“Immunosuppressed mice were transplanted with clinically symptomless skin grafts from patients.”
In this case, the verb “to transplant” in English is being used as an intransitive, thus requiring the preposition “with.” However, because trasplantar is always transitive in Spanish, we must reorganize this sentence to render a coherent translation. Otherwise, we end up with the translation that inspired this post:
Se trasplantaron ratones inmunosuprimidos con injertos de piel asintomática de pacientes.
Whereby the mice with skin grafts were being transplanted.
Not a good experiment.