Rafael M. Nagler

Characterization of the differentiated antioxidant profile of human saliva.

Saliva is armed with various defense mechanisms, such as the immunological and enzymatic defense systems. In addition, saliva has the ability to protect the mucosa against mechanical insults and to promote its healing via the activity of epidermal growth factor. However, another defense mechanism, the antioxidant system, exists in saliva and seems to be of paramount importance. The most interesting finding of the present study was the demonstration of the existence of much higher concentrations of the various salivary molecular and enzymatic antioxidant parameters in the parotid saliva compared with the submandibular/sublingual saliva. For example, peroxidase, superoxide dismutase, uric acid, and total antioxidant status were higher in resting parotid saliva compared with resting submandibular/sublingual saliva by 2405, 235, 245, and 147%, respectively. Another important finding was the distinction between the salivary antioxidant system and the immunological and enzymatic protective systems, as represented by the salivary concentrations of secretory IgA and lysozyme, respectively. These findings suggest that the profound antioxidant capacity of saliva secreted from parotid glands is related either to the different physiological demands related to eating (parotid predominance), to oral integrity maintenance (submandibular/sublingual predominance), or to the high content of deleterious redox-active transitional metal ions present in parotid saliva. This also may signify that our oral cavity environment is only partially protected against oxidative stress during most of the day and night.

Salivary analysis in oral cancer patients: DNA and protein oxidation, reactive nitrogen species, and antioxidant profile.

Free radicals such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), which induce oxidative and nitrative stress, are main contributors to oral carcinogenesis. The RNS (nitrosamines: nitrates, NO3, and nitrites, NO2) are also produced by the reaction of ROS and other free radicals with nitric oxide (NO) and are therefore in equilibrium with it.

Concomitant Analysis of Salivary Tumor Markers—A New Diagnostic Tool for Oral Cancer

Purpose: Oral squamous cell carcinoma (OSCC) is a common human malignancy. Circulatory epithelial tumor markers were previously investigated in the serum of OSCC patients but almost never in their saliva, in spite of the fact that there is a direct contact between the saliva and the oral cancer lesion. The purpose of the current study was to examine tumor markers in the saliva of OSCC patients. Experimental Design: We measured the concentrations of the six most studied epithelial serum circulatory tumor markers in the saliva of OSCC (tongue) patients. Results: Significant increases (of 400%) in salivary concentrations of Cyfra 21-1, tissue polypeptide antigen, and CA125 were shown. Salivary concentrations of CA19-9, SCC, and carcinoembryonic antigen were increased without statistical significance. A concurrent analysis of the three significantly increased markers revealed sensitivity, specificity, and negative and positive predictive values of 71%, 75%, 71%, and 75%, respectively. Conclusions: The increase reported in salivary tumor markers may be used as a diagnostic tool, especially when a concurrent analysis for significantly increased markers is done. Salivary testing is noninvasive, making it an attractive, effective alternative to serum testing, and the possibility of developing home testing kits would further facilitate it as a diagnostic aid, enabling patients to monitor their own health at home and is important for those who live far from their treatment centers and especially for those at risk of developing OSCC.

Saliva as a tool for oral cancer diagnosis and prognosis.

Saliva testing, a non-invasive alternative to serum testing, may be an effective modality for diagnosis and for prognosis prediction of oral cancer, as well as for monitoring post therapy status, by measuring specific salivary macromolecules, examining proteomic or genomic targets such as enzymes, cytokines, growth factors, metalloproteinases, endothelin, telomerase, cytokeratines, mRNAs and DNA transcripts. Salivary analysis has been shown to be a useful diagnostic tool also for distant malignancies such as breast cancer. In recent years, significant alterations have been demonstrated in the saliva of oral cancer patients in the epithelial tumor markers--Cyfra 21-1, TPS and CA12, various oxidative stress-related salivary parameters as ROS and RNS, biochemical and immunological parameters as IGF and MMPs and RNA transcripts of IL8, IL-1B, DUSP1, HA3, OAZ1, S100P, and SAT. Collectively these accumulated data are predicted to alter the field of oral cancer diagnosis by employing highly sensitive new tools which will enable both medical professionals and the patients themselves to monitor their saliva for diagnosis and prognosis prediction, as they relate to oral cancer. At this point however, the aim of salivary analysis is mainly for screening which may be helpful in the future.

Saliva Analysis in the Clinical Setting: Revisiting an Underused Diagnostic Tool

Background One purpose of this study was to compare various biochemical and immunological parameters in blood and saliva that are routinely evaluated only in the blood for general medical requirements. Another purpose was to concomitantly compare these and other oral/salivary parameters differentially in whole, parotid, and submandibular and sublingual saliva to examine the source of those parameters and their specific concentrations. Methods Twelve healthy individuals (6 women, 6 men) were examined in the blood-saliva comparison study, and 30 healthy individuals (15 women, 15 men) were studied in the intersalivary comparison study. Results On the basis of the results we obtained, we suggest a classification scheme using a whole saliva compositional profile as a diagnostic tool in the evaluation of systemic and/or local pathologies. This system may be used to analyze various components of saliva beyond those analyzed in this study, thereby increasing the clinician/s ability to locate and assess specific pathologies. We also suggest that consideration be given to the use of compositional saliva analysis in the diagnosis of general medical conditions in which there is a high correlation between the salivary and blood concentrations of relevant components. Conclusion We think that saliva analysis is a useful, worthwhile diagnostic tool because saliva collection is noninvasive, easy, and inexpensive and may be performed by the patient with no need for the involvement of medical personnel, if so desired.

Inhibition of oral peroxidase activity by cigarette smoke: in vivo and in vitro studies.

Oral peroxidase (OPO), the pivotal enzyme in the salivary antioxidant system, seems to be of paramount importance in the oral defense mechanism, especially against the attack of free radicals related to cigarette smoke (CS) and the evolution of oral cancer. The major inducer of oral cancer is exposure to tobacco, which is responsible for 50-90% of cases worldwide. The purpose of our study was to elucidate the outcome of interaction between CS and OPO in smokers and nonsmokers. After smoking a single cigarette, a sharp drop of OPO activity was observed in both groups: 42.5% in smokers and 58.5% in nonsmokers (p <.05). After 30 min, the level of activity returned to 90-100% of the presmoking level, presumably due to the secretion of new saliva into the oral cavity. The difference between the two groups was also observed after exposure of saliva to one cigarette in smoking flasks (in vitro studies); however, as expected, no recovery of activity was observed in either group. Similarly, the OPO activity loss was accompanied by increased carbonylation of the salivary proteins, an indicator of the oxidative damage to proteins. These results may be of great clinical importance, as heavy smokers smoke 20 cigarettes or more on a daily basis. Accordingly, most of the time the oral epithelium of heavy smokers is essentially unprotected by OPO against the deleterious effects of thiocyanate ions and hydroxyl radicals produced by unremoved hydrogen peroxide in the presence of the salivary redox-active metal ions. This may pave the way for the CS-induced and saliva-mediated initiation and progression of oral cancer.

Early diagnosis and treatment monitoring roles of tumor markers Cyfra 21-1 and TPS in oral squamous cell carcinoma

Mucosal oral squamous cell carcinoma (SCC) accounts for 3–5% of all reported cancers, with a 5‐year survival rate of approximately 50%. Unfortunately, current detection means are of no value in diagnosing lesions early enough for cure, especially when they recur after resection. Postoperative radiotherapy and/or covering the resection site with reconstructive flaps (regional or free vascularized) often makes early diagnosis an impossible task.

Serum and salivary oxidative analysis in Complex Regional Pain Syndrome

&NA; Although both inflammatory and neural mechanisms have been suggested as potential contributors to Complex Regional Pain Syndrome type I (CRPS‐I), the pathogenesis of the syndrome is still unclear. Clinical trials have shown that free radical scavengers can reduce signs and symptoms of CRPS‐I, indirectly suggesting that free radicals and increased oxidative stress are involved in the pathogenesis of CRPS‐I. This study investigated this premise by determining the levels of antioxidants in the serum and saliva of 31 patients with CRPS‐I and in a control group of 21 healthy volunteers. Serum lipid peroxidation products (MDA) and all antioxidative parameters analyzed were significantly elevated in CRPS‐I patients: median salivary peroxidase and superoxide dismutase (SOD) activity values, uric acid (UA) concentration and total antioxidant status (TAS) values were higher in CRPS‐I patients by 150% (p = 0.01), 280% (p = 0.04), 60% (p = 0.0001), and 200% (p = 0.0003), respectively, as compared with controls. Similar although not as extensive pattern of oxidative changes were found in the serum: mean serum UA and MDA concentrations and TAS value in the CRPS‐I patients were higher by 16% (p = 0.04), 25% (p = 0.02), and 22% (p = 0.05), respectively, than in the controls. Additionally, median salivary albumin concentration and median salivary LDH activities in the patients were 2.5 times (p = 0.001) and 3.1 (p = 0.004) times higher than in the controls. The accumulated data show that free radicals are involved in the pathophysiology of CRPS‐I, which is reflected both in serum and salivary analyses. These data could be used for both diagnostic and therapeutic purposes in CRPS‐I patients.

Squamous cell carcinoma of the tongue: the prevalence and prognostic roles of p53, Bcl-2, c-erbB-2 and apoptotic rate as related to clinical and pathological characteristics in a retrospective study.

In the current study, we examined the clinical characteristics and survival probability rates of 116 patients treated for squamous cell carcinoma (SCC) of the tongue. In 55 randomly selected patients these data were correlated with the immunohistological analysis of the tumor and apoptosis-related markers, p53, Bcl-2, c-erbB-2 (Her-2/neu), and to the apoptosis rate assessment by the terminal dUTP nick-end-labeling (TUNEL) method. The overall 5-year survival probability was 55%, which might be the result of the low incidence of smoking and/or alcohol consumption among the patients (21%), the early diagnosis (65% at Stages I-II) and the low histological grades (91% good-moderate). Radiotherapeutic or surgical treatment of the neck did not alter the survival probability achieved by local surgery for Stage I patients, but significantly improved survival for Stage II patients. Independent tumor-related variables which significantly worsened the probability of survival were found. Concomitant non-oral cancer was found to be a poor variable for prognosis prediction. Positive staining of p53, TUNEL (apoptosis rate), c-erbB-2 and Bcl-2 was found in 60, 48, 18 and 15% of the lesions, respectively (P<0.0001). The possible biological significance of these markers in tongue SCC is discussed in relation to the current literature, and an independent role for TUNEL and p53 is suggested.

Age-related changes in unstimulated salivary function and composition and its relations to medications and oral sensorial complaints

Background and aims: The purpose of the current study was to examine the salivary flow rate and composition in relation to drug consumption and idiopathic oral sensorial complaints (OSC). OSC cover xerostomia, disturbed sense of taste, or burning mouth sensitivity with no established classical etiology (e.g., Sjogren’s syndrome, or a response to radiotherapy). Methods: A thorough sialometrical and sialochemical analysis was performed for all subjects who were healthy non-hospitalized individuals ranging in age from 18–89 years. Saliva samples were all collected in unstimulated conditions. Results: The three most significant observations were: a) Elderly people have significantly reduced and altered salivary secretion. Whereas specific concentrations increased, the total values of most salivary components were found to be decreased in the elderly. b) Fifty percent of the elderly make OSC. c) OSC were made mainly by elderly individuals who use drugs. Conclusions: Reduction in salivary function and altered composition are age-related. However, when drugs are not involved, a compensatory capacity which avoids OSC apparently exists. In contrast, the effect of drugs on OSC is extensive. The finding that the total amount of salivary components and not only salivary flow rates are reduced in the elderly is of great clinical importance, since such a reduction is expected to be reflected in compromising various salivary functions.