35 research outputs found
Artemia salina larvae as a test organism in research on mycotoxin synergism
lstraživan je utjecaj koncentracije i vremena djelovanja aflatoksina B1 i diacetoksiscirpenola na larve raÄiÄa Artemia solina, u rasponu temperature od 20 do 35Ā°C. OdreÄeno je toksiÄko djelovanje za svaki mikotoksin zasebno i u kombinaciji razliÄitih koncentracija. Nakon Å”to su odreÄene LC50 i T50 vrijednosti, dokazan je sinergistiÄki odziv na osnovi smanjenja koncentracija za podjednak toksiÄki uÄinak.The effect of concentration and contact time of two mycotoxins, aflatoxin 81 and diacetoxyscirpenol was studied on the larvae of Artemia salina. These organisms are sensitive to sub-microgram quantities of the toxins and can be used as bioassay test organisms. In a study of aflatoxin 81 and diacetoxys-cirpcnol synergism in acute toxicity, the LC50 values of toxin pairs exhibited a distinct increase in toxicity
Calcium and strontium metabolism in lactation
U ovom su prikazu opisane promjene u komparativnom metabolizmu kalcija i stroncija u toku laktacije. Posebno su obraÄena pitanja akumulacije kalcija i stroncija u skeletu u graviditetu, lokalizacije tako akumuliranih zemnoalkalijskih iona u razliÄitim frakcijama skeleta, kao i utjecaja koji laktacija vrÅ”i na tako inkorporirane katione. Dan je pregled metabolizma kalcija i stroncija u stabilnoj i izmjenjivoj frakciji skeleta ovisno o trajanju laktacije, kao i prijenosa skeletnih rezervi tih kationa iz organizma majke u fetus i u mlijeko. Osobita je pažnja posveÄena pitanju moguÄnosti mobilizacije radioaktivnog stroncija iz kosti u toku laktacije, kao i utjecaju laktacije na perzistenciju malignih tumora izazvanih inkorporacijom radiostroncija. Jedan dio ovog prikaza odnosi se na opis odnosa izmeÄu inkorporiranog radiostroncija u skeletu majke i njegovog prelaska laktacijom u mladi organizam.The review deals with the changes in the comparative metabolism of calcium and strontium in the course of lactation. Special emphasis is laid upon skeletal accumulation of calcium and strontium during pregnancy, upon the localization of alkaline earth ions in different fractions of the skeleton as well as upon the influence of lactation on the incorporated cations. A survey of calcium and strontium metabolism in the exchangeable and nonexchano cable fraction of bone is presented as dependent upon the duration of lactation and the transfer of these cations from the mother rat into the Fetus and milk. Particular attention is paid to the possibility of radiostrontium mobilization from the bone during lactation as well as to the influence of lactation on the persistence of malignant tumours due to radiostrontium incorporation. The review also deals with relations between the radiostrontium incorporated in the mother\u27s skeleton and its transfer into the young rat during lactation
Radioprotektivna sredstva u medicini
The diminished probabilily of strategic nuclear confrontation alleviates some of the global concerns about large numbers of radiation casualties in the event of a nuclear war. As a result of the protection of the environment, the management of smaller numbers of radiation casualties assumes a more predictable and more specific role confined to accidents in nuclear energy\u27 projects, industry, technology and science. Recent experience of the consequences of accidents in nuclear power plants, in the field of radiotherapy and in the disposal of radioactive waste and spent fuel, present the medical and scientific communities with formidable problems if such events are to lead to minimal adverse effects on the biosphere. Whereas it is not possible to predict a nuclear or radiation accident, radioprotection is hardly an issue of health science alone, but rather an issue of the strictest quality assurance in all aspects of the utilization of nuclear energy and ionizing radiation. Thus, the medical community concerned with radioprotection will have to confine its emphasis on the management of radiation-induced alterations of the human organism from acute radiation syndromes to the stochastic concepts of chronic alterations of radiosensitive organic systems. Current multidisciplinary research in the field of radioprotection involves all aspects of basic and clinical research ranging from the subatomic mechanisms of free radical formation, macromolecular and intracellular radiation-induced alterations, biochemical and physiological homeostatic mechanisms and organ level manifestations to the clinical management of radiation casualties in a controlled hospital environment. Radioprotective agents, although widely studied in the past four decades and inclu ding several thousand agents, have not reached the level of providing the field of medicine with an agent that conforms to all criteria of an optimal radioprotectant, including effectiveness, toxicity, availability, specificity and to lerance.
This article discusses the current slate of radioprotection in medical therapy, and emphasizes a need for continued research in the area of medical management of radiation casualties from the viewpoint of a realistic probability of nuclear incidents or accidents in the nuclear energy-dependent world at the end of the millennium.Odnedavna smanjena vjerojatnost strateÅ”ke primjene nuklearnog oružja smanjila je i opasnost od masovnih ljudskih gubitaka kao posljedice ionizirajuÄeg zraÄenja. Time se briga oko lijeÄenja radijacijskih sindroma svodi na realnije podruÄje planirane primjene zaÅ”tite od zraÄenja, u industriji, tehnologiji, znanosti i medicini. SkoraÅ”nja iskustva o posljedicama nesreÄa u nuklearnoj industriji, kao i nerijeÅ”eno pitanje radioaktivnog otpada, postavljaju složeno pitanje pred medicinu i znanost o smanjenju Å”tetnih posljedica zraÄenja u poveÄanoj primjeni nuklearne energije.
Kako nije moguÄe predvidjeti nuklearnu nesreÄu, zaÅ”tita od njezinih posljedica prelazi okvire medicinske znanosti. Stalna pozornost o svim pojedinostima primjene nuklearne energije ima biti striktno kontrolirana prema najstrožim kriterijima tehnologije. Time se medicinska zaÅ”tita od zraÄenja usmjeruje na lijeÄenje i na zaÅ”titu organizma u Å”iroku podruÄju od akutnih sindroma radijacijske bolesti do kroniÄnih promjena na staniÄnoj ili molekulskoj razini, uzrokovanih dugotrajnim izlaganjem manjim dozama zraÄenja ili internom kontaminacijom. SadaÅ”nja multidisciplinarna suradnja na podruÄju zaÅ”tite od zraÄenja ukljuÄuje Å”iroko podruÄje temeljnih i kliniÄkih istraživanja, od subatomskih mehanizama, stvaranja slobodnih radikala, makromolekularnih i intracelularnih promjena. Na razini fizioloÅ”kih i biokemijskih promjena homeostaze, temeljna se saznanja prenose u podruÄje kliniÄkih istraživanja i lijeÄenja radijacijske bolesti ti zdravstvenim ustanovama.
Radioprotektivna sredstva unatoÄ intenzivnom prouÄavanju u viÅ”e od protekla Äetiri desetljeÄa joÅ” nisu dovoljno upoznata da bi medicinskoj znanosti pružila sve potrebne elemente koji se traže od lijeka za primjenu u praksi. To ukljuÄuje uÄinak, toksiÄnost, raspoloživost, specifiÄno djelovanje i podnoÅ”ljivost.
Älanak razmatra sadaÅ”nje stanje zaÅ”tite od zraÄenja u razliÄitim oblicima medicinske primjene i naglaÅ”ava nužnost nastavljanja istraživanja o lijeÄenju ozraÄenih osoba u svijetu koji na kraju ovog tisuÄljeÄa sve viÅ”e ovisi o nuklearnoj energiji
Utjecaj sadržaja D vitamina i fosfata u hrani na apsorpciju kalcija i stroncija iz probavnog trakta
The effect of various amounts of phosphates and vitamin D in the diet on calcium and strontium absorption was studied in rats. The animals were kept on experimental diet for 6 days and during that period they received radioactive isotopes of calcium (45Ca) and strontium (85Sr) in drinking water. Skeletal retention of radioactive calcium and strontium was determined. Increased dietary phosphates (from 0.5 to 1.2% P) were found to cause a reduction in the retention of radioactive calcium and strontium after oral administration of isotopes. The effect of phosphates proved to be much stronger on strontium than on calcium absorption. This is in agreement with our earlier results. The effect of phosphates on calcium and strontium metabolism proved independent of the vitamin D content in the diet if this content ranged from 200 to 800 I. U. per 100 g of dry food.Istraživali smo djelovanje razliÄitih koliÄina fosfata i D vitamina u hrani Å”takora na apsorpciju stroncija i kalcija iz probavnog trakta. Å takori su 6 dana bili na odreÄenom dijetnom režimu, i u to su vrijeme primali radioaktivne izotope kalcija i stroncija (45Ca i 85Sr) oralnim putem. Odredili smo retenciju radioaktivnog kalcija i stroncija u skeletu. PoviÅ”eni sadržaj fosfata u hrani (od 0.5 na 1.2% P) izaziva sniženje apsorpcije radioaktivnog kalcija i stroncija iz probavnog trakta. Fosfati djelu i u znatno jaÄe na metabolizam stroncija negoli kalcija. Ti su nalazi u skladu s naÅ”im ranijim rezultatima. Spomenuti efekti fosfata na metabolizam kalcija i stroncija nezavisni su od koliÄine D vitamina u hrani ukoliko ona raste od 200 do 800 i. j. na 100 g suhe hrane
Influence of lactation on 85Sr and 45Ca mobilization from the skeleton
Istraživali smo utjecaj trajanja laktacije na mobilizaciju radioaktivnog stroncija i kalcija iz skeleta Å”takora nakon jednokratne intraperitonealne aplikacije 0.5 ĀµCi 85Sr i 0.3 ĀµCi 45Ca jednoj grupi Äetiri mjeseca starih ženki prije poÄetka noÅ”enja (dublja inkorporacija), drugoj na dan koÄenja (pliÄa inkorporacija) i treÄoj u pet razliÄitih perioda laktacije (povrÅ”inska inkorporacija). Virginalne kontrole i dojilje s leglima od po Å”est mladih žrtvovane su u pokusima pliÄe i dublje inkorporacije treÄeg, dvanaestog i dvadesetog dana laktacije, a u pokusima povrÅ”inske inkorporacije 48 sati nakon aplikacije izotopa izvrÅ”ene na dan koÄenja, te petog, desetog, petnaestog i dvadesetog dana laktacije. Aktivnost 85Sr u otopljenim mineraliziranim uzorcima skeleta odreÄena je u scintilacijskom brojaÄu, a 45Ca u GM brojaÄu s prozorom. Rezultati pokazuju da je mobilizacija radioaktivnog 85Sr i 45Ca iz skeleta upravo razmjerna trajanju laktacije, a obrnuto razmjerna vremenu proteklom od njihove primjene, s tim da je moguÄa i iz dubljih slojeva kosti.The purpose of our work was to find out from which part of mother\u27s bone calcium and strontium are mobilized during the lactation period. We also wanted to estimate the time of maximal transfer of these minerals from mother to newborns. The experiments were performed on three groups of four month-old albino rats which received radioactive isotopes of calcium (45Ca) and strontium (85Sr) by a single intraperitoneal injection at various time intervals so as to enable the labeling of different parts of the mother\u27s skeleton. The first group received radioactive isotopes before the gestation period, the second at the onset of lactation, while the third group received them during the lactation period. The fraction of radioactive isotopes retained in the skeleton was estimated on 3rd, 12th and 20th day of lactation in the first and second group of rats and 48 hours after the radioactive application in the third group of animals. Our results indicate that the minerals transferred to the litter are mobilized mainly from the superficial -or exchangeable parts of the mother\u27s skeleton. A small fraction of minerals originates from deeper layers of the bone. The transfer of minerals from mother to newborns is highest during the second part of the lactation period. The fraction of calcium mobilized to the litter is about twice as high as that of strontium
Djelovanje laktacije na metabolizam kalcija
Nous avons Ć©tudiĆ© les changements du mĆ©tabolisme du calcium chez les rattes pendant la lactation. Si on injecte le calcium-4 7 le douziĆØme jour de la lactation on voit que la chutĆ© de l\u27activitĆ© spĆ©cifique du calcium-47 clans le sĆ©rum est plus rapide et la rĆ©tention du calcium-47 dan; les extrĆ©mitĆ©s et la diaphyse du tibia est beaucoup plus lente que chez les contrĆ“les.Istraživali smo promjene u metabolizmu kalcija za vrijeme laktacije. Ako se ženki Å”takora 12. dana laktacije injicira kalcij-47. vidimo da krivulja specifiÄne aktivnosti kalcija-47 u serumu pada znatno brže negoli u kontrolnih životinja. Krivulja retencije kalcija-47 u srednjem dijelu i krajevima tibije znatno je niža u životinja u fazi laktacije. Na osnovu tih rezultata izvrÅ”it Äemo kinetsku analizu promjena metaboIizma kalcija u fazi laktacije
The Effect of Strength and Plyometric Training on Functional Dance Performance in Elite Ballet and Modern Dancers
Background:
Ballet and modern dance are both art forms that require technique, artistry, grace and precision. Both dance forms require a degree of strength and muscular endurance for optimal performance. It is not known what value strength or plyometric training may have on functional dance performance.
Objective:
To systematically review the effects of strength and/or plyometric training on functional dance performance in elite ballet and modern dancers.
Methods:
A systematic review of literature indexed in the following databases: Medline, CINAHL, SportsDiscus, Physiotherapy Evidence Database (PEDro) and PubMed was conducted. The quality of the studies was graded using the PEDro Scale.
Results:
Eight studies satisfied the eligibility criteria and were included in this review. The studies\u27 population age range was 19?27?years. Methodological scores based on the PEDro scale were 4 to 6 out of 10. All of the included studies (100%) scored 4 out of 10 or higher on the PEDro scale. Strength training resulted in significant improvements in jump height (P?
Conclusion:
Moderate evidence indicates that supplementary strength training interventions via traditional resistance training or whole-body vibration methods and plyometric training interventions may increase certain dance-performance measures such as jump height and general aesthetic facility without changing certain anthropometric measures in elite ballet and modern dancers
Human Lifespan: To Live and Outlive 100 Years?
Starenje populacije je dominantno demografsko obilježje razvijenih zemalja. StogodiÅ”njaci su selekcionirana skupina i samo jedna od 7.000 do 10.000 osoba dosegne tu dob. Äimbenici dugovjeÄnosti vjerojatno su brojni i ukljuÄuju gensko predodreÄenje (lokus na 4. kromosomu), zdrav okoliÅ” i zdrave životne navike (prehrana s malo kalorija), redovita tjelesna i psihiÄka aktivnost, kao i dostupnost te uÄinkovitost zdravstvene zaÅ”tite s primjenom geroprofi lakse. StogodiÅ”njaci se adaptiraju na novi život i na gubitak tjelesnih funkcija koji bivaju postupno sve izraženiji kako se dob povisuje. Granice ljudskog života produžuju se - do sada najstarija poznata osoba doživjela je 128 godina. Pojedina zemljopisna podruÄja bilježe izrazito veÄi broj stogodiÅ”njaka. Navedene su i neke dugovjeÄne osobe s viÅ”e od 100 godina u svijetu i na podruÄju Republike Hrvatske i nekih susjednih zemalja. Iako se uglavnom smatra da se granica trajanja života Äovjeka ne može produžiti iznad 120 godina, za sada je ipak teÅ”ko predvidjeti gdje su njezine granice.Aged population dominates in developed countries. Centenarians are a select group, and only one in 7,000 to 10,000 reach that age. Factors of longevity are numerous and include genetic predisposition (a locus on chromosome 4), environment, healthy lifestyle (hypocaloric diet, regular physical and mental exercise), accessible health services, and effi cient health protection at old age. Centenarians are well adapted to the new life and compensate for the loss of functions with age. The limits of human life are extended, so that nowadays the oldest person has reached the age of 128. Some geographic areas are characterised by higher numbers of centenarians. This article mentions a few individuals who outlived 100 years in the world, Croatia, and neighbouring countries. Although some argue that the limits of human life cannot be extended over the age of 120 years, for now we cannot predict the actual limits of human life
Toxicological Effects of Weapons of Mass Destruction and Noxious Agents in Modern Warfare and Terorrism
Oružja za masovno uniÅ”tavanje najbolji su primjer uporabe civilizacijskih tehnoloÅ”kih dostignuÄa u Å”tetne svrhe i protiv ljudske civilizacije. UnatoÄ nastojanjima oko kontrole i smanjenja njihove koliÄine, rizik zbog samoga postojanja pa Äak i Å”irenja zahtijeva da se o njihovoj uporabi i dalje vodi raÄuna i da se poveÄaju obrambene mjere ā nuklearno-bioloÅ”ko-kemijske obrane (NBKO).
Osim suvremenog vojnika koji je u vojnim i mirovnim operacijama diljem svijeta izložen raznim noksama kemijskog, bioloÅ”kog i radioloÅ”kog podrijetla, nezaÅ”tiÄeno i uglavnom slabo educirano civilno stanovniÅ”tvo može biti izloženo teroristiÄkim napadima.
Oružja za masovno uniÅ”tavanje i nokse kemijskog, bioloÅ”kog i radioloÅ”kog podrijetla uzrokuju razne toksikoloÅ”ke posljedice, a bez obzira na njihovo podrijetlo, imaju zajedniÄki nazivnik djelovanja ā poremeÄaj fi zioloÅ”kog stanja u organizmu. PoremeÄaji proizaÅ”li nakon izlaganja tim noksama nerijetko se teÅ”ko determiniraju, dijagnosticiraju i lijeÄe.
U ovome su radu s biomedicinskog aspekta obraÄene važnije nokse kemijskog, bioloÅ”kog i radioloÅ”kog podrijetla na temelju odabranih primjera iz terorizma i suvremenog ratovanja: polonij-210, osiromaÅ”eni uran, salmonela, bedrenica (antraks), genetiÄki modifi cirane bakterije, polimerno predivo āpauÄinaā i bojni otrovi sarin i iperit.Weapons of mass destruction (WMD) best portray the twisted use of technological achievements against the human species. Despite arm control efforts, WMD threat continues to exist and even proliferate. This in turn calls for improvement in defensive measures against this threat. The modern soldier is exposed to a number of chemical, biological, and radiological agents in military and peace operations, while civilians are mainly exposed to terrorist attacks. Regardless of origin or mode of action, WMDs and other noxious agents aim for the same ā to make an organism dysfunctional. Because their effects are often delayed, these agents are hard to spot on time and treat.
This review presents a biomedical aspect of agents used in warfare and terrorism, including polonium-210, depleted uranium, salmonella, anthrax, genetically modifi ed bacteria, cobweb-like polymer fi bre, sarin, and mustard gas