"We believe this second license agreement
supports the use of our Potelligent Technology as a method for enhancement of
ADCC and its ability to deliver more highly potent antibodies for more
effective clinical response . BioWa creates and develops enhanced
ADCC antibodies for itself and others, offering a full range of antibody
discovery and development capabilities. Sinovac's split flu
vaccine received approval of its New Drug Certificate in March 2005.sinovac.

footprints apres

J.biowa.com.

weil spelunking

Medarex plans to use the
Potelligent Technology to enhance the ADCC function of selected Medarex
antibodies for potential therapeutic applications, including cancer.;
Medarex(R), the Medarex logo and UltiMAb(R) and are trademarks of Medarex,
Inc. The feedback from the attendees
was very positive.

Sinovac is currently the world leader in the development of a SARS
vaccine.
GulfWest also announced that it has successfully re-entered and is
now drilling its second horizontal well in the Glen Rose formation in
the Iola Field of East Texas.

cave communicating

ADCC activity is one mechanism of some already
launched anticancer therapeutic antibodies on the market today., Ltd.

It can be recommended to protect people against Hepatitis A
and Hepatitis B.

Bilive(TM) is a combined vaccine formulated by purified
inactivated Hepatitis A virus antigen and recombinant (yeast)
hepatitis B surface (HBsAg), absorbed into aluminum hydroxide. It is preventable with safe effective vaccines.

GulfWest Update on Financing and Drilling Activity

Speleology is the exploration, study, conservation and enjoyment of caves and other underground structures.

speleo leptospirosis

About Medarex, Inc. Each year in the United
States, an estimated 200,000 persons are newly infected with hepatitis
B virus.

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com.
Medarex is a biopharmaceutical company focused on the discovery,
development and potential commercialization of fully human antibody-based
therapeutics to treat life-threatening and debilitating diseases, including
cancer, inflammation, autoimmune disorders and infectious diseases.com. Medarex disclaims, however, any intent or obligation to update
these forward-looking statements. Risks and uncertainties include risks
associated with product discovery and development, uncertainties related to
the outcome of clinical trials, uncertainties related to product manufacturing
as well as risks detailed from time to time in Medarex's public disclosure
filings with the U.

cavers nothing

Enhancement of
this activity is in the spotlight as one promising possibility for the next
generation of antibody technology. These chronically infected people are at high risk of
death from cirrhosis of the liver and liver cancer, diseases that kill
about one million people each year.

Sinovac now has two vaccines fully approved for sale in China -
Healive(TM) for Hepatitis A and Bilive(TM) for Hepatitis A+B combined.

potentially communicating

Bilive(TM) junior is for use in non-immune children and
adolescents from ages 1 to 15 years, and Bilive(TM) dult is for use in
non-immune adults and adolescents 16 years of age and older.

Sinovac Biotech Ltd.

speleology nothing

, BioWa, Inc.
"We are very pleased to announce the expansion of our relationship with
Medarex, and to have Potelligent Technology combined with Medarex's human
antibody technology and pipeline of therapeutic products," said Dr . Nobuo
Hanai, President and CEO of BioWa. We believe that working with Medarex, a leading
human therapeutic antibody company, is key to advancing the goals of BioWa to
bring about safe and more effective treatments for cancer and other life-
threatening and debilitating diseases. For more information about BioWa
visit its web site at http://www. Copies of Medarex's public disclosure filings are available from its
investor relations department.

About Hepatitis B

Hepatitis B is a very common infection. The successful re-entry and
re-completion of wells in Texas, Louisiana and Colorado is part of
GulfWest's business plan to apply various enhancement technologies to
re -develop previously abandoned and deeper, domestic natural gas and
oil reserves.

cavers leptospirosis

BioWa Grants the Second Potelligent(TM) Antibody Technology License to Medarex

PRINCETON, N."
"We are very excited about the promise of utilizing the Potelligent
Technology for the generation of potentially more efficacious antibodies,"
said Donald L.
Potelligent(TM) Technology involves the reduction of the amount of fucose
in the carbohydrate structure of an antibody. BioWa is the exclusive
worldwide licensor of Potelligent(TM) Technology. ADCC is a critical function of the immune system that enhances the
ability of antibodies to kill tumor cells. The
vaccine induces the body's immune system to generate antibodies as a
reaction against hepatitis A and hepatitis B viruses. Overall, an estimated 1. Nearly 300 million persons in the world are
chronically infected with hepatitis B virus.

For further information please refer to the Company's filings with
the SEC or refer to Sinovac's website at www.com

THIS NEWS RELEASE MAY INCLUDE FORWARD-LOOKING STATEMENTS WITHIN
THE MEANING OF SECTION 27A OF THE UNITED STATES SECURITIES ACT OF
1933, AS AMENDED, AND SECTION 21E OF THE UNITED STATES SECURITIES AND
EXCHANGE ACT OF 1934, AS AMENDED, WITH RESPECT TO ACHIEVING CORPORATE
OBJECTIVES , DEVELOPING ADDITIONAL PROJECT INTERESTS, SINOVAC'S
ANALYSIS OF OPPORTUNITIES IN THE ACQUISITION AND DEVELOPMENT OF
VARIOUS PROJECT INTERESTS AND CERTAIN OTHER MATTERS.

Speleology is a potentially dangerous extreme sport.

leptospirosis caves

Drakeman, President and CEO of Medarex.
27, 2005, did not change.

'Take nothing but pictures, leave nothing but footprints, kill nothing but time.

leptospirosis apres

cancer cells. Top medical professionals and hepatitis specialists
from across China, and about 130 doctors from China's Center of
Disease Control attended the launch. The original maturity date of the loan, Oct.

speleological caving

Twenty-three of these therapeutic product candidates derived from
Medarex technology are currently in human clinical testing, with two of the
most advanced product candidates presently in Phase III clinical trials .medarex. Statements that are not historical
facts, including statements preceded by, followed by , or that include the
words "potential"; "believe"; "anticipate"; "intend"; "plan"; "expect";
"estimate"; "could"; "may"; or similar statements are forward-looking
statements.
(OTCBB:GULF) announced today that it has obtained a one-month
extension on certain changes in the terms and conditions of a loan
from the company's major lender that were to go in effect at the end
of January, 2005 .

leptospirosis nothing

BioWa and Medarex Announce Expansion of Licensing Agreement for BioWa's Potelligent(TM) Technology

Hepatitis is one
of the major diseases of mankind and continues to be a serious global
public health issue.
Final approval of the Company's flu vaccine is expected in 2005 after
GMP certification of the new flu vaccine production line.

It is highly recommended that you contact a local organisation to commence your participation in this fascinating recreation.

cave nothing

About BioWa
BioWa is a wholly owned subsidiary of Kyowa Hakko Kogyo Co, Ltd.

Sinovac Biotech Ltd. Announces That it has Launched the Marketing of its Proprietary Combined Hepatitis A+B Vaccine Bilive'TM'

Preliminary Phase I results show that this SARS vaccine is
safe and induces SARS-neutralizing antibodies in the human body.

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(Nasdaq: MEDX) today announced that BioWa has granted a second license to
Medarex to use BioWa's Potelligent(TM) Technology for the enhancement of
antibody-dependent cellular cytotoxicity (ADCC). Research shows that
Potelligent(TM) Technology significantly enhances binding affinity of
antibodies for Fc receptors and increases ADCC activity in vitro. Medarex
applies its UltiMAb (R) technology and product development and clinical
manufacturing experience to generate, support and potentially commercialize a
broad range of fully human antibody product candidates for itself and its
partners.

Of the 2 billion people who have been infected with the hepatitis
B virus (HBV), more than 350 million have chronic (lifelong)
infections. Sinovac is one of the leading emerging biotechnology
companies in China. For further
discussion regarding the information in the press release and other
risk factors, please refer to the Company's 10-K for Dec. 31, 2003,
and 10Q for the period ended September 30, 2004.

nss leptospirosis

g., Japan's
leading pharmaceutical and largest biotech company . Sinovac held its official marketing launch for the sale of
Bilive(TM) during the period of March 25-27 in Huang Mountain, Anhui
Province, China.
Sinovac expects to record the first sales of Bilive (TM) by May 2005.
The Hepatitis A vaccine, Healive(TM), is currently experiencing strong
sales growth in China.

The matters discussed herein may contain "forward-looking"
statements that involve risks and uncertainties including, without
limitation, competitive factors in the marketplace .

cave weil

BioWa is currently developing ADCC enhanced monoclonal
antibody-based therapeutics to fight cancer and other life-threatening and
debilitating diseases and both BioWa and Kyowa have Potelligent(TM ) antibody
products in various clinical stages.
Medarex is committed to building value by developing a diverse pipeline of
antibody products to address the world's unmet healthcare needs. All rights are reserved. High rates of chronic
infection are found in some parts of China, Southeast Asia, Africa ,
the Pacific islands, the Amazon Basin in South America, and the Middle
East.

About Sinovac Biotech Ltd. specializes in the research, development,
commercialization, and sales of human vaccines for infectious
illnesses such as hepatitis A and hepatitis B, influenza, "SARS", and
avian flu . CDC controls the Chinese vaccine market through its two
main functions: as both the commercial sales agency and the
governmental department in the pharmaceutical sector for China.

speleo spelunking

About Potelligent Technology
Antibody-dependent cellular cytotoxicity (ADCC) activity is an important
function of the human immune system, whereby immune cells can kill target
cells, e.

Business Editors/Energy Editors

HOUSTON----GulfWest Energy Inc.

Speleology, caving, potholing, spelunking and urban speleology are all common terms that refer to these activities.

'

uis speleological

News Editors

BEIJING----Sinovac Biotech Ltd. Bilive(TM) will be sold in two forms based on the age
of vaccinees . Sinovac's Hepatitis A+B combined vaccine,
Bilive(TM), received approval in China in January 2005 and is expected
to achieve similar sales growth to Healive(TM).

clickable speleo

Detailed licensing terms/financial terms were
not disclosed. For more
information about Medarex, visit its website at http://www .

China is a country that has been greatly affected by viral
hepatitis for a long time.25 million people
in the United States have chronic hepatitis B virus infection, and
4,000 to 5,000 people die each year from liver disease or liver cancer
related to hepatitis B.com

If you would like to receive regular updates on Sinovac please
send your email request to info@sinovac.

leptospirosis communicating

Potelligent(TM) Technology
creates high antibody-dependent cellular cytotoxicity (ADCC) monoclonal
antibodies.S.
Potelligent(TM) is the trademark of Kyowa Hakko Kogyo Co. In
addition, the Company is co-developing a human vaccine targeting the
avian flu virus in partnership with the China Center of Disease
Control (CDC). THESE STATEMENTS
ARE MADE UNDER THE "SAFE HARBOR" PROVISIONS OF THE UNITED STATES
PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND INVOLVE RISKS AND
UNCERTAINTIES WHICH COULD CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY
FROM THOSE IN THE FORWARD-LOOKING STATEMENTS CONTAINED HEREIN. Additional
information can also be found on the GulfWest Web page at
gulfwestenergy .

spirochetal speleological

The
agreement provides Medarex with nonexclusive commercial rights to develop
antibodies for an undisclosed number of targets. There can be no assurance that
such development efforts will succeed or that other developed products will
receive required regulatory clearance or that, even if such regulatory
clearance were received, such products would ultimately achieve commercial
success . During the meeting, it was further agreed that the
Chinese vaccine industry will promote the use of inactivated vaccines
such as Sinovac's Bilive(TM) in the prevention of infectious diseases
such as viral hepatitis.

About Bilive(TM)

Bilive(TM) is a state-of-the-art combined hepatitis A and B
vaccine.

cave footprints

and Medarex, Inc. In return, BioWa will
receive license fees, and could receive milestone payments and royalties on
products developed by Medarex. The enhancement of ADCC is seen up
to 100 fold in vitro.

For Medarex: Except for the historical information presented herein,
matters discussed herein may constitute forward-looking statements that are
subject to certain risks and uncertainties that could cause actual results to
differ materially from any future results, performance or achievements
expressed or implied by such statements. Securities and Exchange Commission (SEC), including its
Annual Report on Form 10-K for the fiscal year ended December 31 , 2004 and
subsequent Quarterly Reports on Form 10-Q.
("Sinovac") ("the Company") (AMEX:SVA) announces that it has commenced
the marketing launch of Bilive(TM), its combined Hepatitis A + B
vaccine . More than 11,000 of these people are hospitalized, and 20,000
remain chronically infected. The loan was part of a refinancing that closed at
the end of April, 2004.

karst clickable

One
potential benefit of Potelligent (TM) derived therapeutic antibodies is greater
tumor cell killing activity than with conventional antibodies. The prevention and control of hepatitis is
very important for the country's social development and public health.