For the following block of code:
For I = 0 To listOfStrings.Count - 1
If myString.Contains(lstOfStrings.Item(I)) Then
Return True
End If
Next
The drawback of Contains method is that it doesn't allow to specify comparison type which is often important when comparing strings. It is always culture-sensitive and case-sensitive. So I think the answer of WhoIsRich is valuable, I just want to show a simpler alternative:
listOfStrings.Any(s => s.Equals(myString, StringComparison.OrdinalIgnoreCase))