[Foreign body reaction to materials implanted as biocompatible for internal fixation]. / Fremdkörperreaktion nach Implantation eines biokompatiblen Osteosynthesesystems.

After implantation of resorbable materials for internal fixation, foreign body reactions are described in 0-47% of cases. Copolymers of poly-l-lactic acid (PLLA) and polyglycolic acid (PGA) seem to offer better biocompatibility than other materials. One of our patients had a midfacial fracture, which we fixed using a resorbable system based on PLLA-PGA (82%-18%); a foreign body reaction developed after 22 months. When resorbable materials are used it is essential to be aware specifically of the risk of foreign body reactions, especially when the facial area is involved. This risk must be discussed with the patient in some detail during the preoperative period.

[Ultrastructural localization of nitric oxide synthase (NOS I and III) in human nasal mucosa]. / Immunelektronenmikroskopische Lokalisation von NOS I und NOS III in der menschlichen Nasenschleimhaut.

BACKGROUND: Nasal vasculature and seromucous glands are exposed to complex mechanisms influenced by external as well as internal stimuli. In addition to classic and peptidergic neurotransmitters, Nitric oxide (NO) was increasingly found to be important in the control of various physiological functions. NO regulates nasal immunology, influences macrophages activity and has antiviral and bacteriostatic properties. The aim of this study was to detect the localization of nitric oxide synthases (NOS) I and III in the normal human nasal mucosa with immunoelectron microscopical techniques. METHODS: Specimens of non-inflamed inferior turbinates from 35 patients who required nasal surgery were fixed in phosphate-buffered glutaraldehyde. After dehydration, incubation in unicryl and polymerization ultrathin sections were cut. Primary antibodies against NOS I and III were applied and the immunocomplexes were visualized by an immunocytochemical staining-technique using a gold-labeled antibody. Immunostained structures were photodocumented by using a transmission electron microscope. RESULTS: NOS-immunoreactive nerve fibers were mainly colocated in parasympathetic nerves in the adventitia of arterial vessels and in periglandular axons. Electron microscopy showed that NOS-positive axons were in close contact with acinus cells. A strong NOS III-immunoreactivity was found in endothelial cells of capillaries near the glands as well as in arterial vessels. Furthermore, immunoreaction products were deposited throughout the cytoplasm of fibroblasts. CONCLUSIONS: Nitric oxide in nerval fibers, seromucous glands and endothelial cells of capillaries and arterial vessels suggests that NO takes part in the regulation of physiological processes of the human nasal mucosa. NO was colocalized in parasympathetic nerves and plays a role in the neurotransmission and neuromodulation of the vascular tone and glandular secretion. Arteries showed a distinctly developed nitric innervation and endothelial accumulation. The NO production in axons of the adventitia and in the endothelium of arteries demonstrated that these vessels are influenced by a dual NO system. Mainly NO could act on these structures with vasodilatory effects. Finally NO would be able to influence the functions of perivascular fibroblasts.

[NPY in human nasal mucosa -- an immunocytochemical and immunoelectron microscopical study]. / Neuropeptid Y in der Nasenschleimhaut des Menschen -- eine immunhistochemische und immunelektronenmikroskopische Untersuchung.

BACKGROUND: The functions of the nasal mucosa are regulated by numerous endogenous and exogenous influences. The innervation patterns are important for the control of the physiological nasal functions. In addition to the classic neurotransmitters different neuropeptides might play a regulating and modulating role in the nasal mucosa. Both the significance and the localization of neuropeptide Y (NPY) have not been fully elucidated. PATIENTS AND METHODS: Tissue samples of human inferior turbinates from 42 patients were taken during nasal surgery and preserved in phosphate-buffered paraformaldehyde or glutaraldehyde. Serial sections were incubated with antibodies against NPY and the ABC method was applied. In order to identify immunoelectron microscopic reactions a streptavidin-gold-marker was used. The findings were photodocumented by using a light- and transmission-electron microscope. RESULTS: NPY-positive terminals were mainly located in the adventitia of arterial vessels. There were also NPY-immunoreactive arterioles near to the glands. Periglandular a lower density of immunoreactions could be observed. NPY-positive fibers could be detected in the subepithelial connective tissue and at the glandular ducts. Immunoelectron microscopy revealed NPY within periglandular axons. CONCLUSIONS: Immunohistochemical and immunoelectron microscopical methods allow a detailed identification of the sympathetic cotransmitter NPY in arterial vessels of nasal mucosa in man. These results indicate that NPY-containing nerve fibers innervate arteries as well as nasal glands. These findings suggest that NPY play a significant role as a neuromodulator in the control of both vasculature and glandular secretion. The localisation of NPY in periglandular and periductal nerves confirms the direct influence of glandular functions. NPY-agonists may be a beneficial additional treatment of rhinopathies to reduce nasal obstruction and mucus secretion.