Integrity of proteins in human saliva after sterilization by gamma irradiation.

Microbial contamination of whole human saliva is unwanted for certain in vitro applications, e.g., when utilizing it as a growth substratum for biofilm experiments. The aim of this investigation was to test gamma irradiation for its suitability to sterilize saliva and to investigate the treatment's influence on the composition and integrity of salivary proteins in comparison to filter sterilization. For inhibition of bacterial growth by gamma irradiation, a sterility assurance level of 10(-6) was determined to be reached at a dose of 3.5 kGy. At this dose, the integrity of proteins, as measured by fluorescence, circular dichroism, and gel electrophoretic banding pattern, and the enzymatic activities of salivary amylase and lysozyme were virtually unchanged. Filtration reduced the total protein concentration to about half of its original value and decreased lysozyme activity to about 10%. It can be concluded that irradiation is suitable for sterilizing whole saliva in its native form.

The influence of handheld mobile phones on human parotid gland secretion.

BACKGROUND: Handheld mobile phones (MPHs) have become a 'cultural' accessory device, no less so than a wrist watch. Nevertheless, the use of MPHs has given rise to great concern because of possible adverse health effects from exposure to the radiofrequency radiation (RFR) emitted by the device. Previous studies suggested correlation between MPH and salivary gland tumors. OBJECTIVE: To evaluate whether MPH induces physiologic changes in the adjacent parotid gland, located on the dominant side, in terms of secretion rates and protein levels in the secreted saliva. MATERIALS AND METHOD: Stimulated parotid saliva was collected simultaneously from both glands in 50 healthy volunteers whose MPH use was on a dominant side of the head. RESULTS: A significantly higher saliva secretion rate was noticed in the dominant MPH side compared with that in the non-dominant side. Lower total protein concentration was obtained in the dominant compared with the non-dominant MPH side among the right dominant MPH users. CONCLUSIONS: Parotid glands adjacent to handheld MPH in use respond by elevated salivary rates and decreased protein secretion reflecting the continuous insult to the glands. This phenomenon should be revealed to the worldwide population and further exploration by means of large-scale longitudinal studies is warranted.

Effects of radiation and alpha-tocopherol on saliva flow rate, amylase activity, total protein and electrolyte levels in oral cavity cancer.

OBJECTIVE: The objective of the present study was to evaluate early and late effects of radiation and a-tocopherol on the secretion rate of saliva and on selected saliva salivary parameters in oral cavity cancer patients. PATIENTS & METHODS: Eighty-nine histologically confirmed oral cavity cancer patients (OCC) were enrolled in the study. Resting whole saliva was collected before, during and at the end of the radiation therapy (RT) and simultaneous supplementation with alpha - tocopherol to the radiation treated patients (RT + AT). RESULTS: Salivary flow rate, pH, amylase activity, total protein, sodium and potassium were analyzed. Increased pH, potassium and decreased flow rate, amylase activity, protein content and sodium were observed in 6 weeks of radiation treated patients when compared to OCC patients. A significant improvement of those parameters was observed on alpha - tocopherol supplementation in RT + AT patients. CONCLUSION: Supplementation with alpha - tocopherol improves the salivary flow rate thereby, maintains salivary parameters.

Effect of defocused infrared diode laser on salivary flow rate and some salivary parameters of rats.

This study aims to investigate whether infrared diode low-level laser therapy (LLLT) increased salivary flow rate and altered pH value, protein concentration, and peroxidase and amylase activities in saliva of rats. Wistar rats were used and divided into three groups. Experimental groups (A and B) had their parotid, submandibular and sublingual glands submitted to diode laser, 808-nm wavelength, on two consecutive days. The dose results were 4 and 8 J/cm(2), respectively. A red guide light was used to visualize the irradiated area. Group C was irradiated only with red pilot beam and served as control. The saliva samples were collected after each irradiation step (first and second collection days) and 1 week after the first irradiation (seventh day). Statistical analysis was performed, and differences were observed according to different days of salivary collection. The results showed that salivary flow rate for groups A and B was higher on the seventh day if it is compared to data obtained for the first day (p < 0.05). LLLT applications on salivary glands are a therapy procedure that requires further studies.

Does irradiation affect the protein composition of saliva?

The purpose of this study was to compare the relative amount of low molecular weight salivary proteins in patients with head and neck tumours treated with radiotherapy and healthy subjects. Reverse-phase high-pressure liquid chromatography was used for protein separation. Nine protein fractions (including acidic and basic proline-rich proteins (PRPs), cystatins, histatins and statherin) were identified in saliva from irradiated patients as well as healthy subjects. However, compared with non-irradiated healthy subjects, the fraction of acidic PRPs was significantly reduced in irradiated patients. These data indicate an alteration of the relative amount of low molecular weight salivary proteins in irradiated patients besides the reduction of salivary flow.

Xerostomia and hypofunction of the salivary glands in cancer therapy.

This review presents data from the literature on oral adverse reactions from the perspectives of subjective feelings of dry mouth (xerostomia) and objective measures of salivary gland hypofunction during and after cancer therapy. Special emphasis is paid to the mechanisms behind xerostomia, impaired saliva secretion and changes in the composition of saliva and to how these relate to radiation therapy involving the salivary glands and to systemic chemotherapy. The oral complications that relate to such iatrogenic changes in salivary gland function are also discussed.

Measuring short-term gamma-irradiation effects on mouse salivary gland function using a new saliva collection device.

A restraining device was designed specifically for the collection of whole saliva from mice without using anesthesia. As the procedure does not involve surgical cannulation of the salivary glands, saliva can be collected from the same mouse at different times. The time between the injection of a secretory stimulant (pilocarpine) and the appearance of saliva in the mouth (lag time) was 100.5 +/-8.5 s (mean+/-S.E.M., n=10) for control mice. The volume of saliva collected in the first 5 min was three times greater than that collected between 15 and 20 min. The average flow rate for a collection period of 15 min was 16.7 +/-1.8 microl/min (n=10). The flow rate was decreased 50% (P<0.005) whereas the lag time was increased more than 300% (P<0.05) at 24 h after irradiation. The concentrations of a 23.5-kDa protein and a mucin were decreased after irradiation whereas there was no significant effect on the concentration of amylase or peroxidase.

Salivary epidermal growth factor levels decrease in patients receiving radiation therapy to the head and neck.

OBJECTIVE: The objective of this study was to assess changes in salivary epidermal growth factor (EGF) in patients receiving radiation therapy to the head and neck and to determine whether salivary EGF levels correlate with the severity of radiation-induced oral mucositis. STUDY DESIGN: Thirteen patients and 18 control subjects were enrolled in the study. Saliva was collected before, during (weekly), and after radiation therapy. Salivary total protein (TP) and EGF concentrations were measured and correlated with the severity of oral mucositis. The variability in normalized EGF (ngEGF/mgTP) values and mucositis scores were analyzed with analysis of covariance, and the adjusted correlation coefficient was calculated. RESULTS: EGF levels decreased (P =.004), whereas TP levels increased over time (P =.039). A strong correlation was seen with decreasing normalized EGF values and more severe mucositis (P =. 0001). CONCLUSION: A strong negative correlation between normalized EGF and mucositis severity suggests a possible role for EGF in the progression of radiation-induced mucosal breakdown.

Effect of 24 hours light on circadian rhythms of secretory enzymes and morphology of rat von Ebner's glands.

Von Ebner's glands of the rat are minor salivary serous glands in the posterior portion of the tongue. They secrete two digestive enzymes, lingual lipase and amylase. In this investigation, circadian rhythm in feeding was established under a normal 12 h light/12 h dark cycle, with the rats eating primarily during the dark period. At lights on, the size of the acinar cells and the area of the inclusive secretory granules, and the amount of digestive enzyme activity (lingual lipase and amylase) remaining in the gland was significantly less than in the mid-afternoon, after very little daylight food consumption. However, after 7 days of continuous light the circadian rhythm was altered: the food consumption during the normal night-time hours (5 p.m. to 8 a.m.) went from 88% of total 24 h food consumption to 45%, and during normal daylight hours (8 a.m. to 5 p.m.) from 12% to 55%. These changes were correlated with histometric findings of a near reversal of the areas of acinar cells and secretory granules of a.m. and p.m. samples under continuous light. Lingual lipase activity in the glands went from 35% under 12 h light to 61% under continuous light in the a.m. and from 65% to 39% in the p.m. Amylase activity also showed nearly a reversal in activity remaining in the gland, from 36% at 12 h light to 58% at 24 h light in the a.m. and 64% to 41% for the p.m. samples. These results indicate that the von Ebner's glands of the rat have a circadian rhythm of secretion and storage of secretory proteins that is subject to light entrainment similar to that seen in other exocrine glands such as the parotid and pancreas.

Sialochemical profile of X-irradiated major salivary glands in the rat.

The purpose of this study was to examine various sialochemical parameters in parotid (P) and submandibular (SM) secreted saliva of irradiated rats. Various doses of radiation from 2.5 to 15 Gy were administered to the head and neck region and the saliva was evaluated for its amylase activity and the concentration of sodium (Na), potassium (K) and total protein. Saliva samples containing equal amounts of proteins were also electrophoresed on separatory SDS gels, silver-stained and examined for possible qualitative alterations. The total protein concentrations of P saliva showed a radiation dose-dependent reduction at 3 days and 3 and 9 months following 15 Gy of 93%, 82% and 73% (p < 0.01), respectively. Forty days after the 15 Gy irradiation the reduction was not as severe (55%, NS). Three and 40 days post 15 Gy, amylase activity demonstrated a similar pattern of reduction, 98% and 89% (p < 0.01), respectively. In contrast to the P, no quantitative changes in the protein concentrations of the SM saliva were detected. As for the qualitative profiles of separated proteins, no radiation-induced changes were found for either P or SM at 3 and 40 days or 3 and 9 months, as compared with controls. The electrolyte concentrations were found to be flow-rate dependent. The Na concentrations of P saliva at 3 and 40 days following 15 Gy were reduced by 65% and 83% (p < 0.01), respectively. For SM saliva, the Na concentrations were reduced at 40 days by 58% (p < 0.05). The K concentration of P saliva increased at 40 days by 79% (p < 0.05). The data suggest that the various observed sialochemical changes could result from a reduction in the salivary flow rate and/or the number of surviving, normally functioning parenchymal cells. Thus, it is suggested that no salivary compositional alterations were directly induced by radiation but were secondary effects.

The alterations in the activity of amylase and its salivary isoenzyme in the serum of patients with ovarian carcinoma, submitted to radiotherapy.

Total activity of alpha-amylase and its salivary isoenzyme in the serum of patients with ovarian carcinoma of various types were evaluated before radiotherapy, in the middle of radiotherapy period, in the last day and 2 months after radiotherapy. Before radiotherapy the activity of these enzymes were significantly higher in patients with ovarian serous cystadenocarcinoma. It was found that irradiation resulted in a decrease of both total amylase activity and its salivary isoenzyme in the serum. The proportional participation of salivary isoenzymes in total amylase activity was normalized. It is suggested that the assay of salivary alpha-amylase activity may be useful in the evaluation of radiotherapy effectiveness.

The preparation of an autologous saliva for use with patients undergoing therapeutic radiation for head and neck cancer.

PURPOSE: At the present time there is no general agreement about how to prevent the symptoms and clinical signs that accompany therapeutic irradiation for head and neck cancer. Because saliva is the principal protector of the oral tissues, it is logical to assume that many of these changes are due to the radiation-induced damage to the salivary glands. We have observed that the flow and composition of saliva is normal in most patients before their irradiation. Theoretically, it should, therefore, be possible to collect their saliva before they commence their course of radiation, store it in a "saliva bank," and give it back to them when they undergo radiation. The key to the use of such an autologous saliva is the fabrication of a technique that disinfects or sterilizes the saliva yet preserves its protective properties. The objective of this study was to prepare an autologous saliva that would be used by patients during their irradiation for head and neck cancer. MATERIALS AND METHODS: Stimulated saliva was obtained from healthy subjects; none of the subjects consumed any medications. The saliva was treated by a variety of techniques. Included among them were heat, radiation, filtration, centrifugation, and an antibacterial agent. The samples were analyzed for total protein, amylase, viscosity, and sterility; individual salivary proteins were assessed by sodium dodecylsulfate-polyacrylamide gel electrophoresis. RESULTS: The results showed that beta radiation (> 2.5 kGy) and lyophilization + chlorhexidine (0.03% to 0.12%) could be used to prepare a sterile autologous saliva that retained most of its protective properties.

Change of salivary IgA secretion and caries development in irradiated rats.

Xerostomia is a serious side-effect of radiotherapy for head and neck cancer and often enhances caries activity. However, the relationship between caries induction and the IgA level in saliva in rats subjected to irradiation of the salivary glands is unclear. The effect of salivary gland irradiation on salivary function was examined in specific pathogen-free Sprague-Dawley rats infected with or without Streptococcus mutans MT8148R (serotype c). The flow rate of saliva and the protein concentration in saliva were significantly reduced in irradiated rats, regardless of infection of S. mutans. The caries activity was enhanced in these rats, and and irradiation level of 50 Gy significantly increased the caries score. However, longitudinal study indicated that the salivary concentration of IgA reactive with S. mutans whole cells maintained similar or significantly higher levels in irradiated rats, when compared with those of nonirradiated rats. In addition, there was no negative correlation between the caries score and the salivary concentration of IgA reactive with S. mutans. These findings suggest that the secreted IgA against S. mutans may not play a significant role in the caries induction of hyposalivated rats.

Changes in the protein composition of whole saliva during radiotherapy in patients with oral or pharyngeal cancer.

We analyzed the radiation-induced changes in the flow rate and protein composition of stimulated whole saliva in eleven patients treated for malignant conditions of the head and neck. In all patients the radiation field covered all major salivary glands and a large area of the oral mucosa. Paraffin-stimulated whole saliva samples were collected once 2 to 21 days before therapy and then after 20, 40, and 60 gray (Gy) cumulative dose of irradiation. Five patients also provided samples 6 months after the therapy. Hyposalivation or xerostomia occurred in all patients, although the pretreatment secretion rates were already relatively low. Salivary amylase activities decreased with increasing dose of radiation, especially when expressed as the amount of enzyme secreted per minute. Unusually high salivary concentrations of albumin, lactoferrin, lysozyme, salivary peroxidase, myeloperoxidase, and total protein were observed during the therapy, but most values slowly returned to pretreatment levels after cessation of radiation. It is concluded that the observed qualitative changes in whole saliva components are net effects caused by the cancer itself, radiation therapy given, systemic diseases, or medications, as well as mucosal inflammations.