To determine the maximal safe daily dose of BG8962 (rCD4) which can be administered by continuous subcutaneous infusion (CSCI) over 24 hours; to determine the pharmacokinetics of BG8962 when it is administered by intramuscular and subcutaneous routes; and to look for dose related antiviral activity determined by quantitation of infectious HIV peripheral blood leukocytes (PBLs) and plasma, and by monitoring the blood levels of viral p24 antigen (when present), CD4+ T-cells, and Beta-2- microglobulin. Recombinant soluble CD4 protein (rCD4) is a drug that has been produced by genetic engineering techniques. In laboratory studies, rCD4 binds to HIV and reduces its ability to enter the cell, thus inhibiting its reproduction. Before rCD4 can be tested for therapeutic effectiveness in HIV-infected patients, it is necessary to determine the maximum dose that can be tolerated by humans. AMENDED: To date, Biogen's original sequence recombinant soluble CD4 and Biogen's natural sequence recombinant soluble CD4 have both been referred to as recombinant soluble CD4 (rsCD4). In order to distinguish between these two products, a change in nomenclature has been made. In this protocol, whenever the original sequence CD4 molecule is referred to, it is called recombinant soluble T4 (rsT4). Whenever the natural sequence molecule (currently under study in this protocol) is referred to, it is called BG8962 or rCD4. Whenever the drug is discussed generically, it is referred to as rsCD4.