4/A 1 p1022-4a.txt FORM 4/A FOR LOU L. ROSS ======== FORM 4/A ======== [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(f) of the Investment Company Act of 1940 ================================================================================ 1. Name and Address of Reporting Person* Ross Lou L. -------------------------------------------------------------------------------- (Last) (First) (Middle) 14455 N. Hayden Road, Suite 202 -------------------------------------------------------------------------------- (Street) Scottsdale AZ 85260 -------------------------------------------------------------------------------- (City (State) (Zip) ================================================================================ 2. Issuer Name and Ticker or Trading Symbol National Scientific Corporation; NSCT ================================================================================ 3. I.R.S. Identification Number of Reporting Person, if an Entity (Voluntary) ================================================================================ 4. Statement for Month/Day/Year 04/2002 ================================================================================ 5. If Amendment, Date of Original (Month/Day/Year) 05/10/2002 ================================================================================ 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) [X] Director [ ] 10% Owner [X] Officer (give title below) [ ] Other (specify below) Chairman of the Board --------------------- ================================================================================ 7. Individual or Joint/Group Filing (Check Applicable Line) [X] Form filed by One Reporting Person [ ] Form filed by More than One Reporting Person ================================================================================

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. * If the form is filed by more than one reporting person, see Instruction 4(b)(v). Form 4/A (continued)

Explanation of Responses: (1) This filing is being made to (i) correct the number of shares as reported sold and (ii) correct the total number of shares held at the end of the reporting period to remove 750,000 shares previously included in such amount, which are subject to outstanding options as reported on Form 4 dated 1/9/2002. /s/ Lou L. Ross 10/23/2002 ------------------------------- --------------- **Signature of Reporting Person Date **Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a). Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure. Page 2

ROSS LOU 4/A