Showing papers by "Erhard Haus published in 2002"

Incorporation of titanium mesh in orbital and midface reconstruction.

Abstract: Several authors have demonstrated the safety and effectiveness of titanium in orbital reconstruction. One question posed by clinicians is what happens to large pieces of titanium in communication with the paranasal sinuses or nasal-oral-pharyngeal area. This question becomes increasingly relevant as titanium is used to reconstruct extensive defects for which the destruction of bony architecture requires the placement of mesh in proximity to these areas. The objective of this study was to examine the gross and histologic soft-tissue response to large segments of titanium mesh in the setting of orbital and midface reconstruction, particularly when exposed to the nasal-oral-pharyngeal area and paranasal sinuses. In this study, large segments of titanium mesh were used in eight patients to reconstruct orbital and midface defects, with direct communication between the mesh and nasal-oral-pharyngeal area and paranasal sinuses. Four patients had suffered self-inflicted gunshot wounds; as a result, much of their midface was missing, including the inferior and medial orbital floor, maxilla, nose, naso-orbital-ethmoid complex, and hard palate. Extensive sheets of titanium mesh were used to reconstruct their medial and inferior orbital walls, nasal bridge, and maxilla. In the fifth patient, titanium mesh was used to reconstruct the maxilla after resection of a squamous cell carcinoma of the nasolacrimal duct. In the sixth and seventh patients, mesh was used to reconstruct the nasal bridge after severely comminuted nasal fractures resulted in the loss of bone and mucosa. Finally, the eighth patient had titanium mesh used to replace cocaine-induced bone loss involving the left medial orbital floor and wall and part of the maxilla. On gross examination by either endoscopy or direct inspection, all eight patients had rapid soft-tissue incorporation of the titanium mesh. Initial examination typically revealed budding of soft tissue through mesh interstices, followed by progressive incorporation. One patient's mesh was covered in only 15 days. Two patients underwent biopsies of this newly formed soft tissue. One had biopsies performed at 3, 15, and 31 months after the original operation. Biopsy examination at 3 months revealed incorporation of the titanium with fibrous soft tissue covered by ciliated respiratory epithelium, goblet cells, and squamous epithelium with metaplasia. In addition, the dense, acute inflammation present at 3 months evolved into mild, chronic inflammation at 31 months. The second patient had a single biopsy 4 months after secondary orbital reconstruction for delayed enophthalmos. Biopsy examination revealed a fibrous soft-tissue sheath lined by squamous epithelium with metaplasia. Again, mild chronic inflammation was present within the soft tissue. This study provides evidence of titanium's compatibility with soft tissue. The mesh underwent progressive incorporation with soft tissue that was then resurfaced by indigenous cells, including respiratory epithelia and goblet cells. This phenomenon occurred despite communication with the nasal-oral-pharyngeal area and paranasal sinuses.

Chronobiology of the mammalian response to ionizing radiation potential applications in oncology

Abstract: Ionizing radiation from all sources under appropriate conditions leads to cell death and tissue damage. It is used in cancer treatment under the assumption of a higher radiosensitivity of the fast dividing tumor cells as compared with adjacent host tissues. The radiosensitivities of proliferating host tissues like bone marrow and gastrointestinal lining epithelium are dose limiting. Since these host tissues and many tumors show circadian and other periodicities in their cell proliferation, the timing of radiation treatment according to host and/or tumor rhythms is expected to improve the toxic/therapeutic ratio of the treatment. The experimental data on the chronobiology of radiation exposure show circadian rhythmicity in radiation response after whole body irradiation in mice and rats with highest toxicity in light-dark 12h:12h synchronized animals during their daily activity span. Bone marrow toxicity as well as gastrointestinal epithelial damage show circadian rhythms in part due to radiation damage to the stem cells involved and especially in the intestine also due to damage to the microvasculature. Chronoradiotherapy of malignant tumors seems promising, alone or in combination with response modifiers, provided the host and potential tumor rhythms can be monitored.

Salivary CA130 with and without unilateral autonomic parotid denervation of rats fed different diets.

Abstract: BACKGROUND Tumor markers such as CA130 can be determined in human whole saliva. Saliva represents an attractive body fluid for longitudinal studies. MATERIALS AND METHODS CA130 was determined in parotid saliva from 8 rats fed different diets, with or without autonomic denervation. RESULTS CA130 could be determined in parotid saliva of rats, irrespective of diet and/or autonomic denervation. Whether the numerical decrease in CA130 observed after autonomic denervation is statistically significant requires further work. CONCLUSIONS Since salivary CA130 has been shown to decrease following treatment with anti-cancer drugs in humans, the ability to determine this tumor marker in rat saliva opens new opportunities for optimizing cancer chronotherapy in the experimental laboratory.