Effect of lozenge surface texture, taste and acidity on salivary flow rate: A crossover preclinical trial in healthy subjects.

Dry mouth is a multifaceted condition which is caused by reduced salivary secretion. This study aimed to evaluate and compare the effects of different lozenge surface textures, tastes and acidity levels on stimulated salivary secretion for increased oral moistening in participants without hyposalivation. This randomized, double-blind, clinical crossover trial with before and after comparison involved 33 healthy volunteers. Five lozenges, including a baseline control (C), apple (A), sour (S), sour apple (SA) and granular pectin (P) were tested on five different days with all the subjects. Salivary flow, pH value, and subjective feeling (visual analog scale) were measured before and after consuming the lozenge each day. Throughout all trial days the unstimulated whole salivary flow (UWSF) averaged 0.65 ± 0.26 ml/min. Lozenges S, SA, and P showed higher stimulated whole salivary flow (SWSF) than C (P < 0.001) by more than 0.5 ml/min. Lozenge P, with a rough surface, demonstrated the highest difference between UWSF and SWSF, 2.41 ± 0.69 ml/min. The stimulated saliva with the lozenges containing acidifiers (S, SA and P) was more than 1.4 pH units lower compared to lozenges C and A (P < 0.001). Subjects reported the strongest subjective feeling of increased saliva with lozenges SA and P. Overall lozenges SA and P provided the best objective results in enhancing salivary flow rate and subjective feeling of increased salivary flow.

Salivary flow, amylase, and total protein in hospitalized patients with HIV infection / AIDS complications.

BACKGROUND: Saliva is a complex secretion produced daily by the salivary glands. Saliva consists mainly of water, enzymes, ions and amino acids and performs several important functions in oral health. OBJECTIVE: The aim of this study was to investigate the flow rate and concentrations of amylase and total proteins in the saliva of hospitalized patients due to AIDS complications. METHODS: Ninety-three men and women (20-64 years of age) were divided into two groups (46 HIV-infected patients and 47 controls) and had salivary flow rate and levels of amylase enzyme and total proteins evaluated. RESULT: The mean salivary flow rate was lower in individuals with HIV when compared to controls (P < 0.05). No significant difference between amylase enzyme levels and total proteins were observed in the saliva of patients with HIV infection when compared to controls. CONCLUSION: Individuals with HIV / AIDS infection (in hospital treatment) suffer no interference in levels of amylase and total salivary proteins, but they have significantly reduced salivary flow.

The possible synergistic action of sex hormones and glucagon-like peptide-1 (GLP-1) agonists on body mass decline in patients with type 2 diabetes mellitus.

Adiposity is a chronic disease and one of the major modifiable risk factors for the development of type 2 diabetes mellitus (T2DM). Its prevalence in the world could be considered epidemic with 80% of patients with T2DM being obese. Novel antidiabetic drugs, such as glucagone-like peptide-1 (GLP-1) agonists have demonstrated benefitial effect on weight reduction. Nevertheless, in the last decades the need for new therapeutic strategies in the management of adiposity have emerged. Both adiposity and T2DM have negative effect on hypothalamic-pituitary-gonadal axis. Conversely, it has been known that sex hormone replacement therapy improves metabolic parameters in hypogonadal subjects. Recent research has found potential therapeutic effect of combination therapies with sex hormones and GLP-1 agonists in reducing body weight. Based on the aforementioned, we hypothesize that there is a possible synergistic effect of GLP-1 agonists and sex hormones on body mass reduction in patients with type 2 diabetes. The possible additional effect of sex hormones on weight loss could contribute to more effective treatment of T2DM and its complications.

Botulinum neurotoxin A injection for the treatment of epiphora with patent lacrymal ducts.

HEADINGS: Retrospective longitudinal study to evaluate the efficacy of botulinum neurotoxin A (BoNT/A) therapy for epiphora with patent lacrimal ducts. BACKGROUND/PURPOSE: BoNT/A has been used since 2000 in axillary hyperhidrosis to reduce sweat secretion. Some isolated cases of hyperlacrimation or crocodile tear syndrome have been treated with BoNT/A on this basis. We report our experience in the treatment of tearing despite patent lacrimal ducts by BoNT/A injection into the lacrimal gland. METHODS: We reviewed qualitative and quantitative criteria to evaluate the degree of improvement of epiphora after BoNT/A injections in the palpebral lobe of the lacrimal gland in patients referred for epiphora despite patent lacrimal ducts between 2009 and 2016. Epiphora was graded using a functional questionnaire, Munk score and Schirmer test performed before and after the injections. Side effects were recorded. RESULTS: Sixty-five palpebral lacrimal glands of forty-two patients with epiphora despite patent lacrimal ducts, of mean age 65 years, sex ratio 0.8, were treated with BoNT/A (IncobotulinumtoxinA, XEOMIN®, MERZ Pharma France) from April 2009 to April 2016. The etiology of the epiphora was represented by 56 paroxysmal lacrimal hypersecretion, 2 crocodile tear syndrome and 7 facial palsies. No conventional medical or surgical treatment had been effective in these cases. The technique of injection, dilution and dosage of BoNT/A were specific. We re-injected 33/65 cases a second time upon patient request due to recurrence of epiphora, 16/65 cases three times, 8/65 cases four times, 6/65 cases five times and 3/65 six times. The Schirmer's test measured a decrease of lacrimal secretion in 51/65 glands (78%) after the first botulinum neurotoxin injection. Side effects were limited to ptosis in 2 cases (3%) and six patients (9%) with rapidly regressing diplopia. Two patients experienced immediate lacrimal gland hematoma (3%) with no sequelae. The authors describe the injection techniques, the dosage, the volume and concentration of BoNT/A. CONCLUSION: Patients with intractable epiphora despite patent lacrimal ducts can be effectively treated with BoNT/A (IncobotulinumtoxinA) injection into the palpebral lobe of the lacrimal gland. Most of the patients (80%) were very satisfied with few side effects (hematoma, ptosis or mild diplopia lasting from 3 days to 3 weeks). More studies are needed to delineate which types of epiphora can be treated with BoNT A.

Epithelial disruptions, but not immune cell invasion, induced secretory dysfunction following innate immune activation in a novel model of acute salivary gland injury.

BACKGROUND: Salivary gland (SG) injurious agents are all translated into loss of salivation (xerostomia). An association has been established between activation of innate immunity and SG injury and dysfunction. However, it remains unclear how the secretory epithelia respond by halting saliva production. METHODS: C57BL/6 submandibular glands (SMGs) were acutely challenged using a single dose of the innate immune stimulant: polyinosinic-polycytidylic acid (poly (I:C)). Secretory capacity of the infected SMGs was substantiated by assessing the flow rate in response to pilocarpine stimulation. Depletion of the acute inflammatory cells was achieved by pre-treating mice with RB6-8C5 depletion antibody. Flow cytometry, histology and immunohistochemistry were conducted to verify the immune cell depletion. Epithelial expression of saliva-driving molecules: muscarinic 3 receptor (M3R), aquaporin 5 water channel (AQP5), Na-K-CL-Cotransporter 1 (NKCC1) and transmembrane member 16A (TMEM16A), was characterized using RT-qPCR and immunohistochemistry. Tight junction (TJ) protein; zonula occludens (ZO-1) and basement membrane (BM) protein; and laminin were assessed by immunohistochemistry. RESULTS: Innate immune challenge prompted dysfunction in the exocrine SGs. Dysregulated gene and protein expression of molecules that drive saliva secretion was substantiated. Aberrant expression of TJ and BM proteins followed innate immune activation. Hyposalivation in the current model was independent of myeloperoxidase (MPO)-positive, acute inflammatory cells. CONCLUSIONS: In this study, we developed a novel injury model of the SGs, featuring acute secretory dysfunction and immediate structural disruptions. Our results ruled out the injurious role of aggressively infiltrating inflammatory cells.

Oral health assessment for users of marijuana and cocaine/crack substances.

The objective of this study was to assess the oral health status of users of illicit drugs such as marijuana and cocaine/crack and compare it with individuals not using these chemical substances. Questionnaires were applied to 35 illicit drugs users to gather information on demographic status, general health, and use of drugs. Then, a clinical assessment of the oral health condition was performed to collect data on decayed, missing and filled teeth (DMFT) index, salivary flow rate (SFR), and mucosal lesions. The control group was composed of 35 non-illicit drug users. In the experimental group, 91.43% were males, 80% were smokers, and 42.85% were alcoholics. Cocaine was the most common drug used (77.15%), followed by marijuana (68.6%), and crack (51.4%). The average DMFT index was 9.8 and the SFR was reduced in 60% of subjects. Mucosal alterations were detected, but no potentially malignant disorders or oral cancer were diagnosed. Compared to control group, significantly higher values for gender (40%, p = 0.0001), smoking (22.86%) and heavy drinking (5.7%) habits (p = 0.0001), SFR (31.4%; p = 0.0308), and oral lesions (p = 0.0488) were found for the experimental group, although significantly higher values were found in the control group for DMFT index (p = 0.0148). It can be concluded that the use of illicit drugs contributed to an increased prevalence of oral mucosa lesions. In addition, a decline on SFR and a reduced DMFT index was observed for illicit drug users.

Caries experience and salivary aspects in individuals with fragile X syndrome.

Fragile X syndrome (FXS) is the most common cause of hereditary mental retardation, but studies on the oral health condition of these patients are rare. The aim of this study was to determine the experience of dental caries in individuals with FXS, by examining the saliva profile, oral hygiene, socioeconomic characteristics and use of controlled drugs in these patients. Dental health was estimated using the decayed, missing and filled teeth index (DMF-T) and sialometry, and the pH value and buffering capacity of the saliva, colony forming units of S. mutans (CFU/mL), visible biofilm index, and socioeconomic status were all examined. The sample, comprising 23 individuals, had an average age of 17.3 ± 5.6 years, a DMF-T index of 5.5, a diminished salivary flow (78.3%), and a low (73.9%) saliva buffering capacity. Most (52.2%) individuals presented with a high abundance (CFU/mL) of S. mutans. The experience of caries was correlated with salivary parameters, poor oral hygiene, lower socioeconomic status and an increased count of S. mutans in saliva.

Association between crack cocaine use and reduced salivary flow.

Crack cocaine use appears to have an impact on oral conditions. However, changes in the salivary flow among crack users have not been fully clarified. The aim of this study was to compare stimulated salivary flow and the occurrence of hyposalivation between crack users and non-users. A cross-sectional study was conducted involving 40 crack users and 40 controls matched for sex, age, and smoking habits. Interviews were conducted to acquire data on the perception of dry mouth (xerostomia) and drug use. Stimulated salivary flow was determined using the spitting method. A significant reduction in stimulated salivary flow was found among crack users in comparison to non-users (1.02 vs. 1.59 ml/min). A total of 42.5% and 15% of crack users had very low and low stimulated salivary flow, respectively. Moreover, 65% of users reported xerostomia in comparison to 37.5% non-users (p < 0.012). No significant association was found between xerostomia and hyposalivation (p = 0.384). A multivariate analysis revealed that individuals older than 26 years of age, those with a low household income, and crack users (prevalence ratio: 2.59) had a significant association with the occurrence of hyposalivation. A significant association was found between the use of crack and reduced salivary flow. The use of crack was associated with the occurrence of hyposalivation in the multivariate analysis.

Association of salivary gland hypofunction with diabetes mellitus and drugs among the elderly in Karachi, Pakistan.

AIM: Studies from Pakistan on salivary dysfunction are lacking, and the Pakistani elderly population is rapidly growing. Among the most common problems in the elderly that could have a deleterious impact on their quality of life are salivary gland hypofunction (SGH), diabetes mellitus (DM), and the intake of drugs with adverse effects on salivary function. In the present study, we aimed to find the association of SGH with DM and drugs among the elderly in Karachi, Pakistan. METHODS: The inclusion criterion was affirmative answers to a series of standardized questions related to the symptoms of dry mouth. A total of 110 individuals were selected from a convenience sample of 200 people aged between 60 and 70 years. Diabetes, drug use, and SGH in the participants were determined by detailed medical and drug history, clinical examination, and sialometry. RESULTS: Similar to their international counterparts, the majority of the study participants demonstrated objective evidence of SGH. More importantly SGH was found to be statistically significant with respect to DM and medication (P < 0.05). For participants on medication, the minimum and maximum salivary flow rates were found to be 0.09 mL/min and 0.3 ml/min, respectively, whereas the minimum and maximum salivary flow rates in diabetic participants were 0.01 mL/min and 0.09 mL/min, respectively. CONCLUSION: In the present study, the majority of elderly participants whose presenting complaint was oral dryness was found to have objective evidence of SGH, with a statistically-significant association with DM and drugs.

Oral health assessment for users of marijuana and cocaine/crack substances

Abstract: The objective of this study was to assess the oral health status of users of illicit drugs such as marijuana and cocaine/crack and compare it with individuals not using these chemical substances. Questionnaires were applied to 35 illicit drugs users to gather information on demographic status, general health, and use of drugs. Then, a clinical assessment of the oral health condition was performed to collect data on decayed, missing and filled teeth (DMFT) index, salivary flow rate (SFR), and mucosal lesions. The control group was composed of 35 non-illicit drug users. In the experimental group, 91.43% were males, 80% were smokers, and 42.85% were alcoholics. Cocaine was the most common drug used (77.15%), followed by marijuana (68.6%), and crack (51.4%). The average DMFT index was 9.8 and the SFR was reduced in 60% of subjects. Mucosal alterations were detected, but no potentially malignant disorders or oral cancer were diagnosed. Compared to control group, significantly higher values for gender (40%, p = 0.0001), smoking (22.86%) and heavy drinking (5.7%) habits (p = 0.0001), SFR (31.4%; p = 0.0308), and oral lesions (p = 0.0488) were found for the experimental group, although significantly higher values were found in the control group for DMFT index (p = 0.0148). It can be concluded that the use of illicit drugs contributed to an increased prevalence of oral mucosa lesions. In addition, a decline on SFR and a reduced DMFT index was observed for illicit drug users.

Caries experience and salivary aspects in individuals with fragile X syndrome

Abstract Fragile X syndrome (FXS) is the most common cause of hereditary mental retardation, but studies on the oral health condition of these patients are rare. The aim of this study was to determine the experience of dental caries in individuals with FXS, by examining the saliva profile, oral hygiene, socioeconomic characteristics and use of controlled drugs in these patients. Dental health was estimated using the decayed, missing and filled teeth index (DMF-T) and sialometry, and the pH value and buffering capacity of the saliva, colony forming units of S. mutans (CFU/mL), visible biofilm index, and socioeconomic status were all examined. The sample, comprising 23 individuals, had an average age of 17.3 ± 5.6 years, a DMF-T index of 5.5, a diminished salivary flow (78.3%), and a low (73.9%) saliva buffering capacity. Most (52.2%) individuals presented with a high abundance (CFU/mL) of S. mutans. The experience of caries was correlated with salivary parameters, poor oral hygiene, lower socioeconomic status and an increased count of S. mutans in saliva.

Association between crack cocaine use and reduced salivary flow

Abstract Crack cocaine use appears to have an impact on oral conditions. However, changes in the salivary flow among crack users have not been fully clarified. The aim of this study was to compare stimulated salivary flow and the occurrence of hyposalivation between crack users and non-users. A cross-sectional study was conducted involving 40 crack users and 40 controls matched for sex, age, and smoking habits. Interviews were conducted to acquire data on the perception of dry mouth (xerostomia) and drug use. Stimulated salivary flow was determined using the spitting method. A significant reduction in stimulated salivary flow was found among crack users in comparison to non-users (1.02 vs. 1.59 ml/min). A total of 42.5% and 15% of crack users had very low and low stimulated salivary flow, respectively. Moreover, 65% of users reported xerostomia in comparison to 37.5% non-users (p < 0.012). No significant association was found between xerostomia and hyposalivation (p = 0.384). A multivariate analysis revealed that individuals older than 26 years of age, those with a low household income, and crack users (prevalence ratio: 2.59) had a significant association with the occurrence of hyposalivation. A significant association was found between the use of crack and reduced salivary flow. The use of crack was associated with the occurrence of hyposalivation in the multivariate analysis.

Irradiation-induced secretion of BMP4 by marrow cells causes marrow adipogenesis post-myelosuppression.

Pre-transplant myeloablation is associated with marrow adipogenesis, resulting in delayed engraftment of hematopoietic stem cells (HSCs). This is strongly undesirable, especially when the donor HSCs are fewer in numbers or have compromised functionality. The molecular mechanisms behind irradiation-induced marrow adipogenesis have not been extensively investigated. Here we show that bone marrow (BM) cells, especially T-cells and stromal cells, express and secrete copious amounts of BMP4 in response to irradiation, which causes the bone marrow stromal cells to commit to adipocyte lineage, thereby contributing to an increase in bone marrow adipogenesis. We further demonstrate that Simvastatin inhibits the BMP4-mediated adipogenic commitment of marrow stromal cells by inhibiting Ppar-γ expression. Importantly, Simvastatin does not prevent BMP4 secretion by the BM cells, and thus does not interfere with its salutary role in post-transplant hematopoietic regeneration. Our data identify previously unknown mechanisms operative in marrow adipogenesis post-myeloablation. They also reveal the molecular mechanisms behind the advantage of using Simvastatin as a niche-targeting agent to improve HSC engraftment.

Drugs or disease: evaluating salivary function in RA patients.

Oral complications of RA may include temporomandibular joint disorders, mucosa alterations and symptoms of dry mouth. The aim of this study was to evaluate the salivary gland function of subjects with rheumatoid arthritis (RA) comparing it to healthy controls. Subjects with other systemic conditions known to affect salivary functions were excluded. A questionnaire was applied for the evaluation of xerostomia. Resting and chewing-stimulated salivary flow rates (SFR) were obtained under standard conditions. There were 145 subjects included of the study (104 RA and 38 controls). About 66.7% of the RA subjects and 2.4% in control group presented xerostomia. The median resting SFR were 0.24 ml/min for RA subjects and 0.40 mL/min for controls (p = 0.04). The median stimulated SFR were 1.31 mL/min for RA subjects and 1.52 ml/min for controls (p = 0.33). No significant differences were found between resting and stimulated SFR of RA subjects not using xerogenic medications and controls. There was significantly higher number of subjects presenting hyposalivation in the RA group than among controls, even when subjects using xerogenic medications were eliminated from the analysis. In conclusion, hyposalivation and xerostomia were more frequent among RA subjects not using xerogenic medication than among controls, although there were no significant differences in the median SFR between groups.

Sedative load and salivary secretion and xerostomia in community-dwelling older people.

OBJECTIVE: The aim was to investigate how sedative load and the total number of drugs used are related to hyposalivation and xerostomia among 75-year-old or older dentate, non-smoking, community-dwelling people. MATERIALS AND METHODS: The study population consisted of 152 older people from the Oral Health GeMS study. The data were collected by interviews and clinical examinations during 2004-2005. Sedative load, which measures the cumulative effect of taking multiple drugs with sedative properties, was calculated using the Sedative Load Model. RESULTS: The results showed that participants with a sedative load of either 1-2 or ≥3 had an increased likelihood of having low stimulated salivary flow (<0.7 ml/min; OR: 2.4; CI: 0.6-8.6 and OR: 11; CI: 2.2-59; respectively) and low unstimulated salivary flow (<0.1 ml/min; OR: 2.7, CI: 1.0-7.4 and OR: 4.5, CI: 1.0-20, respectively) compared with participants without a sedative load. Participants with a sedative load ≥3 had an increased likelihood of having xerostomia (OR: 2.5, CI: 0.5-12) compared with participants without a sedative load. The results showed that the association between the total number of drugs and hyposalivation was weaker than the association between sedative load and hyposalivation. CONCLUSION: Sedative load is strongly related to hyposalivation and to a lesser extent with xerostomia. The adverse effects of drugs on saliva secretion are specifically related to drugs with sedative properties.

Radiotherapy-induced xerostomia, pre-clinical promise of LMS-611.

PURPOSE: Radiotherapy-induced xerostomia (RIX) is the most common permanent side effect of radiotherapy (RT) to the head and neck (H&N). There is no effective topical treatment. LMS-611 is a mimetic of a natural lamellar body which prevents thick secretions like saliva from congesting organs. The primary objective of this study was to assess saliva properties before and during RT to the H&N. The secondary objectives were to re-assess saliva properties with the addition of LMS-611, measure inter-patient variability, correlate patient-reported symptoms with laboratory measurements and design subsequent first-in-human clinical trial of LMS-611. METHODS: Patients with H&N cancer receiving RT as primary treatment were recruited. Patients completed the Groningen RIX (GRIX) questionnaire and provided saliva samples at baseline and weeks 2, 4 and 6 of RT. Saliva adhesiveness and viscosity were tested by measuring time taken to travel 5 cm down an inclined plane. RESULTS: Thirty patients were enrolled. The inclined plane test (IPT) results (s) were as follows: baseline 31.3, week 2 49.7, week 4 51.1 and week 6 55.7. Wide inter-patient variability was seen at baseline. GRIX scores increased as RT progressed. Spearman rank correlation coefficient of inclined plane tests with GRIX scores was -0.06 at baseline, 0.25 at week 2, 0.12 at week 4 and 0.08 at week 6. LMS-611 concentrations of 10 and 20 mg/ml significantly reduced IPT times on saliva samples. CONCLUSIONS: Saliva becomes more visco-adhesive and RIX worsens as RT progresses. There is little correlation between objective and subjective measures of RIX. The addition of LMS-611 to thick, sticky saliva restores its fluidity ex vivo. This warrants in vivo analysis of the effect of LMS-611 upon RIX.

Drugs or disease: evaluating salivary function in RA patients

Abstract Oral complications of RA may include temporomandibular joint disorders, mucosa alterations and symptoms of dry mouth. The aim of this study was to evaluate the salivary gland function of subjects with rheumatoid arthritis (RA) comparing it to healthy controls. Subjects with other systemic conditions known to affect salivary functions were excluded. A questionnaire was applied for the evaluation of xerostomia. Resting and chewing-stimulated salivary flow rates (SFR) were obtained under standard conditions. There were 145 subjects included of the study (104 RA and 38 controls). About 66.7% of the RA subjects and 2.4% in control group presented xerostomia. The median resting SFR were 0.24 ml/min for RA subjects and 0.40 mL/min for controls (p = 0.04). The median stimulated SFR were 1.31 mL/min for RA subjects and 1.52 ml/min for controls (p = 0.33). No significant differences were found between resting and stimulated SFR of RA subjects not using xerogenic medications and controls. There was significantly higher number of subjects presenting hyposalivation in the RA group than among controls, even when subjects using xerogenic medications were eliminated from the analysis. In conclusion, hyposalivation and xerostomia were more frequent among RA subjects not using xerogenic medication than among controls, although there were no significant differences in the median SFR between groups.

Effects of Multi-glycosides of Tripterygium wilfordiion in the Treatment of Sjögren's Syndrome in the Non-obese Diabetic Mouse Model.

OBJECTIVE: To investigate the effects of the multi-glycosides of Tripterygium wilfordii (GTW) on Sjögren's syndrome (SS) in the non-obese diabetic (NOD) mouse model. METHODS: Twenty-seven 8-week-old, female NOD mice were divided into the GTW group, the hydroxychloroquine (HCQ) group, and control (normal saline) group, and received corresponding treatment for 16 weeks. The treatment-induced changes in stimulated total saliva flow rate (STFR), level of serum anti-SSA/SSB, ratio of regulatory T (Treg) cells, histology of the submandibular gland (SMG) and the gene expression profile that is related to inflammation and autoimmunization were evaluated. RESULTS: Compared to the untreated (control) mice, STRF, SMG index and Treg/CD4+ cell ratio were significantly higher, whereas anti-SSA, anti-SSB and lymphoid foci were remarkably lower in GTW-treated mice. HCQ-treated mice showed similar results except SMG index was not different from the untreated mice. NOD mice showed 19.03% altered gene expression with maturation from the age of 8 weeks to 24 weeks. Treatment with HCQ and GTW reduced the change in gene expression to 13.09% and 7.14%, respectively. CONCLUSION: GTW is as effective as HCQ in the treatment of Sjögren's syndrome in the NOD mouse model.

The effect of antacid on salivary pH in patients with and without dental erosion after multiple acid challenges.

PURPOSE: To evaluate the effect of antacid swish in the salivary pH values and to monitor the pH changes in subjects with and without dental erosion after multiple acid challenge tests. METHODS: 20 subjects with tooth erosion were matched in age and gender with 20 healthy controls according to specific inclusion/exclusion criteria. Baseline measures were taken of salivary pH, buffering capacity and salivary flow rate using the Saliva Check System. Subjects swished with Diet Pepsi three times at 10-minute intervals. Changes in pH were monitored using a digital pH meter at 0-, 5-, and 10- minute intervals and at every 5 minutes after the third swish until pH resumed baseline value or 45 minutes relapse. Swishing regimen was repeated on a second visit, followed by swishing with sugar-free liquid antacid (Mylanta Supreme). Recovery times were also recorded. Data was analyzed using independent t-tests, repeated measures ANOVA, and Fisher's exact test (α= 0.05). RESULTS: Baseline buffering capacity and flow rate were not significantly different between groups (P= 0.542; P= 0.2831, respectively). Baseline salivary pH values were similar between groups (P= 0.721). No significant differences in salivary pH values were found between erosion and non-erosion groups in response to multiple acid challenges (P= 0.695) or antacid neutralization (P= 0.861). Analysis of salivary pH recovery time revealed no significant differences between groups after acid challenges (P= 0.091) or after the use of antacid (P= 0.118). There was a highly significant difference in the survival curves of the two groups on Day 2, with the non-erosion group resolving significantly faster than the erosion group (P= 0.0086).

Plasma and ovarian oestradiol and the variability in the LH surge induced in ewes by the ram effect.

The proportion of anoestrous ewes ovulating after exposure to a sexually active ram is variable mainly due to whether an LH surge is induced. The aim of this study was to determine the role of oestradiol (E2) in the ram-induced LH surge. In one study, we measured the plasma concentrations of E2 in ewes of different breeds before and after the 'ram effect' and related these patterns to the presence and latency of the LH surge, while another compared ovarian responses with the 'ram effect' following exposure to rams for 2 or 12 h. In all ewes, the concentration of E2 increased 2-4 h after rams were introduced and remained elevated for 14.5 ± 0.86 h. The quantity of E2 secreted before the LH surge varied among breeds as did the mean concentration of E2. The granulosa cells of IF ewes collected after 12 h exposure to rams secreted more E2 and progesterone and had higher levels of StAR than the 2 h group but in MV ewes there was no differences between these groups for any of these parameters. These results demonstrate that the LH surge induced by the rams is a result of increased E2 secretion associated with increased levels of STAR in granulosa cells and that these responses varied among breeds. The results suggest that the variable occurrence of a LH surge and ovulation may be the result of variable ovarian responses to the 'ram effect' and insensitivity of the hypothalamus to the E2-positive feedback signal.