Salivary Sialic Acid Research Articles

Estimation of salivary sialic acid levels as a prognostic marker in patients with oral leukoplakia - A case control study

Estimation of salivary sialic acid levels as a prognostic marker in patients with oral leukoplakia - A case control study

Sialic acid as a biomarker of oral potentially malignant disorders and oral cancer.

Carcinogenesis is a multistep process where a healthy cell has initially a precancerous stage and finally an early cancerous stage. The process of carcinogenesis can be divided into three stages of initiation, promotion, and progression. In this process, there is increased turnover, secretion, and/or shedding from malignant cells. Glycoproteins like sialic acid are expressed on the cell surface. In oral potentially malignant disorders (OPMDs) and oral cancer (OC), the sialic acid level is seen to increase due to high cell turnover and shedding of malignant cells which, in turn, results in the release of glycoproteins like sialic acid into circulation. Glycoproteins also form an important constituent of salivary mucins and hence due to the same mechanism, an increase in sialic acid level is also seen in saliva. The aim is to estimate serum and salivary sialic acid levels in healthy controls, patients with OPMDs and patients with OC. In this observational cross-sectional study, serum and salivary sialic acid levels were estimated in thirty healthy controls, thirty patients with OPMDs and thirty patients with OC. Serum and salivary sialic acid levels obtained were subjected to statistical analysis. Post hoc Tukey test was used to compare the serum and salivary sialic acid levels of the two study groups to the control group. ANOVA test was used for the comparison of sialic acid levels between the groups. Pearson's correlation coefficient was used to assess correlation (P < 0.05 was considered statistically significant). The mean serum and salivary sialic acid levels were increased significantly in subjects with OPMDs and OC when compared to healthy controls. This study highlights the high expression of sialic acid on outer cell membranes, due to the significant increase in subjects with OPMDs and OC when compared to healthy controls. A significant increase in sialic acid level is also seen in saliva. Hence, it can be stated that saliva can be used as a reliable, noninvasive tool in diagnosis and management of OPMDs and OC.

Association between salivary sialic acid and periodontal health status among smokers.

BackgroundSmoking is an environmental risk factor causing poor dental health. Sialic acid is a salivary marker of oxidative stress for research of periodontal diseases.AimsTo identify diagnostic sialic acid fraction and its scavenger effect for periodontal diseases among smokers and periodental health status.Subject and methodThis study carried out in the Khanzad specialized dental center – Erbil city. The study population is composed of 62 convenient samples. A structured interview questionnaire form was used to collect data about socio-demographic properties and smoking history. Clinical measurements were carried out to measure periodontal health status. Un-stimulated whole saliva samples were collected for measuring sialic acid fractions. Statistical package for social science (SPSS, version 18), was used for analysis and odds ratio.ResultsRisk of smoking increased significantly in young to mid ages, which included most of the current smokers, with periodontal diseases, and high total free sialic acid. Risk of periodontitis and teeth missing increased significantly by long duration of smoking, bad tooth brushing, and poor eating habits. Risk of teeth mobility and loss decreased significantly by early smoking cessation and low income. High levels of free sialic acid correlated significantly in current smokers with medium and deep pocket depth.ConclusionSalivary free sialic acid may be used as a diagnostic oxidative stress biomarker for periodontal diseases among young current smokers. Cumulative destructive effect of long duration of smoking on the periodontum can be controlled by smoking cessation, good oral hygiene and diet habit in early old ages.

Salivary Sialic Acid Levels in Smokeless Tobacco Users.

BackgroundSmokeless tobacco chewing is one of the known risk factors for oral cancer. It is consumed widely by residents of southeastern Iran.ObjectivesIn this study, salivary free and total sialic acid, and total protein were compared in paan consumers and non-consumers.Patients and MethodsIn this cross-sectional study, unstimulated saliva of 94 subjects (44 paan consumers and 50 non-consumers) who were referred to the oral medicine department of the dentistry school of Zahedan were collected. Salivary free and total sialic acid, and total protein concentration were measured by standard biochemical methods, and the obtained data were analyzed using SPSS 20 through the non-parametric Mann-Whitney test.ResultsThe concentration of salivary free sialic acid (23.21 ± 18.98 mg/L) was significantly increased in paan consumers. The concentration of salivary Total sialic acid (TSA) (39.57 ± 26.58 mg/L) and total protein (0.77 ± 0.81 mg/mL) showed increases in paan consumers, however, the results were not statistically significant.ConclusionsSalivary free and total sialic acid, and total protein were higher in the paan consumers compared to non-consumers. Due to the carcinogenic effect of smokeless tobacco, measurement of these parameters in saliva may be useful in early detection of oral cancer.

Estimation of salivary sialic acid in oral premalignancy and oral squamous cell carcinoma.

Aims:Oral cancer is the most life-threatening disease of oral tissues. In societies where the incidence of oral cancer is high, clinically recognizable premalignant lesions are particularly common. Diagnosing oral cancers at an early stage is critical in improving the survival rate and reducing the morbidity associated with the disease. Alterations in the sialic acid levels in cancer patients have stimulated interest in this sugar residue as a possible tumor marker.Settings and Design:The purpose of this study was to estimate the salivary sialic acid levels in patients with oral premalignancy and squamous cell carcinoma and to correlate it with their grades to develop a cost-effective and noninvasive diagnostic parameter.Materials and Methods:Unstimulated whole saliva was collected from the groups under study and subjected to biochemical analysis for determination of sialic acid levels.Statistical Analysis Used:The salivary sialic acid levels were correlated with the clinical stage and histological grade by one-way ANOVA (SPSS software version 15).Results:Salivary sialic acid was elevated in oral squamous cell carcinoma (OSCC) compared to oral premalignancy and control group. A statistically significant correlation was observed between the grades of squamous cell carcinoma, grades of dysplasia in premalignancy, and sialic acid level.Conclusion and Clinical Significance:Evaluation of salivary sialic acid levels in premalignant and malignant lesions can serve as a screening tool. The mortality and morbidity of OSCC can be reduced if the lesions are diagnosed in early precancerous states using such noninvasive diagnostic methods for screening and monitoring of the population.

Salivary Sialic Acid as a Diagnostic Indicator in Premalignant Lesions

Salivary Sialic Acid as a Diagnostic Indicator in Premalignant Lesions

The Association of Early Weaning and Formula Feeding with Autism Spectrum Disorders

Breastfeeding MedicineVol. 9, No. 5 Letters to the EditorThe Association of Early Weaning and Formula Feeding with Autism Spectrum DisordersTouraj Shafai, Monika Mustafa, Tannaz Hild, Jeffrey Mulari, and Antonio CurtisTouraj ShafaiRiverside, California.Search for more papers by this author, Monika MustafaRiverside, California.Search for more papers by this author, Tannaz HildRiverside, California.Search for more papers by this author, Jeffrey MulariDepartment of Mathematics, Riverside Community College, Riverside, California.Search for more papers by this author, and Antonio CurtisDepartment of Mathematics, Riverside Community College, Riverside, California.Search for more papers by this authorPublished Online:9 Jun 2014https://doi.org/10.1089/bfm.2013.0104AboutSectionsView articleView Full TextPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article"The Association of Early Weaning and Formula Feeding with Autism Spectrum Disorders." Breastfeeding Medicine, 9(5), pp. 275–276FiguresReferencesRelatedDetailsCited byAssociation of Breastfeeding for the First Six Months of Life and Autism Spectrum Disorders: A National Multi-Center Study in China23 December 2021 | Nutrients, Vol. 14, No. 1Associations between Prenatal Education, Breastfeeding and Autistic-Like Behaviors in Pre-Schoolers9 February 2021 | Children, Vol. 8, No. 2OTİZMLİ ÇOCUKLARDA DOĞUM ÖYKÜSÜ, ANNE SÜTÜ ALMA SÜRESİ, TELEVİZYON İLE TANIŞMA YAŞI, TELEVİZYON, CEP TELEFONU VE TABLET KULLANIM ALIŞKANLIKLARININ İNCELENMESİ29 November 2020 | Kırıkkale Üniversitesi Tıp Fakültesi DergisiAssociation of breastfeeding status with risk of autism spectrum disorder: A systematic review, dose-response analysis and meta-analysisAsian Journal of Psychiatry, Vol. 48Levels of Salivary Sialic Acid in Children with Autism Spectrum Disorder; Could It Be Related to Stereotypes and Hyperactivity?Clinical Psychopharmacology and Neuroscience, Vol. 17, No. 3Risk Factors for Unhealthy Weight Gain and Obesity among Children with Autism Spectrum Disorder4 July 2019 | International Journal of Molecular Sciences, Vol. 20, No. 13Maternal breastfeeding and autism spectrum disorder in children: A systematic review and meta-analysis18 October 2017 | Nutritional Neuroscience, Vol. 22, No. 5The role of marine omega-3 in human neurodevelopment, including Autism Spectrum Disorders and Attention-Deficit/Hyperactivity Disorder – a review18 March 2019 | Critical Reviews in Food Science and Nutrition, Vol. 41Association between breastfeeding duration and cognitive development, autistic traits and ADHD symptoms: a multicenter study in Spain15 November 2016 | Pediatric Research, Vol. 81, No. 3Maternal stress and perinatal features in autism and attention deficit/hyperactivity disorder2 February 2016 | Pediatrics International, Vol. 58, No. 4Breastfeeding History in Children with Autism and Attention Deficit Hyperactivity Disorder Gökçe Nur Say, Zehra Babadağı, and Koray Karabekiroğlu9 June 2015 | Breastfeeding Medicine, Vol. 10, No. 5Choosing to Breastfeed: Finding the Answers Ruth A. Lawrence14 October 2014 | Breastfeeding Medicine, Vol. 9, No. 8The Risks of Not Breastfeeding: New Associations Ruth A. Lawrence9 June 2014 | Breastfeeding Medicine, Vol. 9, No. 5 Volume 9Issue 5Jun 2014 InformationCopyright 2014, Mary Ann Liebert, Inc.To cite this article:Touraj Shafai, Monika Mustafa, Tannaz Hild, Jeffrey Mulari, and Antonio Curtis.The Association of Early Weaning and Formula Feeding with Autism Spectrum Disorders.Breastfeeding Medicine.Jun 2014.275-276.http://doi.org/10.1089/bfm.2013.0104Published in Volume: 9 Issue 5: June 9, 2014Online Ahead of Print:February 7, 2014PDF download

Serum and salivary sialic acid as a biomarker in oral potentially malignant disorders and oral cancer.

Background: Aberrant glycosylation is the universal feature of cancer and components of various glycoconjugates, such as sialic acid is found to rise in various malignancies. The objective of this study was to evaluate the serum and salivary sialic acid in oral potentially malignant disorders (OPMD) and oral cancer (OC) to investigate the possibility of using this as a diagnostic marker. Materials and Methods: The study included 85 subjects, who were grouped as control (30), OPMD patients (25), and oral cancer patients (30). Serum and unstimulated whole saliva was collected from subjects of all groups and sialic acid estimation was done using spectrophotometry. The results were tabulated and analyzed statistically. Results: The mean serum sialic acid levels in normal, OPMD, and oral cancer group were 7.515, 19.620, and 55.235 mg/dL, respectively, whereas the levels of salivary sialic acid were 1.5113, 2.3302, and 9.0304 mg/dL, respectively. A very highly significant rise (P < 0.005) in serum and salivary sialic acid was observed in the study subjects compared with that of the control. Conclusions: The present study showed a significant and gradual increase in serum and salivary sialic acid from control to oral potentially malignant disorders to oral cancer. From this study we can suggest that sialic acid can be used as a reliable biomarker. As this monosaccharide is observed in saliva in detectable quantity, saliva can be used as a diagnostic medium for screening and early detection of oral cancer.

Assessment of salivary total antioxidant levels and oral health status in children with Down syndrome

Down syndrome (DS) is an autosomal chromosomal disorder caused by trisomy of all or a critical part of chromosome 21. Individuals with DS have high levels of oxidative stress throughout their lifespan. It has been suggested that levels of antioxidants could be altered in response to an infection or disease. To assess the total antioxidant capacity (TAC), nitric oxide (NO), and sialic acid (SA) of saliva in children with DS and its relation to their oral health status. Thirty-four noninstitutionalized children in the age group of 7-12 years having DS formed the study group. The control group consisted of 34 normal, healthy children. The W.H.O. criteria were used for diagnosis and recording of dental caries. Oral hygiene status was assessed using the simplified oral hygiene index. Estimation of TAC, NO, and SA levels in saliva was done. Data obtained were subjected to statistical analysis. In comparison to normal children, DS children showed significantly lower TAC of saliva and significantly higher salivary SA levels. In both groups of children, dental caries was higher in primary dentition when compared to their permanent dentition.

Evaluation of Salivary Sialic Acid in Patients With Different Clinico-Pathological Stages of Oral Leukoplakia and Oral Squamous Cell Carcinoma - A Cross Sectional Study

1,5Department Of Oral Medicine & Radiology , Sree Balaji Dental College & Hospital, Bharath University, Chennai, Tamil Nadu, India. 2Rajah Muthiah Dental College & Hospital, Annamalai University, Chidambaram, Tamil Nadu, India. 3Department of Periodontics , Sree Balaji Dental College & Hospital, Bharath University, Chennai, Tamil Nadu, India. 4Department Of Oral Medicine & Radiology , Sree Balaji Dental College & Hospital, Bharath University, Chennai, Tamil Nadu, India.

Evaluation of Salivary Sialic Acid Levels in Acute Lymphoblastic Leukemic Children and Its Correlation with Dental Caries Experience

The aim of present study was to evaluate the salivary sialic acid levels in Acute Lymphoblastic Leukemic (ALL) children and to correlate it with dental caries experience. A total of 120 children aged 4-10 yrs were divided into 4 groups of 30 each. Dental caries experience was recorded followed by un-stimulated saliva collection. The mean salivary sialic acid levels of the study group were much higher when compared with the control group, which was statistically significant. A linear relationship between salivary sialic acid levels and dental caries in leukemic children was observed. The findings of our study conclude that salivary sialic acid levels may have a potent activity in dental caries process and can be used as a useful marker in cancer

Micronuclei and sialic acid as markers of genotoxic damage in tobacco-related oral lesions

Background: Carcinogens and co-carcinogens act in an additive, synergistic and antagonistic manner. Tobacco is the most common carcinogen related to oral cancer. The aim of this study was to assess the effect of tobacco on the oral epithelium by evaluating genotoxic damage to cells as quantitated by micronuclei and also the alterations to the cell membrane were correlated by the measurement of free sialic acid and protein-bound sialic acid in saliva and in serum. Materials and Methods: Blood samples collected from 15 untreated oral squamous cell carcinoma patients, 15 patients with oral precancerous conditions, 15 tobacco chewers without clinically evident lesion and 15 non-tobacco chewers. Serum and salivary sialic acid levels both in free and bound form were measured spectrophotometrically. Smear was taken from the same patient from the suspicious site and assessment of micronuclei was done by acridine orange method. Results: Serum free sialic acid and micronuclei assessment showed greater level of signifi cance (P=?0.05) between all other groups. This implies it’s potential use as an indicator of oral cancer. Predictability of occurrence of oral Cancer = 0.561+ 0.005× serum protein-bound sialic acid+ 0.244 serum free sialic acid + 0.71 M, where M=mean of micronuclei in 500 exfoliated oral cells. Predictability of occurrence of oral Premalignancy = 0.13+ 0.909× serum free sialic acid+ 0.045 M, where M=mean of micronuclei in 500 exfoliated oral cells. Conclusion: Micronuclei, serum and salivary sialic acid levels may be a good marker for prediction of premalignancy and oral squamous cell carcinoma transformation. Journal of Pathology of Nepal (2013) Vol. 3, No.1, Issue 5, 379-385 DOI: http://dx.doi.org/10.3126/jpn.v3i5.7862

Total sialic acid, total protein and total sugar levels in serum and saliva of oral squamous cell carcinoma patients: A case control study.

Background:Detection of cancer at an early stage is of utmost importance to decrease the morbidity and mortality of the disease. Apart from the conventional biopsy, non-invasive methods like analysis of serum and saliva may provide cost-effective approach for screening a large population. Tumor markers are a major part of secondary prevention and thus, the detection of malignancies. The aim of this study was to evaluate total sialic acid (TSA), total protein and total sugar (TS) in serum and saliva of oral squamous cell carcinoma (OSCC) and controls to assess their role as a diagnostic marker.Materials and Methods:Unstimulated whole saliva and sera were collected from 40 squamous cell carcinoma patients and 20 controls. Serum and salivary TSA, total protein and TS estimation was carried out. This was correlated with clinical stages and histopathological grades of OSCC. The data obtained was analyzed statistically using Chi-square test, ANOVA and Student's t-test with SPSS statistical software.Results:A highly significant rise in the salivary sialic acid, serum sialic acid and serum protein was noted in OSCC subjects compared to controls. Salivary protein, serum and salivary sugar did not show any significance. Furthermore, serum and salivary sialic acid levels were found to be significantly increased with increasing level of histopathological grading.Conclusion:The present study showed a significant increase in serum sialic acid, salivary sialic acid and serum protein from control to OSCC and suggests that these markers may be reliable in diagnosis and predicting prognosis.

Salivary Sialic Acid Levels and Dental Health In Children with Congenital Heart Disease

Congenital cardiac disease is one of the most common developmental anomalies in children. Higher caries prevalence and gingivitis compared to healthy children have been shown in children with congenital heart disease which has a significant implication in the medical care of these patients associated with bacteraemia and endocarditis. Sialic acids being terminal sugar components and marker of chronic inflammatory response are found to be present at higher levels in children with poor oral health status. So the present study aimed to evaluate the oral health status and salivary sialic acid levels among the children with congenital heart disease and normal healthy siblings. A total of 71 children with heart diseases aged 6-10 years attending various heart institutes were examined for oral hygiene status, gingival status and dental caries status by using modified WHO oral assessment form. A case-matched control group of 50 children were also examined. Salivary flow rate, pH and sialic acid levels were measured after saliva collection. The results were subjected to Unpaired t test and Pearson's Correlation Coefficient Test. The salivary pH, salivary flow rate, dental caries status, oral hygiene and the gingival status were significantly compromised with a positive correlation with the sialic acid levels in saliva, leading to increased treatment needs in the study group. Therefore the amount of sialic acid in the saliva can be a useful index of the severity of oral disease.

Ovulation detection through salivary levels of sialic acidand glycosaminoglycans

Background: One in ten couples of reproductive age encounter some level of infertility. Identification of the period of ovulation in humans is critical in the treatment of infertility. Success in in vitro fertilization and embryo transfer has been associated with the exact time of ovulation. Saliva is a unique diagnostic fluid, the composition of which immediately reflects the sympathetic nervous system, parasympathetic nervous system, hypothalamic- pitutaryadrenal axis and immune system response to stress. The study aims at evaluating the changes in salivary sialic acid and Glycosaminoglycans in the regular menstrual cycle. Thus, the presence of these carbohydrates in the ovulatory saliva makes the possibility to develop a biomarker for the detection of ovulation by noninvasive methods. Subjects, materials and methods: Randomly, seventy five volunteer females were recruited and divided into 5 groups; each contains 15 subjects as follow: Nine years old females and postmenopausal females as control groups, pre-ovulatory period, ovulatory period and post-ovulatory period females as experimental groups. Each female, of the experimental groups, underwent sonographic examination to estimate her period regarding ovulation. Unstimulated whole saliva was collected using the spitting method. Colorimetric procedure was used for total sialic acid determination and for Glycosaminoglycans quantitative determination, the method of ELISA was used. Results: The concentration of sialic acid was significantly decreased in saliva of females in the ovulatory phase of the menstrual cycle; whereas, a significant increase in salivary sialic acid concentration was in the post-ovulatory phase. Glycosaminoglycan concentration showed a gradual increase from the pre-ovulatory phase then ovulatory to reach its maximum in the post-ovulatory phase with a significant difference between the pre-ovulatory and post-ovulatory phases. A significant correlation was not found between sialic acid and Glycosaminoglycans in different study groups. Conclusions: On the basis of the results arrived at, the study concluded that there are remarkable cyclic variations in sialic acid and glycosaminoglycans during the menstrual cycle but in conclusion, glycosaminoglycans and sialic acid salivary levels cannot be used for the precise prediction of ovulation.

Evaluation of salivary sialic acid, total protein, and total sugar in oral cancer: A preliminary report

Detection of cancer at the early stage is of utmost importance to decrease the morbidity and mortality of the disease. Apart from the conventional biopsy, noninvasive methods like analysis of saliva may provide a cost-effective approach for screening a large population. Thus, this study aimed to estimate salivary levels of sialic acid, total protein, and total sugar in the oral cancer patients and in healthy control group to evaluate their role in diagnosis and prognosis of oral cancer. Unstimulated whole saliva samples were collected from 30 healthy controls (Group I) and 30 squamous cell carcinoma patients (group II). Estimations of salivary levels of sialic acid, total protein, and total sugar were performed. This was correlated histopathologically with the grades of carcinoma. The Student's ' t ' test and multivariate regression analysis were performed. The results showed that salivary levels of total protein, total sugar, protein-bound sialic acid, and free sialic acid were significantly higher in oral cancer patients compared to those of normal healthy controls ( P values in all the results were less than 0.001). The salivary free sialic acid levels were found to be significantly higher in well-differentiated squamous cell carcinoma than in moderately differentiated carcinoma ( P < 0.001). However, protein-bound sialic acid, total proteins, and total sugars did not show any statistical significance between well and moderately differentiated carcinomas. Biochemical analysis of saliva can be used in early detection of cancer and is best correlated with histopathological degree of squamous cell carcinoma.

A longitudinal study of salivary sialic acid in preterm infants: Comparison of human milk–fed versus formula-fed infants

We found that the saliva of preterm infants fed human milk contains twice the level of sialic acid as that in infants fed commercial formulas. The higher sialic acid level suggests greater viscosity and enhanced protection of the mucosal surfaces in breast-fed infants. Human milk itself is a rich source of sialylated oligosaccharides. (J Pediatr 2001;138:914-6)

Evaluation of salivary sialic acid level and Cu-Zn superoxide dismutase activity in type 1 diabetes mellitus.

In this study, our aim was to determine whether or not type 1 diabetes mellitus affects salivary sialic acid level and SOD activity. For this purpose, unstimulated saliva specimen was collected. Saliva sialic acid level and SOD activity were measured by the methods of Warren and Sun, respectively. We found significantly decline in salivary sialic acid level and SOD activity. The decrease of salivary sialic acid level in type 1 diabetes may be due to changes in the activities of the enzymes taking part of in the synthesis and catabolism of sialic acid. The main reason for the decrease of salivary SOD activity may be increased glycation of the enzyme and/or deleterious effect of increased free oxygen radicals by glycated proteins on SOD activity in diabetes. We conclude the decline both in sialic acid and SOD in saliva may be a possible factor leading to oral complications of diabetes mellitus.

Salivary sialic acid, protein, salivary flow rate, pH, buffering capacity and caries indices in subjects with Down's syndrome

Objectives: The aim of this study was to compare salivary sialic acid, protein, salivary flow rate, pH and buffering capacity and caries indices between subjects with Down's Syndrome and healthy controls. Methods: Unstimulated mixed saliva was collected from 26 Down's syndrome subjects and 25 healthy subjects of age range 6–24 years. Total protein was determined by the method of Lowry and total sialic acid using Ehrlich reagent. Laemmli SDS–polyacrylamide gel electrophoresis was also carried out. Results: Buffering capacity and pH were quite similar for both groups. For permanent dentition subjects pH was significantly higher ( P=0.03) in the Down's syndrome group. The salivary flow rate of the Down's syndrome subjects was significantly lower ( P<0.01) than that of healthy controls and the Down's syndrome subjects' salivary protein and sialic acid levels were significantly higher ( P<0.001). The ratios of total sialic acid to total protein were significantly higher ( P<0.001) in the Down's syndrome group. However, salivary sialic acid expectoration rates, a means of compensating for flow rate differences, were significantly lower ( P=0.01) in the Down's syndrome subjects than in controls. Electrophoresis revealed no significant differences between the protein bands of the groups. There were no significant differences in caries indices between groups, even when compensated for age, nor in the salivary parameters within groups between sexes. Conclusions: Total salivary sialic acid in Down's syndrome subjects, higher in terms of levels but lower in terms of expectoration rates, was significantly different from that of controls of similar caries indices.

The Relationship between the Sialic Acid Concentrations in the Serum and Whole Saliva in Rats with Naturally Occurring Gingivitis

Pocket probing depth was correlated with the amount of salivary sialic acid in pilocarpine-stimulated saliva in ODU plaque-susceptible rats (ODUS/Odu) (r = 0.657, P < 0.01), but not with the content of serum sialic acid. There was no difference in the amount of serum sialic acid content between ODUS/Odu and plaque-resistant rats. These results suggest that the amount of sialic acid in the saliva can be a useful index of the severity of periodontal disease.