Complex sentence: In the 1920s and 1930s, Grasslands Hospital specialized in treating adults and children with Tuberculosis, Polio, Scarlet Fever, and Diphtheria but later became known for its cardiovascular services and became one of the first public institutions to establish a Renal Dialysis Unit.
Split into simpler sentences: In the 1920s and 30s, Grasslands Hospital became devoted to treating adults and children with Tuberculosis, Polio, Scarlet Fever, and Diphtheria. Later, Grasslands Hospital became known for its Cardio-Vascular services and was one of the first public institutions to establish a Renal Dialysis Unit.