( BW)(BIOTIME)(BTIM) BioTime products, Hextend® and PentaLyte,

presented at medical and scientific meetings



    Business Editors & Medicine Industry Writers



    BERKELEY, Calif.--(BUSINESS WIRE)--May 1, 1996--BioTime Inc.

(NASDAQ: BTIM) Wednesday announced that Dr. George V. Letsou

presented the results of his research on ice-cold blood substitution

with Hextend®, BioTime's blood plasma volume expander and hypothermic

blood substitute.

    In this study, whole body perfusion with cold, oxygenated Hextend®

was shown to protect the heart and brain of laboratory animals

during four hours of deep hypothermia.  The presentation was made

yesterday by Letsou at the 76th Annual Meeting of the American

Association For Thoracic Surgery, held at the San Diego Convention

Center.  Letsou is associate professor of surgery at the Baylor

College of Medicine in Houston.

    Letsou said, "chilled blood substitution with Hextend® can

potentially allow extended periods of time for surgery on the heart

and brain, during which circulation can be substantially reduced, or

even arrested.  When adapted to clinical surgery, these techniques

should prove valuable in the repair of ancurysms of the aorta and

the cerebral circulation, and in reducing the body temperature of

transplant donors prior to removal and transplantation of vital

organs."

    Letsou's talk follows a series of presentations describing

research with Hextend® made at the Experimental Biology '96 meeting

held in April at the Washington Convention Center in Washington,

D.C.  Dr. Roger Jacobs, director of the Surgical Research Laboratory

at New York's Metropolitan Hospital Center, reported on studies in

which Hextend®, and PentaLyte (a physiologically balanced

pentastarch-based solution recently developed by BioTime for

indications which require the replacement of lesser volumes of

blood compared with Hextend®) were substituted for more than 3/4 of

the circulating blood of rats.  Results indicated that both

solutions could adequately replace blood volume, but that blood

albumin and total protein levels returned faster in the

PentaLyte-hemodiluted animals compared with those whose blood was

diluted with Hextend®.

    Jacobs said "these findings suggest that PentaLyte may be

eliminated from the blood more quickly than Hextend®.  Since overall

survival of rats in which a large amount of their blood volume was

replaced by Hextend® was slightly better than when the replacement

was with PentaLyte, PentaLyte may prove to be more ideal for

clinical use when smaller volumes of blood are lost, as patients may

more quickly restore smaller amounts of blood constituents.

However, when replacement of large amounts of blood volume is

necessary, it may be better to use a product such as Hextend®, which

can endure longer in the circulation."

    Stephen Kehrer, director of BioTime's Surgical Research

Laboratory, also presented data at this conference which showed that

rats subjected to partial blood substitution after fasting and severe

cold stress were much more likely to survive if their blood volume

was maintained with Hextend® than with a commercially used plasma

expander.  Dr. Paul Segall, BioTime president and chief executive

officer, said "better survival in Hextend®-treated animals may be

related to the higher blood glucose levels observed.  Hextend®

provides glucose whereas the commercially available product does

not.  BioTime has submitted an Investigational New Drug Application

to the Food and Drug Administration and is currently planning Phase

III clinical trials of Hextend® for use in surgery in which large

volumes of blood are lost."

    Additional research on the use of Hextend® supplemented with

cold-protective agents was presented by Dr. Hal Sternberg, BioTime's

research vice president.  He described experiments in which hamsters

were completely blood substituted at hypothermic temperatures with

BioTime solutions, and then placed in sub-zero freezing baths for



periods of up to 2 hours.  These animals reached deep body

temperatures as low as -4 C, and then were revived to consciousness

and reactivity.  An analysis of brain tissue immediately following

revival indicated that substantial freezing and thawing of the

tissues of the brain had occurred.  Sternberg said "these

experiments reveal that mammals can survive - at least for short

periods - partial freezing of vital organs, if their blood is

replaced with solutions which guard against some of the damage caused

by ice crystallization.  These studies suggest that techniques for

maintaining a wide variety of tissues and organs in frozen or

partially frozen states for extended time periods may be achievable

when adequate solutions and protocols are developed.  This

breakthrough could lead to long term organ and tissue banking for

transplantation."

    BioTime, with headquarters in Berkeley, is engaged in the

research and development of synthetic blood plasma volume expanders

and low temperature blood substitute solutions and technology for

use in surgery, emergency trauma treatment, the preservation of

organs awaiting transplant, and other applications.


    CONTACT:  BioTime Inc.

              Victoria Bellport, 510/845-9535