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Biomedical subjects

J A Beeley

Publications and source records attributed to J A Beeley.

At least 37 records · Page 2Linked to original sources

Salivary protein interactions with oral bacteria: an electrophoretic study.

The relatively low levels of human salivary proteins in whole saliva as compared to the ductal secretions may be related to their interaction with oral bacteria. These interactions are thought to play an important role in the microbial colonisation of the mouth, and salivary proteins adsorbed to oral surfaces have been implicated in adherence. In this study we attempted to investigate the prevalence of interactive strains by screening a range of oral bacteria. Parotid saliva was incubated with bacterial suspensions and consequent alterations to the salivary protein profile determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A number of salivary components were found to be preferentially removed, particularly by those species known to be primary colonizers of clean tooth surfaces.

Animals↗

Food and oral health: 2. Periodontium and oral mucosa.

Dental schools tend to teach only the rudiments of this subject and this does not provide a good basis for dentists to advise patients and combat the misinformation surrounding the topic. The first article in the two-part series examined nutrition as it applies to dental caries, while part two discusses some of the general principles of nutrition in relation to oral health, periodontal disease and the oral mucosa.

Aged↗

Food and oral health: 1. Dental caries.

Dental schools tend to teach only the rudiments of this subject and this does not provide a good basis for dentists to advise patients and combat the misinformation surrounding the topic. The first article in the two-part series examines nutrition as it applies to dental caries, while part two will discuss some of the general principles of nutrition in relation to oral health, periodontal disease and the oral mucosa.

Animals↗

Clinical applications of electrophoresis of human salivary proteins.

Human salivary proteins have been studied by electrophoresis in denaturing and non-denaturing polyacrylamide gel electrophoresis (PAGE) as well as by isoelectric focusing (IEF) and two-dimensional procedures, and the clinical applications of this have been reviewed. Whilst non-denaturing PAGE is useful in studying polymorphisms, sodium dodecylsulphate PAGE appears to be otherwise preferable. Immobilized pH gradients containing carrier ampholytes (CAs) give better resolution than CA-based IEF and overcome the problems of cathode drift and loss of basic material. Proline-rich proteins stain poorly with conventional procedures and special techniques are necessary. In clinical studies, findings must be viewed over and above the large number of polymorphisms which occur normally. Studies relating salivary protein and peptide profiles to dental caries susceptibility are encouraging. Specific protein abnormalities have been associated with connective tissue disorders and could form the basis of new non-invasive diagnostic procedures. Protein differences associated with cystic fibrosis and diabetes mellitus, however, merit reinvestigation with the new procedures now available. Detection of HIV antigens in saliva is a new area of research. In the light of new techniques available and new information which has arisen from DNA studies, future prospects for the clinical applications of electrophoresis of saliva look good.

Clinical Laboratory Techniques↗

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of human parotid salivary proteins.

The proteins in human parotid saliva have been separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis into 20 or more well resolved species. The Coomassie Brilliant Blue (CBB) R-250 and silver staining procedures have been modified to overcome the problems encountered with staining of proline-rich proteins. By means of the CBB R-250 procedure which stains proline-rich proteins pink-violet, immunoblotting, concanavalin A binding, periodate-Schiff staining and zinc binding, all of the major proteins have been characterised. Substantial individual-to-individual differences were observed in the protein patterns formed. Comparison of parotid, submandibular, and whole saliva from a single individual indicated that fewer proline-rich proteins are expressed in submandibular saliva than in parotid, but whole saliva contains much lower levels than either duct secretion. The results will form a useful base for future research into the functions of salivary proteins.

Electrophoresis, Polyacrylamide Gel↗

Salivary secretion of albumin in type 1 (insulin-dependent) diabetes.

The concentration of albumin in saliva is low in healthy humans. To determine whether alterations in capillary permeability in diabetes affects the salivary glands, the concentration of albumin in parotid saliva was measured in 26 Type 1 (insulin-dependent) diabetic patients, and compared to 32 non-diabetic control subjects. The diabetic patients were subdivided into 3 groups on the basis of the urinary excretion of albumin in timed overnight collections of urine: (1) normal albumin excretion (less than 30 micrograms/min) n = 13; (2) microalbuminuria (30-300 micrograms/min) n = 7, and (3) macroalbuminuria (greater than 300 micrograms/min) n = 6. Saliva was collected for one minute following stimulation with 1 ml 10% citric acid, and the concentration of albumin was measured by a sensitive ELISA method. No significant difference in salivary albumin concentration was found between the control group and any of the diabetic groups. Thus, although urinary albumin excretion was increased, suggesting altered capillary permeability, simultaneous leakage of albumin into saliva was not observed. Measurement of salivary albumin concentration does not, therefore, provide a marker of occult microvascular disease in diabetes.

Adult↗

Isoelectric focusing of human parotid salivary proteins in hybrid carrier ampholyte-immobilized pH gradient polyacrylamide gels.

Isoelectric focusing of human salivary proteins with carrier ampholyte-isoelectric focusing systems requires prior desalting and concentration of samples, a procedure which is time-consuming and requires relatively large volumes of samples. By contrast, immobilized pH gradient gels are more tolerant to salt loads. Thus pretreatment of samples consists only of centrifugation prior to isoelectric focusing. If larger loads (greater than 50 micrograms) are required, the samples may be concentrated by lyophilization and reconstitution in a smaller volume of water or by dialysis against 30% w/v polyethylene glycol. Immobilized pH gradient polyacrylamide gels (incorporating a hybrid carrier ampholyte system) of two pH ranges (pH 4-9 and pH 3.5-5.0) have been used to separate the proteins in human parotid saliva. The effects of urea on focused patterns were studied; in pH 4-9 gels it gave improved resolution of protein bands, whereas in pH 3.5-5.0 gels it prevented protein precipitation. The salivary proteins were then visualized by staining with Coomassie Brilliant Blue G-250 or a silver procedure. Using the latter, 25-30 well-resolved bands were formed on a pH 4-9 gel loaded with 20 micrograms of proteins. The method offers considerable advantages compared with carrier ampholyte-isoelectric focusing.

Acrylic Resins↗

An enzyme-linked immunoassay for human salivary albumin.

An ELISA method has been developed for the determination of albumin in human parotid saliva. The range of sensitivity is 2-80 micrograms/l and it is suitable for use with volumes of 5 microliters or less of freshly collected parotid fluid, without prior sample preparation. Calibration data were fitted by microcomputer to an exponential function. The albumin concentration of parotid saliva was 1.9 +/- 1.53 mg/l, but levels fell on sample storage. Isoelectric focusing, followed by immunoblotting with antiserum to human serum albumin, showed identical double bands of pI 4.9-5.0 in albumin from both serum and saliva, thereby confirming that the antigens from the two sources are identical.

Adolescent↗

Anionic salivary proteins associated with connective tissue disorders: sialated tissue kallikreins.

Parotid saliva was collected from 32 patients with rheumatoid arthritis, 10 with systemic lupus erythematosus, three with mixed connective tissue disease, 12 with progressive systemic sclerosis, two with primary Sjögren's syndrome, and four with Raynaud's syndrome. Tissue kallikreins were measured by radioimmunoassay, and saliva samples were subjected to isoelectric focusing followed by immunoblotting or silver staining. The results showed that the saliva of patients with connective tissue diseases contained increased amounts of immunoreactive tissue kallikrein. In addition, there was an increase in the multiple forms of anionic tissue kallikreins, resulting mainly from a shift in their distribution towards that of higher sialic acid content and lower isoelectric point. These changes were most obvious in patients with systemic lupus erythematosus. Novel or unusual glycosylation may explain the occurrence of increased amounts of anionic salivary proteins in connective tissue diseases.

Adolescent↗

Isoelectric focusing of human salivary secretory-IgA.

A method using overlays of 131I-labelled antisera to IgA or SC was developed for the specific detection of s-IgA in unpurified saliva after isoelectric focusing in polyacrylamide gels. The pI range of salivary s-IgA was 4.8-6.5; that of colostral s-IgA was slightly lower (4.5-5.5).

Autoradiography↗

Partial characterization of abnormal salivary proteins associated with rheumatoid arthritis.

Isoelectric focusing of parotid saliva from 33 patients with rheumatoid arthritis but without clinical evidence of salivary gland involvement revealed multiple abnormal proteins of pI 3.95-4.25 in all cases, whereas only two out of 16 samples from normal healthy individuals exhibited any similar bands. Although rheumatoid factors of abnormally low isoelectric point and restricted heterogeneity were detected in this pI region in five of the diseased samples, these could not account for all of the bands even in these cases. The abnormal proteins did not otherwise cross-react with antisera to immunoglobulin (Ig) G, IgA or albumin. Analysis of rheumatoid arthritis parotid saliva by a method involving adsorption of rheumatoid factors to immobilized rabbit immunoglobulin revealed the presence of salivary rheumatoid factors (in seven patients) of all the major immunoglobulin classes, including secretory-IgA in two patients. Although these abnormal proteins are as yet uncharacterized, their presence could form the basis of a non-invasive procedure in the diagnosis of salivary gland and connective tissue disorders.

Adult↗

Effect of extracellular polysaccharides on diffusion of NaF and [14C]-sucrose in human dental plaque and in sediments of the bacterium Streptococcus sanguis 804 (NCTC 10904).

It has been postulated that extracellular polysaccharides form a barrier to diffusion in dental plaque. Diffusion coefficients, D, were measured for NaF and [14C]-sucrose in glucan-free and glucan-containing sediments of Strep. sanguis 804 at 37 degrees C. There was a tendency for NaF and [14C]-sucrose to diffuse faster as the carbohydrate concentration in the sediments increased. NaF diffused only 38 per cent more slowly in cell-free glucan sediment than in water, suggesting that glucan per se does not form a barrier to diffusion. The diffusion coefficient for NaF was positively correlated with carbohydrate concentration in individual plaque samples from 15 subjects and incubation of 3 plaque samples with sucrose resulted in both an increase in carbohydrate concentration in the plaque and an increase in D for NaF. Thus the presence of extracellular polysaccharides in plaque leads to slightly faster rates of diffusion. Nevertheless, the total time for diffusion through plaque may be increased if the presence of extracellular polysaccharides results in thicker layers of plaque.

Adult↗

Serum alpha-amylase isozymes in mumps: estimation of salivary and pancreatic isozymes by isoelectric focusing.

Serum alpha-amylase isozymes were separated into three major isozymes by thin-layer gel isoelectric focusing and detected by a starch-iodine zymogram procedure. Of the three groups of isozymes, one (S isozyme) corresponded to a salivary specific form, one (P isozyme) to a pancreatic specific form and the third (SP isozyme) to isozymes of similar isoelectric point common to both secretions. The levels of total alpha-amylase and of these three isozymes were estimated in the sera of 54 patients with mumps. Total alpha-amylase and salivary isozyme concentrations were greatly increased in the sera of all patients compared with controls. Pancreatic isozyme concentrations however, were only slightly increased and did not correlate with clinical pancreatitis. Indeed, in patients with mumps associated with pancreatitis, meningoencephalitis or orchitis, levels of total serum amylase, although higher than controls, were lower than levels in patients who presented solely with mumps sialadenitis.

Adolescent↗

Genetic analysis of human salivary alpha-amylase isozymes by isoelectric focusing.

The isozymes of human salivary alpha-amylase have been separated by thin-layer gel isoelectric focusing in a pH 4-8 gradient followed by a starch-iodine zymogram procedure. The normal isozyme pattern (N) consisted of five major isozymes together with a number of minor ones. In addition, seven variant isozyme phenotypes were also observed, which had a combined frequency of 11.7% in a random population of 368 individuals. Analysis of familial data is indicative of the inheritance of autosomal codominant alleles.

Amylases↗