Overexpression of deubiquitinase (usp 36) in oral squamous cell carcinoma

Aim

Oral cancer is one of the top three types of cancer and is of significant public health importance in India. A common post-translational modification in cells is ubiquitination/deubiquitination, and its dysregulation is closely associated with the development of cancer. Studies on the role of ubiquitination in oral squamous cell carcinoma (OSCC) are lacking. Increased expression of usp36 has been observed in various types of cancer, and this study aimed to check the gene expression of usp36 in OSCC patients. In this study, we analyzed the expression of ubiquitin-specific proteases (USPs) 36 in OSCC.

Materials and Methods

A total of 15 OSCC patients at different stages of tumor differentiation and age- and sex-matched controls were recruited for the study. The patients were categorized based on their differentiation patterns. RNA was extracted from the tissues, and usp36 gene expression was checked in these samples using a quantitative real-time PCR technique.

Results

Our study showed increased expression of usp36 gene in OSCC patients. The usp36 mRNA was 231.8 ± 137.94 folds higher in well-differentiated squamous cell carcinoma patients, 38.18 ± 3.77 folds higher in moderately differentiated squamous cell carcinoma patients, and 25.49 ± 7.30 folds higher in poorly differentiated squamous cell carcinoma patients compared to control tissues.

Conclusion

Our study reports, for the first time, an increased gene expression of usp36 in OSCC tissues.

Regulation of human cortical interneuron development by the chromatin remodeling protein CHD2

Mutations in the chromodomain helicase DNA binding protein 2 (CHD2) gene are associated with neurodevelopmental disorders. However, mechanisms by which CHD2 regulates human brain development remain largely uncharacterized. Here, we used a human embryonic stem cell model of cortical interneuron (hcIN) development to elucidate its roles in this process. We identified genome-wide CHD2 binding profiles during hcIN differentiation, defining direct CHD2 targets related to neurogenesis in hcIN progenitors and to neuronal function in hcINs. CHD2 bound sites were frequently coenriched with histone H3 lysine 27 acetylation (H3K27ac) and associated with high gene expression, indicating roles for CHD2 in promoting gene expression during hcIN development. Binding sites for different classes of transcription factors were enriched at CHD2 bound regions during differentiation, suggesting transcription factors that may cooperatively regulate stage-specific gene expression with CHD2. We also demonstrated that CHD2 haploinsufficiency altered CHD2 and H3K27ac coenrichment on chromatin and expression of associated genes, decreasing acetylation and expression of cell cycle genes while increasing acetylation and expression of neuronal genes, to cause precocious differentiation. Together, these data describe CHD2 direct targets and mechanisms by which CHD2 prevents precocious hcIN differentiation, which are likely to be disrupted by pathogenic CHD2 mutation to cause neurodevelopmental disorders.

Anticancer Effects of Carica papaya L. and Benzyl Isothiocyanate on an Oral Squamous Cell Carcinoma Cell Line: An In Vitro Study

AIM

The study aimed to assess the anticancer effects of leaves of the male and female plant and seeds Carica papaya L. extract and the active compound benzyl isothiocyanate on oral squamous cell carcinoma (OSCC) cell line.

MATERIALS AND METHODS

Extracts of CO₂ strain C. papaya L. seeds were prepared using water, ethanol, and ethanol:water by maceration, and benzyl isothiocyanate was quantified. Alkaloid fractions of leaves of male and female plants of C. papaya L. were prepared and quantified. The anticancer effects of the test substances on the SCC-25 cell line were assessed by MTT, apoptosis assay, cell cycle analysis, and determination of mitochondrial membrane potential.

RESULTS

The ethanol:water extract of C. papaya L. (seeds) demonstrated the highest quantity of benzyl isothiocyanate. Male plant leaves demonstrated greater alkaloid content. The leaves of the male plant exhibited apoptosis induction and S-phase arrest, whereas the leaves of the female plant and seeds of C. papaya L. demonstrated G2M-phase arrest and apoptosis induction.

CONCLUSION

C. papaya L. and benzyl isothiocyanate demonstrated anticancer effects. There was a difference in the anticancer effects of leaves of male and female plants of C. papaya L.

CLINICAL SIGNIFICANCE

The anticancer effects of papaya leaves and seeds could be further explored to develop an adjunct therapy for oral cancer to improve prognosis and reduce recurrence rates.

Centromere Protein F (CENPF): A novel marker for salivary gland pathology

Background

Salivary gland tumours are relatively uncommon, and there exists considerable diagnostic difficulty. This is due to individual lesions having diverse histopathological features, presence of number of types and variants, and overlapping histological features in different tumour entities.

Aim

The current study aimed at assessing the expression of centromere protein F (CENPF) in benign and malignant salivary gland tumours and to evaluate the efficacy of CENPF as a proliferative marker to aid in the diagnosis of malignancy so that it will help in surgical pathology practice.

Materials and Methods

The study group involved 20 cases of benign salivary gland tumours, 20 cases of malignant salivary gland tumours, and 10 normal salivary gland tissues. All the cases were subjected to immunohistochemical analysis for CENPF expression and were assessed by two independent observers and further taken up for evaluation.

Statistical Analysis

The results were analysed statistically among different groups using analysis of variance (ANOVA) or Kruskal-Wallis test with Chi-squared test using IBM's Statistical Package for the Social Sciences (SPSS) version 17.0.

Results

CENPF expression in normal salivary gland was negative with gradual increase in expression from benign salivary gland tumours to malignant salivary gland tumours. CENPF expression was high in malignant salivary gland tumours.

Conclusion

Findings of the study suggest that CENPF can be regarded as a new cell proliferation marker for malignant salivary gland tumours.

Characterisation of Clinicopathological and Molecular Features of Leukoplakia not Associated with Tobacco- A Literature Review

Tobacco has been implicated as the strongest risk factor for oral malignancies and common potentially malignant disorders. Recent trend shows an increase in the prevalence of these lesions in non tobacco population. Studies suggest that clinicopathological features of leukoplakia differ in tobacco users and non users. Also, leukoplakia without known risk factors is at a higher risk of malignant transformation. Preliminary studies on carcinogenesis of non tobacco-associated head and neck cancers have identified a difference in the key genes involved in the pathogenesis of cancers associated with and without tobacco. While the genetic characterization of non tobacco oral cancers is gaining focus in the literature, there is a paucity of studies on non tobacco leukoplakia. An understanding of the non tobacco leukoplakia, possibly a distinct subgroup, may provide an insight into the inception of non tobacco oral cancers, leading to avenues for prevention, early diagnosis and precision medicine-led treatment approaches. Through this narrative review, authors revisit and summarize the existing literature on leukoplakia among non tobacco population.

Pleomorphic Sarcoma of the Oral Cavity: A Rare Case Entity

Pleomorphic sarcomas are extremely rare in the oral cavity, representing only 5% of all soft tissue sarcomas in the extremities of adults. They form a group of highly undifferentiated pleomorphic malignant tumors. A 36-year-old male reported to the OP with a chief complaint of a tooth ache in the right lower quadrant for the past 6 months. The patient gave a history of extraction of a mobile tooth in that region. A radiograph of the region was advised. An incisional biopsy was also done and sent for histopathological examination. The microscopy revealed the presence of spindle-shaped cells showing dysplastic features. A panel of immunohistochemical markers were performed to identify the tissue of origin of the lesion. The article details the clinical, radiographic, and microscopic features of a pleomorphic soft tissue lesion along with the array of immunohistochemical markers, leading to the final diagnosis of such enigmatic lesions.

In vitro anticancer activity of a pentacyclic triterpenoid via the mitochondrial pathway in bone-invasive oral squamous cell carcinoma

Context:

Oral cancer is the most dreadful cancer worldwide with a 5-year survival rate of approximately 50%. Anticancer therapies such as chemotherapy and radiotherapy result in severe side effects.

Aim:

We aimed to evaluate the in vitro anticancer activity of Asiatic acid (AA) on bone-invasive oral squamous cell carcinoma (BHY) cell line.

Settings and Design:

This was an in vitro laboratory setting.

Materials and Methods:

BHY cell lines were used for the experiment. Confocal microscopy was used to observe cellular alterations. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the IC50 concentration of AA and flow cytometry to analyze the percentage of cells in each phase of the cell cycle post treatment. Immunoblot assays and semiquantitative reverse transcriptase-polymerase chain reaction (rt-PCR) were used to study the expression level of genes involved.

Statistical Analysis Used:

Student's t-test and one-way analysis of variance were used for statistical analysis.

Results:

IC50 concentration of AA was 15.6 μM. On flow cytometry analysis, treatment with 15.6 μM and 31.25 μM of AA for 24 h increased the percentage of cells in the G2/M phase to 45.63% and 53.12%, respectively, compared to 9.62% in control group. Immunoblot analysis and semiquantitative rt-PCR demonstrated an upregulation of p53, cyclin-dependent kinase inhibitors (p21 and p27), caspase-3, caspase-9, cytochrome c and Bax in a time-dependent manner and downregulation of cyclins and anti-apoptotic protein Bcl-2 (**P < 0.05, ***P < 0.001 versus control) post AA treatment.

Conclusion:

AA induces apoptosis via the mitochondrial-dependent pathway and causes cell cycle arrest at the G2/M phase in BHY cell line.

In Vitro Anticancer Effects of Cinnamomum verum J. Presl, Cinnamaldehyde, 4 Hydroxycinnamic Acid and Eugenol on an Oral Squamous Cell Carcinoma Cell Line

AIM AND OBJECTIVE

The present study was conducted to assess the in vitro anticancer effects of Cinnamomum verum J. Presl extract and its active constituents, such as cinnamaldehyde, 4 hydroxycinnamic acid, and eugenol on oral squamous cell carcinoma cell line.

MATERIALS AND METHODS

Aqueous, ethanolic, and hydroalcoholic extracts of C. verum J. Presl (bark) were prepared using standardized protocols. Cinnamaldehyde, 4 hydroxycinnamic acid, and eugenol were quantified in the extracts. Total saponins, tannins, and polyphenols were quantified in the selected extracts. A commercially available SCC-25 cell line was cultured according to standard protocol. The anticancer effects of the extract, active compounds, and standard cisplatin were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity, acridine orange/ethidium bromide staining, DNA, fragmentation assay, cell cycle analysis by flow cytometry, and JC-1 staining (5,5',6,6'-tetrachloro1,1',3,3'tetraethylbenzimidazolylcarbocyanine iodide).

RESULTS

The hydroalcoholic extracts demonstrated a higher quantity of the active ingredients cinnamaldehyde, 4 hydroxycinnamic acid, and eugenol. The selected extract and active compounds demonstrated anticancer effects via apoptosis induction and S-phase arrest. Apoptosis induction was exerted by the extract via alteration in mitochondrial membrane potential.

CONCLUSION

Cinnamomum verum J. Presl and its active compounds exhibited in vitro anticancer effects on oral squamous cell carcinoma. Further studies in animal models have to be carried out to assess toxicity and in vivo effects.

CLINICAL SIGNIFICANCE

The anticancer properties of Cinnamomum verum J. Presl could be explored further for prevention and management of oral squamous cell carcinoma.

Prevalence of Common Clinically Manifested Developmental Anomalies of the Oral Cavity Among Adults - An Epidemiological Study in a South Indian Population

Introduction

Developmental anomalies are malformation which arises due to the disturbances during the development of the organs. Although there have been many studies that have described the prevalence of these anomalies in the oral cavity, none have specified the prevalence of clinically manifested anomalies and their distribution between gender.

Materials and methods

In this study, 500 patients aged 18 to 50 years were screened for clinically manifested developmental anomalies. These were then divided based on age, sex, and jaws, which were then analyzed using a chi-square test and tabulated.

Results

We detected anomalies in 12.2% of the study population. Supernumerary teeth were the most prevalent anomaly detected (4.25%). The frequency of developmental anomalies was higher in men (57.1%).

Conclusions

Supernumerary teeth were the most widely recognized anomaly. Other anomalies identified were related to the shape and size of teeth. These anomalies can lead to severe orofacial problems. Therefore, proper care of these anomalies should be taken.

Evaluation of Oral Health Status Using the Geriatric Oral Health Assessment Index Among the Geriatric Population in India: A Pilot Study

Introduction and aim Clinical indicators alone are insufficient for evaluating oral health. In addition to health and disease, oral health includes socio-dental indicators of physical, psychological, and social aspects of well-being. The adaptive capacity of an individual influences the perception of oral health-related quality of life (OHRQoL). Indices such as the Oral Health Impact Profile, Oral Impacts on Daily Performances, and the Geriatric Oral Health Assessment Index (GOHAI) have been used to measure OHRQoL. This study was designed to assess OHRQoL in older individuals using the GOHAI. Methods Subjects aged older than 65 years who visited our institution from January to March 2016 were included. Subjects with cognitive behavior disorders were excluded. Subjects were assigned into three groups based on age: 65-69 years, 70-74 years, and 75 years or older. The participants were asked 12 questions, and their responses were assessed by age group. Our Institutional Ethics Committee approved the study protocol. Results The 219 subjects recruited included 126 (57.5%) patients aged 65-69 years, 57 (26.0%) patients aged 70-74 years, and 36 (16.4%) patients aged 75 years or older. Several physical, physiological, and psychological aspects of the GOHAI differed significantly among these three groups, with overall OHRQoL decreasing with age. Conclusion Although oral healthcare problems were widespread in the geriatric population, they were not a primary concern. Attitudes toward dentistry require improvement. However, further studies in larger populations are required to assess geriatric oral health.

Oral medullary plasmacytoma: Rare case reports

Medullary plasmacytoma (MP) or osseous or solitary bone plasmacytoma is a specializing hematopathology lesion typically present with local symptoms, such as pain, paresthesia and pathologic bone fractures as a result of proliferation of plasma cells. The most often involved sites are active hematopoietic long bones and the vertebrae. The clinical course of disease is identical to spectrum of other plasma cell dyscrasias. The diagnostic criteria include punched-out radiolucencies, monoclonal plasma cells and M protein. This lesion should be considered for the differential diagnosis of bone tumors. It is highly radiosensitive although combination modalities of radiation, surgery and chemotherapy have been used in the treatment. The long-term follow-up is essential. We report two rare cases of oral MP with unusual clinical presentation.

Oral Lichen Planus in a 7-year-old Child: A Rare Case Report

Lichen planus is a chronic inflammatory mucocutaneous disease reported most frequently in adults and relatively rare in children with the prevalence being 0.03%. This article reports a case of oral lichen planus (OLP) in a 7-year-old girl without any attendant skin lesions, diagnostic workup, and management protocol for the same. This article also emphasizes the need to consider OLP as a differential diagnosis for white lesions of oral mucosa in children.

How to cite this article: Chinnasamy NK, Venugopal DC, Sankarapandian S, et al. Oral Lichen Planus in a 7-year-old Child: A Rare Case Report. Int J Clin Pediatr Dent 2020;13(1):91–93.

Characterization of oral fibroblasts: An in vitro model for oral fibrosis

Background:

Oral submucous fibrosis (OSMF) is a chronic debilitating condition of the oral mucosa that has been classified as a potentially malignant disorder with a malignant transformation rate of 2%–8%. Several in vitro and in vivo experiments have been performed to formulate a treatment modality for OSMF, yet no ideal in vitro primary oral fibroblast model has been developed.

Aim:

To establish an in vitro primary oral fibroblast model.

Setting and Design:

In vitro laboratory setting.

Materials and Methodology:

Primary cell culture protocol was performed after obtaining normal oral tissue. Karyotyping was performed to rule out chromosomal abnormalities. Immunofluorescence staining was carried with a panel of fibroblast-specific markers (vimentin, phalloidin, transforming growth factor-β receptor 1 [TGFβR1] and s100a4) and Masson trichrome staining (MTS) to demonstrate the presence of extracellular matrix (ECM) qualitatively.

Results:

A monolayer of oral fibroblasts was observed on the 9^th-day postseeding. No chromosomal abnormality was observed in the patient samples. Positive staining was observed with vimentin, phalloidin, TGFβR1 and s100a4, thereby confirming the cell type. MTS revealed fibroblasts with spindle morphology and scanty ECM.

Conclusion:

The present study lays down a protocol to design and characterize primary buccal fibroblast cell culture model that would aid researchers in performing in vitro preliminary experiments in areas concerning fibrosis.

A Rare Case of Intraoral Psoriasis

Psoriasis is a chronic inflammatory mucocutaneous disease predominantly affecting the skin. While oral manifestations are common in many papulosquamous conditions, the occurrence of oral lesions in psoriasis is relatively rare. This case report highlights the presence of oral lesions in cutaneous psoriasis and the need for early identification of such lesions for timely management and better symptomatic improvement.

Toxicity of xylene in occupationally exposed workers: A high-performance liquid chromatography analysis

Background:

Xylene is one of the most commonly used solvents in industrial and medical technologies. Several health hazards of xylene have been documented in literature. Workers in certain forces appear to have the greatest potential for exposure to high concentrations of xylene – histopathology technicians and painters are two such groups. This study was undertaken with the aim to determine the level of xylene exposure and the various systemic health effects among these groups.

Methodology:

The study was performed by analyzing the urine samples of the participants for methylhippuric acid, the established biomarker of xylene with the aid of high-performance liquid chromatography.

Results and Conclusion:

The work hours per week of the occupationally exposed participants were statistically analyzed with that of the excretory values of the metabolites of xylene, and the P value was found to be highly significant. Various side effects of xylene including respiratory, dermatological, neurological and gastrointestinal symptoms were observed among the study groups.

Immunohistochemical quantification of mast cells in inflamed and noninflamed pulp tissue

Background

Dental pulp inflammation is a very complex process due to its situation in low compliance (confined environment) surrounded by mineralized dentin. Mast cells are one of the mediators of inflammation. Immunohistochemical localization of mast cells by anti-tryptase antibodies in formalin-fixed paraffin-embedded sections has been shown to be highly specific. The aim of the present study is to quantify the mast cells in inflamed and noninflamed human pulp tissue using immunohistochemical analysis.

Materials and Methods

Immunohistochemical localization of mast cells by anti-tryptase antibody was done in 15 inflamed and 15 noninflamed formalin-fixed paraffin-embedded pulp tissue. A number of mast cell per five high-power fields were performed using three observers and the mean was calculated. Statistical analysis was performed using t-test.

Results

The results of the present study showed an increased number of mast cells in inflamed pulp in comparison with noninflamed pulp.

Conclusion

Thus, the presence of mast cells in pulp inflammation could be used as a diagnostic marker. It can also aid in the management of pulpitis as mast cell stabilizers and antihistaminic agents could be used to control pulpal pain and inflammation.

The effect of fluorosis on human teeth under light microscopy: A cross-sectional study

Background

Fluoride is needed for the normal development of bone and teeth; in high levels, it affects developing teeth and bone. Dental fluorosis (DF) is caused by ingestion of excess fluoride mainly through drinking water.

Aim

The present study aims to observe and understand the histological changes of fluorosed teeth under light microscope (LM).

Materials and Methods

Teeth which were indicated for extractions for orthodontic or periodontal problems were selected. Thirty extracted teeth were selected with varying degrees of DF based on modified Dean's fluorosis index. Ground sections of these teeth were prepared and the sections were studied under binocular LM. Photomicrographs were taken under high power objective using 15 megapixels Nikon camera.

Results and Conclusion

Qualitative histologic changes in different grades of fluorosed teeth were evaluated in enamel, dentin, cementum and between their junctions. Fluoride interacts with enamel in both mineral phases and organic macromolecules by strong ionic and hydrogen bonds resulting in incomplete crystal growth at prism peripheries. This presents as hypomineralization of enamel and dentin, increased interglobular dentin, increased secondary curvatures and changes in cementum such as diffuse cementodentinal junction and increased thickness of Tomes' granular layer. Changes in the structure of the teeth with Dean's index below 2 and teeth with Dean's index of 2 and above were compared using Chi-square test. P value was found to be highly significant being 0.00047. Many of the features of dental fluorosis seen in the present study under light microscope are comparable to those results studied under specialized microscopes.

Estimation of time since death based on light microscopic, electron microscopic, and electrolyte analysis in the gingival tissue

Background:

Estimation of time since death is an important parameter in forensic science. Although there are various methods available, precise estimation is still to be established.

Aim:

The present study aimed to evaluate the histological and ultrastructural changes in the gingival tissue along with the changes in electrolyte levels (sodium, potassium, calcium, and magnesium) among the three groups which included normal, 2, and 4 h since death.

Materials and Methods:

For light microscopic examination and electrolyte analysis, five normal gingival tissue samples were collected from patient following impaction procedure and five gingival tissue samples were obtained from postmortem specimen at 2 and 4 h since death. Each sample was divided into two parts. The first part was fixed in 10% formalin solution for the light microscopic analysis, and microscopic changes were observed between the groups. The second part was snap frozen at −80°C, until measurement of electrolyte using inductively coupled plasma-optical emission spectrometer, and the values were compared among the groups using Kruskal–Wallis test. For electron microscopic examination 2 and 4 h postmortem, gingival tissue samples were collected from the same individual and immediately fixed in 2.5% buffered glutaraldehyde, and the ultrastructural changes were compared with the normal gingival tissue.

Results:

The light microscopic changes were observed as early as 2 h since death, but there was no significant difference observed between 2 and 4 h postmortem samples whereas ultrastructurally significant difference in morphology was observed between 2 and 4 h postmortem gingival tissue. Our results can confirm histomorphological changes within 2 and 4 h since death.

Intraoral neurilemmoma of mental nerve mimicking as traumatic fibroma: An unusual presentation - A case report and literature review

Neurilemmoma, neurinoma or schwannoma is a benign tumor of neurogenic origin, arising from the myelin sheath of a neuron. Head and neck region accounts for 25%-48% of these tumors reported till date. On the contrary, intraoral sites form only 1% of the cases accounted. Although a few cases of intraoral neurilemoma of mental nerve has been reported in English literature, none has been reported to arise from the terminal fibers of the mental nerve. In this particular article, we present a case were the tumor was noted in the lower labial mucosa.

Immunohistochemical Localization of Epithelial Mesenchymal Transition Markers in Cyclosporine A Induced Gingival Overgrowth

INTRODUCTION

Cyclosporine, an immunosuppressive agent used in the management of renal transplant patients is known to produce Drug Induced Gingival Overgrowth (DIGO) as a side effect. Several mechanisms have been elucidated to understand the pathogenesis of DIGO. Recently, epithelial mesenchymal transition has been proposed as a mechanism underlying fibrosis of various organs.

AIM

The aim of the study was to investigate if Epithelial Mesenchymal Transition (EMT) operates in Cyclosporine induced gingival overgrowth.

MATERIALS AND METHODS

The study involved obtaining gingival tissue samples from healthy individuals (n=17) and subjects who exhibited cyclosporine induced gingival overgrowth (n=18). Presence and distribution of E-Cadherin, S100 A4 and alpha smooth muscle actin (α-SMA) was assessed using immunohistochemistry and cell types involved in their expression were determined. The number of α- SMA positive fibroblasts were counted in the samples.

RESULTS

In control group, there was no loss of E-Cadherin and a pronounced staining was seen in the all layers of the epithelium in all the samples analysed (100%). S100 A4 staining was noted in langerhans cells, fibroblasts, endothelial cells and endothelial lined blood capillaries in Connective Tissue (CT) of all the samples (100%) while α - SMA staining was seen only on the endothelial lined blood capillaries in all the samples (100%). However in DIGO, there was positive staining of E-Cadherin only in the basal and suprabasal layers of the epithelium in all the samples (100%). Moreover there was focal loss of E-Cadherin in the epithelium in eight out of 18 samples (44%). A break in the continuity of the basement membrane was noted in three out of 18 samples (16%) on H & E staining.

CONCLUSION

Based on the analysis of differential staining of the markers, it can be concluded that EMT could be one of the mechanistic pathways underlying the pathogenesis of DIGO.

Immunohistochemical Evaluation of Mast Cells in Leukoplakia and Oral Squamous Cell Carcinoma

INTRODUCTION

More than 90% of oral cancers are squamous cell carcinomas with oral leukoplakia being the most common potentially malignant disorder. Among the cell types in the stroma, mast cells play an important role in tumourigenesis through various mechanisms.

AIM

The present study was aimed at comparing the mast cell count among normal oral mucosa, leukoplakia and Oral squamous cell carcinoma (OSSC) and to evaluate the possible role of mast cells in carcinogenesis.

MATERIALS AND METHODS

Mast cell count was assessed immunohistochemically using anti-mast cell tryptase amongst 20 cases of leukoplakia and OSSC each and 10 normal gingival samples. Overall comparison was done using Kruskal Wallis test and intergroup comparison was done using Mann-Whitney U test.

RESULTS

The results of the present study showed an increase in mast cell count from normal oral mucosa (Mean: 7.73) to leukoplakia (Mean: 15.11) to squamous cell carcinoma (Mean: 22.73). Comparison of mean number of mast cells amongst three groups (p-value: 0.001) and intergroup comparisons showed statistical significance.

CONCLUSION

Mast cells favour malignant transformation and can be used as indicators of disease progression.

The prevalence of dental fluorosis and its associated factors in Salem district

Context:

There are various regions in India that have high levels of fluoride in drinking water sources. Many people residing in such places suffer from dental fluorosis (DF).

Aims:

To evaluate the prevalence of DF in children residing in Salem and also to find any correlation between DF and other related factors.

Materials and Methods:

One school from each block of Salem (total 21 blocks) was selected for the study. A single examiner had evaluated untreated caries, lesions, and DF (for permanent anterior teeth and molars) using the Dean's fluorosis index, in all children. Water fluoride level determination at each school was done using the Tamil Nadu Water Fluoridation and Drainage Board field kit. Other factors that may have contributed to DF were assessed using a questionnaire, which was provided to each student. The data obtained were statistically analyzed using the SPSS software version 11.5.

Statistical Analysis:

Chi-square test was used for statistical analysis.

Results:

DF was present in 56.9% of the children examined. It was mostly seen in 9 years old (72%) and male (59%) children. A positive correlation was found between the occurrence of DF and the duration of residence in a place with high water fluoride content, consumption of borewell water (64%), the parts per million of fluoride in drinking water, consumption of black tea (59%). However, no correlation was found between DF, dental caries, consumption of milk, or consumption of foods cooked in aluminum vessels.

Conclusion:

There was a correlation between DF and factors such as male gender, bore well water consumption, black tea consumption and the duration of residence in a place with high water fluoride content.

Gender determination: Role of lip prints, finger prints and mandibular canine index

Personal identification has a pivotal role in forensic investigations. Gender determination is an essential step in personal identification. Despite the advent of advanced techniques such as DNA fingerprinting, methods such as lip print and fingerprint analysis and mandibular canine index calculations are routinely used in gender determination, as they are simple and cost-effective. The present study investigated the hypothesis that lip print analysis is an effective tool in gender determination compared with fingerprint analysis and the mandibular canine index. The predominant patterns of lip prints and fingerprints were analyzed in males and females, and the efficacy of the mandibular canine index in gender determination was evaluated. The study group comprised 50 students, 25 males and 25 females who were 18-25 years of age. Lip prints and fingerprints were obtained and classified according to Tsuchihashi's classification and Kücken and Newell's classification, respectively. Mandibular impressions were made and the mandibular canine index was calculated. Type I and Type I' lip prints were predominant in females, and Type IV lip prints were predominant in males. The analysis of fingerprints revealed that the loop fingerprint pattern was predominant in both males and females. The mandibular canine index was not found to be significant in gender identification. The predominant patterns of lip prints were distinct for males and females; conversely, fingerprints were demonstrated to be similar in both genders. Therefore, lip prints hold an increased potential for gender determination, as compared with fingerprints, and the mandibular canine index is not a reliable indicator of gender.

Qualitative Analysis of Collagen Fibers in Oral Submucous Fibrosis using Picrosirius Red Stain and Polarising Microscope

INTRODUCTION

Oral Submucous Fibrosis (OSMF) is an oral potentially malignant condition caused predominantly by areca nut chewing. Early recognition with accurate staging of the disease and appropriate treatment planning is of utmost importance to prevent the malignant transformation and to improve the quality of life of the patient. Picrosirius red stain is specific for collagen and enhances its birefringence under polarising light producing different colours in different stages of the disease.

AIM

To compare the clinical and functional staging with histopathologic staging methods used to assess the severity of OSMF and to perform a qualitative analysis of the collagen fibres in various histopathologic stages of OSMF using picrosirius red stain and polarising microscope.

MATERIALS AND METHODS

It is a retrospective study done on archival samples. The study sample included a total of 30 cases which was divided into two groups. Group I comprised of 20 OSMF samples and Group II comprised of 10 normal tissue samples. Clinical, functional and histopathological staging was performed for all OSMF samples. Comparative analysis between clinical and functional stages with the histopathological staging was done using chi square test. Picrosirius red- stained sections of OSMF were analysed using polarising microscopy to evaluate the qualitative changes in the collagen fibers.

STATISTICAL ANALYSIS USED

Descriptive data which includes frequency and percentages were calculated for each group. Categorical data were analysed by chi-square test. A p-value of 0.05 or less was considered statistically significant.

RESULTS

Comparative analysis between clinical and functional stages with the histopathological staging revealed a significant correlation (p < 0.05) between the functional and histopathological stage. Enhanced birefringence of the collagen fibers due to picrosirius red stain yielded characteristic prominent polarising colours in different stages of OSMF.

CONCLUSION

Comparison of functional staging with histopathologic grading is more reliable in determining the severity of the disease than the clinical staging. Production of characteristic polarising colours by various stages of picrosirius red stained sections of OSMF substantiates the use of picrosirius red stain and polarising microscope as a tool in assessing the severity of this condition thereby aiding in better treatment planning.

Non Infiltrating Angiolipoma of the Palate in Geriatric Patient: A Case Report with Review of Literature

Angiolipoma is one of the rare variant of lipoma. This benign tumour consists of both fatty and vascular elements. It mostly occur in the trunk and extremities and is uncommon in head and neck region. Angiolipoma is classified as infiltrating and non- infiltrating types. Among all neoplasms of the oral cavity, lipomas account for 1 to 5% and the incidence of angiolipoma is 5 to 17% in it. There is no sex predilection for this tumour. It is classified as infiltrative and non-infiltrative type. Surgical excision is the method to be considered for both the types of angiolipoma, however the infiltrating type recurs post-surgery. We report a rare case report of 55-year-old female with non-infiltrating angiolipoma of the hard palate mimicking a mucocele treated by surgical excision with no signs of recurrence and good wound healing after three months follow up with minimal scar formation.

Antifibrotic effect of Centella asiatica Linn and asiatic acid on arecoline-induced fibrosis in human buccal fibroblasts

AIM

The aim of the present study was to investigate the in vitro antifibrogenic effects of Centella asiatica Linn (CA) and its bioactive triterpene aglycone asiatic acid (AA) on arecoline-induced fibrosis in primary human buccal fibroblasts (HBF).

METHODS

An ethanolic extract of CA was prepared, and AA was purchased commercially. High-performance thin-layer chromatography (HPTLC) was performed to quantify AA in the CA extract; colorimetric assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) was performed to determine an half-maximal inhibitory concentration. HBF were cultured and stimulated with arecoline. The inhibitory effects of CA and AA at different concentrations were assessed using gene-expression studies on fibrosis-related markers: transforming growth factor-β1, collagen 1 type 2, and collagen 3 type 1. The stimulatory effect of arecoline and the inhibitory effect of AA on fibroblast morphology and extracellular matrix were assessed qualitatively using Masson trichrome stain.

RESULTS

The HPTLC analysis determined 1.2% AA per 100 g of CA extract. Arecoline produced a concentration-dependent increase in the fibrotic markers, treatment with CA significantly downregulated fibrotic markers at higher concentrations, and AA downregulated at lower concentrations. Arecoline altered fibroblast morphology and stained strongly positive for collagen, and AA treatment regained fibroblast morphology with faint collagen staining.

CONCLUSION

CA and AA can be used as antifibrotic agents.

Expression of Osteopontin in Oral Squamous Cell Carcinoma and its Surgical Margins-An Immunohistochemical Study

INTRODUCTION

Despite the advances in the treatment modalities offered for oral squamous cell carcinoma. The recurrence rate of it still remains quite high. Early detection of recurrence will improve the outcome and the survival of the patient. Osteopontin, a transformation-related phosphorylated protein in epithelial cells has been closely related with tumourigenesis. This study was undertaken to explore the potential of OPN as a tumour marker of recurrence in OSCC.

AIM

To analyse the expression of Osteopontin (OPN) in Oral Squamous Cell Carcinoma (OSCC), patient matched tumour free surgical margins and normal oral mucosa and to correlate with local & loco regional recurrence.

MATERIALS AND METHODS

Twenty cases each of formalin fixed paraffin embedded blocks of histopathologically diagnosed cases of OSCC, patient matched tumour free surgical margins and normal oral mucosal tissues were obtained from the archives of the Oral Pathology & Microbiology Department, Faculty of Dental Sciences, SRU and Govt. Arignar Anna Memorial Cancer Hospital, Kancheepuram. Immunohistochemical analysis was performed with an antibody to Osteopontin protein. Patients with secondary tumours and those treated with chemotherapy and radiotherapy were excluded from this study.

RESULTS

The expression of OPN was elevated in 95% of tumours & 55% of histologically tumour free margin samples. There was negative OPN expression in normal mucosal samples. The result of the study was statistically analysed using Pearson chi-square test and was found to be statistically significant.

CONCLUSION

OPN can be used as a diagnostic marker in Oral Squamous Cell Carcinoma. In the tumour free surgical margins, elevated levels of OPN may predict a significantly increased risk of recurrence.

Invitro Anti-mycotic Activity of Hydro Alcoholic Extracts of Some Indian Medicinal Plants against Fluconazole Resistant Candida albicans

BACKGROUND

Candidiasis is one of the most common opportunistic infections caused by Candida albicans. Fluconazole is the drug of choice for prevention and management of this condition. However, the emergence of fluconazole resistant candidal strains has become a major concern. Many herbs like fenugreek, cinnamon, papaya, oregano, garlic are rich in phytochemical constituents known to express antimycotic activity. With the available information, the present research study was carried out to assess the invitro anti-mycotic activity of hydro alcoholic extracts of Trigonella foenum-graecum seeds, Cinnamomum verum bark and Carica papaya leaves and seeds against fluconazole resistant Candida albicans.

MATERIALS AND METHODS

Hydro alcoholic extracts of Trigonella foenum-graecum (seeds), Cinnamomum verum (bark), Carica papaya CO.2 strain (male and female leaves) and Carica papaya CO.2 strain (seeds) were prepared by maceration. The anti-mycotic activity of the prepared extracts against Candida albicans was assessed by agar well diffusion method. Three independent experiments were performed in triplicates and the mean and standard deviation were calculated. Minimum inhibitory concentration was determined.

RESULTS

The results of the present study revealed that all the extracts exhibited anti-mycotic activity in a dose dependent manner and minimum inhibitory concentration of all the extracts was found to be 15.62 μg/ml.

CONCLUSION

The results of the present study shed light on the fact that plant extracts could be used not only as an alternate drug for management of fluconazole resistant candidiasis but also explored further for oral cancer prevention as a therapeutic adjunct.

Odontogenic Myxoma of the Maxilla- A Rare case Report

Odontogenic myxoma (OM) is an uncommon, benign, locally invasive, non-metastasizing neoplasm arising from the odontogenic ectomesenchyme that usually occurs in the tooth bearing areas of the jaws. These lesions arouse special interest as they pose high diagnostic challenge. Here, we present a rare case of OM of the maxilla in an 18-year-old male. The clinical, radiographic and histopathological features of the lesion are discussed in this paper.

Langerhans Cell Expression in Oral Submucous Fibrosis: An Immunohistochemical Analysis

INTRODUCTION

Langerhans cells (LCs), are dendritic cells of the epithelium which play a role in an array of oral lesions from gingivitis to oral cancer. Oral Submucous Fibrosis (OSMF), a potentially malignant disorder (PMD), is an insidious chronic disease with juxta-epithelial inflammatory changes leading to fibrosis. Langerhans cells (LCs) may play a part in the ongoing inflammatory dysregulation of OSMF.

OBJECTIVE

The study was aimed at elucidating the distribution of LCs in varying grades of OSMF.

MATERIALS AND METHODS

A retrospective study using 39 cases of OSMF, graded using Haematoxylin and Eosin (H&E) stained section. Immunohistochemistry was performed using polyclonal anti- CD1a antibodies to identify LCs in 5 cases of normal tissue and 39 samples of OSMF. The distribution of LCs among the various grades and normal mucosa analysed using Mann-Whitney U test.

RESULTS

LC population in the OSMF was significantly higher when compared to the normal epithelium (p<0.001). Within the grades the advanced stage had more LCs than the other stages.

CONCLUSION

The increase in LCs might indicate the role of antigenic exposure in turn leading to cell mediated immunity in OSMF. Thus the fibrosis in OSMF might have a direct link to LCs.

Prevalence of Hepatitis B surface antigen in dental personnel

Context:

Hepatitis B, a viral disease affecting the liver has high morbidity and mortality. Hepatitis B surface antigen (HBsAg) in serum is used to detect presence of active disease and chronic carrier status. The disease is transmitted predominantly through blood and saliva, hence dental professionals are considered a high risk group.

Aim:

To detect presence of HBsAg in serum of dental professionals.

Subjects and Methods:

The study was conducted in two parts viz., one in the year 1991 on 100 dental professionals in Nagpur using reverse passive hemagglutination and the other in 2012 on 50 dental professionals in Chennai using immunochromatography.

Results:

Ten percent of dental professionals screened in 1991 and 2% of dental professionals screened in 2012 showed HBsAg positive status and were predominantly periodontists with a history of needle-stick injury.

Conclusion:

This study highlights the importance of Hepatitis B vaccination and periodic evaluation of antibody titer to prevent spread of the disease.

Expression of Mucin 4 in leukoplakia and oral squamous cell carcinoma: An immunohistochemical study

Background:

Mucins are large glycosylated proteins that act as a selective molecular barrier on the epithelial surface and engage themselves in morphogenetic signal transduction pathways. MUC4 (Mucin 4) is a transmembrane mucin, that protects and lubricates the mucous membranes of the human body and involves itself in various cellular functions like growth, differentiation and signaling. An aberrant expression of MUC4 has been demonstrated in various human cancers. A thorough literature survey shows very few studies about MUC4 expression in normal and cancerous oral mucosa.

Aim:

Our study aimed at investigating the expression pattern of MUC4 in normal oral mucosa, oral leukoplakia and oral squamous cell carcinoma (OSCC) in an attempt to analyze its role played in oral carcinogenesis.

Materials and Methods:

Formalin-fixed paraffin-embedded tissues of five cases of normal tissue, 15 cases of leukoplakia, 10 cases of well-differentiated squamous cell carcinoma and 10 cases of moderately differentiated squamous cell carcinoma were retrieved from the archives of the department and MUC4 antigen was immunohistochemically localized.

Statistical Analysis:

The result was subjected to statistical analysis using Pearson's Chi-square test and an intergroup analysis was performed using one-way analysis of (ANOVA).

Results:

A total of 46.7% of leukoplakia and 70% of OSCC were stained positive with MUC4 antigen. Maximum intensity of staining was noted in well-differentiated OSCC. A steady increase in MUC4 staining was noted from normal oral tissues to leukoplakia to OSCC.

Conclusion:

The findings of the study suggest that MUC 4 plays a vital role in the pathogenesis of OSCC and can be regarded as a useful marker for oral dysplasia and OSCC.

Immunolocalization of Ki-67 in different periodontal conditions

BACKGROUND

Ki-67 which is a non-histone nuclear protein which is expressed in proliferating cells, during all the active phases of the cell cycle. Increased Ki-67 expression has been seen in several inflammatory and malignant conditions like diabetes, rheumatoid arthritis, atherosclerosis, pancreatitis and squamous cell carcinoma.

AIM

The aim of the present study is to analyze the expression of Ki-67 in gingival tissues by immunohistochemistry in smokers and non-smokers with healthy gingiva and chronic periodontitis.

MATERIALS AND METHODS

Gingival biopsies (n = 32) were obtained from smokers who had clinically healthy gingiva (n = 8), smokers with periodontitis (n = 8), chronic periodontitis (n = 8) and healthy gingiva (n = 8). The expression of Ki-67 was evaluated immunohistochemically.

STATISTICAL ANALYSIS USED

Mean and standard deviation were estimated for the gingival tissue extract sample for each study group. Mean values were compared between different study groups by, one way ANOVA, post hoc analysis. In this study P < 0.05 was considered as the level of significance.

RESULTS

The mean number of Ki-67 positive cells/field was higher in the smokers with periodontitis group. When the mean Ki-67 positive cells were compared between different groups, statistical significant difference was observed between healthy and both the periodontitis groups (P = 0.000) and between smokers group (P = 0.001).

CONCLUSIONS

Ki-67 was maximally expressed in smoker with periodontitis followed by chronic periodontitis patients, healthy smokers and healthy control patients which shed light on the toxic effects of tobacco in dysregulating the cell cycle and cellular proliferation. The findings of this study also help us to understand the role of the cell cycle in resolution of periodontal inflammation which is a salient feature in the pathogenesis of chronic periodontitis.

Spindle cell carcinoma of the gingiva: A rare occurrence

Of the many neoplasms known, squamous cell carcinoma (SCC) is the most common to affect the oral cavity. Spindle cell carcinoma (SpCC) is considered a rare high malignant variant of SCC occurring predominantly in the upper aerodigestive tract. Soft-tissue spindle cell neoplasms are quite uncommon in the oral cavity reportedly accounting for lesser than 1% of all tumors in the oral region. Our case shows an unusual presentation of SpCC involving the mandibular gingiva in a 46-year-old smoker patient, which presented as a firm, erythematous swelling with surface necrosis. An incisional biopsy was performed for microscopic evaluation to confirm the clinical diagnosis and for treatment planning.

A comparison of oral and dental manifestations in diabetic and non-diabetic uremic patients receiving hemodialysis

BACKGROUND

The purpose of the study was to evaluate the oral and dental findings of uremic patients receiving hemodialysis and to compare the Results between diabetic and non-diabetic groups.

MATERIALS AND METHODS

A total of 100 patients undergoing hemodialysis were classified into diabetic and non-diabetic groups and examined for uremic oral manifestations, dental caries (DMFT), and periodontal status (CPITN). Mann-Whitney test of significance has been applied for analyzing DMFT score and chi-square test is used for analyzing CPITN score.

RESULTS

Of the study group, 46% were diabetic and only 11% of them did not have any oral manifestation. Oral manifestations observed were xerostomia and uremic odor, which contributed to 47 (23%) and 37 (17%), respectively. Hyperpigmentation was present in 26 (12%), macroglossia in 23 (11%), and uremic tongue coating in 24 (11%). Mucosal petechiae were seen in 17 patients contributing to 8% of total patients. Eleven patients had tongue pallor (5%), 9 patients had glossitis with depapillation (4%), and 7 patients had dysgeusia (3%). Angular cheilitis and gingival swelling were seen in 5 patients (2%).

CONCLUSION

The oral and dental manifestations were higher in prevalence in the study group. However, there was no significant difference between the two groups.

Lipoid proteinosis presenting with an unusual nonsense Q32X mutation in exon 2 of the extracellular matrix protein 1 gene

Lipoid proteinosis (LP) is a rare disorder characterized by extensive hyaline-like deposits on the skin, mucous membranes and various internal organs with varying clinical manifestations. The disorder has been recently shown to result from loss-of-function mutations in the extracellular matrix protein 1 gene (ECM1) on 1Q21. The two cases reported here had typical clinical and histological features consistent with LP. Direct sequencing of amplified DNA from the second patient showed a single nucleotide substitution (C > T) at nucleotide 94 within exon 2 of the ECM1 gene, nonsense mutation Q32X. This is the second case reported of LP with involvement of exon 2 of ECM1.

Venlafaxine induces P-glycoprotein in human Caco-2 cells

PURPOSE

The objective of this study was to evaluate the effect of a treatment with venlafaxine on the expression of multidrug resistance-associated protein (MRP) gene and multidrug resistance-related proteins (MDR) in human colon carcinoma cells (Caco-2) compared to a known P-glycoprotein (PGY1) inducer, rifampine.

METHODS

Caco-2 cells were treated with venlafaxine (50 microM, 100 microM, 250 microM, and 500 microM) and rifampin (25 microM and 50 microM) to test the possible induction of MRP and MDR expression. The treatment times used were 1.5, 3, 6, 12, 24, 48, and 72 h. RNA was isolated from the cells, and MDR and MRP genes were amplified using PCR.

RESULTS

Both venlafaxine and rifampine had the most dramatic effect at the 50 microM concentration. There was an increase in MDR and MRP expression in Caco-2 cells after the acute treatment (1.5, 3, and 6 h) with venlafaxine. These results were similar to those with rifampine.

CONCLUSIONS

PGY1 contributes to renal and biliary elimination of drugs by transporting the drug out of the cell and back into the intestinal lumen, where drugs may be further metabolized by intestinal enzymes such as Cytochrome P (CYP)-450 3A4. Its function is to limit the bioavailability of orally administered compounds. Due to the increase in MDR and MRP gene expression seen after the acute treatment with venlafaxine, there could be a potential drug-drug interaction with other medications that are metabolized via CYP450-3A4 when coadministered with venlafaxine.

Treatment-refractory depression: definitions and characteristics

Forty to 50% of depressed patients who are initially prescribed antidepressant medications or administered electroconvulsive therapy do not experience a timely remission. This group typifies treatment-refractory depression (TRD), defined as a failure to demonstrate an "adequate" response to an "adequate" treatment trial (i.e., sufficient intensity of treatment for sufficient duration). The approach to the patient with TRD must be methodical. The clinician should examine potential factors contributing to apparent non-response: trial adequacy, compliance, differential diagnosis, and treatable comorbid conditions. After addressing these variables, a patient who does not demonstrate a remission may be considered treatment resistant (relative or absolute). Although many of these patients will respond to a subsequent treatment regimen, there are no (or only nominally useful) predictors for the initial selection of that "subsequent" antidepressant treatment. Hence, the initial treatment is typically chosen on the basis of safety and convenience, not differential efficacy. The search for the clinical and biological correlates of long-term or acute outcome presents a major nosologic conundrum: Who will respond to treatment? Which treatment? In this manner, TRD challenges the prognostic utility of our current phenomenologic-based diagnostic system.

A randomized clinical trial of repetitive transcranial magnetic stimulation in the treatment of major depression

BACKGROUND

Multiple groups have reported on the use of repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant major depression. The purpose of this study is to assess the efficacy of rTMS in unmedicated, treatment-resistant patients who meet criteria for major depression.

METHODS

Depressed subjects, who had failed to respond to a median of four treatment trials, were assigned in a randomized double-blind manner to receive either active (n = 10; 20 2-sec trains of 20 Hz stimulation with 58-sec intervals; delivered at 80% motor threshold with the figure-of-eight coil positioned over the left dorsolateral prefrontal cortex) or sham (n = 10; similar conditions with the coil elevated and angled 45 degrees tangentially to the scalp) rTMS. These sequences were applied during 10 consecutive weekdays. Continuous electroencephalogram sampling and daily motor threshold determinations were also obtained.

RESULTS

The group mean 25-item Hamilton Depression Rating Scale (HDRS) score was 37.2 (+/- 2.0 SEM) points. Adjusted mean decreases in HDRS scores were 14.0 (+/- 3.7) and 0.2 (+/- 4.1) points for the active and control groups, respectively (p <.05). One of 10 subjects receiving active treatment demonstrated a robust response (i.e., HDRS decreased from 47 to 7 points); three other patients demonstrated 40-45% decreases in HDRS scores. No patients receiving sham treatment demonstrated partial or full responses.

CONCLUSIONS

A 2-week course of active rTMS resulted in statistically significant but clinically modest reductions of depressive symptoms, as compared to sham rTMS in a population characterized by treatment resistance.

Transient depressive relapse induced by catecholamine depletion: potential phenotypic vulnerability marker?

BACKGROUND

Although state-related alterations in catecholamine function have been well-described in depressed subjects, enduring abnormalities have been less reliably identified. In our study, medication-free subjects with fully remitted major depression underwent a paradigm of catecholamine depletion, via use of the tyrosine hydroxylase inhibitor alpha-methylparatyrosine.

METHOD

Subjects underwent 2 sets of testing conditions in a double-blind, random-ordered, crossover design, approximately 1 week apart. They underwent active catecholamine depletion (via oral administration of 5 g alpha-methylparatyrosine) or sedation-controlled, sham catecholamine depletion (via oral administration of 250 mg diphenhydramine hydrochloride), during a 2-day observation. Serial mood ratings and blood samples were obtained.

RESULTS

Fourteen subjects completed the active testing condition; 13 completed sham testing. Subjects experienced marked, transient increases in core depressive and anxiety symptoms, as demonstrated by a mean 21-point increase on Hamilton Depression Rating Scale scores. Furthermore, 10 (71%) of 14 subjects fulfilled relapse criteria during active testing, whereas 1 (8%) of 13 subjects did so during sham testing. The severity of the depressive reaction correlated with baseline plasma cortisol levels (r = 0.59; P =.04).

CONCLUSIONS

Euthymic, medication-free subjects with a history of major depression demonstrate significant depressive symptoms when undergoing testing with alpha-methylparatyrosine. This depressive reaction may represent a reliable marker for a history of depression. Further work is needed to clarify the significance of this finding.

Carbohydrate binding and resistance to proteolysis control insecticidal activity of Griffonia simplicifolia lectin II

Griffonia simplicifolia leaf lectin II (GSII), a plant defense protein against certain insects, consists of an N-acetylglucosamine (GlcNAc)-binding large subunit with a small subunit having sequence homology to class III chitinases. Much of the insecticidal activity of GSII is attributable to the large lectin subunit, because bacterially expressed recombinant large subunit (rGSII) inhibited growth and development of the cowpea bruchid, Callosobruchus maculatus (F). Site-specific mutations were introduced into rGSII to generate proteins with altered GlcNAc binding, and the different rGSII proteins were evaluated for insecticidal activity when added to the diet of the cowpea bruchid. At pH 5.5, close to the physiological pH of the cowpea bruchid midgut lumen, rGSII recombinant proteins were categorized as having high (rGSII, rGSII-Y134F, and rGSII-N196D mutant proteins), low (rGSII-N136D), or no (rGSII-D88N, rGSII-Y134G, rGSII-Y134D, and rGSII-N136Q) GlcNAc-binding activity. Insecticidal activity of the recombinant proteins correlated with their GlcNAc-binding activity. Furthermore, insecticidal activity correlated with the resistance to proteolytic degradation by cowpea bruchid midgut extracts and with GlcNAc-specific binding to the insect digestive tract. Together, these results establish that insecticidal activity of GSII is functionally linked to carbohydrate binding, presumably to the midgut epithelium or the peritrophic matrix, and to biochemical stability of the protein to digestive proteolysis.

Adhesion molecules (E-selectin and ICAM-1) in pulmonary allograft rejection

Vascular endothelial cells act as antigen-presenting cells in the lung allograft and stimulate alloreactive host lymphocytes. Activated lymphocytes and cytokines can induce expression of leukocyte-endothelial adhesion molecules that facilitate invasion of the allograft by circulating leukocytes. To define the role of endothelial HLA class II antigen and adhesion molecule expression in lung allograft rejection, we prospectively analyzed endothelial expression of HLA class II, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) antigens in 52 transbronchial biopsy specimens from 24 lung allograft recipients as compared to normal control subjects. Thirty-one of 52 specimens showed histologic rejection and 8 of 24 patients developed histologic obliterative bronchiolitis (OB) by the end of the study period. Increased expression of HLA class II antigen was seen in 32 of 52 (62%) lung allograft specimens, but increased expression did not correlate with acute rejection or OB. In contrast, E-selectin expression was seen in 30 of 52 (58%) biopsy specimens and was associated with acute rejection (p < 0.005) and with the development of OB (p < 0.05). Increased expression of ICAM-1 was seen in only 18 of 52 (35%) biopsy specimens and did not correlate with acute rejection or OB. These data suggest that E-selectin expression may be a tissue marker of acute and chronic lung rejection possibly by promoting leukocyte adhesion to the allograft endothelium. The high levels of endothelial HLA class II expression may reflect long-term antigenic stimulation of the allograft even in the absence of rejection.

A NaCl-regulated plant gene encoding a brain protein homology that activates ADP ribosyltransferase and inhibits protein kinase C

A cDNA clone pCZ1, with a 1.1 kb insert, was isolated from a NaCl-adapted tobacco cell cDNA library that encodes an apparently full-length 29 kDa protein (251 amino acids) with a calculated pI of 5.7. The encoded peptide had a high amino acid sequence identity with bovine 14-3-3 protein which was originally found as an abundant protein in the animal central nervous system. Recently, proteins with sequence identity to 14-3-3 protein have also been found in plants, insects and yeast, and appear to have diverse physiological functions. Similar to the bovine brain 14-3-3 protein, the recombinant pCZ1 protein stimulated ADP-ribosylation of protein substrate by ADP-ribosyltransferase from the plant and animal pathogenic bacterium Pseudomonas aeruginosa. This recombinant protein also inhibited protein kinase C activity in vitro. Southern blot analyses indicated that most likely five genes encoding 14-3-3-like proteins are present in tobacco. The pCZ1 cDNA insert hybridized to a single mRNA of 1.1 kb from cultured tobacco cells. The level of this mRNA transcript in tobacco cells was downregulated upon adaptation to NaCl but was unaffected by short-term treatment with NaCl, ABA or ethylene. In tobacco plants, expression of transcript that hybridized to pCZ1 was tissue specific, and was most abundant in roots and flower parts. Monoclonal antibody raised against GF14 protein, a maize protein with substantial sequence identity with 14-3-3 protein detected two bands on SDS-PAGE of total proteins from unadapted tobacco cells and only a single band from cells adapted to NaCl. The GF14 antibody was also used to illustrate that the G-box element of a salt-induced gene is associated with a 14-3-3-type protein.

Derived amino acid sequence and identification of active site residues of Escherichia coli beta-hydroxydecanoyl thioester dehydrase

The nucleotide sequence of the fabA gene encoding beta-hydroxydecanoyl thioester dehydrase, a key enzyme of the unsaturated fatty acid synthesis pathway of Escherichia coli, has been determined by the dideoxynucleotide sequencing technique. Most of the sequence was obtained by sequencing intragenic insertions of the transposon, Tn1000, isolated in vivo. A synthetic primer complementary to a portion of the inverted repeat sequences at the ends of the transposon was used to prime DNA synthesis into the flanking fabA sequences. The gene is composed of 516 nucleotides (171 amino acid residues) encoding a protein with a molecular weight of 18,800. Approximately half of the derived amino acid sequence was confirmed by automated Edman sequencing of peptides obtained by cyanogen bromide cleavage. The active site histidine residue (His-70) has been identified by analysis of the peptides labeled by reaction with 14C-labeled 3-decynoyl-N-acetylcysteamine, a specific mechanism-activated inhibitor. A cysteine residue (Cys-69) adjacent to the active site histidine may play the role in catalysis previously assigned to a tyrosine residue. We also report a simplified purification process for the dehydrase beginning with extracts of a brain which greatly overproduces the enzyme.