natgillin/translations-raw huggingface dataset:
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.
La încheierea testului, trebuie efectuată o evaluare a potențialelor efecte ale solventului.
Table 3 provides an overview of the measurement endpoints and the corresponding observation time points.
Aceasta se realizează printr-o comparație statistică a grupului de control din vasul cu solvent și a grupului de control din vasul cu apă curată.
More detailed information for technical procedures for measurement of apical endpoints and histological assessments is available in the OECD guidance documents (9).
Cei mai relevanți parametri pentru această analiză sunt stadiul de dezvoltare, SVL și greutatea umedă, deoarece acestea pot fi afectate prin toxicități netiroidiene.
Observation time points for primary endpoints in the AMA
În cazul în care sunt constatate diferențe semnificative din punct de vedere statistic ale acestor parametri între grupul de control din vasul cu apă curată și grupul de control din vasul cu solvent, trebuie determinați parametrii studiului pentru măsurătorile răspunsului folosind grupul de control din vasul cu apă curată.
Apical Endpoints
Dacă nu se constată diferențe semnificative din punct de vedere statistic între grupul de control din vasul cu apă curată și grupul de control din vasul cu solvent pentru toate variabilele măsurătorilor răspunsului, trebuie determinați parametrii studiului pentru măsurătorile răspunsului utilizând un grupurile de control comasate din vasul cu apă de diluție și din cel cu solvent.
Daily
Grupurile de tratament care ating un stadiu de dezvoltare superior sau egal cu 60
Mortality
Una dintre metode constă în luarea în considerare exclusiv a mormolocilor cu stadii de dezvoltare mai mici sau egale cu 60 pentru analizele statistice ale greutății umede și/sau ale lungimii bot-cloacă.
Hind Limb Length
Această metodă este considerată a furniza informații suficient de solide cu privire la severitatea posibilelor efecte asupra creșterii, cu condiția ca proporția animalelor de testare excluse din analize să fie mică (≤ 20 %).
Snout-Vent Length
Dacă un număr crescut de mormoloci se caracterizează printr-un stadiu de dezvoltare mai mare decât 60 (≥ 20 %) pentru una sau mai multe concentrații nominale, atunci trebuie realizată o structură ANOVA bifactorială cu o varianță ierarhică pentru toți mormolocii pentru a evalua efectele asupra creșterii ale tratamentelor chimice, luând în considerare în același timp efectul stadiului târziu de dezvoltare asupra creșterii.
Wet Body Weight
Apendicele 3 furnizează orientări privind analiza ANOVA bifactorială pentru greutate și lungime..
Thyroid Gland Histology
Lofts, B. (ed.), Academic Press, New York, pp.
Developmental stage, hind limb length, SVL and wet weight are the apical endpoints of the AMA, and each is briefly discussed below.
467-599
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.
Condiții experimentale pentru testul de metamorfoză la amfibieni de 21 de zile
The developmental stage of X. laevis tadpoles is determined using the staging criteria of Nieuwkoop and Faber (8).
Animale utilizate în test
Developmental stage data are used to determine if development is accelerated, asynchronous, delayed or unaffected.
Larve de Xenopus laevis
Acceleration or delay of development is determined by making a comparison between the median stage achieved by the control and treated groups.
Stadiul larvar inițial
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.
Stadiul 51 conform Nieuwkoop și Faber
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.
Perioada de expunere
Hind limb development is used qualitatively in the determination of developmental stage, but is considered here as a quantitative endpoint.
21 de zile
Therefore, hind limb length is measured as an endpoint to detect effects on the thyroid axis (Figure 2).
Criteriile de selecție a larvelor
For consistency, hind limb length is measured on the left hind limb.
Stadiul de dezvoltare și lungimea totală (opțional)
Hind limb length is evaluated both at day 7 and at day 21 of the test.
Concentrațiile de testare
On day 7, measuring hind limb length is straightforward, as illustrated in Figure 2.
Minimum 3 concentrații care acoperă aproximativ un ordin de magnitudine
However, measuring hind limb length on day 21 is more complicated due to bends in the limb.
Regimul de expunere
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.
Cu flux continuu (preferat) și/sau static cu reînnoire
Changes in hind limb length at day 7, even if not evident at day 21, are still considered significant for potential thyroid activity.
Debitul sistemului de testare
Length measurements are acquired from digital photographs using image analysis software as described in the OECD Guidance Document on Amphibian Thyroid Histology (9).
25 ml/min (înlocuirea completă a volumului la aproximativ fiecare 2,7 h)
Body Length and Wet Weight
Parametri studiați principali /zile de determinare
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.
Z 7 și 21
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).
Histologia glandei tiroide
For consistency, use the cranial aspect of the vent as the caudal limit of the measurement.
Apa de diluție/control de laborator
Snout to vent length (SVL) is used to assess tadpole growth as illustrated in Figure 2.
Apă de robinet declorurată (cu filtru de carbon) sau sursă echivalentă de laborator
Types of body length measurements and (B) Hind limb length measurements for X. laevis tadpoles (1)
Densitatea larvelor
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.
20 larve/vas de testare (5/l)
Some changes may only be observable by routine histopathological analysis.
Soluție de testare/vas de testare
Diagnostic criteria include thyroid gland hypertrophy/atrophy, follicular cell hypertrophy, follicular cell hyperplasia, and as additional qualitative criteria:
4– 10 l (10– 15 cm de apă minimum)/vas de testare din sticlă sau din oțel inoxidabil (de exemplu, 22,5 cm × 14 cm × 16,5 cm)
follicular lumen area, colloid quality and follicular cell height/shape.
Replică
Severity grading (4 grades) should be reported.
4 vase-replică de testare/concentrație de testare și control
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).
Rată de mortalitate admisă în grupurile de control
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.
≤ 10 % per vas-replică de testare
Overt and significant changes in apical endpoints indicating developmental acceleration or asynchrony may preclude the necessity to perform histopathological analysis of the thyroid glands.
Fixare tiroidiană
However, absence of overt morphological changes or evidence of developmental delay warrants histological analyses.
Număr fixat
All test tanks should be checked daily for dead tadpoles and the numbers recorded for each tank.
Toți mormolocii (5/replică sunt evaluați inițial)
The date, concentration and tank number for any observation of mortality should be recorded.
Regiune
Dead animals should be removed from the test tank as soon as observed.
Cap sau întregul corp
Mortality rates exceeding 10 % may indicate inappropriate test conditions or toxic effects of the test chemical.
Lichide de fixare
Additional Observations
Fixatorul Davidson
Cases of abnormal behaviour and grossly visible malformations and lesions should be recorded.
Hrană
The date, concentration and tank number for any observation of abnormal behaviour, gross malformations or lesions should be recorded.
Sera Micron® sau echivalent
Normal behaviour is characterised by the tadpoles being suspended in the water column with tail elevated above the head, regular rhythmic tail fin beating, periodic surfacing, operculating, and being responsive to stimulus.
Cantitate/frecvență
Abnormal behaviour would include, for example, floating on the surface, lying on the bottom of the tank, inverted or irregular swimming, lack of surfacing activity, and being nonresponsive to stimulus.
A se vedea tabelul 1 pentru regimul de hrănire cu Sera Micron®
In addition, gross differences in food consumption between treatments should be recorded.
Iluminat
Gross malformations and lesions could include morphological abnormalities (e.g. limb deformities), hemorrhagic lesions, bacterial or fungal infections, to name a few.
Perioadă de expunere la lumină
These determinations are qualitative and should be considered akin to clinical signs of disease/stress and made in comparison to control animals.
12 h lumină:
If the occurrence or rate of occurrence is greater in exposed tanks than in the controls, then these should be considered as evidence for overt toxicity.
12 h întuneric
Data Collection
Intensitate
All data should be collected using electronic or manual systems which conform to good laboratory practices (GLP).
600 – 2000 lux (măsurată la suprafața apei)
Characterisation of the test chemical:
Temperatura apei
physical-chemical properties;
6,5 – 8,5
information on stability and biodegradability;
Concentrația oxigenului dizolvat (OD)
Chemical information and data:
> 3,5 mg/l (> 40 % saturația în aer)
method and frequency of preparation of dilutions.
Program de eșantionare pentru analize chimice
Test chemical information includes actual and nominal concentrations of the test chemical, and in some cases, non-parent chemical, as appropriate.
O dată/săptămână (4 eșantionări/test)
Test chemical measurements may be required for stock solutions as well as for test solutions;
Tabele pentru raportarea datelor brute și de sinteză
Solvent (if other than water):
Informații generale privind substanțele chimice testate
justification of the choice of solvent, and characterisation of solvent (nature, concentration used);
Informații privind substanțele chimice
Operational records:
A se introduce substanța chimică testată, unitățile concentrațiilor și tratamentele
these consist of observations pertaining to the functioning of the test system and the supporting environment and infrastructure.
Unități ale concentrațiilor:
Typical records include:
Tratament 1
ambient temperature, test temperature, photoperiod, status of critical components of the exposure system (e.g. pumps, cycle counters, pressures), flow rates, water levels, stock bottle changes, and feeding records.
Tratament 2
General water quality parameters include:
Tratament 3
pH, DO, conductivity, total iodine, alkalinity, and hardness;
Tratament 4
Deviations from the test method:
Data (ziua 0):
this information should include any information or narrative descriptions of deviations from the test method;
A se introduce data (ll/zz/aa)
Biological observations and data:
Data (ziua 7):
these include daily observations of mortality, food consumption, abnormal swimming behaviour, lethargy, loss of equilibrium, malformations, lesions, etc.
Data (ziua 21):
Observations and data collected at predetermined intervals include:
Fișe de colectare a datelor primare pentru zilele 7 și 21
developmental stage, hind limb length, snout vent length, and wet weight;
ZIUA X
Statistical analytical techniques and justification of techniques used;
DATA 00/00/00
results of the statistical analysis preferably in tabular form;
Număr tratament
Histological data:
Număr replică
these include narrative descriptions, as well as graded severity and incidence scores of specific observations, as detailed in the histopathology guidance document;
Număr individual
Ad hoc observations:
Identificator individual
these observations should include narrative descriptions of the study that do not fit into the previously described categories.
Lungimea SVL (mm)
Data reporting
Lungimea membrelor posterioare (mm)
Appendix 2 contains daily data collection spreadsheets that can be used as guidance for raw data entry and for calculations of summary statistics.
Greutatea umedă a întregului organism (mg)
Additionally, reporting tables are provided that are convenient for communicating summaries of endpoint data.
Sinteze calculate pentru datele parametrilor din zilele 7 și 21
Reporting tables for histological assessments can be found in Appendix 2.
Calculele din celule sunt asociate cu datele introduse în tabelul 2.
Performance Criteria and Test Acceptability/Validity
Greutate (mg)
Generally, gross deviations from the test method will result in unacceptable data for interpretation or reporting.
MEDIANĂ
Therefore, the following criteria in Table 4 have been developed as guidance for determining the quality of the test performed, the general performance of the control organisms.
MEDIE
Table 4
STADIU DE DEZVOLTARE
Performance criteria for the AMA
Date privind mortalitatea zilnică
Criterion
Calculele din celule sunt asociate cu datele introduse în tabelul 1.
Acceptable limits
Ziua de testare
Test concentrations
Număr per replică
Maintained at ≤ 20 % CV (variability of measured test concentration) over the 21 day test
Număr per tratament
Mortality in controls
Tabelul 5
≤ 10 % — mortality in any one replicate in the controls should not exceed 2 tadpoles
Criterii privind calitatea apei
Minimum median developmental stage of controls at end of test
Sistemul de expunere (cu flux continuu/static cu reînnoire):
Spread of development stage in control group
Intensitatea luminii:
The 10th and the 90th percentile of the development stage distribution should not differ by more than 4 stages
Ciclul lumină-întuneric:
Dissolved Oxygen
Hrană:
≥ 40 % air saturation [8]
Frecvența hrănirii:
pH should be maintained between 6,5-8,5.
pH-ul apei:
The inter-replicate/inter-treatment differentials should not exceed 0,5.
Concentrația de iod în apa utilizată pentru testare
± 1 °C — the inter-replicate/inter-treatment differentials should not exceed 0,5 °C
Tabelul 6
Test concentrations without overt toxicity
Data de sinteză privind substanțele chimice:
Replicate performance
Denumirea substanței chimice:
≤ 2 replicates across the test can be compromised
Tabelul 7:
Special conditions for use of a solvent
Tabele de raportare a histopatologiei pentru criteriile de bază
If a carrier solvent is used, both a solvent control and clean water control should be used and results reported
Data:
Statistically significant differences between solvent control and water control groups are treated specially.
Substanța chimică:
See below for more information
Patolog:
Ammonia levels should be measured immediately prior to renewal
Hipertrofia celulelor foliculare
All water quality parameters listed in Table 1of Appendix 1 should be measured immediately prior to renewal
Hiperplazia celulelor foliculare
Renewal period should not exceed 72 hours
Control Animal ID – replică 1
Appropriate feeding schedule (50 % of the daily food ration of commercial tadpole feed)
Doză Animal ID – replică 1
Valid experiment in a test determined to be negative for thyroid activity:
Tabelul 8:
For any given treatment (including controls), mortality cannot exceed 10 %.
Criterii histopatologie suplimentare
For any given replicate, mortality cannot exceed three tadpoles, otherwise the replicate is considered compromised
Creșterea ariei lumenului folicular
At least two treatment levels, with all four uncompromised replicates, should be available for analysis
Scăderea ariei lumenului folicular
At least two treatment levels without overt toxicity should be available for analysis
Tabelul 9
Valid experiment in a test determined to be positive for thyroid activity:
Descrieri ale concluziilor histopatologice
Mortality of no more than two tadpoles/replicate in the control group can occur
Descriere
Decision logic for the conduct of the AMA
Tabelul 10
Decision logic was developed for the AMA to provide logical assistance in the conduct and interpretation of the results of the bioassay (see flow chart in Figure 3).
Tabel sintetic de raportare pentru ziua x (7 sau 21) a AMA
The decision logic, in essence, weighs the endpoints in that advanced development, asynchronous development and thyroid histopathology are weighed heavily, while delayed development, snout-vent length and wet body weight, parameters that can potentially be affected by general toxicity, are weighed less heavily.
Doza 1
Advanced development (determined using developmental stage, SVL and HLL)
Doza 2
Advanced development is only known to occur through effects which are thyroid hormone related.
Doza 3
These may be peripheral tissue effects such as direct interaction with the thyroid hormone receptor (such as with T4) or effects which alter circulating thyroid hormone levels.
Parametru studiat
In either case, this is considered sufficient evidence to indicate that the chemical has thyroid activity.
Replică
Advanced development is evaluated in one of two ways.
Medie
First, the general developmental stage can be evaluated using the standardised approach detailed in Nieuwkoop and Faber (8).
valoare p
Second, specific morphological features may be quantified, such as hind limb length, at both days 7 and 21, which is positively associated with agonistic effects on the thyroid hormone receptor.
Medie:
If statistically significant advances in development or hind limb length occur, then the test indicates that the chemical is thyroid active.
Greutate umedă
The evaluation of test animals for the presence of accelerated development relative to the control population will be based on results of statistical analyses performed for the following four endpoints:
Tabelul 11
hind limb length (normalised by SVL) on study day 7
Model de tabel sintetic de raportare pentru ziua x (7 sau 21) a datelor privind stadiile de dezvoltare pentru testul AMA
hind limb length (normalised by SVL) on study day 21
Mediană
developmental stage on study day 7
Minim
developmental stage on study day 21.
Maxim
Statistical analyses of hind limb length should be performed based on measurements of the length of the left hind limb.
Analiză alternativă a greutății și a lungimii în caz de stadiu târziu de dezvoltare care afectează peste 20 % dintre mormoloci pentru una sau mai multe concentrații
Acceleration of development is then indicated by a significant increase of mean hind limb length (normalised) in a chemical treatment group compared to the control group on study day 7 and/or study day 21 (see Appendix 3).
Aceasta se poate realiza cu o ANOVA bifactorială cu o varianță ierarhică.
Statistical analyses of developmental stage should be performed based on determination of developmental stages according to the morphological criteria described by Nieuwkoop and Faber (8).
Se definește LateStage =«Da» pentru un animal dacă stadiul său de dezvoltare este 61 sau mai mare.
Acceleration of development is indicated when the multi-quantal analysis detects a significant increase of developmental stage values in a chemical treatment group compared to the control group on study day 7 and/or study day 21.
Altfel, se definește LateStage = «Nu».
In the AMA test method, a significant effect on any of the four endpoints mentioned above is regarded sufficient for a positive detection of accelerated development.
Ulterior, poate fi realizată o ANOVA bifactorială concentrație și LateStage și interacțiunea acestora, cu Rep(Conc) un factor aleatoriu și Tadpole(Rep) alt efect aleatoriu.
Asynchronous development is characterised by disruption of the relative timing of the morphogenesis or development of different tissues within a single tadpole.
O analiză a tipului de tendințe poate fi efectuată utilizând contraste corespunzătoare sau prin comparații simple pe perechi dacă există dovezi ale unei relații doză-răspuns nemonotone în cadrul unui nivel al variabilei LateStage.
The inability to clearly establish the developmental stage of an organism using the suite of morphological endpoints considered typical of any given stage indicates that the tissues are developing asynchronously through metamorphosis.
O ajustare Bonferroni-Holm a valorilor p se efectuează numai dacă diviziunea F corespunzătoare nu este semnificativă.
Asynchronous development is an indicator of thyroid activity.
Aceasta se poate realiza în SAS și, probabil, cu ajutorul altor pachete de software statistic.
The only known modes of action causing asynchronous development are through effects of chemicals on peripheral thyroid hormone action and/or thyroid hormone metabolism in developing tissues such as is observed with deiodinase inhibitors.
Pot apărea complicații atunci când nu există animale în stadiu târziu pentru anumite concentrații, însă aceste situații pot fi gestionare în mod direct.
The evaluation of test animals for the presence of asynchronous development relative to the control population will be based on gross morphological assessment of test animals on study day 7 and study day 21.
TEST DE REPRODUCERE A COLEMBOLELOR ÎN SOL
The description of normal development of Xenopus laevis by Nieuwkoop and Faber (8) provides the framework for identifying a sequential order of normal tissue remodelling.
Prezenta metodă de testare este echivalentă cu Orientarea OCDE privind testarea (test guideline – TG) nr.
The term “asynchronous development” refers specifically to those deviations in tadpole gross morphological development that disallow the definitive determination of a developmental stage according to the criteria of Nieuwkoop and Faber (8) because key morphological landmarks show characteristics of different stages.
232 (2009).
As implicated by the term “asynchronous development”, only cases showing deviations in the progress of remodelling of specific tissues relative to the progress of remodelling of other tissues should be considered.
Această metodă de testare este concepută pentru a evalua efectele substanțelor chimice asupra producției reproductive a colembolelor în sol.
Some classical phenotypes include delay or absence of fore limb emergence despite normal or advanced development of hind limbs and tail tissues, or the precocious resorption of gills relative to the stage of hind limb morphogenesis and tail resorption.
Ea se bazează pe procedurile existente (1) (2).
An animal will be recorded as showing asynchronous development if it cannot be assigned to a stage because it fails to meet a majority of the landmark developmental criteria for a given Niewkoop and Faber stage (8), or if there is extreme delay or acceleration of one or more key features (e.g. tail completely resorbed, but forelimbs not emerged).
Specia Folsomia candida, care se reproduce partenogenetic, și specia Folsomia fimetaria, care se reproduce sexual, sunt două dintre cele mai accesibile specii de colembole care pot fi cultivate și care sunt disponibile comercial.