Biomedical subjects

Kerby C Oberg

Publications and source records attributed to Kerby C Oberg.

4 recordsLinked to original sources

PubMed2003

A unique combination of infrared and microwave radiation accelerates wound healing.

Light or electromagnetic radiation has been reported to enhance wound healing. The use of selected spectra, including infrared and microwave, has been described; however, no studies to date have examined the potential benefit of combining these spectra. In this study, a device that emits electromagnetic radiation across both the infrared and microwave ranges was used. To test the effects of this unique electromagnetic radiation spectrum on wound healing, two clinically relevant wound-healing models (i.e., tensile strength of simple incisions and survival of McFarlane flaps) were selected. After the creation of a simple full-thickness incision (n = 35 rats) or a caudally based McFarlane flap (n = 33 rats), animals were randomly assigned to one of three treatment groups: untreated control, infrared, or combined electromagnetic radiation. Treatment was administered for 30 minutes, twice daily for 18 days in animals with simple incisions, and 15 days in animals with McFarlane flaps. The wound area or flap was harvested and analyzed, blinded to the treatment regimens. A p value of less than 0.05 obtained by analysis of variance was considered to be statistically significant. Animals receiving combined electromagnetic radiation demonstrated increased tensile strength (2.62 N/mm2) compared with animals receiving infrared radiation (2.36 N/mm2) or untreated controls (1.73 N/mm2, p < 0.001). Animals with McFarlane flaps receiving combined electromagnetic radiation had increased flap survival (78.0 percent) compared with animals receiving infrared radiation (69.7 percent) and untreated controls (63.1 percent, p < 0.01). Thus, combined electromagnetic radiation provided a distinct advantage in wound healing that might augment current treatment regimens.

Animals↗

PubMed2002

Efficient ectopic gene expression targeting chick mesoderm.

The chick model has been instrumental in illuminating genes that regulate early vertebrate development and pattern formation. Targeted ectopic gene expression is critical to dissect further the complicated gene interactions that are involved. In an effort to develop a consistent method to ectopically introduce and focally express genes in chick mesoderm, we evaluated and optimized several gene delivery methods, including implantation of 293 cells laden with viral vectors, direct adenoviral injection, and electroporation (EP). We targeted the mesoderm of chick wing buds between stages 19 and 21 (Hamburger and Hamilton stages) and used beta-galactosidase and green fluorescent protein (GFP) to document gene transfer. Expression constructs using the cytomegalovirus (CMV) promoter, the beta-actin promoter, and vectors with an internal ribosomal entry sequence linked to GFP (IRES-GFP) were also compared. After gene transfer, we monitored expression for up to 3 days. The functionality of ectopic expression was demonstrated with constructs containing the coding sequences for Shh, a secreted signaling protein, or Hoxb-8, a transcription factor, both of which can induce digit duplication when ectopically expressed in anterior limb mesoderm. We identified several factors that enhance mesodermal gene transfer. First, the use of a vector with the beta-actin promoter coupled to the 69% fragment of the bovine papilloma virus yielded superior mesodermal expression both by markers and functional results when compared with several CMV-driven vectors. Second, we found the use of mineral oil to be an important adjuvant for EP and direct viral injection to localize and contain vector within the mesoderm at the injection site. Lastly, although ectopic expression could be achieved with all three methods, we favored EP confined to the mesoderm with insulated microelectrodes (confined microelectroporation- CMEP), because vector construction is rapid, the method is efficient, and results were consistent and reproducible.

Actins↗

PubMed2002

ACTH-secreting islet cell tumor of the pancreas presenting as bilateral ovarian tumors and Cushing's syndrome.

A 41-year-old woman presented with hirsutism, a pelvic mass, and Cushing's syndrome. Imaging studies revealed bilateral ovarian masses and a solid and cystic mass within the pancreas. Partial pancreatectomy, bilateral oophorectomy, and excision of several peritoneal tumor nodules were performed. Pathological examination revealed a neuroendocrine islet cell tumor of the pancreas with bilateral ovarian metastases. The tumor was immunoreactive for ACTH, chromogranin, neuron-specific enolase, and keratin. The patient received postoperative chemotherapy and has been disease-free for 6 years. To our knowledge, this is the first reported case of an ACTH-secreting pancreatic neuroendocrine tumor presenting as bilateral ovarian metastases.

Adrenocorticotropic Hormone↗

PubMed2002

Necrotizing fasciitis: a fourteen-year retrospective study of 163 consecutive patients.

This review was prompted by continued public and professional interest of necrotizing fasciitis as well as worldwide increases in the incidence of streptococcal invasive infections. Our objective was to outline the clinical course of necrotizing fasciitis and delineate factors relating to mortality among 163 diagnosed patients. Over 14 years patients diagnosed with necrotizing fasciitis were reviewed for patient history, comorbid conditions, and progression of clinical course. A logistic regression model was used to identify factors increasing mortality risk among necrotizing fasciitis patients. Nearly 17 per cent of the patients showed no identifiable antecedent trauma. Seventy-one per cent of tissue culture-positive patients (145) had multibacterial infections. Although no streptococcal species were recovered from one-third of these culture-positive patients there was an increase in mortality noted with beta-Streptococcus infections. Ninety-six per cent of the patient deaths were correlated with variables organized into the following categories: 1) patient history (intravenous drug use and age <1 or >60 years), 2) comorbid conditions (cancer, renal disease, and congestive heart failure), 3) characteristics of clinical course (trunk involvement, positive blood cultures, peripheral vascular disease, and positive cultures for beta-streptococcus or anaerobic bacteria), and 4) quantitative timeline of clinical course (time: injury to diagnosis, diagnosis to treatment). Mortality is correlated to patient history, comorbid conditions, and progression of clinical course. Necrotizing fasciitis can occur idiopathically and is generally a polymicrobial infection that sometimes occurs in the absence of streptococci. Clearly the mortality and morbidity associated with necrotizing fasciitis can be decreased with clinical awareness, early diagnosis, adequate surgical debridement, and intensive supportive care.

Adolescent↗