sodium-dodecyl-sulfate and Down-Syndrome

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.. 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.. 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.. 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.

Topics: Adolescent; Adult; Age Factors; Buffers; Child; DMF Index; Down Syndrome; Electrophoresis, Polyacrylamide Gel; Female; Humans; Hydrogen-Ion Concentration; Male; N-Acetylneuraminic Acid; Saliva; Salivary Proteins and Peptides; Secretory Rate; Sex Factors; Sodium Dodecyl Sulfate; Surface-Active Agents

Previous studies have shown increased susceptibility to periodontal diseases in children with Down's syndrome (DS). The mechanisms involved in the periodontal inflammatory processes in DS are not fully understood. The present study characterized the periodontal status of 9 non-institutionalized DS children 9 to 17 years old (mean 13.6 years) relative to their age-matched systemically and periodontally healthy controls. The periodontal status was assessed by visible plaque index (VPI), gingival bleeding index (GBI), and probing depth. We also assessed, by sodium dodecyl sulphate polyacrylamide gel electrophoresis/laser densitometry and by zymography, the collagenase and gelatinase activities in the gingival crevicular fluid (GCF) and saliva samples collected from DS patients and from the controls. Eight of the nine DS children showed a periodontium comparable to that seen in healthy controls; beginning alveolar bone loss was radiographically seen in the DS patient with deep periodontal pockets. The endogenously active collagenase and total collagenase activities were slightly higher in GCF of DS children compared to healthy controls. Western blot demonstrated that GCF collagenase of DS patients was human neutrophil collagenase (MMP-8 or collagenase-2), which occurred in 75 kDa proMMP-8 and in DS patients, but not in controls, also in 65 kDa active MMP-8 form and occasionally lower 40-50 kDa MMP-8 species. Zymographic analysis revealed the presence of 120 kDa (MMP-9 complexed with neutrophil gelatinase associated lipocalin or NGAL), 92 kDa (MMP-9) and 72 kDa (MMP-2) gelatinases in DS and control GCF. Especially in DS GCF MMP-9 occurred in part in 82-85 kDa activated form. Salivary collagenase in DS was high when compared to controls but of the same MMP-8 type as in control saliva. Our findings suggest that in vivo activated MMP-8 in GCF derived from triggered PMNs and/or cytokine-induced periodontal fibroblasts may reflect periodontal tissue and alveolar bone destruction seen in the early stages of gingivitis/periodontitis associated with Down's syndrome.

Topics: Adolescent; Alveolar Bone Loss; Blotting, Western; Case-Control Studies; Child; Collagenases; Densitometry; Dental Plaque Index; Disease Susceptibility; Down Syndrome; Electrophoresis, Polyacrylamide Gel; Female; Fibroblasts; Gingival Crevicular Fluid; Gingivitis; Humans; Lasers; Male; Matrix Metalloproteinase 8; Matrix Metalloproteinase 9; Neutrophils; Periodontal Index; Periodontal Pocket; Periodontitis; Radiography; Saliva; Salivary Proteins and Peptides; Sodium Dodecyl Sulfate

Temporal cortex from 14 cases of Alzheimer-type dementia and 6 cases of Down's syndrome, all selected for severe Alzheimer pathology, was homogenised in distilled water, NaOH, or sodium dodecylsulphate (SDS) containing 0.1% beta-mercaptoethanol. The homogenates were stained with Congo red, and the neurofibrillary tangles and plaque cores were counted under crossed-polarisation microscopy. The number of tangles and plaque cores in the water-treated extracts was not related to age, sex, post-mortem interval or duration of dementia. The number of tangles after extraction in SDS or NaOH, as a percentage of tangles in water-treated extracts, was 57 +/- 25 (mean +/- SD) for 1% SDS, 43 +/- 17 for 5% SDS and 37 +/- 22 for 0.2 M NaOH. Plaque cores were essentially insoluble in all three agents. The percentage of tangles insoluble in 1% SDS did not correlate with age or post-mortem interval but decreased with increasing duration of dementia. Enhanced tangle solubility with increasing duration of dementia suggests that the nature of tangles changes with time; one possibility is that this reflects transformation of intracellular to extracellular tangles. Paired helical filament (PHF) length and the number of repeats per PHF were measured in electron micrographs of PHF prepared with and without treatment by 1% SDS. There was no significant multimodality of PHF length to suggest that PHF broke at regular intervals. The mean repeat length (PHF length/number of repeats) was greater for PHF isolated in the presence of 1% SDS than in its absence, showing that SDS affects ultrastructure by untwisting PHF.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Down Syndrome; Female; Humans; Male; Middle Aged; Neurofibrils; Sodium Dodecyl Sulfate; Solubility; Temporal Lobe

Considerable controversy exists concerning the origin and composition of Alzheimer neurofibrillary tangles (ANT) and of paired helical filaments (PHF), the abnormal cytoplasmic fibers which ultrastructurally are the major components of ANT. Thus far, the unusual solubility properties of PHF have hindered the analysis of ANT. A new procedure is presented for isolating purified PHF which are soluble in the presence of sodium dodecyl sulfate. The purification protocol involves differential and rate zonal centrifugation, treatment with the detergents sarcosyl and sulfobetain 3-14, and sonication. The isolated PHF from Alzheimer disease/senile dementia of the Alzheimer type (7 cases) and Down's syndrome (one case) have been characterized structurally by negative-stain electron microscopy, biochemically by PAGE, and immunologically by both the ELISA technique and Western blot analysis using a monoclonal antibody prepared against ANT. Distinct polypeptides were shown to be associated with this structure and not seen in preparations from young and age-matched normal brains.

Topics: Adult; Aged; Alzheimer Disease; Brain Chemistry; Collodion; Down Syndrome; Electrophoresis, Polyacrylamide Gel; Female; Humans; Male; Microscopy, Electron; Middle Aged; Molecular Weight; Neurofibrils; Paper; Sodium Dodecyl Sulfate; Solubility