Salivary Gland Stem Cells and Tissue Regeneration: An Update on Possible Therapeutic Application

The aim of this review is to combine literature and experimental data concerning the impact of salivary gland (SG) stem cells (SCs) and their therapeutic prospects in tissue regeneration. So far, SCs were isolated from human and rodent major and minor SGs that enabled their regeneration. Several scaffolds were also combined with "SCs" and different "proteins" to achieve guided differentiation, although none have been proven as ideal. A new aspect of SC therapy aims to establish a vice versa relationship between SG and other ecto- or endodermal organs such as the pancreas, liver, kidneys, and thyroid. SC therapy could be a cheap and simple, non-traumatic, and individualized therapy for medically challenging cases like xerostomia and major organ failures. Functional improvement has been achieved in these organs, but till date, the whole organ in vivo regeneration was not achieved. Concerns about malignant formations and possible failures are yet to be resolved. In this review article, we highlight the basic embryology of SGs, existence of SG SCs with a detailed exploration of various cellular markers, scaffolds for tissue engineering, and, in the later part, cover potential therapeutic applications with a special focus on the pancreas and liver. Keywords: Salivary gland stem cells, Stem cell therapy, Tissue regeneration.

Expression of ras p21 and myc p64 oncoproteins in imprint smears of lung-cancer

The expression of ras p21 and myc p64 was examined in imprint smears of 52 patients with lung cancer and 44 patients with benign disorders, by immunochemistry. Imprint smears were-taken from fresh bronchial biopsies during diagnostic bronchoscopy. Both ras and mye oncoproteins were found to give negative reaction in all benign examined cases; Of the 52 malignant bronchial tissue imprint smears, 28 (54%) and 30 (58%) were positively stained with ms p21 and mye p64 antibodies respectively. Positive staining of ras p21 was demonstrated in 54.5% of squamous cell carcinoma, in 80% of adenocarcinoma and in 0% of small cell carcinoma imprint smears. Positive staining of myc p64 was demonstrated in 45.4% of squamous cell carcinoma, in 50% of adeno-carcinoma and in 100% of small cell carcinoma. The results of this study indicate that both ras and myc oncoproteins detected in bronchial biopsies, may play a crucial role in lung cancer.

Expression of IGF-I, TGF-alpha and p53 protein in imprint smears of bronchial biopsy specimens of lung cancer

The expression of insulin-like growth factor-I (IGF-I), transforming growth factor-alpha (TGF-alpha) and p53 protein was examined in bronchial biopsy imprint smears of patients with primary lung cancer and benign lung disorders, by immunohistochemistry. Of the 44 malignant imprint smears, 26 (59%) were positively stained for IGF-I, 18 (41%) for TGF-alpha and 29 (66%) for p53 protein. In contrast, of the 36 benign imprint smears none was positively stained for IGF-I (p<0.001), whereas 7 were positively stained for TGF-alpha (p>0.05) and 3 for p53 protein (p<0.001). There was no correlation between the expression of the examined markers and the histological type of lung cancer. The most sensitive indicator of malignancy was p53 overexpression (65.9%), the most specific was IGF-I (100%) whereas both revealed 77.5% accuracy. The combination of IGF-I and p53 revealed 75% sensitivity, 91.6% specificity and 82.5% accuracy. When one marker was positive the relative possibility of lung cancer was 67.1%. This possibility increased to 77.7% when two markers were positive and to 100% when three markers were positive. These results suggest that the evaluation of IGF-I and p53 in imprint smears could be of value in diagnosis of lung cancer.

Preclinical evaluation of amiodarone for the treatment of murine leukemia P388. In vivo and in vitro investigation

PURPOSE

The purpose of the present study was the investigation of antileukemic effect of amiodarone in leukemia P388 BDF1 bearing mice and its genotoxic and cytostatic effect in cultured normal human lymphocytes.

METHODS

Leukemia P388 was used in this study. BDF1 mice were used for chemotherapy evaluation in vivo. The antitumor activity was assessed by the oncostatic parameter T/C, representing the increase of life span of drug-treated animals vs. controls. Lymphocyte cultures were used to study the genotoxic and cytostatic effect in vitro, expressed by enhanced sister chromatid exchange (SCE) and reduced proliferation rate indices (PRIS).

RESULTS

Amiodarone was found to exert antileukemic potency against leukemia P388 bearing mice at all three different treatment schedules used, yielding T/C values of 155%, 163% with one cure and 230%. In the in vitro cytogenic experiments, significant increase of SCE rates by amiodarone was observed at 0.2 μM, while at the same concentration significant suppression of PRIS was achieved.

CONCLUSION

According to the National Cancer Institute (NCI), a compound is characterized as potential chemotherapeutic deserving further evaluation if it produces T/C values≥125%. On the other hand the SCE assay has predictive value as a clinical assay for drugs exhibiting a strong correlation between cell killing and induction of SCEs. Further studies are warranted to clarify the structure-activity relationship of amiodarone.

Endosonographic features of unicentric Castleman Disease

BACKGROUND

Castleman disease (CD) is a rare lymphoproliferative disorder most frequently occurring in the mediastinum. Peripancreatic forms are less frequent. Few cases of endoscopic ultrasonography-fine-needle aspiration (EUS-FNA) findings of this lesion have been reported, where no real-time tissue elastography (RTTE) has been described in the literature to our knowledge.

METHODS

We describe the endosonographic, elastographic, cytologic and immunocytochemistry findings in two cases of unicentric CD of the hyaline vascular variant.

RESULTS

Two females, aged 41 and 34 year were referred to our hospital for further EUS evaluation of a peripancreatic mass found incidentally on computed tomography. EUS examination revealed around, well-demarcated, uniformly hypoechoic mass measuring 52 and 23 mm respectively, with smaller adjacent hypoechoic lymph nodes. Doppler examination revealed intense peripheral vascularity, together with prominent penetrating feeding vessels entering a distinct hilum. RTTE revealed a relatively homogenous soft elastographic pattern. EUS-FNA provided smears with clusters of lymphocytes in a hemorrhagic background. Cell block preparation showed immature lymphocytes surrounding lymphocyte-poor centers with vascular proliferation. Immunohistochemical staining of the cell block sections showed CD45-leukocyte common antigen, CD20, CD23, CD79a, Bcl-2 and CD5 positivity in small lymphocytes. Cytology was suggestive of non-Hodgkin's lymphoma. Surgical excision was performed in both cases and histopathology was consistent with CD of the hyaline vascular type.

CONCLUSION

The echo features of a solitary hypoechoic homogenous well-demarcated mass with prominent vasculature and increased elasticity should raise the possibility of unicentric CD. EUS-FNA usually cannot make a definitive distinction from certain kinds of lymphoma.

The impact of radiographic examination timing and gag reflex on dental fear and cooperation in children: a comparative clinical study

PURPOSE

Identifying factors that disrupt cooperation during radiographic examination, such as dental fear and the gag reflex, is crucial for achieving optimal radiographic outcomes. The aim of the present study is to evaluate the levels of dental fear and cooperation amongst children aged 4-9 years undergoing intraoral radiographic examination at different stages of dental treatment. It also investigates the impact of the gag reflex on children's behaviour during intraoral radiographic examination.

METHODS

A total of 89 children with no prior dental experience were randomly divided into two groups (G1, G2). Children in G1 underwent radiographic examination during their first dental visit, whilst children in G2 underwent the same after the completion of dental prophylaxis at their second visit. Variables assessed included dental fear, gagging and behaviour during radiographic examination. Multivariate logistic and linear regression analysis were performed to assess the variables that have an impact on behaviour during radiographic examination and on dental fear, respectively.

RESULTS

Children in G2 were more likely to exhibit better behaviour during radiographic examination than G1children (OR: 4.709, p value = 0.036). In addition, G1 children demonstrated a greater increase of CFSS-DS score compared to G2 children (β = - 0.698, p value = 0.001) after the second appointment. Gagging during radiographic examination was significantly associated with lower Frankl score during the examination (p = 0.015).

CONCLUSION

Gradual exposure to radiographic examination may significantly enhance children's cooperation during the procedure and confine the progression of dental fear. In contrast, the presence of a gag reflex can compromise patient's cooperation during intraoral radiographic assessment.

The value of expression of EGFR, telomerase and topoisomerase IIα in malignant effusion smears before and after chemotherapy

PURPOSE

To evaluate the significance of expression of epidermal growth factor receptor (EGFR), telomerase and topoisomerase IIα (topo IIα) in cells of malignant effusions of patients under chemotherapy.

METHODS

We studied the expression of EGFR, telomerase and topo IIα in malignant effusion smears of 95 cancer patients before and after chemotherapy. Immunocytochemical and in situ hybridization techniques were applied.

RESULTS

Positive expression before chemotherapy of telomerase, topo IIα and EGFR was found in 64.2, 63.2 and 69.5% of the cases, respectively; the expression of these markers following chemotherapy was 43.6, 28.2 and 53.8%, respectively. The stronger prognostic factor affecting survival before chemotherapy was telomerase (p=0.0002), whereas after chemotherapy the strongest factor was EGFR (p<0.0001). A positivity for all three markers following chemotherapy was associated with shorter survival compared with positivity for only 1 or 2 markers (p<0.0001) or with a negative expression.

CONCLUSION

It seems that expression of EGFR, telomerase and topo IIα in malignant effusion smears is adversely affecting prognosis and survival.

The effect of needle demonstration during local anaesthesia on the child's dental fear, pain perception and behaviour: a randomised controlled trial

PURPOSE

The aim of the current study is to evaluate the possible effects of the sight of the dental needle as part of the "Tell-Show-Do" technique on children's fear, pain perception and behaviour, during anaesthesia administration.

METHODS

A total of 60 4-8 year-old children with no previous experience of local anaesthesia (LA), in need of restorations under LA, were randomly assigned in G1:Hiding-Needle-Technique (HN-T) and G2:Showing-Needle-Technique (SN-T). Children's Fear Survey Schedule-Dental Subscale, Wong-Baker Faces Pain Rating Scale (WBFPS), Frankl Behaviour Scale and heart rate (HR) were used.

RESULTS

Objective evaluation of fear, using heart rate, was significantly higher for G1:(HN-T) compared to G2:(SN-T) during demonstration at the first appointment (p value = 0.013) and needle insertion at both appointments (p value = 0.08, p value = 0.04 respectively). No statistically significant relationship was found between the two groups regarding WBFPS questionnaire and Frankl Behaviour Rating Scale.

CONCLUSIONS

The sight of the needle was not found to affect reported fear. Statistical increases in HR were observed in children, independent of age and gender. Changes in HR indicated that not viewing the needle elicited greater fear than seeing it, for children aged 4 to 8 years when "Tell-Show-Do" is used. Pain perception and behaviour were not affected.