User:Dvmphd/Mark A. Kukucka

Mark A. Kukucka (b. 1960 -) is a biomedical researcher, veterinary physician, biochemist, nanotechnology scientist, CAP professional development officer, aviator and a Fortune 200 company sales executive.

Early life and education
Kukucka is a Baltimore, Maryland native and the oldest of three children to Alma and Joseph A. Kukucka of Kingsville, Maryland.

Kukucka attended Sinclair Lane Elementary (Baltimore City) thru the middle of the 4th grade and then transferred to Kingsville Elementary School (Baltimore County). He then went to Perry Hall Middle School (grades 7 thru 9) before being selected to attend Eastern Vocational Technical High School where he graduated with scholastic honors in 1978.

In the Fall of 1979, Mark enrolled in the Animal Science program at the University of Maryland in College Park, Maryland. Three years later, he received his Bachelor of Science (B.S.) degree with academic honors. Following admission to the graduate school at the University of Maryland in the Fall of 1982, he began graduate work under Donna L. Kern and W. Ray Stricklin. In 1985 he earned his Master of Science (M.S.) degree in Animal Behavior from the Department of Animal Sciences.

During the Fall of 1985, Mark was selected for the Veterinary Medical program at the Virginia-Maryland Regional College of Veterinary Medicine in Blacksburg, Virginia. Following his acceptance to the Graduate School at Virginia Polytechnic Institute & State University (Virginia Tech) in 1987, Mark joined the Parallel DVM/PhD program in Veterinary Medical Sciences and began graduate work under the direction of Hara P. Misra. In 1989, Mark received his Doctor of Veterinary Medicine (D.V.M.) professional degree. He then completed his remaining dissertation requirements and was granted his second doctorate in 1993, a Doctor of Philosophy (Ph.D.) degree in Biochemistry/Cell Biology/Free Radical Toxicology.

Collegiate Degrees

 * University of Maryland, B.S. 1982
 * University of Maryland, M.S. 1985
 * Virginia-Maryland Regional College of Veterinary Medicine, D.V.M. 1989
 * Virginia Tech, Ph.D. 1993

The Academic Genealogy of Dr. Mark A. Kukucka

Professional Career
Kukucka is a biomedical researcher, veterinary physician and nanotechnology scientist who currently works as a sales executive at Danaher where he consults on nanotechnology needs for biological and material scientists employed with academic/pharma/government research labs including the National Institutes of Health (NIH), National Cancer Institute (NCI), National Institute of Standards & Technology (NIST), Department of Defense (U.S. Army, Navy & Air Force), Federal Bureau of Investigation (FBI), Department of Homeland Security (DHS), Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), Food & Drug Administration (FDA), U.S. Department of Agriculture (USDA), National Aeronautics & Space Administration (NASA), Johns Hopkins Applied Physics Laboratory (APL), Howard Hughes Medical Institute (HHMI), Centers for Disease Control (CDC) and the Smithsonian Institution.

Kukucka is a member of the American Institute of Aeronautics and Astronautics, the University of Maryland NanoCenter, the Maryland Aviation Museum and the World Veterinary Association.

Civil Air Patrol Career
Kukucka joined the Civil Air Patrol (CAP), U.S. Air Force auxiliary, in 1975 where he rose through the ranks and achieved the following awards and honors:


 * Billy Mitchell Award in 1975
 * Amelia Earhart Award in 1976.
 * Solo aviator wings in 1977
 * IACE ambassador in 1978
 * CAP Model Rocketry badge in 1979
 * General Carl A. Spaatz Award (#569) in 1981 for which he received a congratulatory letter from former president Richard M. Nixon and a personal meeting with Paul E. Garber (First Curator of the National Air & Space Museum) - Only 0.05% of CAP cadets actually achieve the Spaatz award..
 * CAP college scholarships in 1981 & 1982
 * Ira C. Eaker Award ex post facto in 1981.

In 2009, Kukucka was awarded the General Charles E. Yeager Aerospace Award in addition to an Air Force Association CAP Unit Aerospace Education Grant. and the General Benjamin O. Davis, Jr. Leadership Award. In 2010, Kukucka earned the Grover Loening Award, A. Scott Crossfield Award, Paul E. Garber Award and was selected as Maryland Wing's Aerospace Education Officer (AEO) of the Year. He also attended the Northeast Regional Staff College at McGuire Air Force Base and received the Lamplighter Award for being selected the Top Graduate. During 2013, Kukucka attended National Staff College at Maxwell Air Force Base. He then received the Gill Robb Wilson Award numbered 3004.

Maj. Kukucka is currently assigned to Maryland Wing HQ staff where he is serving as the Missions Directorate (A7) in addition to the Director of Professional Development (Assistant Deputy Chief of Staff - A7P) and Testing Control Officer. Kukucka is also active in the Glenn L. Martin Composite Squadron where he serves as the unit’s Aerospace Education Officer and Medical Officer in addition to being a commercial instrument rated CAP pilot.

FAA Certifications

 * Private Pilot - 1998
 * Instrument Pilot - 1999
 * Commercial Pilot - 2000

Research Career
The 1980s heralded the discovery and identification of extra-pituitary sources of the neurohypophysial hormone oxytocin in non-neural tissues of several animal species. The presence, location and biosynthesis of significant amounts of oxytocin in the ovarian corpus luteum was followed by the immunocytochemical demonstration of an oxytocin-like peptide in the testicular interstitial cells. Leydig cells, which comprise up to 80% of the testicular intertubular cell population, are known to synthesize testosterone in situ. Indirect evidence indicated that an oxytocin-like peptide was also present in Leydig cells. The question arose whether this peptide was synthesized de novo by Leydig cells or was taken up and stored by the cells following biosynthesis at some other intra- and/or extra-gonadal source(s). Since luteinizing hormone (LH) and ascorbate are known to augment the production of oxytocin in ovarian granulose cells, varying concentrations of these two stimulants were used to monitor the biosynthesis of oxytocin from isolated Leydig cells in culture.

Highly enriched populations of guinea pig Leydig cells were isolated using a method that employed enzymatic dissociation and Percoll gradient centrifugation. Since ambient oxygen tensions are toxic to cultured Leydig cells leading to decreased steroidogenic capacity, the antioxidant defense system of isolated Leydig cells was discerned. Decreased levels of several antioxidants including superoxide dismutase, glutathione reductase, glucose-6-phosphate dehydrogenase and total glutathione were measured. Using the dichlorofluorescin (DCF-DA) assay, it was determined that isolated Leydig cells were capable of accumulating hydrogen peroxide (H2O2). Leydig cells maintained in an atmosphere composed of 19% oxygen produced H2O2 at a faster rate than similar cells incubated at 3% oxygen.

Using a polyclonal antibody (Ab)-based immunoaffinity column, oxytocin biosynthesis was monitored in Leydig cells incubated with a mildly stimulating dose (0.1 ng/ml) of ovine LH for 24, 48 and 72 hours in the presence of increasing concentrations of sodium ascorbate (1- 500 mM) under culture conditions of hypoxia and normoxia. Following solid phase extraction and immunoaffinity purification, sample supernatants were analyzed for both testosterone and oxytocin content as measured by radioimmunoassay (RIA) and high performance liquid chromatography-electrochemical detection (HPLC-ECD) respectively. Hypoxic culture conditions and low (1-10 mM) concentrations of sodium ascorbate augmented the production of oxytocin from Leydig cells in culture. Higher (50-500 mM) levels of ascorbate and normoxic culture conditions suppressed both testosterone and oxytocin production in isolated Leydig cells. Because oxytocin synthesis was found to be cycloheximide-sensitive, we conclude that Leydig cells possess the biosynthetic machinery necessary to manufacture oxytocin. The isolated oxytocin peptide was purified by HPLC with fraction collection followed by polyclonal-Ab immunoaffinity column chromatography. Comparison of the amino acid sequence of the isolated octapeptide with authentic oxytocin provides unequivocal evidence that Leydig cells synthesize oxytocin de novo. Considering the widespread use of vitamin C as a dietary supplement, the research reported yields valuable mechanistic information on the reproductive biologic role of vitamin C in gonadal steroid and peptide hormone metabolism.

Research Projects
Redox potential of oxytocin <---> oxytoceine

Vitamin C (aka ascorbate) is another non-enzymatic antioxidant found in significant levels within the testes. As an antioxidant, ascorbate's primary role is to donate electrons to neutralize reactive species of oxygen including superoxide (to H2O2) and hydroxyl free radicals (to H2O). When ascorbate acts as a scavenger (by donating an electron to a free radical), ascorbate is oxidized in the process to the ascorbate free radical and dehydro-ascorbate. The ascorbate free radical and the dehydro-ascorbate are reduced back to ascorbate either by NADH (catalyzed by semidehydroascorbate reductase and forming NAD) or reduced glutathione (GSH)(catalyzed by dehydroascorbate reductase and forming oxidized glutathione (GSSG)).

Nota Bene: Vitamin C also works along with glutathione peroxidase (a major free radical-fighting enzyme) to revitalize vitamin E.

Interestingly, Kukucka et. al. reported finding significant levels of oxytocin (a disulfide containing octapeptide) in isolated Leydig cells. Kukucka theorized in the introduction of his PhD dissertation that open chain oxytoceine (the reduced form of oxytocin) may also act as a scavenger (by donating an electron to a free radical), oxytoceine may then be oxidized back to oxytocin. As noted above, the ascorbate free radical and the dehydro-ascorbate are reduced back to ascorbate either by NADH catalyzed by semidehydroascorbate reductase (and forming NAD) or reduced glutathione (GSH) catalyzed by dehydroascorbate reductase (and forming oxidized glutathione (GSSG)).... why couldn't the ascorbate free radical and dehydro-ascorbate be reduced back to ascorbate by reduced oxytoceine (forming closed-ring oxytocin)?

Thus, the redox potential of oxytocin <---> oxytoceine may drive ascorbate <---> dehydro-ascorbate or vice versa as part of the non-enzymatic antioxidant defense system.

With that said: Could the redox potential of oxytoceine drive the formation of reduced ascorbate and oxytocin.... is this chemistry right? What is the redox potential of oxytocin <---> oxytoceine? What is the redox potential of ascorbate <---> dehydro-ascorbate?