Search

Dentists can play an important role in detecting patients with Sjogren's syndrome. Sjogren's syndrome is an autoimmune disease that primarily affects the salivary and lacrimal glands. This causes the major symptoms: dry mouth and dry eyes. Saliva plays a role in taste and maintains tooth structure as well as maintaining proper pH and producing natural antibiotics. Sjogren's syndrome can lead to taste and smell disorders, difficulty swallowing, and problems speaking. Dentists should ask all patients about mouth dryness and provide appropriate follow-up treatment.

Interferon (IFN)-gamma is a class of gamma interferons that prevents the proliferation of a number of cell types. Human salivary gland (HSG) cells treated with fetal bovine albumin serum showed rapid increases in internal calcium concentration but treatment with IFN-gamma in the presence of tumor necrosis factor (TNF)-alpha suppressed this proliferative effect. Likewise, carbachol- and thapsigargin-stimulated increases in intracellular Ca2+ stores decreased upon treatment with IFN-gamma plus TNF-alpha. These results suggest that IFN-gamma and TNF-alpha causes the depletion of intracellular Ca2+ stores in HSG cells.

A study on the kinetic analysis of muscarinic receptors in the human brain and salivary gland in vivo shows that (SS)-IQNB, a muscarinic acetylcholine receptor antagonist, is not a successful probe for nonspecific IQNB distribution but (RR)-IQNB, another antagonist, may serve well. Clearance from blood is much faster in the case of (SS)-IQNB than (RR)-IQNB. Two cortical regions have the highest binding potential of (RR)-IQNB, the parotid gland shows intermediate binding and the lowest binding in cerebellum.

Optimization of the uptake and expression of DNA in rat submandibular glands in vivo is accomplished using the replication-deficient adenovirus infection. Luciferous expression increases after around 18 hours of infection and begins to fall after 24 hours. The replication-deficient adenovirus is equally able to augment DNA transfer in vivo. It seems possible to use ultraviolet-inactivated virus to transfer DNA to salivary gland in vivo because the endosomolytic activity of adenovirus was found in the surface protein.

Applications of gene therapy to dental and oral problems illustrate the potential impact of this technology on dentistry. Gene therapy is the transfer of a foreign gene into a cell. University of Texas researchers are using gene therapy to treat oral cancer and precancerous lesions. The transferred genes prohibit cancer cells from producing a protein necessary for tumor formation. Researchers at the State University of New York at Stony Brook are transferring foreign genes into a type of skin cell called a keratinocyte. The foreign gene produces protein products that are pharmaceutical agents. This approach may be used in the future to increase subnormal hormone secretion or to correct genetic skin disorders. Researchers at the National Institute of Dental Research in Maryland are using gene therapy to repair damaged salivary gland cells. In addition, gene transfer into salivary cells may stimulate the production of foreign protein products that may one day prevent oral fungal infection or plaque formation.

Morphological studies of unmedicated individuals indicate the retention of secretory capacity by parotid glands of persons of various ages even under conditions of intense stimulation. However, gustatory stimulus induces variations in fluid secretion by the submandibular gland, depending on the age of the individual. Younger individuals exhibit an increase in salivary flow rate with stimulation.

Adenovirus vectors can efficiently deliver genes to various cell types in the salivary glands of rats in vivo, to cell lines derived from salivary glands in vitro and to human salivary glands ex vivo. Treatment of the recombinant adenovirus vectors, Ad alpha 1 AT comprising of the human alpha(sub 1) antitrypsin, a secreted protein, and Ad.RSV beta gal comprising of the intracellular protein beta-galactosidase to salivary gland cell lines in vitro exhibits exogenous gene expression.

An analysis of the correlation between propylbenzilylcholine mustard (PBCM) and synthesis of agonist-induced inositol trisphosphate (IP3) with that between PBCM and muscarinic cholinergic receptors (mAChRs) reveals that PBCM inhibits the activity of mAChRs in rat parotid cells. l-(N-methyl-3H) scopolamine methyl chloride (NMS)-binding studies facilitate the analysis. Quantification of receptors, using experimental or theoretical values for 3H NMS binding demonstrates that the decline in receptor number is greater than the corresponding receptor number for induced IP3 synthesis.

A study was conducted to find the level of salivary parts in incited parotid saliva in healthy people by using the longitudinal approach. Total protein, lactoferrin, proteins rich in proline, sodium and potassium, which are the five salivary constituents, were measured in stimulated saliva over a period of 10 years. The data collected revealed that there was no lowering related to age in these five constituents, thereby indicating that the working of the parotid gland is retained in healthy aging people.

Brain tissues are compared with ligand influx, nonspecific binding and specific binding to reveal certain characteristics which resemble those of the parotid gland. The active (RR) and inert (SS) quinuclidinyl iodobenzilate enantiomers (IQNB) reveal a likeness in the measured permeability surface area products of brain and parotid gland. The transfer across blood vessels and the cell membrane does not display any substantial variations between (SS) and (RR) IQNB. The parotid gland shows a higher rate of nonspecific binding compared to the brain and heart.

Since abnormal salivary flow can be associated with a variety of oral disorders, it is important to assess normal flow rates; however, the considerable variation in rates for an individual and for people with disease make determination of ''normal'' levels difficult. To learn more concerning salivary flow rates and their relationship to oral health in healthy people, 102 white, middle class subjects (50 men, 52 women) not under drug treatment for a systemic disease or medical problem were studied. The output of the subjects' parotid and submandibular glands (two of the salivary glands) was collected and measured in both the unstimulated and stimulated (by citric acid) states prior to the completion of a questionnaire concerning xerostomia (dry mouth). In addition, the number of teeth, number of cavities, and number of restorations present were recorded for each participant, and an evaluation was made of participants' periodontal health (condition of the gums and supporting structures). Results showed no effects on salivary flow rates due to age or sex. The flow rate for the lowest tenth percentile in the unstimulated condition was zero milliliters per minute; for the highest tenth percentile, it was more than 0.150 milliliter per minute. During stimulation, the lowest and highest percentile rates were, respectively, 0.201 and 0.180 milliliters per minute for males and females, and 0.800 milliliters per minute (for both sexes). Flow rates for the unstimulated submandibular gland were higher than for the parotid gland, while stimulated rates were approximately the same. Each participant had a wide range of flow rates. No differences in oral health variables were seen for subjects with different flow rates, with two exceptions: pocket depth (the space between the tooth root and the gum), which was greater in subjects in the highest tenth percentile of stimulated output; and percent of dental surfaces with gingival bleeding, which was greater for subjects in the lowest tenth percentile of stimulated output. Ultimately, the results did not answer the question ''How much saliva is enough?''; however, they show the tremendous range of salivary output among people. (Consumer Summary produced by Reliance Medical Information, Inc.)

Many factors may contribute to the loss of oral sensory capacities in the elderly, including memory distortions and changes in emotional and social contexts, as well as actual sensory deficits. The loss of oral sensitivity has been attributed to both a decline in the ability to taste and to a lack of response to nontaste stimuli. This study has examined the reactions of a group of 46 men and 41 women between the ages of 25 and 93 years with regard to five different types of oral stimuli. The effects of the stimuli types were measured according to response size, range of response, judgment quality, and rate of increased reaction with stimulus strength. The five types of oral stimuli used were sugar water, salt water, heated or chilled water, local pressure on the dorsal tongue, and thickened water to measure response to viscosity. Most of the oral sensitivities that were tested proved to be age-stable. The only factor that declined with age was lingual (tongue) pressure; the reliability and the magnitude of intensity judgments associated with this stimulus were also diminished in the elderly. The apparent decline in the sensory experience as a result of the other types of oral stimuli may be caused by a deterioration of cognitive function. Perception of intensity of various oral stimuli types varied with age, but were detected with similar accuracy by all age groups. The accuracy of intensity judgments was retained for all of the oral sensitivities tested except the perception of localized lingual pressure. (Consumer Summary produced by Reliance Medical Information, Inc.)