natgillin/translations-raw huggingface dataset:
Establishing the High Test Concentration
Glede na različne načine kemijskega delovanja se lahko pojavijo različni splošni morfološki fenotipi.
For the purposes of this test, the high test concentration should be set by the solubility limit of the test chemical;
Nekateri klasični fenotipi vključujejo zakasnitev ali odsotnost razvoja sprednjega kraka kljub normalnemu ali naprednemu razvoju zadnjih krakov ali repnih tkiv, zgodnji resorpciji škrg glede na zadnje krake in preoblikovanju repa.
the maximum tolerated concentration (MTC) for acutely toxic chemicals;
Histopatologija
or 100 mg/l, whichever is lowest.
Če kemikalija ne povzroča očitne strupenosti in ne pospešuje razvoja ali povzroča asinhronega razvoja, se histopatologija ščitnične žleze oceni na podlagi ustrezne smernice (9).
The MTC is defined as the highest test concentration of the chemical which results in less than 10 % acute mortality.
Razvojna zaostalost, kadar ni strupenosti, je pomemben kazalnik protiščitničnega delovanja, vendar je analiza razvojne faze manj občutljiva in manj diagnostična kot histopatološka analiza ščitnične žleze.
Using this approach assumes that there are existing empirical acute mortality data from which the MTC can be estimated.
Zato je v tem primeru treba izvajati histopatološke analize ščitničnih žlez.
Although the use of regression models may be the most technically sound approach to estimating the MTC, a useful approximation of the MTC can be derived from existing acute data by using 1/3 of the acute LC50 value.
V odsotnosti razvojnih učinkov so bili dokazani učinki na histologijo ščitnične žleze.
However, acute toxicity data may be lacking for the species on test.
Če se histopatologija ščitnice spremeni, se šteje, da kemikalija vpliva na ščitnico.
If species specific acute toxicity data are not available, then a 96-hour LC50 test can be completed with tadpoles that are representative (i.e., same stage) of those on test in the AMA.
Če v ščitničnih žlezah ni ugotovljen zakasnjeni razvoj ali histološke lezije, se šteje, da kemikalija ne vpliva na ščitnico.
Optionally, if data from other aquatic species are available (e.g. LC50 studies in fish or other amphibian species), then professional judgment may be used to estimate a likely MTC based on inter-species extrapolation.
Ta odločitev se utemelji s tem, da na ščitnično žlezo vpliva TSH, pri čemer bodo vse kemikalije, ki kroženje ščitničnega hormona spremenijo dovolj, da se spremeni sekrecija TSH, povzročile histopatološke spremembe ščitničnih žlez.
Alternatively, if the chemical is not acutely toxic and is soluble above 100 mg/l, then 100 mg/l should be considered the highest test concentration (HTC), as this concentration is typically considered “practically non-toxic.”
Kroženje ščitničnega hormona se lahko spremeni zaradi različnih načinov in mehanizmov delovanja.
Although not the recommended procedure, static renewal methods may be used where flow-through methods are inadequate to achieve the MTC.
Čeprav raven ščitničnega hormona kaže na učinek, ki je povezan s ščitnico, to ni dovolj za določitev, kateri način ali mehanizem delovanja je povezan z odzivom.
If static renewal methods are used, then the stability of the test chemical concentration should be documented and remain within the performance criteria limits.
Ker ta končna točka ni primerna za osnovne statistične pristope, je treba učinek, povezan z izpostavljenostjo kemikaliji, določiti s strokovnim mnenjem patologa.
Twenty-four hour renewal periods are recommended.
Zakasneli razvoj (določen z uporabo razvojne faze, HLL, BW in SVL)
Renewal periods exceeding 72 hours are not acceptable.
Zakasneli razvoj lahko povzročijo protiščitnični mehanizmi in posredna strupenost.
Additionally, water quality parameters (e.g. DO, temperature, pH, etc.) should be measured at the end of each renewal period, immediately prior to renewal.
Verjetno je, da zmeren zakasneli razvoj in očitni znaki strupenosti kažejo nespecifičen strupeni učinek.
Test Concentration Range
Ocenjevanje neščitnične strupenosti je bistven del preskusa, da se zmanjša verjetnost lažno pozitivnih rezultatov.
There is a required minimum of three test concentrations and a clean water control (and vehicle control if necessary).
Čezmerna smrtnost je jasen znak, da se pojavljajo drugi strupeni mehanizmi.
The minimum test concentration differential between the highest and lowest should be about one order of magnitude.
Zmerna zmanjšanja rasti, kot so določena z mokro težo in/ali dolžino od ust do zadnjične odprtine, podobno kažejo neščitnično strupenost.
The maximum dose separation is 0,1 and the minimum is 0,33.
Očitna povečanja rasti se pogosto ugotovijo pri kemikalijah, ki negativno vplivajo na normalen razvoj.
Test Initiation and Conduct
Zato prisotnost večjih živali še ne pomeni neščitnične strupenosti.
The exposure should be initiated when a sufficient number of tadpoles in the pre-exposure stock population have reached developmental stage 51, according to Nieuwkoop and Faber (8), and which are less than or equal to 17 days of age post fertilisation.
Vendar se pri določanju ščitnične strupenosti ne sme nikoli zanašati izključno na rast.
For selection of test animals, healthy and normal looking tadpoles of the stock population should be pooled in a single vessel containing an appropriate volume of dilution water.
Za določanje delovanja ščitnice je treba uporabiti rast skupaj z razvojno fazo in histopatologijo ščitnice.
For developmental stage determination, tadpoles should be individually removed from the pooling tank using a small net or strainer and transferred to a transparent measurement chamber (e.g. 100 mm Petri dish) containing dilution water.
Pri določanju očitne strupenosti je treba obravnavati tudi druge končne točke, vključno z edemi, hemoragičnimi lezijami, letargijo, manjšo porabo hrane, neenakomernim/spremenjenim načinom plavanja itd. Če vse preskusne koncentracije kažejo znake očitne strupenosti, je treba preskusno kemikalijo ponovno oceniti pri nižjih preskusnih koncentracijah, preden se določi, ali bi lahko vplivala na ščitnico ali ne.
For stage determination, it is preferred not to use anaesthesia, however one may individually anaesthetise the tadpoles using 100 mg/l tricaine methanesulfonate (e.g. MS-222), appropriately buffered with sodium bicarbonate (pH 7,0), before handling.
Statistično značilen zakasneli razvoj, kadar ni drugih znakov očitne strupenosti, kaže, da kemikalija vpliva na ščitnico (antagonistično).
If used, methodology for appropriately using e.g. MS-222 for anaesthesia should be obtained from experienced laboratories and reported with the test results.
Kadar ni pomembnih statističnih odzivov, se lahko ta rezultat popravi z rezultati histopatologije ščitnice.
Animals should be carefully handled during this transfer in order to minimise handling stress and to avoid any injury.
Statistične analize
The developmental stage of the animals is determined using a binocular dissection microscope.
Za vse stalne kvantitativne končne točke (HLL, SVL, mokra teža), skladne z monotonim odzivom na odmerek, je treba za vzpostavitev znatnega učinka tretiranja na regresiven način uporabiti preskus po Jonckheere-Terpstraju.
To reduce the ultimate variability in developmental stage, it is important that this staging be conducted as accurately as possible.
Za stalne končne točke, ki niso skladne z monotonim odzivom na odmerek, je treba pri podatkih oceniti normalnost (priporoča se uporaba Shapiro-Wilkovega ali Anderson-Darlingovega preskusa) in homogenost varianc (priporoča se uporaba Levenejevega preskusa).
According to Nieuwkoop and Faber (8), the primary developmental landmark for selecting stage 51 organisms is hind limb morphology.
Oba preskusa se izvedeta na ostankih iz analize variance.
The morphological characteristics of the hind limbs should be examined under the microscope.
Namesto formalnih preskusov za normalnost in homogenost varianc se lahko uporabi strokovna presoja, čeprav se priporoča uporaba formalnih preskusov.
Prominent morphological staging landmarks based on Neuwkoop and Faber guidance
Če so podatki (morda po pretvorbi) normalno porazdeljeni s heterogenostjo varianc, se znaten učinek tretiranja določi na podlagi Tamhane-Dunnettovega preskusa, preskusa T3 ali Mann-Whitney-Wilcoxonovega U-preskusa.
Prominent Morphological Landmarks
Visoka smrtnost ni pričakovana, vendar jo je treba oceniti na podlagi regresivnega Cochran-Armitageovega preskusa, kadar so podatki skladni z monotonostjo odziva na odmerek, sicer pa na podlagi Fisherjevega eksaktnega preskusa z Bonferroni-Holmovo prilagoditvijo.
Developmental Stage
Znaten učinek tretiranja za razvojno stopnjo se določi na podlagi regresivne uporabe preskusa po Jonckheere-Terpstraju, ki se uporablja za mediane ponovitev.
Hindlimb
Namesto tega je treba za določitev učinka uporabiti večkvantni Jonckheerov preskus od 20. do 80. centila, kar je tudi priporočljivo, ker upošteva spremembe profila porazdelitve.
Forelimb
Ustrezna enota analize je ponovitev, da podatke sestavljajo mediane ponovitev, če se uporablja preskus po Jonckheere-Terpstraju ali Mann-Whitneyjev U-preskus, ali ponovljena srednja vrednost, če se uporablja Dunnettov preskus.
Craniofacial structure
Monotonost odziva na odmerek se lahko oceni vizualno na podlagi ponovitve in sredin tretiranj ali na podlagi formalnih preskusov, kot so opisani zgoraj (11).
Olfactory nerve morphology
Pri manj kot petih ponovitvah na tretirani vzorec ali kontrolo je treba uporabiti točne različice permutacije preskusa po Jonckheere-Terpstraju in Mann-Whitneyevega preskusa, če so na voljo.
Tail length
Statistična značilnost vseh navedenih preskusov je ocenjena na raven značilnosti 0,05.
For test initiation, all tadpoles should be at stage 51.
Slika 4 je diagram poteka za izvedbo statističnih preskusov stalnih podatkov.
The most prominent morphological staging landmark for that stage is hind limb morphology, which is demonstrated in Figure 1.
Diagram poteka za statistične pristope za podatke o zveznem odzivu.
Hind limb morphology of a stage 51 X. laevis tadpole
Posebni pomisleki o analizi podatkov
In addition to the developmental stage selection, an optional size selection of the experimental animals may be used.
Uporaba ogroženih stopenj tretiranja
For this purpose, the whole body length (not SVL) should be measured at day 0 for a sub-sample of approximately 20 NF stage 51 tadpoles.
Pri določanju, ali se očitna strupenost kaže s ponovitvijo ali celotnim tretiranjem, se obravnava več dejavnikov, ki jih je treba izključiti iz analize.
After calculation of the mean whole body length for this group of animals, minimum and maximum limits for the whole body length of experimental animals can be set by allowing a range of the mean value ± 3 mm (mean values of whole body length range between 24,0 and 28,1 mm for stage 51 tadpoles).
Očitna strupenost je opredeljena kot več kot dva smrtna primera v kateri koli ponovitvi, ki ju je mogoče pojasniti le s strupenostjo in ne s tehnično napako.
However, developmental staging is the primary parameter in determining the readiness of each test animal.
Drugi znaki očitne strupenosti vključujejo hemoragijo, nenormalno obnašanje, nenormalne načine plavanja, anoreksijo in vse druge klinične znake bolezni.
Tadpoles exhibiting grossly visible malformations or injuries should be excluded from the assay.
Za subletalne znake strupenosti bodo lahko potrebne kvalitativne ocene, ki jih je vedno treba izvesti za kontrolno skupino s čisto vodo.
Tadpoles that meet the stage criteria described above are held in a tank of clean culture water until the staging process is completed.
Kontrole s topilom
Once the staging is completed, the larvae are randomly distributed to exposure treatment tanks until each tank contains 20 larvae.
Uporabo topila je treba obravnavati le kot zadnjo možnost, ko so bile obravnavane že vse druge možnosti dovajanja kemikalije.
Each treatment tank is then inspected for animals with abnormal appearance (e.g., injuries, abnormal swimming behaviour, etc.).
Če se uporabi topilo, je treba skladno izvesti kontrolo s čisto vodo.
Overtly unhealthy looking tadpoles should be removed from the treatment tanks and replaced with larvae newly selected from the pooling tank.
Ob koncu preskusa je treba izvesti oceno potencialnih učinkov topila.
For more in-depth information on test termination procedures and processing of tadpoles, refer to the OECD Guidance Document on Amphibian Thyroid Histology (9).
Ocena se izvede s statistično primerjavo kontrolne skupine s topilom in kontrolne skupine s čisto vodo.
The random procedure used should give each organism on test equal probability of being selected.
Če za nobeno izmerjeno spremenljivko odziva ni statistično značilne razlike med kontrolo s čisto vodo in kontrolo s topilom, je treba končne točke študije za merila odziva določiti z združenimi kontrolami z vodo za redčenje in topilom.
Tadpoles not selected are returned to the tank of origin and the selected tadpoles are humanely euthanised in 150 to 200 mg/l e.g. MS-222, appropriately buffered with sodium bicarbonate to achieve pH 7,0.
Prvi pristop je, da se za statistično analizo mokre teže in/ali dolžine od ust do zadnjične odprtine obravnavajo le paglavci, katerih razvojna faza je nižja ali enaka 60. fazi.
The euthanised tadpoles are rinsed in water and blotted dry, followed by body weight determination to the nearest milligram.
S tem pristopom naj bi se zagotovile ustrezno zanesljive informacije o resnosti možnih učinkov na rast, če se iz analiz umakne le majhen del preskusnih živali (≤ 20 %).
Hind limb length, snout to vent length, and developmental stage (using a binocular dissection microscope) are determined for each tadpole.
Če večje število paglavcev v eni ali več nominalnih koncentracijah kaže razvojno fazo, višjo od 60. (≥ 20 %), je treba pri vseh paglavcih opraviti dvofaktorsko analizo variance in ugnezdeno strukturo variance, da se ocenijo učinki na rast zaradi kemične obdelave, pri čemer se upošteva učinek pozne razvojne faze na rast.
Day 21 Measurements (Test Termination)
V Dodatku 3 so navedene smernice za analizo teže in dolžine z dvofaktorsko analizo variance.
At test termination (day 21), the remaining tadpoles are removed from the test tanks and humanely euthanised in 150 to 200 mg/l e.g. MS-222, appropriately buffered with sodium bicarbonate, as above.
Series on Testing and Assessment.
Tadpoles are rinsed in water and blotted dry, followed by body weight determination to the nearest milligram.
No.
Developmental stage, SVL, and hind limb lengths are measured for each tadpole.
77, Pariz.
All larvae are placed in Davidson's fixative for 48 to 72 hours either as whole body samples or as trimmed head tissue samples containing the lower jaw for histological assessments.
E 1439–98.
For histopathology, a total of five tadpoles should be sampled from each replicate tank.
Lofts, B. (ur.), Academic Press, New York, str. 467–599.
Since follicular cell height is stage dependent (10), the most appropriate sampling approach for histological analyses is to use stage-matched individuals, whenever possible.
Poskusni pogoji za 21-dnevni preskus preobrazbe dvoživk
In order to select stage-matched individuals, all larvae should first be staged prior to selection and subsequent processing for data collection and preservation.
Preskusna žival
This is necessary because normal divergence in development will result in differential stage distributions within each replicate tank.
Ličinka Xenopus laevis
Animals selected for histopathology (n = 5 from each replicate) should be matched to the median stage of the controls (pooled replicates) whenever possible.
Začetna faza ličinke
If there are replicate tanks with more than five larvae at the appropriate stage, then five larvae are randomly selected.
faza po Nieuwkoopu in Faberju
That is, if the chemical treatment is associated with a retardation of development, then additional larvae should be sampled from the next lower stage.
Merila za izbiro ličink
In turn, if the chemical treatment is associated with an acceleration of development, then additional larvae should be sampled from the next upper stage.
razvojna faza in celotna dolžina (neobvezno)
In cases of severe alterations of tadpole development due to treatment with a test chemical, there might be no overlap of the stage distribution in the chemical treatments with the calculated control median developmental stage.
Preskusne koncentracije
In only these cases, the selection process should be modified by using a stage different from the control median stage to achieve a stage-matched sampling of larvae for thyroid histopathology.
najmanj 3 koncentracije v približno enem redu velikosti
Furthermore, if stages are indeterminate (i.e., asynchrony), then 5 tadpoles from each replicate should be randomly chosen for histological analysis.
Režim izpostavljenosti
The rationale underlying sampling of any larvae that are not at a stage equivalent to the control median developmental stage should be reported.
pretočni (priporočen) in/ali s statičnim obnavljanjem
Determination of Biological Endpoints
Pretok preskusnega sistema
During the 21 day exposure phase, measurement of primary endpoints is performed on days 7 and 21, however daily observation of test animals is necessary.
25 ml/min (prostornina se v celoti zamenja približno vsake 2,7 ure)
Table 3 provides an overview of the measurement endpoints and the corresponding observation time points.
Primarne končne točke/dnevi določitve
More detailed information for technical procedures for measurement of apical endpoints and histological assessments is available in the OECD guidance documents (9).
in 21. dan
Observation time points for primary endpoints in the AMA
histologija ščitnice
Apical Endpoints
Voda za redčenje/laboratorijska kontrola
Daily
deklorirana vodovodna voda (prečiščena z ogljem) ali enakovreden laboratorijski vir
Mortality
Gostota ličink
Hind Limb Length
20 ličink/preskusno posodo (5/l)
Snout-Vent Length
Preskusna raztopina/preskusna posoda
Wet Body Weight
4–10 l (najmanj 10–15 cm vode)/stekleno preskusno posodo ali preskusno posodo iz nerjavnega jekla (npr. 22,5 cm × 14 cm × 16,5 cm)
Thyroid Gland Histology
Ponovitev
Developmental stage, hind limb length, SVL and wet weight are the apical endpoints of the AMA, and each is briefly discussed below.
4 ponovitvene preskusne posode/preskusno koncentracijo in kontrolo
Further technical information for collecting these data is available in the guidance documents referenced including procedures for computer-assisted analysis which are recommended for use.
Sprejemljiva stopnja smrtnosti v kontrolah
The developmental stage of X. laevis tadpoles is determined using the staging criteria of Nieuwkoop and Faber (8).
≤ 10 % na ponovitveno preskusno posodo
Developmental stage data are used to determine if development is accelerated, asynchronous, delayed or unaffected.
Fiksiranje žleze
Acceleration or delay of development is determined by making a comparison between the median stage achieved by the control and treated groups.
Število fiksiranih
Asynchronous development is reported when the tissues examined are not malformed or abnormal, but the relative timing of the morphogenesis or development of different tissues is disrupted within a single tadpole.
vsi paglavci (najprej se jih oceni 5/ponovitev)
Differentiation and growth of the hind limbs are under control of thyroid hormones and are major developmental landmarks already used in the determination of developmental stage.
Regija
Hind limb development is used qualitatively in the determination of developmental stage, but is considered here as a quantitative endpoint.
glava ali celo telo
Therefore, hind limb length is measured as an endpoint to detect effects on the thyroid axis (Figure 2).
Fiksacijska tekočina
For consistency, hind limb length is measured on the left hind limb.
Davidsonov fiksativ
Hind limb length is evaluated both at day 7 and at day 21 of the test.
Hrana
On day 7, measuring hind limb length is straightforward, as illustrated in Figure 2.
Sera Micron® ali enakovredna
However, measuring hind limb length on day 21 is more complicated due to bends in the limb.
Količina/pogostost
Therefore, measurements of hind limb length at day 21 should originate at the body wall and follow the midline of the limb through any angular deviations.
za način hranjenja s Sera Micron® glej tabelo 1
Changes in hind limb length at day 7, even if not evident at day 21, are still considered significant for potential thyroid activity.
Osvetlitev
Length measurements are acquired from digital photographs using image analysis software as described in the OECD Guidance Document on Amphibian Thyroid Histology (9).
Obdobje osvetljenosti
Body Length and Wet Weight
12 h svetlobe:
Determinations of snout to vent length (SVL) (Figure 2) and wet weight are included in the test protocol to assess possible effects of test chemicals on the growth rate of tadpoles in comparison to the control group and are useful in detecting generalised toxicity to the test chemical.
12 h teme:
Because the removal of adherent water for weight determinations can cause stressful conditions for tadpoles and may cause skin damage, these measurements are performed on the day 7 sub-sampled tadpoles and all remaining tadpoles at test termination (day 21).
Jakost
For consistency, use the cranial aspect of the vent as the caudal limit of the measurement.
600 do 2000 luksov (izmerjeno na vodni gladini)
Snout to vent length (SVL) is used to assess tadpole growth as illustrated in Figure 2.
Temperatura vode
Types of body length measurements and (B) Hind limb length measurements for X. laevis tadpoles (1)
6,5–8,5
While developmental stage and hind limb length are important endpoints to evaluate exposure-related changes in metamorphic development, developmental delay cannot, by itself, be considered a diagnostic indicator of anti-thyroidal activity.
Koncentracija raztopljenega kisika (DO)
Some changes may only be observable by routine histopathological analysis.
> 3,5 mg/l (> 40 % nasičenosti z zrakom)
Diagnostic criteria include thyroid gland hypertrophy/atrophy, follicular cell hypertrophy, follicular cell hyperplasia, and as additional qualitative criteria:
Časovni razpored vzorčenja za analitično kemijo
follicular lumen area, colloid quality and follicular cell height/shape.
enkrat/teden (4 vzorčenja/preskus)
Severity grading (4 grades) should be reported.
Tabele za poročanje za neobdelane podatke in povzete podatke
Information on obtaining and processing samples for histological analysis and for performing histologic analyses on tissue samples is available in “Amphibian Metamorphosis Assay: Part 1 — Technical guidance for morphologic sampling and histological preparation” and “Amphibian Metamorphosis Assay: Part 2 — Approach to reading studies, diagnostic criteria, severity grading and atlas” (9).
Splošne informacije o preskusni kemikaliji
Laboratories performing the assay for the first time(s) should seek advice from experienced pathologists for training purpose prior to undertaking histological analysis and evaluation of the thyroid gland.
Kemijske informacije
Overt and significant changes in apical endpoints indicating developmental acceleration or asynchrony may preclude the necessity to perform histopathological analysis of the thyroid glands.
Vnesite preskusno kemikalijo, enote koncentracije in tretiranja
However, absence of overt morphological changes or evidence of developmental delay warrants histological analyses.
Enote koncentracije:
All test tanks should be checked daily for dead tadpoles and the numbers recorded for each tank.
Tretiranje 1
The date, concentration and tank number for any observation of mortality should be recorded.
Tretiranje 2
Dead animals should be removed from the test tank as soon as observed.
Tretiranje 3
Mortality rates exceeding 10 % may indicate inappropriate test conditions or toxic effects of the test chemical.
Tretiranje 4
Additional Observations
Datum (dan 0):
Cases of abnormal behaviour and grossly visible malformations and lesions should be recorded.
Vnesite datum (mm/dd/ll)
The date, concentration and tank number for any observation of abnormal behaviour, gross malformations or lesions should be recorded.
Datum (7. dan):