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We introduce the cardinal invariant $\theta$-$a{L}^{\text{'}}\left(X\right)$, related to $\theta$-$aL\left(X\right)$, and show that if $X$ is Urysohn, then $\left|X\right|\le 2^{\theta \text{-}a{L}^{\text{'}}\left(X\right)\chi \left(X\right)}$. As $\theta$-$a{L}^{\text{'}}\left(X\right)\le aL\left(X\right)$, this represents an improvement of the Bella-Cammaroto inequality. We also introduce the classes of firmly Urysohn spaces, related to Urysohn spaces, strongly semiregular spaces, related to semiregular spaces, and weakly $H$-closed spaces, related to $H$-closed spaces.