Madhukar Anant Pathak, dermatologist; his research helped develop sunscreen; 77

Madhukar Anant Pathak left his homeland of India in 1956 with $18, a small suitcase, and big dreams of making a better life for himself in the United States.

After years of studying and practicing dermatology, Dr. Pathak became a leader in his field, researching and determining the causes of many skin diseases and disorders, according to two of his sons. His research also contributed to the development of a skin-care product that has become a staple in the medicine chests and beach bags of sun lovers around the world: sunscreen.

Dr. Pathak died Saturday at his Belmont home. He was 77.

''He was a true representation of the American dream," said his son Ajay, speaking from his parents' home yesterday. ''He always put us first, his children and grandchildren. He worked hard so we could enjoy life."

Dr. Pathak was born in Baroda on July 10, 1927. He was the first in his family to receive a college education, his sons said. After moving to the United States, he attended the University of Oregon, where he received his medical degree.

Soon after graduation, his wife, Sushma, emigrated from India and the couple settled in Boston, where they became naturalized citizens.

Dr. Pathak was hired at Massachusetts General Hospital, where he worked with a team of other dermatologists to develop the first commercial sunscreens in the 1960s.

''A lot of his work helped put the hospital on the map in the world of dermatology," Ajay Pathak said. ''He was very committed to his field."

Dr. Pathak was also professor emeritus at Harvard Medical School, where he taught until his retirement in 1995. After retiring, he continued his studies of skin disorders, focusing much of his time testing the effects of light on the skin.

His research was published in numerous medical journals, including the New England Journal of Medicine and the Journal of the American Medical Association.

He also contributed as a writer and editor to various medical texts, including ''Sunlight and Man," ''The Pharmacological Basics of Therapeutics" and ''Dermatology and Modern Medicine," which became a manual for practicing dermatologists.

Dr. Pathak's research took him around the world, where he presented lectures to fellow researchers and students.

He was also a founding doctor of the New York-based Skin Cancer Foundation, which today promotes awareness of proper skin care and cancer prevention.

His children remember his passion for his research but also his devotion to family.

''Research was his passion, his hobby, just as many people love something like golf," said his son Raju, of Milton. ''But he was also a very good family person, immersed in the Indian culture where family is everything. He instilled very good values in all three of the boys. Education was important to him. We're all caring brothers, and it's because of what he taught us."

His sons said he traveled often with his family and was also deeply religious, steeped heavily in the Hindu faith.

As his family gathered yesterday afternoon on Father's Day to remember Dr. Pathak, Ajay Pathak, a Belmont resident, shared a piece of fatherly advice he had received.

''What he told me as I struggled through some things in my life was, 'Son, you're my responsibility until the day I die,' " he said. ''I'm over 40 years old now, and I understand exactly what he meant. Other people knew him as a great doctor, but to me he was the greatest father anyone could ever have."

In addition to his wife and two sons, Dr. Pathak leaves another son, Sanjay of Sudbury.

Burial is private.