Sentence:  Serum potassium at this time was 3.8 mEq. per liter , and the <WSD>hemoglobin</WSD> was 13.9 gm. By Dec. 1 , 1958 , the weakness in the pelvic and quadriceps muscle groups was appreciably worse , and it became difficult for the patient to rise unaided from a sitting or reclining position . 
Meaning of the word marked with <WSD> tags:  a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues