NY -- Standard&Poor's CreditWire 4/22/98 – Standard&Poor's today assigned its single-'A'-plus rating to New Jersey Health Care Facilities Financing Authority's $70 million refunding revenue bonds series 1998 dated May 1, 1998 due July 1, 2028, issued for the Medical Center at Princeton, N.J. The bonds are scheduled to sell April 30, 1998. At the same time, Standard&Poor's raised its rating on the authority's $52.7 million outstanding revenue bonds series A issued for the medical center, to single-'A'-plus from single-'A'. The rating reflects the hospital's strong finances, additional resources outside the obligated group, and Princeton's favorable competitive position in a strong economy. Leverage remains high compared to other similarly rated medical centers. Bond proceeds from