What was going on when I was born?

Congressional taxwriters have taken a tentative step toward imposing price controls on the medical profession by proposing to freeze Medicare fees for 15 months and assess penalties against doctors in the program who increase their charges. The step came Thursday night in a compromise agreement of House and Senate members seeking to reduce the Federal deficit, but its full effect on the Federal health insurance program for the elderly and disabled did not become apparent until today. House-Senate conference deliberations on overall deficit-reducing legislation continued today. (Page 8.) The move was criticized as coercion by some medical societies and praised as progress against soaring health costs by the American Association of Retired Persons. (Page 9.)

United States intelligence sources uncovered a plot by right-wing Salvadoran extremists to kill the United States Ambassador here last month, according to an Administration official in Washington and two sources in El Salvador. They said Roberto d'Aubuisson, leader of the National Republican Alliance, known as Arena, was among a small group of Arena members who were said to have planned to kill the Ambassador, Thomas R. Pickering. (In Washington, senior officials confirmed that the Administration had learned of a right-wing Salvadoran plot to assassinate the Ambassador and that a high-level official had been sent to El Salvador to issue warnings to the plot leaders. (Senator Jesse Helms, Republican of North Carolina, who had been a strong supporter of Mr. d'Aubuisson's candidacy, said: ''I think it's an absolute falsehood. There is no evidence that I have seen that he is contended to have been linked'' to the reported plot to murder Mr. Pickering. Page 5.)

It began, innocently enough, with a series of late-night cab rides. When Kenneth Petricig finished his job as a night proofreader at the law firm of Skadden, Arps, Slate, Meagher & Flom, he would often find Stephen L. Wallis driving the cab he rode home. Gradually, their conversation turned to corporate takeovers - the firm's specialty. And by November 1982 the two men had formed a partnership that seemed full of promise, but which ended two and a half years later with Mr. Wallis's arrest as he was preparing to leave for Switzerland. Their partnership, as outlined in court papers, was simple and, it seemed, foolproof: Mr. Wallis would pay Mr. Petricig for information on planned corporate takeovers that Mr. Petricig gleaned from proofreading Skadden, Arps documents. Mr. Wallis would then trade stock on the basis of this information.

Senator Gary Hart promised today to pursue his quest for the Democratic Presidential nomination, but he sounded much more conciliatory toward the foe who has apparently already locked up the prize, Walter F. Mondale. A top Hart strategist said he had inferred from signals from the Mondale camp that the former Vice President, weighing his choices for a running mate, would be watching Mr. Hart's behavior carefully in the next few days. And speaking today to members of the National Press Club, Mr. Hart left the door open to accepting the second spot. 'Race Isn't Over' ''The race isn't over,'' Mr. Hart said. ''We intend to press our case.'' He dismissed talk of the Vice Presidency as ''premature.'' Previously, the Colorado Senator has said the job did not interest him.

Eleven Latin American nations, including some of the most heavily indebted countries in the world, took their first concrete step today toward unity in dealing with the world debt crisis. The nations meeting here agreed in a statement they called the Consensus of Cartagena to set up a rotating secretariat among themselves and come together in frequent meetings. The agreement called for the meetings in order to ''reflect together'' on the debt crisis. In the agreement, the Latin Americans called for the establishment of a working group of industrial and third world nations inside the World Bank's development committee to consider a wide- ranging list of proposals.

About 140 state police officers and social service workers raided 20 homes near here early this morning and took into custody 112 children of the Northeast Kingdom Community Church because members had refused to answer complaints about child abuse and neglect. However, a state judge released the children of the first 16 families to appear in court. (By the time court action ended at 10:30 P.M., all the children and their parents were sent home, The Associated Press reported. Forty cases were dismissed when the parents refused to give the names of their children, officials said, while some other cases were continued.)

The heart, long thought to be little more than a muscle that pumps blood, has been shown to produce biologically powerful substances that probably act as hormones. The heart substances were discovered, identified and purified in recent months. Scientists involved in the research said they expect new and better treatments for high blood pressure and some heart and kidney conditions to result from further studies of the hormone-like chemicals. In experiments with animals, the heart substances powerfully stimulated the kidneys to excrete salt and water. In other laboratory experiments such substances made blood vessels relax.

Governor Cuomo and Mayor Koch took sharply different positions today on what government should do to provide transportation services for the physically handicapped. Their exchange, in news conferences and interviews during the day, followed Mr. Koch's announcement Thursday night that he was withdrawing his support for a compromise in which some subway stations due for modernization would be made accessible to the disabled by the installation of elevators. Mr. Cuomo said that the law required all New York City subway stations to be made accessible to wheelchair- bound riders as the stations were modernized, and that doing this, or at least some portion if it, would be a worthwhile expense. Mr. Koch said this would be a waste of large amounts of money, because the subways would still be unsafe for riders in wheelchairs and thus few of them would use the system. He suggested special bus service as an alternative, even if the subway fare had to be raised to pay for it.

In the days before Poland's local elections this week, Gen. Wojciech Jaruzelski, the Polish Communist Party leader, was often shown on television kissing the hands of female shoppers and workers, just like a Polish noble of the 18th century. This was hardly unusual, since in Poland truck drivers, coal miners, police officers, professors, journalists, party sympathizers and Solidarity activists all kiss the hands of women upon meeting, and women all routinely extend their hands to be kissed. As the 40th anniversary of the Polish People's Republic approaches next month, men and women who have rejected terms of address like ''comrade'' still cling to chivalric forms that in the past were limited to the aristocracy. ''Obviously, to some extent hand kissing is a profession of nationalism,'' a Polish writer said in a recent conversation. ''Through it, we Poles are consciously or unconsciously differentiating ourselves from our neighbors.''

The White House today continued its emphasis on promoting peaceful relations with the Russians as a group of students cheered President Reagan in the Rose Garden after he cautioned them against nuclear freeze demonstrations. ''Four more years!'' shouted the young people as Mr. Reagan once again used a routine White House occasion to address a campaign issue of major concern to the President's political strategists. The President, as he has done almost daily, offered a statement of optimism that ''we are going to succeed'' in reopening arms negotiations with the Soviet Union.

The Pol Pot forces said Friday that they killed 79 Vietnamese soldiers in a two-day battle near the southern Cambodian port city of Kampong Som. In a clandestine Khmer-language radio broadcast monitored in Aranyprathet, on the Thai-Cambodian border, the Cambodian rebels said their guerrillas attacked a Vietnamese base 135 miles southwest of Phnom Penh on Monday, killing 75 Vietnamese troops and wounding another 87. The broadcast said another four Vietnamese died and five were wounded Tuesday when they stepped on land mines planted by the Pol Pot forces.

The State Department disclosed in detail today how it deliberately complicates the lives of foreign diplomats posted in the United States if their governments harass American envoys overseas. The retaliation involves unplugging telephones, cutting off utilities, restricting travel, holding up shipments of goods from overseas and refusing certain countries the right to buy property in the United States, according to a report by the department's two-year- old Office of Foreign Missions. The department also said it would soon require all of the 25,000 motor vehicles driven by diplomats in the United States to carry new and distinctive red, white and blue Federal license plates.