Nasta laid the foundations for the teaching of modern epidemiology of tuberculosis, set up the first Chair of Phthisiology at the Bucharest Faculty of Medicine and fostered research in the field of bacteriology.

He founded and directed a leading hospital and research center in the field of respiratory medicine called Institutul de Ftiziologie.

After the fall of communism in Romania in 1989, his contributions to the scientific, medical and academic field were once again recognised and the institute was renamed Institutul de Pneumoftiziologie Marius Nasta in his honour.

[3] Alexandru's wife Irina (born Constantinidis), descended from a Greek family which counted linguists, writers and diplomats among its members.

[4] The early death of Alexandru Nasta in 1897, caused the family to fall on hard times and forced Irina to teach piano lessons in order to support and raise her four children.

[5] At the Bucharest Faculty of Medicine, Nasta was taught by Ioan Cantacuzino who took him under his wing and who had a major influence on his early professional career and personal life.

[6] An outgoing and complex personality, Cantacuzino combined outstanding teaching with a passion for rigorous scientific research, a vast clinical experience, and wider interests which included music and the etchings of baroque French printmakers.

[8] By integrating Cantacuzino's team, Nasta joined a group whose members left an indelebile mark on the Romanian scientific and medical world.

It combined scientific research in fields such as microbiology, experimental pathology, epidemiology and hygiene with the production of vaccines to protect against a number of human diseases such as intestinal infections, polio, diphtheria, tetanus, typhus, and malaria.

[11] Between 1928 and 1934, Nasta continued his scientific research at the Cantacuzino Institute and practiced as a physician specialised in pulmonary diseases at the Casa Asigurărilor Sociale.

[12] Nasta's research, carried out either by himself or in teams, covered the most important fields of phthisiology such as bacteriology, immunology and the physiophathology of respiratory diseases.

That same year, working in close partnership with Albert Calmette's laboratory in Paris, the Cantacuzino team was responsible for the introduction of the BCG vaccine in Romania.

In 1934, the year of Ioan Cantacuzino's death, the League was established by law[15] and received significant funding from the Romanian state as well as from the private sector.

[16] The latter was responsible for building state of the art sanatoria and dispensaries throughout the country (at Balotesti, Moroeni, Dobriṭa, Marila, Vorniceni, Valea Iasului, Alexandria and the Regina Elisabeta dispensary in Bucharest), for launching major tuberculosis awareness programs (through advertising campaigns, lecture programs and radio broadcasts), and for championing the introduction of special medical insurance cover against tuberculosis.

[17] In the aftermath of World War II, the League was renamed the "Direction of Tuberculosis" ("DT") and became a department of the Ministry of Health under the newly installed communist regime.

He and his wife Lucia, counted among their friends the painters Jean Steriadi, Theodor Pallady, and Dumitru Ghiață, the sculptors Milița Petrașcu and Ion Jalea, the musician Vasile Jianu, the philosopher Dimitrie Cuclin, and the literary critic Alice Voinescu.

[23] The writer Panait Istrati, who has TB, became a friend of the Nasta family after receiving much needed medical assistance from Marius at the Filaret hospital in the final years of his life.

[26] On a spiritual level, Nasta developed a set of beliefs based on his lifelong experiences treating patients and on the inspiration that he drew from the writings of two of his favorite authors: Michel de Montaigne and Sir Thomas Browne.

Michel de Montaigne's goal, as stated in his "Essays", of describing himself with utter frankness and honesty ("bonne foi") guided Nasta in his continuous quest for self-improvement and in his desire for living "with a purpose".

Cantacuzino and his deputies (Constantin Ionescu-Mihăesti, Mihai Ciucă, and Alexandru Slătineanu) were instrumental in setting up several mobile hospitals and pest houses which were used to treat patients and vaccinate the entire IVth Romanian army corps.

Its staff, including Nasta, was responsible for the production of cholera, typhus, and TB vaccines distributed to the Romanian, Russian, and Allied Mission in the Balkans.

He was convinced of the importance of microbial genetics in his field and increasingly critical of some of the influential Romanian scientists who favored Trofim Lysenko's pseudo scientific ideas.

Nasta favored the introduction of new methods for the detection of TB based on chemo-prophylaxis, and became increasingly concerned about the excessive use of outdated X ray machines which had damaging side effects on patients.

[5] By the end of the 1950s, Romania's Stalinist rulers felt increasingly threatened by the changes in leadership in the Soviet Union and by possible internal unrest following the Hungarian Revolution of 1956.

[36] The accusations leveled against them consisted in "making disparaging comments against the popular-democratic regime and against socialism, listening to imperialist radio stations, and spreading rumors and insults against the foreign policy of the Soviet Union".

[39] Thousands of doctors taught and trained by Nasta and his team[40] over several decades, now worked in hospitals and clinics throughout Romania in cities such as Cluj, Iași, Târgu Mureș, and Timișoara, where over 30,000 beds (compared to only 3,500 in 1945) were reserved for patients with pulmonary and extra-pulmonary TB.

[42] The Institute remains to this day a leading hospital, teaching and research centre in the field of pulmonary diseases, which includes the Pneumology Clinic of the Carol Davila University of Medicine and Pharmacy.

Stoicescu, Miron Bogdan (a physician and member of the Romanian Academcy of Medical Sciences), Florin Mihălțan, Ștefan Rujinski, and Claudia Toma to name but a few.