Salivary Gland Damage Research Articles

What is the evidence for Sjögren's syndrome being triggered by viral infection? Subplot: infections that cause clinical features of Sjögren's syndrome.

To clarify the involvement of viral infections in the pathogenesis of Sjögren's syndrome and to discuss whether viruses can be a trigger for the development of Sjögren's syndrome. Although some viruses are candidate triggers of Sjögren's syndrome, we focus on human T lymphotropic virus type I (HTLV-I). Clinicoepidemiological studies show a relationship between HTLV-I and Sjögren's syndrome with a low frequency of salivary gland damage in magnetic resonance imaging, autoantibody production and ectopic germinal center in HTLV-I-associated myelopathy (HAM) patients with Sjögren's syndrome. Our recent study showed that HTLV-I has the potential to infect salivary gland epithelial cells (SGECs). After a coculture of HCT-5 (an HTLV-I-infected T-cell line derived from the cerebrospinal fluid) of an HAM patient and SGECs, we observed time-dependent increases in the levels of soluble intracellular adhesion molecule1, interferon gamma-induced protein 10 kDa and regulated on activation, normal T-cell expressed and secreted. In addition, SGECs themselves express these molecules along with the expression of HTLV-I proteins. HTLV-I is involved in the pathogenesis of HTLV-I-seropositive patients with Sjögren's syndrome. By infecting CD4 T cells in vivo, HTLV-I induces specific clinicopathological conditions. In addition, HTLV-I-infected SGECs have the potential to augment the expression of molecules involved in cell adhesion, inflammation and migration.

The protective effects of different treatments on rat salivary glands after radiotherapy.

This study was aimed to evaluate the efficacy of treatment modalities for minimizing salivary gland damage caused by radiotherapy. Forty rats were divided into five groups. Group 1 had no irradiation or any treatment. Group 2 underwent only 15Gy single dose radiotherapy. N-acetylcysteine, dexamethasone, hyperbaric oxygen treatment were given, respectively to the group 3, 4 and 5 for 5days. 15Gy single dose radiotherapy was applied to the group 3, 4 and 5 on the second day. Pyknosis, lysis, and vacuolization were examined in ductal cells and pyknosis, lysis, vacuolization, inflammation and collective duct damage in acinar cells. Dexamethasone and hyperbaric oxygen did not prove to have a positive effect on acinar and ductal cell. N-acetylcysteine-applied group had statistically significantly lower amount of damage. We determined that the decrease of ductal and acinar cell damage in parotid glands of N-acetylcysteine-applied rats was more distinct and statistically.

Radioprotective Effect of Epigallocatechin-3-Gallate on Salivary Gland Dysfunction After Radioiodine Ablation in a Murine Model.

Objectives.Radioiodine (RI) therapy is known to subject cellular components of salivary glands (SG) to oxidative stress leading to SG dysfunction. However, the protective effects of antioxidants on RI-induced SG damage have not been well investigated. The authors investigated the morphometric and functional effects of epigallocatechin-3-gallate (EGCG) administered prior to RI therapy and compared this with the effects of amifostine (a well-known antioxidant) in a murine model of RI sialadenitis.Methods.Four-week-old female C57BL/6 mice (n=48) were divided into four groups; a normal control group, a RI-treated group (0.01 mCi/g mouse, orally), an EGCG and RI-treated group, and an amifostine and RI-treated group. Animals in these groups were divided into 3 subgroups and euthanized at 15, 30, and 90 days post-RI treatment. Salivary flow rates and lag times were measured, and morphologic and histologic examinations and TUNEL (terminal deoxynucleotidyl transferase biotin-dUDP nick end labeling) assays were performed. Changes in salivary 99mTc pertechnetate uptake and excretion were followed by single-photon emission computed tomography.Results.Salivary flow rates and lag times to salivation in the EGCG or amifostine groups were better than in the RI-treated group. Histologic examinations of SGs in the EGCG or amifostine group showed more mucin-rich parenchyma and less periductal fibrosis than in the RI-treated group. Fewer apoptotic cells were observed in acini, ducts, and among endothelial cells in the EGCG or amifostine group than in the RI group. In addition, patterns of 99mTc pertechnetate excretion were quite different in the EGCG or amifostine group than in the RI group.Conclusion.EGCG supplementation before RI therapy could protect from RI-induced SG damage in a manner comparable to amifostine, and thus, offers a possible means of preventing SG damage by RI.

Melatonin's protective effect on the salivary gland against ionized radiation damage in rats.

The aim of this study was to examine the effects of melatonin on ionized radiation-induced salivary gland damage using an experimental model. Thirty-two rats were randomized into four groups: (i) the control group (C, n = 8) that received intraperitoneal (i.p.) 0.9% NaCl; (ii) the melatonin group (M, n = 8) that received i.p. 5 mg/kg melatonin; (iii) the radiotherapy group (RT, n = 8) that underwent irradiation; (iv) the melatonin plus radiotherapy group (M+RT, n = 8) that received i.p. 5 mg/kg of melatonin, followed by irradiation 30 min later; and (v) the radiotherapy plus melatonin group (RT+M, n = 8) that received irradiation followed by i.p. 5 mg/kg of melatonin 30 min later. The medications and irradiation were administered for 5 days and the salivary glands of the rats were excised 10 days later; the histopathological changes in the salivary glands were assessed and biochemical analyses were conducted (tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI)). Regardless of whether melatonin was administered before or after radiotherapy, melatonin decreased the radiation-induced parotid and submandibular histological damage. In addition, regardless of whether administration occurred before or after radiotherapy, melatonin decreased oxidative stress markers, such as MDA, TOS, and OSI. On the contrary, levels of antioxidative markers, such as CAT and GPx, were increased by melatonin. Melatonin may have a significant protective effect on salivary gland damage secondary to ionizing radiation.

Clinical Studies of Nonpharmacological Methods to Minimize Salivary Gland Damage after Radioiodine Therapy of Differentiated Thyroid Carcinoma: Systematic Review.

Purpose. To systematically review clinical studies examining the effectiveness of nonpharmacological methods to prevent/minimize salivary gland damage due to radioiodine treatment of differentiated thyroid carcinoma (DTC). Methods. Reports on relevant trials were identified by searching the PubMed, CINHAL, Cochrane, and Scopus electronic databases covering the period 01/2000–10/2015. Inclusion/exclusion criteria were prespecified. Search yielded eight studies that were reviewed by four of the present authors. Results. Nonpharmacological methods used in trials may reduce salivary gland damage induced by radioiodine. Sialogogues such as lemon candy, vitamin E, lemon juice, and lemon slice reduced such damage significantly (p < 0.0001, p < 0.05, p < 0.10, and p < 0.05, resp.). Parotid gland massage also reduced the salivary damage significantly (p < 0.001). Additionally, vitamin C had some limited effect (p = 0.37), whereas no effect was present in the case of chewing gum (p = 0.99). Conclusion. The review showed that, among nonpharmacological interventions, sialogogues and parotid gland massage had the greatest impact on reducing salivary damage induced by radioiodine therapy of DTC. However, the studies retrieved were limited in number, sample size, strength of evidence, and generalizability. More randomized controlled trials of these methods with multicenter scope and larger sample sizes will provide more systematic and reliable results allowing more definitive conclusions.

Binge Drinking of Ethanol during Adolescence Induces Oxidative Damage and Morphological Changes in Salivary Glands of Female Rats.

This study investigates morphological and biochemistry effects of binge ethanol consumption in parotid (PG) and submandibular (SG) salivary glands of rats from adolescence to adulthood. Female Wistar rats (n = 26) received ethanol at 3 g/kg/day (20% w/v) for 3 consecutive days/week from the 35th until the 62nd day of life. Animals were treated in two periods: 1 week (G1) and 4 weeks (G2), with a control (treated with distilled water) and an ethanol group to each period. In morphological analysis, morphometric and immunohistochemistry evaluation for smooth muscle actin (αSMA), cytokeratin-18 (CK-18), and vimentin (VIM) were made. Biochemical changes were analyzed by concentration of nitrites and levels of malondialdehyde (MDA). The difference between groups in each analysis was evaluated by Mann-Whitney U test or Student's t-test (p ≤ 0.05). PG showed, at one week of ethanol exposure, lower CK-18 and α-SMA expression, as well as MDA levels. After four weeks, lower CK-18 and higher MDA levels were observed in PG exposed to ethanol, in comparison to control group. SG showed lower α-SMA expression after 1 and 4 weeks of ethanol exposure as well as higher MDA levels after 1 week. Ethanol binge consumption during adolescence promotes tissue and biochemical changes with only one-week binge in acinar and myoepithelial PG cells.

A Randomized Controlled Trial for the Effectiveness of Aromatherapy in Decreasing Salivary Gland Damage following Radioactive Iodine Therapy for Differentiated Thyroid Cancer.

Objective. The aim of this study was to investigate effects of aromatherapy in decreasing salivary gland damage for patients undergoing radioactive iodine (RAI) therapy with differentiated thyroid cancer (DTC). Materials and Methods. The subjects were 71 patients with DTC. They were divided into aromatherapy group (group A, n = 35) and a control group (group B, n = 36). We blended 1.0 mL of lemon and 0.5 mL of ginger essential oils. The patients in the inhalation aromatherapy group inhaled this blend oil and those in the control group inhaled distilled water as placebo for 10 min during admission. We statistically compared salivary gland function before and after treatment between groups A and B. Results. In comparison with group B, the rate of change of the accumulation rate was significantly higher in the parotid glands and submandibular glands of group A (P < 0.05). In comparison with group B, a significant increase in rate of secretion change before and after treatment was noted in the bilateral parotid glands in group A (P < 0.05). Conclusion. Because an amelioration of salivary gland function was observed in the present study, our results suggest the efficacy of aromatherapy in the prevention of treatment-related salivary gland disorder. This trial is registered with UMIN Clinical Trial Registry: UMIN000013968.

Botulinum Toxin Confers Radioprotection in Murine Salivary Glands

Xerostomia is a common radiation sequela, which has a negative impact on the quality of life of patients with head and neck cancer. Current treatment strategies offer only partial relief. Botulinum toxins (BTX) have been successfully used in treating a variety of radiation sequelae such as cystitis, proctitis, fibrosis, and facial pain. The purpose of this study was to evaluate the effect of BTX on radiation-induced salivary gland damage. We used a previously established model for murine salivary gland irradiation (IR). The submandibular glands (SMGs) of C5BL/6 mice (n=6/group) were injected with saline or BTX 72 hours before receiving 15 Gy of focal irradiation. Saliva flow was measured 3, 7, and 28 days after treatment. The SMGs were collected for immunohistochemistry, confocal microscopy, and Western blotting. A cytokine array consisting of 40 different mouse cytokines was used to evaluate cytokine profiles after radiation treatment. Irradiated mice showed a 50% reduction in saliva flow after 3 days, whereas mice preinjected with BTX had 25% reduction in saliva flow (P<.05). Cell death detected by TUNEL staining was similar in SMG sections of both groups. However, neutrophil infiltrate, detected by myeloperoxidase staining, was 3-fold lower for the BTX treated mice. A cytokine array showed a 2-fold upregulation of LPS-induced chemokine (LIX/CXCL5) 3 days after IR. BTX pretreatment reduced LIX levels by 40%. At 4 weeks after IR, the saline (control) group showed a 40% reduction in basal SMG weight, compared with 20% in the BTX group. Histologically, BTX-pretreated glands showed relative preservation of acinar structures after radiation. These data suggest that BTX pretreatment ameliorates radiation-induced saliva dysfunction. Moreover, we demonstrate a novel role for CXCL5 in the acute phase of salivary gland damage after radiation. These results carry important clinical implications for the treatment of xerostomia in patients with head and neck cancer.

Adipose Mesenchymal Stem Cell Secretome Modulated in Hypoxia for Remodeling of Radiation-Induced Salivary Gland Damage

Background and PurposeThis study was conducted to determine whether a secretome from mesenchymal stem cells (MSC) modulated by hypoxic conditions to contain therapeutic factors contributes to salivary gland (SG) tissue remodeling and has the potential to improve irradiation (IR)-induced salivary hypofunction in a mouse model.Materials and MethodsHuman adipose mesenchymal stem cells (hAdMSC) were isolated, expanded, and exposed to hypoxic conditions (O2 < 5%). The hypoxia-conditioned medium was then filtered to a high molecular weight fraction and prepared as a hAdMSC secretome. The hAdMSC secretome was subsequently infused into the tail vein of C3H mice immediately after local IR once a day for seven consecutive days. The control group received equal volume (500 μL) of vehicle (PBS) only. SG function and structural tissue remodeling by the hAdMSC secretome were investigated. Human parotid epithelial cells (HPEC) were obtained, expanded in vitro, and then irradiated and treated with either the hypoxia-conditioned medium or a normoxic control medium. Cell proliferation and IR-induced cell death were examined to determine the mechanism by which the hAdMSC secretome exerted its effects.ResultsThe conditioned hAdMSC secretome contained high levels of GM-CSF, VEGF, IL-6, and IGF-1. Repeated systemic infusion with the hAdMSC secretome resulted in improved salivation capacity and increased levels of salivary proteins, including amylase and EGF, relative to the PBS group. The microscopic structural integrity of SG was maintained and salivary epithelial (AQP-5), endothelial (CD31), myoepithelial (α-SMA) and SG progenitor cells (c-Kit) were successfully protected from radiation damage and remodeled. The hAdMSC secretome strongly induced proliferation of HPEC and led to a significant decrease in cell death in vivo and in vitro. Moreover, the anti-apoptotic effects of the hAdMSC secretome were found to be promoted after hypoxia-preconditioning relative to normoxia-cultured hAdMSC secretome.ConclusionThese results show that the hAdMSC secretome from hypoxic-conditioned medium may provide radioprotection and tissue remodeling via release of paracrine mediators.

Large multinodular goiter--outpatient radioiodine treatment.

131-I treatment of nodular, especially nontoxic, goitre is still reserved mainly for elderly patients, whose numerous concomitant diseases disqualify them from surgery. Therapy often involves isolation and is available only in selected centres, which may be located far from some patients' places of residence, which is inconvenient for elderly people. The aim of the study was to assess the effectiveness of outpatient fractionated 131-I treatment of patients with large nodular goitres, as well as to evaluate complications and the factors affecting treatment results. The study included 35 patients with a large nodular goitre. Thyroid volume and treatment results were evaluated using US and CT neck examination. Mean thyroid volume prior to treatment was 104.36 mL (range 36.23-301.09 mL). An average administered 131-I activity was 1806 MBq (range 800-4000). The average reduction of goitre volume was 43.18% (range -17.23-89.66%). Final treatment results correlated with the thyroid size reduction obtained three months after treatment (r = 0.74; p = 0.001). Symptoms of transient hyperthyroidism were observed in 8.57% of patients, in 5.4% Graves disease was induced (including severe Graves' orbitopathy in 2.7%), and in 2.86% TRAb increase without development of hyperthyroidism was observed. The treatment results were not influenced by initial thyroid volume (r = -0.01; p = 0.95). An increase in thyroid volume during the treatment was reported in 20% of patients, with a mean increase of 22.3% (range 0.63-55.03%). Post-treatment hypothyroidism was diagnosed in 42.9% of patients. One patient was diagnosed with salivary gland damage. Fractionated 131-I treatment of large nodular goitres is an effective method, the results of which are comparable to those obtained from the administration of one-time high doses of radioiodine.

Systematic evaluation of salivary gland damage following I-131 therapy in differentiated thyroid cancer patients by quantitative scintigraphy and clinical follow-up.

Radioiodine therapy is a common adjunct to thyroidectomy in papillary thyroid cancer treatment. However, a variety of associated adverse effects have been reported. In this study, we assessed radioiodine-induced salivary gland dysfunction using quantitative scintigraphy, and evaluated the associated complications. Patients were divided into five groups on the basis of the cumulative I-131 dosage received. Scintigraphic dynamic images of the salivary glands were obtained and converted into clinically relevant parameters: uptake index (UI), maximum secretion rate (%SR), and combined gland function scores. Patients were followed up for 3-66 months and interviewed for side effects including xerostomia, taste alteration, bitter taste, dental caries, xerophthalmia, and pain/swelling. An increase in I-131 doses resulted in a reduction in the UI and %SR and an increase in the combined scintigraphy score. Parotid glands were more affected than submandibular glands. A cumulative dosage of greater than 600 mCi resulted in complete loss of %SR in the parotid glands. No significant difference in either the UI or the %SR was observed between nontreated patients and patients receiving an I-131 dosage of up to 150 mCi. The occurrence of xerostomia was significantly correlated with the gland scintigraphic score, the number of treatment cycles, and I-131 dosage. The occurrence of pain and swelling was extremely low and only lasted for a short time. Although the side effects associated with radioiodine treatment were apparent, they were usually small and temporary. Nevertheless, more consideration should be placed on careful dosing of I-131.

Protective efficacy of intravenous transplantation of adipose-derived stem cells for the prevention of radiation-induced salivary gland damage

ObjectiveHigh-dose radiation therapy in the head and neck area can lead to irreversible damage to salivary glands (SGs) with consequent xerostomia. Adipose-derived stem cells (ADSCs) have been shown to repair or rescue damaged SGs. Thus, we investigated the protective efficacy of ADSCs in the prevention of SG damage induced by high dose radiation. MethodsThird-passage ADSCs (1×106) were transplanted by intravenous infusion into the tail-vein of 8-week-old C57BL/6 mice, immediately after local irritation at a dose of 18Gy. The process was repeated twice a week during a period of six consecutive weeks. Eight weeks after radiation, functional evaluations were conducted by measuring salivary flow rate (SFR). Histological, immunohistochemical and transmission electron microscopic (TEM) examinations were performed to analyze microstructural and ultrastructural changes, microvessel density, amylase production, apoptosis, and proliferation activity. ResultsIntravenously administrated ADSCs could home to irradiated SGs within 24h after infusion, significantly increasing SG weights, improving SFR, and preserving the microscopic morphologies of SGs eight weeks post-radiation. More functional acini, higher amylase production levels, and higher microvessel densities were observed in ADSC-treated SGs than in irradiated SGs. Additionally, enhanced cell proliferation activity and reduced radiation-induced SG apoptosis was observed in the ADSC-treated group when compared with the irradiated group. ConclusionSystemic administration of ADSCs immediately after radiation at a dose of 18Gy can protect both the morphology and function of SGs eight weeks after radiation in mice, and can be used as a protective measure for the prevention of SG damage induced by high-dose radiation.

Natural remedies for the dry mouth associated with non-functioning salivary glands

Persistent xerostomia may be encountered in a substantial number of patients particularly head and neck cancer patients who received radiation, and patients with Sjogren's syndrome. Unfortunately many of these patients have lost all salivary function due to the irreversible destruction of salivary gland parenchyma. Management of this problem becomes palliative and requires the administration of salivary substitutes. This review considers the evidence regarding natural salivary substitutes that may be used to relieve severe dry mouth associated with irreversible damage of salivary glands.

Increased Expression of TGF-β Signaling Components in a Mouse Model of Fibrosis Induced by Submandibular Gland Duct Ligation.

Transforming growth factor-β (TGF-β) is a multi-functional cytokine with a well-described role in the regulation of tissue fibrosis and regeneration in the liver, kidney and lung. Submandibular gland (SMG) duct ligation and subsequent deligation in rodents is a classical model for studying salivary gland damage and regeneration. While previous studies suggest that TGF-β may contribute to salivary gland fibrosis, the expression of TGF-β signaling components has not been investigated in relation to mouse SMG duct ligation-induced fibrosis and regeneration following ductal deligation. Following a 7 day SMG duct ligation, TGF-β1 and TGF-β3 were significantly upregulated in the SMG, as were TGF-β receptor 1 and downstream Smad family transcription factors in salivary acinar cells, but not in ductal cells. In acinar cells, duct ligation also led to upregulation of snail, a Smad-activated E-cadherin repressor and regulator of epithelial-mesenchymal transition, whereas in ductal cells upregulation of E-cadherin was observed while snail expression was unchanged. Upregulation of these TGF-β signaling components correlated with upregulation of fibrosis markers collagen 1 and fibronectin, responses that were inhibited by administration of the TGF-β receptor 1 inhibitors SB431542 or GW788388. After SMG regeneration following a 28 day duct deligation, TGF-β signaling components and epithelial-mesenchymal transition markers returned to levels similar to non-ligated controls. The results from this study indicate that increased TGF-β signaling contributes to duct ligation-induced changes in salivary epithelium that correlate with glandular fibrosis. Furthermore, the reversibility of enhanced TGF-β signaling in acinar cells of duct-ligated mouse SMG after deligation indicates that this is an ideal model for studying TGF-β signaling mechanisms in salivary epithelium as well as mechanisms of fibrosis initiation and their resolution.

A critical role of Th17 cells in the development of murine Sjogeren’s syndrome (BA11P.132)

Abstract Sjögren’s syndrome (SS) is characterized by progressive inflammation and tissue damage of salivary glands (SG) and lacrimal glands, leading to dry-mouth and dry-eye symptoms as a result of reduced saliva and tears secretion. Histopathologically, CD4+ T cells were the major population in the infiltration and mediated tissue destruction. However, a role of IL-17-producing CD4+ T cell (Th17 cell) has not yet been elucidated in SS pathogenesis. In the present study, experimental SS was induced in normal mice by immunization with proteins extracted from SG. A rapid increase of Th17 cells was observed in the spleen and draining cervical lymph node at acute stage. Interestingly, this pattern also emerged in the draining lymph node of non-obese diabetic mice, another murine model of SS. Further, SG-infiltrating Th17 cells were detected and increased along disease progression. In IL-17 deficient (IL-17-/-) mice, no apparent salivary dysfunction and autoantibodies were observed upon immunization. However, upon adoptive transfer of Th17 cells from wild type mice, high titer of autoantibodies, salivary dysfunction with lymphocytic infiltration were fully restored in IL-17-/- mice. Together, our findings have demonstrated a critical role of Th17 cells in SS pathogenesis.

Double blind randomized prospective trial of bethanechol in the prevention of radiation-induced salivary gland dysfunction in head and neck cancer patients

This study assessed the prophylactic bethanechol use to prevent salivary gland dysfunction during radiotherapy. A total of 97 head and neck cancer patients were allocated into two groups: Bethanechol or Placebo. Bethanechol group presented significantly improve of salivary parameters. Bethanechol was effective in decreasing the salivary gland damage.

Transdifferentiation of mouse adipose-derived stromal cells into acinar cells of the submandibular gland using a co-culture system

A loss of salivary gland function often occurs after radiation therapy in head and neck tumors, though secretion of saliva by the salivary glands is essential for the health and maintenance of the oral environment. Transplantation of salivary acinar cells (ACs), in part, may overcome the side effects of therapy. Here we directly differentiated mouse adipose-derived stromal cells (ADSCs) into ACs using a co-culture system. Multipotent ADSCs can be easily collected from stromal vascular fractions of adipose tissues. The isolated ADSCs showed positive expression of markers such as integrin beta-1 (CD29), cell surface glycoprotein (CD44), endoglin (CD105), and Nanog. The cells were able to differentiate into adipocytes, osteoblasts, and neural-like cells after 14days in culture. ADSCs at passage 2 were co-cultured with mouse ACs in AC culture medium using the double-chamber (co-culture system) to avoid mixing the cell types. The ADSCs in this co-culture system expressed markers of ACs, such as α-amylases and aquaporin5, in both mRNA and protein. ADSCs cultured in AC-conditioned medium also expressed AC markers. Cellular proliferation and senescence analyses demonstrated that cells in the co-culture group showed lower senescence and a higher proliferation rate than the AC-conditioned medium group at Days 14 and 21. The results above imply direct conversion of ADSCs into ACs under the co-culture system; therefore, ADSCs may be a stem cell source for the therapy for salivary gland damage.

The effect of 2100 MHz radiofrequency radiation of a 3G mobile phone on the parotid gland of rats

PurposeWe aimed to evaluate the effect of 2100 MHz radiofrequency radiation on the parotid gland of rats in short and relatively long terms. Material and methodsThirty Wistar albino rats were divided into four groups. Groups A and B served as the control groups (for 10 days and 40 days, respectively), and each group included six rats. Groups C and D were composed of nine rats each, and they were the exposure groups. The rats were exposed to 2100 MHz radiofrequency radiation emitted by a generator, simulating a third generation mobile phone for 6 hours/day, 5 days/week, for 10 or 40 days. Following exposure, the rats were sacrificed and parotid glands were removed. Histopathological and biochemical examinations were performed. ResultsAlthough there were no histopathological changes in the control groups except for two animals in group A and three animals in group B, the exposure groups C (10 days) and D (40 days) showed numerous histopathological changes regarding salivary gland damage including acinar epithelial cells, interstitial space, ductal system, vascular system, nucleus, amount of cytoplasm and variations in cell size. The histopathological changes were more prominent in group D compared to group C. There was statistically significant different parameter regarding variation in cell size between the groups B and D (p=0.036). ConclusionThe parotid gland of rats showed numerous histopathological changes after exposure to 2100 MHz radiofrequency radiation, both in the short and relatively long terms. Increased exposure duration led to an increase in the histopathological changes.

Розвиток оксидативного стресу в тканинах слинних залоз щурів за умов глутаматіндукованого ожиріння

Pathogenic mechanisms of damage of salivary glands under obesity are an insufficiently studied problem of modem medicine. On experimental model of obesity induced by monosodium glutamate, free-radical processes and antioxidant defense system were studied in the tissues of salivary glands of rats. Under experimental obesity induced by monosodium glutamate there is a significant increase of the content of thio-barbituric acid reactive substances and a significant decrease in the activity of superoxide dismutase and catalase. Thus, it indicates to the misbalance of prooxidant and antioxidant systems and the development of oxidative stress.

Differentiated thyroid cancer—personalized therapies to prevent overtreatment

The concept of individualized therapy is rapidly gaining recognition in the management of patients with differentiated thyroid cancer (DTC). This Review provides an overview of the most important elements of this paradigm shift in DTC management and discusses the implications for clinical practice. In the majority of patients with DTC who have an inherently good prognosis, the extent of surgery, the dosage of (131)I therapy and the use of levothyroxine therapy are all aspects suitable for individualization, on the basis of both the stage of disease and the response to treatment. In individuals with advanced disease, newer imaging techniques, advances in (131)I therapy and the use of targeted molecular therapies (such as multitargeted kinase inhibitors) have provided new options for the personalized care of patients, for whom until recently no effective therapies were available. Individualized therapies could reduce adverse effects, including the sometimes debilitating hypothyroidism that used to be required before initiation of (131)I treatment, and major salivary gland damage, a common and unpleasant side effect of (131)I therapy. Highly individualized interdisciplinary treatment of patients with DTC might lead to improved outcomes with reduced severity and frequency of complications and adverse effects. However, in spite of ongoing research, personalized therapies remain in their infancy.