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PubMedDate not supplied

Sterilization of a new medical device using broad-spectrum pulsed light.

In the development of implantable medical devices, effective sterilization is an essential design element. This article outlines how broad-spectrum pulsed light (BSPL) has been implemented to sterilize a novel, implantable medical device. Components of the device have properties incompatible with most sterilization techniques. The unique characteristics of the device and sterilization method are described. Results are presented that show BSPL can be an effective sterilization method that has the potential to meet validation requirements to allow parametric release of the treated product.

Equipment Contamination↗
PubMedDate not supplied

[Main principles of radiobiology].

During all the history of the development of radiation biology a problem of "energy paradox"--low consumption of energy of ionizing and non-ionizing radiation in realization of irradiation effect--has been in the focus. The first principle, which contributed much to quantitative concepts of radiation biology, is a hit principle. The hit principle, as is well known, is based on physical properties of ionizing radiations: their discontinuity, quantization and probabilistic distribution in space. Hits, i.e. acts of energy interaction with substance elements, do not depend on each other and are obeyed to Poisson distribution. The other well-known principle--a target principle--is based on the understanding that a living system has some peculiarities: a structure of elements as well as their functions are heterogeneous, unequal and differ in response to the same hits. Along with a unique DNA macromolecule, a critical target structure, biological membranes (BM) with their barrier-matrix, energy and regulatory functions, which make a basis of living processes, are also can be considered as a sensitive target structure. One more principle--a principle of amplification of primary radiation lesions in critical target structures is based on the radiation post-effect, a well-known phenomenon in radiation biology. The fourth principle is a principle of target damage recovery (regulations of cell homeostasis) that means a system response to irradiation involving mechanisms of protection and reparation of lesions in DNA and BM. The progress in molecular biology and radiation biophysics achieved for the last two decades provided an especially powerful impetus to the development of those principles, which are based on the analysis of the radio-biological effects developing in time. The main principles of radiation biology consider peculiarities of physical and biological action of ionizing radiation.

Animals↗
PubMedDate not supplied

[Evaluation of the occupational exposure risk to non-ionizing radiation in the working environment in a metal mechanical industry].

Among the various sources of risk present in a metal engineering industry, it is important to take into account the risk related to non ionizing radiations. New technologies, in fact, use radiations in different equipment to an ever increasing extent. It is therefore important, on the basis of the current regulations, to carry out a census, since the frequencies used in the workplaces vary widely. It is also important to measure exposure, in order to limit access areas, but, above all, to measure personal doses, since it is useful to record the personal doses in view of the uncertain regulation and in connection with exposure levels lower than the reference in order to limit non-stochastic effects, as was shown in our study. Information and training of personnel, health surveillance and the specific observation of critical groups of workers, are also of fundamental importance.

Humans↗
PubMed2002

Can electromagnetic radiations induce changes in the kinetics of voltage-dependent ion channels?

Ion channels are protein molecules, which can assume distinct open and closed conformational states, a phenomenon termed ion channel kinetics. The transitions from one state to another depend on the potential energy barrier that separates those two states. Therefore, it is rational to suppose that electromagnetic waves could interact with this barrier and induce changes in the rate transitions of this kinetic process. Our aim is to answer the question: can electromagnetic radiations induce changes in the kinetics of voltage-dependent ion channels? We simulated the effects of the low and high frequency electromagnetic waves on the sodium and potassium channels of the giant axon of Loligo. The key parameter measured was the fractional open time (fv), because it reflects the voltage dependence of the kinetics of channels. The electromagnetic radiations induced the following changes in the kinetics of the potassium and sodium channels: i/ low frequency waves kept the potassium channel 50% of the time open independent on the mean voltage applied through the membrane; ii/ a gradual inhibition of the inactivation on the sodium channel, when the amplitudes of the low frequency waves were increased; iii/ high frequency waves on the potassium channel, decreased both Vo (voltage in which the channel stays 50% open) and the steepness of fv (d fv/dV) as the amplitudes of the waves increased, and iv/ high frequency and low amplitude radiations on the sodium channel decreased the maximum value of fv (in relation to control), while high amplitudes increased this value. In conclusion, high and low frequency electromagnetic radiations were able to change the kinetics of the potassium and sodium channels in a squid giant axon model.

Animals↗
PubMedDate not supplied

[The occupational risk in IRCCS of Neurosciences].

The results of meta-analysis carried out on all documents for the valuation of the risk, recorded by IRCCS of Neuroscience, has led to identify a risk matrix for the medical personnel of the Scientific Institute of Neuroscience. Such analysis allowed to tackle the day to day risk faced by hospital staff. As a general rule the IRCCS of Neurosciences distinguishes themselves as structures of mainly neurologic typology and as structures of more typical psychiatric interest. In the first case the analogy with the traditional Hospital structures are more noticeable, in the second case instead the kind of patients and the particular relations between the health worker and the patient himself may represent an important differentiation factor. This is, above all, evident on the biological risk; for it's determinism has an important rule the interpersonal relationship between the health worker and the patient. Concerning other risk factors such as the chemical and the allergic one, it is noticeable a closed analogy with the actual Hospital reality. On work organization level, manual handling of patients is often necessary and also the relatives risks. In this kind of structures the stress factor is of the greatest importance, it should therefore have a strong consideration on the valuation of risk by the IRCCS.

Academies and Institutes↗
PubMedDate not supplied

[Environmental risk factors and epidemiologic study].

The problems regarding communication of risks in the environmental sector and the analysis of certain causes of pollution, together with their effects on human health are the subjects of this article. In an illustrative and concise manner results of the most important epidemiological studies concerning the effects of non-ionizing radiations, of radon and of air pollution have been analyzed. Throughout this analysis emphasis has been placed on the difficulty of obtaining clear and scientifically based results. Such results are needed in order to provide the population with satisfying information and thus meet the increasing demand for unambiguous answers. Among the risk factors for human health are the high frequency electromagnetic fields used for mobile phones (radiofrequency--RF) nd extremely low frequency electromagnetic fields (ELF-EMFs) of power-lines. Even though these risk factors may be minimal the high number of persons exposed could make them an important impact on public health. Regarding the topic of air pollution, effects on particular segments of the population (children, elderly people and subjects with chronic diseases) have been found in various studies; for example, for an increase of PM(10) of 10 microg/m(3) an increase in daily mortality of 0.69% (CI 0.40-0.98) due to cardiovascular and respiratory causes has been estimated as well as an increase in general daily mortality of 0.54% (CI 0.33-0.76). Due to the populations' low risk perception (caused by unawareness of the problem) radon is undoubtedly the environmental pollutant which has the most impact on public health. This is true even in Italy where 4,000 cases of lung cancer attributable to radon (about 11% of total lung cancer) have been estimated per year; this risk is heightened by the combined effect with smoking. When dealing with health risks the tools of communication must be simple and correct; the mass-media are the most important mediators between the scientific community and the public. It is therefore vital for the public health operators to maintain a continuous relationship with the mass media which should be based on reciprocal trust and full collaboration.

Air Pollution↗
PubMedDate not supplied

[Electromagnetic fields of millimeter range: effect on the structure and functional properties of erythrocyte membranes].

The effect of coherent and non-coherent electromagnetic fields of millimetre range on biophysical and biochemical indices of blood erythrocytes and plasma of the animals totally exposed to radiation at various periods of observation (day 1, 5, 10) was studied. The following structure-functional shifts were revealed: deviations in the content of separate phospholipid fractions of erythrocyte membranes, the changes of lipid peroxidation products in erythrocyte membranes and blood plasma of the irradiated animals, statistically significant increase of K ions out-flow from the erythrocytes, as well as the alteration of the value of membrane potential of erythrocytes.

Animals↗
PubMedDate not supplied

[Electromagnetic fields and people's health].

A lot of data has been presently accumulated on an unfavorable effect produced by electromagnetic fields (EMF) of various frequencies on human organism. However, the mechanisms of the low-intensity EMF biological actions or the possibility of development of remote consequences are not clear until now. Due to this, the WHO formulated a so-called warning concept. The prerequisites of the mentioned recommendations as well as their topicality and possible application are under discussion.

Electromagnetic Fields↗
PubMed2003

Radio frequency radiation exposure of the F-15 crewmember.

INTRODUCTION: In the United States Air Force, pilots of F-15 fighter aircraft use fire control radars to search for enemy targets and to launch beyond visual range radar missiles. The fire control radars must be of a sufficient power output to enable a target return, but pilots are concerned about deleterious health effects from the levels of radio frequency radiation (RFR) they are exposed to. Measurement of RFR while actually in flight in the F-15 has never been performed. This study was designed to document the RFR levels that pilots are exposed to on normal missions while in flight with the radar on and active. METHODS: A hand-held meter was used to measure electromagnetic fields during three F-15 flights. Instrumentation consisted of a Narda Microwave Model 8718 digital survey meter and Model 8723 broadband isotropic E-field probe with a frequency range between 300 MHz and 50 GHz. The measurements were conducted in the rear cockpit of an F-15D aircraft. Three missions were flown representing the standard missions an F-15 pilot flies on an everyday basis. The missions were: night intercepts, offensive basic fighter maneuvers, and defensive basic fighter maneuvers. RESULT: Based on the data collected during three F-15 missions, all recorded RFR exposure to the crewmember in the F-15 was within the OSHA Permissible Exposure Limit (PEL) of 10 mW x cm(-2). CONCLUSION: Based on a limited sample, RFR exposures in F-15 cockpits appear to be well below the PEL.

Aerospace Medicine↗
PubMed2003

[Physiotherapeutic treatment of gastroduodenal ulcer].

The review presents 69 references of current literature on the problem of gastroduodenal ulcer physiotherapy which has a good potential of impact on gastroduodenal motility, lipid peroxidation, microcirculation, physiological and reparative regeneration of epithelial and glandular cells. The choice of a physiotherapeutic method depends on the disease stage and to a less extent on location of the ulcer defect.

Duodenal Ulcer↗
PubMed2003

[Specific and non-specific electromagnetic irradiation effects on biological objects].

There are the pecularities of the biophysical influence of the ultraviolet, light and infra-red irradiation in connection with their frequent and energetic characteristics. The specific resonant and non-specific heating effects are educed (distinguished). [table: see text] It is shown that the radial area of electromagnetic spectrum corresponding to the non-ionising. Sun irradiation, contains the evolutionary fixed molecular mechanisms of the energy acception activizing biochemical and biophysical metabolic reactions. The living beings, deprived of heliofugal influences (cave and deep-watered specimen objects) reached only the primitive development stages. The dosed wage of the non-ionising radiation generators in the clinic medicine promotes the restoration of the self sanogenic mechanisms and deficit restoration of the natural influences caused by the contemporary human being's mode of life changes.

Animals↗