondary lesions in the spiral ganglion. One side stimulation of above mentioned artery caused the unilateral brainstem lesions as well as the spiral ganglion ones. The more expressed lesions were found in the cochlear nuclei in the ligation group.

Animals↗
PubMed1990

Experimental ischaemia of the vertebral artery and its effect on brain stem auditory evoked responses in guinea pigs.

The aim of the study was to examine the effect of artificial ischaemia of the vertebral artery region on brain stem evoked auditory potentials (BAEP) in guinea pigs. The results indicate that BAEP are influenced mainly by unilateral irritation of the vertebral artery. An increase in the audibility threshold was observed in the experimental guinea pigs in group C (an increase of 10-40 dB on the side of irritation of the vertebral artery and of 10 dB on the opposite side). Lengthening of the latency period of the P2 wave and of the conduction period between waves P1 and P5 was also observed.

Animals↗
PubMed1990

[The morphometry of the ear ossicles in humans during development].

The dimensions and the mass of the auditive ossicles was determined bilaterally in 100 human fetuses, of each sex aged from 21 to 40 weeks and 20 individual adults aged 18 to 40 years. It was found that the development of auditive ossicles in human is not completed during fetal life. The analyzed parameters of malleus (a, b, c, d1, d2, e) in the over fetal life period increased adequately by 14.02%, 11.22%, 16.70%, 12.80%, 12.01%, 21.98%, incus by (a, b, c1, c2, d, e) - 7.61%, 11.48%, 11.40%, 23.59%, 12.14%, 14.94%, stapes by (a, b, c, d, e, f) - 6.28%, 7.66%, 8.40%, 4.54%, 4.54%, 4.16%. In the over fetal life period increase of weight of malleus by 22.05%, incus by 26.49%, stapes by 11.57% was also observed. Described parameters of ossicles system are very important with respect to classification to the operations improving hearing in the system convecting of vibration of the tympanic membrane in children.

Adult↗
PubMed1990

Influence of experimental ischemia on the acoustic organ of guinea pigs in electron microscopic studies.

The aim of the paper was the histological evaluation of the influence of prolonged irritation or ligation of the vertebral artery on the brain stem and the spiral organs of guinea pigs. Electron microscopic studies of cochlear nuclei and spiral organs of 20 guinea pigs, both sexes, body weight of 250 to 300 g, were performed. By electron microscopic analysis, it was found that a greater lesion of spiral organs is observed in the group B (irritation of the vertebral artery at one side). This mostly concerns the outer hair cells, both the receptor and basic part. Lesion of the spiral organs of guinea pigs in the group C (ligature of the vertebral artery at one side) is only described in the basic part of the outer hair cells and their afferent nerve endings. It seems that the observed lesion is a secondary effect. Primary changes caused by ischemia are mostly observed in the cochlear nuclei.

Animals↗
PubMed1989

Field monitoring versus individual miner dosimetry of radon daughter products in mines.

The paper presents the results realised simultaneously by two different and independent systems of measurement of an assessment of miners' exposure to radon daughter products which naturally occur in the air of mines. The first one, called the Air Sampling System (ASS), was based on the field monitoring of radon progeny in air, the second one, called the Individual Dosimetry System (IDS), was based on the individual dosimeters worn by miners. Experimental comparison of these two systems has been conducted for six years in eleven Polish underground metal-ore mines. This study reveals that no correlation exists between the concentration and annual miners' exposures evaluated by the ASS and IDS. The ratio ASS/IDS for mine population varies from 11.0 to 0.14 in respect of annual concentration means, and in respect to annual exposures, this ratio varies from 4.5 to 0.14. The conclusion to be drawn from six years' observation and comparison of both systems is that correct and true evaluation of miners' exposure to radon progeny can be made only by the use of the Individual Dosimetry System, since the Air Sampling System is too sensitive and too dependent on the Strategy of sampling and its radiation.

Air Pollutants, Occupational↗