WASHINGTON – The Cuban dissident who as a desperate prison protest took a knife to his face and body – carving into his forehead the letters “I,” for “inocente,” or “innocent,” and “L,” for “libertad,” or “liberty” – was released yesterday after 27 months spent languishing in Fidel Castro’s gulag.

The release came the day after his plight was highlighted Wednesday in a front-page article in The New York Sun that compared his action to that of Medal of Honor winner James Stockdale, who, while imprisoned by communists in Hanoi, mutilated his face by beating it with a wooden stool to dissuade his captors from exploiting him for propaganda purposes.

The dissident released yesterday, Mario Enrique Mayo, is one of the 75 Cuban dissidents jailed during Fidel Castro’s infamous “primavera negra,” or “black spring,” crackdown in March 2003. As Mr. Mayo became the 15th of the 75 pro-democracy activists to be released, the news was met with a mix of joy and frustration, as other members of the Cuban opposition on the island and in America remained mindful of hundreds of other prisoners of conscience still suffering in Mr. Castro’s dungeons.

The New York Sun reported Wednesday that Mr. Mayo was a leading figure in the movement among Cuba’s prisoners of conscience protesting the regime and drawing international attention to their plight by using hunger strikes, suicide attempts, and acts of self-disfiguration amid increasingly desperate conditions inside Mr. Castro’s jails.

Early yesterday morning, according to reports out of Havana, the fruits of Mr. Mayo’s resistance took the form of a conditional release issued by the regime, which cited health concerns as the reason for letting him out of Camaguey’s Kilo 7 prison. It was the fifth prison in which Mr. Mayo had served some of his 20-year sentence for endangering “the independence and territorial integrity of the state.” The dissident’s permission to exit the gulag and serve time at home is valid for one year.

Mr. Mayo, 41, is a lawyer and independent journalist who contributed to free Miami-based press outlets, including an opposition Web site, www.nuevaprensacubana.org, and Radio Marti.

While in prison, Mr. Mayo underwent several hunger strikes and twice attempted suicide by trying to strangle himself with a plastic cord. In October, Mr. Mayo took a knife to his face and body, carving the letters into his forehead.

Confronted with Mr. Mayo’s deteriorating health brought on by his imprisonment – which, according to the international free-speech organization Reporters Without Borders, included “glaucoma in the left eye, high blood pressure, pulmonary emphysema and prostate inflammation, as well as acute depression” – along with his acts of self-disfiguration, the regime was probably concerned about the consequences of his dying in jail, a leading Cuban pro-democracy activist, Martha Beatriz Roque Cabello, told the Sun in a phone interview from her Havana home yesterday.

One of Mr. Mayo’s sisters, Carmen Mayo Hernandez, told the Sun in a phone interview from the family’s home in Camaguey that the entire family was thrilled by Mr. Mayo’s release.

“My thoughts are that my God, my Lord, has, with his power, helped my family and saved the life of my brother,” Ms. Mayo, 34, said in Spanish. “He has fulfilled his promise of liberty for my brother.”

Mr. Mayo, his sister said, was still ill as a result of his imprisonment, but added that “bit by bit he is recuperating.” When Mr. Mayo was released, she added, “We all hugged him together – my mother, my sister, his wife.”

Ms. Roque, who was rounded up during the March 2003 crackdown and is free under the same conditional release terms as Mr. Mayo, cautioned that her fellow democracy activist had not been granted total freedom. She also called for the release of other prisoners of conscience unjustly detained by Mr. Castro.

“There are many, many more,” Ms. Roque said in Spanish, citing the 60 remaining prisoners from the March 2003 crackdown in addition to “the hundreds of political prisoners in our jails.”

“It’s important to keep working on this case by case,” Ms. Roque said. “That’s why we are asking the world to keep an eye on Cuba, and to keep an eye on these violations of human rights.”

Ms. Roque’s sentiments were echoed in Washington, where a leading Cuban-American member of Congress, Rep. Ileana Ros-Lehtinen, Republican of Florida, also urged sustained pressure on Havana’s strongman.

Ms. Ros-Lehtinen in an e-mail noted that Mr. Mayo had been “unjustly jailed and now he is correctly freed,” yet cautioned that “the dictator will arrest more to continue filling up his jail cells with freedom fighters and human rights advocates who challenge his totalitarian and ruthless ways.”

“The international community,” Ms. Ros-Lehtinen continued, “must keep working for the release of all political prisoners. We cannot accept anything less.”