Phuu Pwint Han

Dry mouth: a critical topic for older adult patients.

PURPOSE Diminished salivary flow, or dry mouth impacts the oral health of many older adults, dentate and edentulous. As a result typical oral conditions can prove more challenging to both the patients comfort and home care and the treatment selected by the clinician. This paper will review issues of dry mouth from a clinical and symptomatic perspective and will include the conditions causes, treatment and prevention. STUDY SELECTION We performed a review of PubMed using the words: older adults, dry mouth, xerostomia, radiation-induced xerostomia, and salivary gland hypofunction. We selected 90 articles with a clinical application perspective. RESULTS When it comes to treatment of dry mouth conditions, either objective or subjective, there are no easy answers as to the best course of action for a specific individual. While most of the cited studies have examined the most difficult cases of dry mouth (e.g., Sjögrens syndrome, and that seen during and post head and neck cancer treatments), there are many older adults who demonstrate dry mouth from the use of multiple medications. This paper presents a summary of the etiology, diagnosis, prevention, and pharmacological and non-pharmacological treatment of dry mouth (salivary hypofunction and xerostomia in older adults). CONCLUSIONS It is important to understand the causes of dry mouth and to educate our patients. Starting a prevention program as early as possible considering the most practical, cost effective and efficient treatments with the best risk-benefit ratio will help to diminish dry mouth symptoms and sequelae.

Differential expression of canonical and non-canonical Wnt ligands in ameloblastoma.

BACKGROUND Canonical and non-canonical Wnt signaling pathways modulate diverse cellular processes during embryogenesis and post-natally. Their deregulations have been implicated in cancer development and progression. Wnt signaling is essential for odontogenesis. The ameloblastoma is an odontogenic epithelial neoplasm of enamel organ origin. Altered expressions of Wnts-1, -2, -5a, and -10a are detected in this tumor. The activity of other Wnt members remains unclarified. MATERIALS AND METHODS Canonical (Wnts-1, -2, -3, -8a, -8b, -10a, and -10b), non-canonical (Wnts-4, -5a, -5b, -6, 7a, -7b, and -11), and indeterminate groups (Wnts-2b and -9b) were examined immunohistochemically in 72 cases of ameloblastoma (19 unicystic [UA], 35 solid/multicystic [SMA], eight desmoplastic [DA], and 10 recurrent [RA]). RESULTS Canonical Wnt proteins (except Wnt-10b) were heterogeneously expressed in ameloblastoma. Their distribution patterns were distinctive with some overlap. Protein localization was mainly membranous and/or cytoplasmic. Overexpression of Wnt-1 in most subsets (UA = 19/19; SMA = 35/35; DA = 5/8; RA = 7/10) (P < 0.05), Wnt-3 in granular cell variant (n = 3/3), and Wnt-8b in DA (n = 8/8) was key observations. Wnts-8a and -10a demonstrated enhanced expression in tumoral buddings and acanthomatous areas. Non-canonical and indeterminate Wnts were absent except for limited Wnt-7b immunoreactivity in UA (n = 1/19) and SMA (n = 1/35). Stromal components expressed variable Wnt positivity. CONCLUSION Differential expression of Wnt ligands in different ameloblastoma subtypes suggests that the canonical and non-canonical Wnt pathways are selectively activated or repressed depending on the tumor cell differentiation status. Canonical Wnt pathway is most likely the main transduction pathway while Wnt-1 might be the key signaling molecule involved in ameloblastoma tumorigenesis.

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature.

BackgroundPigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.MethodsA case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.ResultsThe pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.ConclusionThe present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.

Differential expression of Notch receptors and their ligands in desmoplastic ameloblastoma

BACKGROUND In mammals, the Notch gene family encodes four receptors (Notch1-4), and all of them are important for cell fate decisions. Notch signaling pathway plays an essential role in tooth development. The ameloblastoma, a benign odontogenic epithelial neoplasm, histologically recapitulates the enamel organ at bell stage. Notch has been detected in the plexiform and follicular ameloblastoma. Its activity in the desmoplastic ameloblastoma is unknown. METHOD Notch1-4 and their ligands (Jagged1, Jagged2 and Delta1) were examined immunohistochemically in 10 cases of desmoplastic ameloblastoma. RESULTS Ameloblastoma tumor epithelium demonstrated positive expression for Notch1 (n = 5/10), Notch3 (n = 8/10), Notch4 (n = 10/10), Jagged1 (n = 6/10) and Delta1 (n = 5/10), but no reactivity for Notch2 (n = 10/10) and Jagged2 (10/10). Expression patterns were distinct with some overlap. Positive activity was detected largely in the cell membrane and cytoplasm of peripheral and central neoplastic epithelial cells, and sometimes in the nucleus. Staining score was highest for Notch4. Stromal components namely endothelial cells and fibroblasts showed overexpression for Notch4 but were mildly or non-reactive for the other Notch members and their ligands. CONCLUSIONS These findings suggest that Notch receptors and their ligands may play differing roles during the development of the desmoplastic ameloblastoma with Notch4 probably playing a greater role in the acquisition of tissue-specific cellular characteristics in the desmoplastic ameloblastoma.

Heparanase and cyclooxygenase-2 gene and protein expressions during progression of oral epithelial dysplasia to carcinoma

Heparanase and cyclooxygenase-2 (COX-2) are 2 key enzymes that modulate diverse physiological processes during embryonic development and in adult life. Their deregulations have been implicated in the growth and progression of many cancer types. To date, comparatively little is known about the roles of these molecules during oral carcinogenesis. The aim of this study was to investigate the expression patterns of heparanase and COX-2 during progression of oral epithelial dysplasia (OED) to carcinoma. In situ hybridization and immunohistochemistry were performed on 5 cases of normal mucosa, 15 cases of OED, 5 cases of carcinoma in situ and/or microinvasive carcinoma, and 40 cases of oral squamous cell carcinoma (OSCC). Results demonstrated that heparanase and COX-2 messenger RNA and protein were absent in normal oral mucosa but were coexpressed in increasing intensity as OED progressed to OSCC. Concomitant heparanase- and COX-2-positive staining in the stromal cells suggests that OED/OSCC progression may be modulated by stromal-cancer cell interactions. Diffuse intense staining of poorly differentiated OSCC compared with staining localized to tumor nest periphery in well- and moderately differentiated OSCC suggests that heparanase and COX-2 overexpressions correlated with tumor grade. Strong expression of these enzymes in tumor cells at the advancing front suggests a role in local tumor spread. These results, taken together, suggest that heparanase and COX-2 might play complementary roles in the stepwise progression of OED to carcinoma.

Assessment of Student Interprofessional Education (IPE) Training for Team-Based Geriatric Home Care: Does IPE Training Change Students’ Knowledge and Attitudes?

Our study assesses changes in students’ knowledge and attitudes after participation in an interprofessional, team-based, geriatric home training program. Second-year medical, physician assistant, occupational therapy, social work, and physical therapy students; third-year pharmacy students; and fourth-year dental students were led by interprofessional faculty teams. Student participants were assessed before and after the curriculum using an interprofessional attitudes learning scale. Significant differences and positive data trends were noted at year-end. Our study suggests that early implementation, assessment, and standardization of years of student training is needed for optimal interprofessional geriatric learning. Additionally, alternative student assessment tools should be considered for future studies.

Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor

Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs) are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites). Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT), their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4) and three ligands (Jagged1, Jagged2 and Delta1) was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive.

Oral Corticosteroid Therapy for Preventing Postherpetic Neuralgia: A Systematic Review and Meta-analysis

The purpose of this systematic review was to examine the efficacy of oral corticosteroids for prevention of postherpetic neuralgia (PHN). Randomized controlled trials of patients suffering from herpes zoster comparing corticosteroids to control therapy (placebo or carbamazepine) or acyclovir were included. Three electronic databases (MEDLINE via PubMed, Web of Science and The Cochrane Library) were searched. Two authors assessed all eligible studies for risk of bias. Ninety-one references were found. After applying inclusion/exclusion criteria 7 studies were eligible for this systematic review. All 7 studies were at high risk of bias. Corticosteroids, rather than carbamazepine, protected the patients against PHN (Relative Risk [RR] = 0.543, 95% CI 0.087 to 3.376, p=0.512), however the results were not statistically significant. Additionally, a second meta-analysis showed that the use of corticosteroids does not prevent PHN compared to the use of a placebo (RR=0.990, 95% CI 0.092 to 10.663, p=0.994). Mild and reversible side effects were reported in patients taking only corticosteroids; two serious cardiovascular events were reported in the patients prescribed acyclovir and corticosteroid, though those two events were probably unrelated to the therapy. Individual studies reported quality of life improvements and reduction in the incidence and severity of pain with the addition of prednisone to acyclovir therapy; however the heterogeneity of the outcomes and comparison group prevented from performing meta-analyses on these outcomes. Due to the low number of studies, high risk of bias, heterogeneity of the outcomes and comparison groups, the evidence this systematic review provided was of low quality.