Exhibit 3.105

                                     BY-LAWS

                                       OF

                             MEDIC ONE OF COBB, INC.

                                   ARTICLE ONE

                                     Offices

     1.1 The address of the registered office of the Corporation is 2279 Benson
Poole Road, Smyrna, Georgia 30081, and the name of the registered agent at this
address is Mark Westbrook.

     1.2 The Corporation may have offices at such place or places (within or
without the State of Georgia) as the Board of Directors may from time to time
determine, or the business of the Corporation may require or make desirable.

                                   ARTICLE TWO

                                 Shares of Stock

     2.1 Share certificates shall be numbered in the order in which they are
issued. They shall be signed by the President and the seal of the Corporation
shall be affixed thereto. Share certificates shall be bound in a book and shall
be issued in consecutive order therefrom. On the sheet provided for each
certificate in the certificate book there shall be entered the name of the
person or persons owning the shares, the number of shares and the date of issue.
Share certificates exchanged or returned shall be canceled by the Secretary and
placed in their original place in the certificate book.

     2.2 Transfers of shares shall be made in the certificate book of the
Corporation by the holder in person or by power of attorney, or by surrender of
the old certificates for such shares, duly assigned.

     2.3 The holder of the common shares shall be entitled to one vote for each
share of stock outstanding in his or her name.

                                  ARTICLE THREE

                              Shareholder's Meeting

     3.1 The annual meeting of shareholders of the Corporation shall be on the
first Monday of the second month after the close of the fiscal year, within or
without the State of Georgia, at such place or places as may from time to time
be fixed by the Board of Directors.

     3.2 At all meetings of shareholders, the holders of common stock shall be
entitled to cast their one vote for each share of common stock either in person
or by written proxy.

     3.3 Written notice stating the place, day and hour of the meeting, and in
case of a special meeting, the purpose(s) for which the meeting is called, shall
be delivered not less than ten (10) nor more than fifty (50) days before the
date of the meeting to each shareholder of record entitled to vote at such
meetings. Special meetings of shareholders may be called at any time by the
President, Board of Directors or any holder of as much as one-fourth of the
outstanding shares of stock of the Corporation. Attendance at such meeting in
person or by proxy shall constitute a waiver of notice thereof except when a
shareholder attends solely for the stated purpose of objecting to the
transaction of business. Such purpose must be manifested at the very beginning
of the meeting.

     3.4 Notice of any special meeting of shareholders all state the purpose or
purposes for which the meeting is called.

     3.5 At all meetings of shareholders a majority of the outstanding shares of
stock present at the meeting shall constitute a quorum for the transaction of
business, and no resolution or business shall be transacted without the
favorable vote of a majority of the shares represented at the meeting and
entitled to vote. A lesser number may adjourn from day to day.

     3.6 Any action to be taken at a meeting of the shareholders of the
Corporation, or any action that may be taken at a meeting of shareholders, may
be taken without a meeting if a consent in writing setting forth the action so
taken shall be signed by all of the shareholders entitled to vote with respect
to the subject matter thereof.

                                  ARTICLE FOUR

                                    Directors

     4.1 Subject to these By-Laws, Articles of Incorporation or any lawful
agreement between the shareholders, the full and entire management of the
affairs and business of the Corporation shall be bested in the Board of
Directors, which shall have and may exercise all of the powers that may be
exercised or performed by the Corporation, which are not by the laws of Georgia,
by the Certificate of Incorporation or by these By-Laws directed or required to
be done or exercised by the shareholders.

     4.2 The Board of Directors shall consist of at least one (1) member and not
more than seven (7) members who shall be elected at the Annual Meeting of
Shareholders and shall serve for a term of one year, or until such time as their
successors are duly elected. A quorum shall be constituted only by presence of
all Directors and all resolutions adopted or business transacted by the Board of
Directors shall require the affirmative vote of a majority of the Board of
Directors.

     4.3 The majority of the remaining Board of Directors may fill the position
of any Director which may become vacant prior to the expiration of his term,
such appointment by the


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Board of Directors to continue until the expiration of the term of the Director
whose position has become vacant.

     4.4 The Board of Directors shall meet annually following the annual meeting
of shareholders. Special meetings of the Board of Directors may be called at any
time by the President, Chairman of the Board, or by any Director on two days'
notice. Notice of such meeting, including the time, place and subject matter
thereof, may be waived only by proper instrument in writing signed by any member
of the Board of Directors affected thereby. However, attendance in person at
such meeting shall constitute a waiver of notice thereof, except where such
appearance is to object to the calling of the meeting, the time or subject
matter thereof and where such purpose is manifested at the very beginning of the
meeting. The signature of any Director approving the minutes of any meeting of
the Board of Directors entered thereon, shall be effective to the same extent as
if such Director had been present at such meeting. Any meeting of the Board of
Directors may be held within or without the State of Georgia at such place as
may be determined by the person or persons calling the meeting.

     4.5 Any action taken at a meeting of the Board of Directors, or any action
that could have been taken at a meeting of the Board of Directors, shall be
recorded in written minutes setting forth the action so taken, and shall be
signed by all of the Directors. Furthermore, any such action may be taken
without a meeting if a consent in writing setting forth the action so taken is
signed by all of the Board of Directors.

     4.6 The Board of Directors, as such, or as members of any standing or
special committee, may receive such compensation for their services as may be
fixed from time to time by resolution of the Board.

     4.7 Nothing herein contained shall be construed to preclude any Director
from serving the corporation in any other capacity or receiving compensation
therefor.

     4.8 The Board of Directors may at any time by a majority vote select one
(1) or more of the existing Directors of the Corporation to serve as an
executive committee of the Board of Directors empowered to do any and all acts
of the Board of Directors during the interim period between meetings of such
Board. The members of such committee may be selected and removed at will, at any
time by the Board of Directors.

                                  ARTICLE FIVE

                                    Officers

     5.1 The officers of the Corporation shall consist of at least a President,
a separate Secretary, and a Treasurer whose function may be performed by the
person performing as either the President or the Secretary. Other officers,
including a Chairman of the Board, a Vice-President or Vice-Presidents and such
assistants to any of these officers as the Board of Directors shall determine
from time to time, shall also be authorized. Notwithstanding anything herein to
the contrary, the President and the Secretary shall not be the same person. All
officers shall be elected by the Board of Directors and shall serve at the
pleasure of the Board of Directors. All


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required officers and any other official position not inconsistent with these
By-Laws shall be elected at the first Board meeting after each annual
Shareholders Meeting.

     5.2 The President shall be the chief executive officer of the Corporation
and shall have general and active management of the operation of the
Corporation. He shall be responsible for the administration of the Corporation,
including general supervision of the policies of the Corporation, general and
active management of the financial affairs of the Corporation, and shall execute
bonds, mortgages or other contracts under the seal of the Corporation. He shall
only borrow money on behalf of the Corporation pursuant to specific authority
from the Board of Directors. The President shall have the authority to institute
or defend legal proceedings when the Directors are deadlocked.

     5.3 The Chairman of the Board will preside at all meetings of the Board of
Directors.

     5.4 The Vice-President shall perform all the duties of the President in his
absence and as directed by the President or by the Board of Directors.

     5.5 The Secretary shall keep the minutes of all meetings of the
shareholders and Directors and have charge of the minute books, stock books and
seal of the Corporation, and shall perform such other duties and have such other
powers as may from time to time be delegated to him or her by the President or
the Board of Directors.

     5.6 The Treasurer shall be charged with the management of the financial
affairs of the Corporation and shall have the power to recommend action
concerning the Corporation's financial affairs to the President.

     5.7 One person may hold two or more offices, except that the President and
Secretary may not be the same person.

     5.8 Salaries of officers are to be determined by the Board of Directors.

     5.9 Any officer may be removed at any time with or without cause.

     5.10 Assistants to any of the officers herein described may be appointed by
and shall have such duties as shall be delegated to them by the President or the
Board of Directors.

                                   ARTICLE SIX

                                      Seal

     6.1 The seal of the Corporation shall be in such form as the Board of
Directors may from time to time determine. In the event it is inconvenient to
use such a seal at any time, the signature of the company followed by the word
"Seal" enclosed in parentheses or scroll, shall be deemed the seal of the
Corporation. This seal shall be in the custody of the Secretary or his or her
designated authority, and affixed by him or her along with his or her signature
on the certificates of stock and such other papers as may be directed by law, by
these By-Laws or by the


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Board of Directors. All documents shall be signed by the President or other
chief executive officer and shall be attested to by the Secretary along with the
seal.

                                  ARTICLE SEVEN

                                    Dividends

     7.1 Subject to applicable law, dividends may be declared and paid out of
any funds available therefor, as often, in such amounts and at such time or
times as the Board of Directors may determine.

                                  ARTICLE EIGHT

                                  Reimbursement

     8.1 If any payment or other benefit bestowed by the Corporation on any
employee and deducted by the Corporation against its income for federal income
tax purposes is finally disallowed in whole or in part as a deduction on the
ground that it is unreasonably high compensation or on any other ground, the
portion thereof for which said deduction is not allowed shall be repaid to the
Corporation by the employee upon whom the payment or other benefit was
originally bestowed, within three (3) years from the time such deduction is
finally disallowed, unless the Board otherwise deems same to be a dividend, loan
or other emolument recognizing the services of the employee affected.

     8.2 It shall be the duty of the Board of Directors to designate the
disallowed employee compensation under the categories herein denominated and,
where appropriate, to enforce repayment of any sums it may deem unreasonably
high compensation.

     8.3 The corporation shall give reasonable notice to any employee of any
attempt to disallow as a deduction any payment or benefits to such employee so
that he may protect his interest. However, any good faith settlement by the
Corporation as to the amount to be disallowed shall be binding on the employee,
unless the employee requests in writing that additional measures be pursued,
agrees to pay the additional cost of such measures including reasonable
attorney's fees, and furnishes security to the Corporation satisfactory in the
opinion of the Board of Directors to cover such additional costs and also any
potential liability for additional income taxes attributable to the disallowance
of the deduction.

                                  ARTICLE NINE

                                   Fiscal Year

     9.1 The fiscal year of the Corporation shall begin on January 1 and end on
December 31.

                                   ARTICLE TEN


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                              Amendment of By-Laws

     10.1 All by-laws of the Corporation shall be subject to alteration or
repeal, and new by-laws may be made by a majority vote of the shareholders at
the time entitled to vote in the election of directors.

The undersigned certifies that the foregoing by-laws have been adopted as the
first by-laws of the Corporation, in accordance with the requirements of the
Georgia Business Corporation Code.


Date: 6-5-91                                 /s/ Mark Wistbrook
                                             -----------------------------------
                                             Director


Date: 6-5-91                                 /s/ Eddie Randall Lummus
                                             -----------------------------------
                                             Director


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STATE OF GEORGIA

COUNTY OF COBB

AMENDMENT TO BY-LAWS OF
MEDIC ONE OF COBB, INC.

     COMES NOW, the sole shareholder/director of MEDIC ONE OF COBB, INC., and
hereby amends the by-laws of said corporation by deleting Articles 5.1 and 5.7
in their entirety and substituting in lieu thereof the following new and
additional paragraphs denominated as paragraphs 5.1 and 5.7 as follows:

     5.1 The officers of the corporation shall consist of least a president,
secretary and a treasurer. Other officers including a chairman of the board,
vice president and such assistant to any of these officers as the board of
directors shall determine from time to time, shall also be authorized. All
officers shall be elected by the board of directors and shall serve at the
pleasure of the Board of Directors. All required officers and any other official
position not inconsistent with these by-laws shall be elected at the first board
meeting after each annual shareholders meeting.

     5.7 One person may hold two or more offices.

     The undersigned certifies that the foregoing Amendment To By-Laws of Medic
One of Cobb, Inc. has been adopted by the corporation in accordance with the
requirements of the Georgia Business Corporation Code.


                                        ----------------------------------------
                                        Eddie Randall Lummus
                                        Director/Shareholder


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