Department of microbiology and molecular genetics

Faculty profile

• BS biology - Andrews University - 1964
• MS microbiology - Loma Linda University - 1968
• PhD microbiology - Loma Linda University - 1974
• Postdoctoral - California State Department of Health (Berkeley) 1975-77
• Current research interests
• Recent publications
• Teaching

Current research interests

H238-BALBc tumor immunology

H238 cells are BALB/c mouse epithelial cells that have been transformed by Herpes simplex Type II virus. Injection of 0.5 million of these cells will allow solid tumors to form in the mouse host, due to the production of transforming growth factor-beta 1 (TGF§-1) by the H238 cells. TGF-§ has the ability to down-regulate a host's immune system. We have engineered H238 cells by transfecting them with murine interleukin 2 and anti-sense TGF-§1. While the modified H238 tumor cells may still cause tumor formation, such tumors are significantly smaller in size and fewer in numbers. Furthermore, analysis of the immune system using mitogen stimulation and flow cytometry has shown that tumor bearing mice have lower stimulation indices in comparison to non tumor bearing animals. Levels of CD71 (a late immune activation marker) has been shown to be higher in non-tumor bearing mice. Ongoing studies are attempting to clarify the steps involved in tumor progression and how cytokine and anti-sense gene therapy might interfere with tumor formation processes. Reactivation of immune competence in the tumor-bearing hosts is a main goal of this study.

Dentally Related Projects

My laboratory has worked with a number of dental investigators from Loma Linda University's School of Dentistry on a variety of projects. One long term collaboration has been in endodontics (root canal dentistry) biology. We have contributed to a clarification of the immune processes involved in periapical abscesses, studies involving relevant dental materials and the microbiology of endodontic lesions. We have worked extensively with dental and dental hygiene students on table clinic research projects. Several of these have been published and won competition awards at local, state and national meetings. Controlling bacterial levels in dental unit water lines is a current professional concern, and we are collaborating with dental researchers on several aspects of this problem. In periodontal studies, we have identified oral pathogens from dental plaque samples by using a DNA-DNA hybridization Dot-Blot process using probes from genomic DNA of known bacteria.

Interactions with clinical medicine

As a microbiologist with a strong interest in clinical problems related to microbiology, my laboratory has been able to work collaboratively with several departments in the School of Medicine. I currently consult with the Medical Center's clinical laboratory on diagnostic virology. We have provided the microbiological expertise and facilities for studies in ophthalmology, helping to develop a rabbit model to test antimicrobial treatments of induced bacterial keratitis and to assess viral transmission in tissue plumes produced by excimer laser use. We are currently involved in a study evaluating high level disinfection of endoscopes with colleagues from internal medicine (gastroenterology). We have also provided limited immunological assessments of subjects involved in nutrition studies.

Recent publications

Click on the symbol beside the reference to read the corresponding abstract.

Haddad EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. 1999. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr 70 (3 Suppl):586S-93S.

Hodson, JDC., L.A. Sanchez, S.M. Sanchez, J.D. Kettering, and K.A. Simpson. 1999. Comparison of the autoclavable vs. non autoclavable ultrasonic handpiece: A bacteria free environment? Cal. Dent. Hyg. Journal. 15(1):20-22.

Kovacs, B.J., Y.K. Chen, J.D. Kettering, R.M. Aprecio and I. Roy. 1999. High-level disinfection of gastrointestional endoscopes with glutaraldehyde: Are current guidelines adequate? Gastroenterology. Accepted for Publication. 94(6):1546-1550.

Kettering, J.D. and D.S. Gridley. 1999. Chlamydia, Mycoplasma and Rickettsia (Chapter 23). For: Essentials in Diagnostic Microbiology, L. Shimeld, ed. Delmar Publishers, Inc. pp. 303-316.

Kettering, J.D. 1999. Basic concepts and techniques in virology (Chapter 48). For: Essentials of Diagnostic Microbiology, L. Shimeld, ed. Delmar Publishers, Inc. pp. 635-646.

Kettering, J.D. 1999. Specimen collection and processing of viral samples (Chapter 49). For: Essentials in Diagnostic Microbiology, L. Shimeld, ed. Delmar Publishers, Inc. pp. 647-654.

Kettering, J.D. 1999. Clinically significant viruses and their identification (Chapter 50). Essentials in Diagnostic Microbiology, L. Shimeld, ed. Delmar Publishers, Inc. pp. 655-670.

Eldridge, K.R. S.F. Finnie, J.A. Stephens, A.M. Mauad, C.A. Munoz and J.D. Kettering. 1998. The efficacy of an alcohol-free chlorhexidine mouthrinse as an antimicrobial agent. The Jour. of Prosthetic Dent. 80:685-690.

Kovacs, B.J., R.M. Aprecio, J.D. Kettering and Y.K. Chen. 1998. Efficacy of various disinfectants in killing a resistant strain of Pseudomonas aeroginosa by comparing zones of inhibition implications for endoscopic equipment processing. Am. J. of Gastroenterology. 93(11)2057-2059.

Guzek, J.P., D. Cline, P.K. Row, S. Beeve, S. Ispirescu, R.M. Aprecio, I.F. Wessels, J.D. Kettering, D. Gano, and G.M. Nelson. 1998. Rabbit Streptococcus pneumoniae keratitis model and topical therapy. Investigative Ophthalmology and Visual Science. 39(11):2012-2017.

Waterman, P.A., M. Torabinejad, P.J. McMillan and J.D. Kettering. 1998. Development of periapical lesions in immunosuppressed rats. Oral Surg, Oral Medicine, Oral Path. 85:720-725.

For a complete list of my publications, you can download my curriculum vitae. You'll need Adobe Acrobat Reader, which you can download here.

Teaching

My general teaching responsibilities include virology and bacteriology for all students we teach:

MICR 511 Medical Microbiology - Medical School: Virology and Bacteriology (11 lectures)
MICR 501 Principles of Microbiology - Dental: Coordinate this class and teach virology and bacteriology (13 lectures)
MICR 565 Virology - Graduate School: Coordinate and teach virology (6-8 lectures - Offered every other year)
GRDN 622 Biomedical Sciences I - Dental Graduate Class: Coordinate and teach virology and bacteriology (8 lectures)
DNHY 418 Critical Issues of Health Care - Dental Hygiene: Teach about HIV and AIDS (10 lectures)

Graduate School Mentoring: Currently am the research advisor for two PhD candidates and one Master's student.

I also participate as a facilitator in the School of Medicine MABS programs.

School of Medicine - Graduate School - Loma Linda University

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