0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
ARTICLE |

MIGRATING EPIDERMAL CELLS

JAMA. 1965;194(9):1008. doi:10.1001/jama.1965.03090220064021.
Text Size: A A A
Published online

The human epidermis, far from being a static organ, renews itself constantly. Until recently, the replacement time remained in doubt, with estimates ranging from 7 to 258 days. In 1961 investigators measured the appearance of radioactivity in stratum corneum after intravenous infusion of aminoacetic acid (glycine) labeled with radioactive carbon (14C) and estimated a 13- to 14day renewal time for the stratum corneum and 12 to 15 days for the viable epidermis (basal, prickle, and granular layers).1 A communication in the October issue of the Archives of Dermatology confirms that at least a portion of the human epidermis renews itself every two to three weeks.2 The investigators injected thymidine labeled with radioactive hydrogen (3H) intradermally in 21 volunteers and secured biopsies sequentially for six weeks.

Examination of autoradiograms revealed that 5% of germinative cells incorporated the labeled substance into DNA within 40 minutes of injection. Calculations

Topics

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

First Page Preview

View Large
First page PDF preview

Figures

Tables

References

Letters

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
brightcove.createExperiences();