P.A.M. van den Keijbus

Inadequate salivary flow and poor oral mucosal status in intubated intensive care unit patients.

ObjectiveTo investigate salivary flow and frequency of oral mucositis in intensive care unit patients compared with patients admitted because of elective coronary artery bypass graft (CABG) surgery. In addition, the pattern of oropharyngeal colonization was investigated in these patients. DesignProspective study. SettingMixed intensive care unit and cardiosurgical ward. PatientsIn this study, 24 ventilated intensive care unit patients and 20 CABG patients were included. Measurements and Main ResultsTwo dental hygienists examined intensive care unit patients for the presence of periodontal disease and mucositis at admission and subsequently every week during their stay in the intensive care unit. At the same time, stimulated salivary flow and salivary total immunoglobulin A output were measured. Oropharyngeal cultures were obtained as well. CABG patients were examined the day before the operation, 1 day, 1 wk, and 2 wks after the operation. The following results were obtained: a) temporarily reduced postoperative stimulated salivary flow and total salivary immunoglobulin A output in CABG patients and nearly absent stimulated salivary flow in intensive care unit patients; b) oropharyngeal colonization with potentially pathogenic microorganisms in intensive care unit and not in CABG patients; and c) the increase in mucositis index in intensive care unit patients paralleled the increase in potentially pathogenic microorganism oropharyngeal colonization, especially Enterobacteriaceae and Pseudomonas aeruginosa. ConclusionsAbsence of adequate salivary flow in intubated intensive care unit patients causes severe xerostomia, which may contribute to the development of mucositis and oropharyngeal colonization with Gram-negative bacteria.

Bactericidal activity of LFchimera is stronger and less sensitive to ionic strength than its constituent lactoferricin and lactoferrampin peptides

The innate immunity factor lactoferrin harbours two antimicrobial moieties, lactoferricin and lactoferrampin, situated in close proximity in the N1 domain of the molecule. Most likely they cooperate in many of the beneficial activities of lactoferrin. To investigate whether chimerization of both peptides forms a functional unit we designed a chimerical structure containing lactoferricin amino acids 17-30 and lactoferrampin amino acids 265-284. The bactericidal activity of this LFchimera was found to be drastically stronger than that of the constituent peptides, as was demonstrated by the need for lower dose, shorter incubation time and less ionic strength dependency. Likewise, strongly enhanced interaction with negatively charged model membranes was found for the LFchimera relative to the constituent peptides. Thus, chimerization of the two antimicrobial peptides resembling their structural orientation in the native molecule strikingly improves their biological activity.

Detection and Quantification of MUC7 in Submandibular, Sublingual, Palatine, and Labial Saliva by Anti-peptide Antiserum

The large carbohydrate moiety of low-Mr salivary mucin MUC7 (originally referred to as MG2) is subject to variations. Biochemical analysis and quantification of MUC7 in saliva samples require recognition tools that are independent of the carbohydrate moiety. Therefore, we have evoked three antisera to synthetic peptides of MUC7. One of these (CpMG2), raised against the C-terminal peptide, recognized native MUC7 in saliva and was characterized further. Recognition of MUC7 by CpMG2 turned out to be specific, resistant to dissociating and reductive treatments, and independent of glycosylation differences, as indicated by Western analysis and ELISA. The antiserum could be used to monitor MUC7 during purification procedures. MUC7 was demonstrated in small volumes of saliva from all (sero)mucous glands, including the palate and lip. Analysis with antibodies and lectins indicated large variations in amount as well as in glycosylation of MUC7. An ELISA was developed to determine the relative quantity of MUC7 in the glandular salivas: mean values of approximately 220, 980, and 100 μg mucin per mL were found in submandibular, sublingual, and palatine saliva, respectively.

Immunohistochemical Detection of Salivary Agglutinin/gp-340 in Human Parotid, Submandibular, and Labial Salivary Glands

Salivary agglutinin is a Streptococcus mutans binding protein and a member of the scavenger receptor cysteine-rich superfamily. It is identical to lung gp-340 and brain DMBT1, which possibly play a role in innate immunity and tumor suppression, respectively. The goal of this study was to localize salivary agglutinin in human salivary glands. Two monoclonal antibodies, directed against gp-340, were characterized. mAb 213-1 reacted with sialic acid epitopes and cross-reacted with MUC7. The reaction with mAb 213-6 disappeared after reduction, suggesting that a protein epitope was recognized. In the parotid gland, immunohistochemical labeling with mAb 213-6 was found in the duct cells. In the submandibular gland and labial gland, both serous acini and demilune cells were labeled. In the labial gland, labeling was found at the luminal side of the duct cells. Salivary agglutinin was distinctly localized in salivary glands, but in distinct glandular secretions, no differences in electrophoretic behavior were observed.

Histatins Enhance Wound Closure with Oral and Non-oral Cells:

The role of human saliva in oral wound-healing has never been fully elucidated. We previously demonstrated that parotid-salivary histatins enhance in vitro wound closure. The question remains whether other salivary-gland secretions enhance wound closure, and also the effects of histatins on primary and non-oral cells. Since the presence of histatins is not limited to parotid saliva, we expected to observe wound-closure activity of other salivary-gland secretions. However, here we show that non-parotid saliva does not stimulate wound closure, most probably due to the presence of mucins, since the addition of MUC5B to parotid saliva abolished its effect. Furthermore, we found that histatins stimulated wound closure of (primary) cells of both oral and non-oral origin. This suggests that the cellular receptor of histatins is widely expressed and not confined to cells derived from the oral cavity. These findings encourage the future therapeutic application of histatins in the treatment of all kinds of wounds.