Coherence in the radial degree of freedom.

Coherence quantifies the statistical fluctuations in an optical field and has been extensively studied in the space, time, and polarization degrees of freedom. In the context of space, coherence theory has been formulated between two transverse positions as well as between two azimuthal positions, referred to as transverse spatial coherence and angular coherence, respectively. In this paper, we formulate the theory of coherence for optical fields in the radial degree of freedom and discuss the associated concepts of coherence radial width, radial quasi-homogeneity, and radial stationarity with some physically realizable examples of radially partially coherent fields. Furthermore, we propose an interferometric scheme for measuring radial coherence.

Low level of BRCA2 in peripheral blood lymphocytes is associated with an increased risk for head and neck squamous cell carcinoma (HNSCC) in a population of North-East India: a case-control study.

Background: We investigated the role of DNA repair proteins breast cancer susceptibility 2 (BRCA2), xeroderma pigmentosum group D (XPD) and apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) in determining the risk for head and neck squamous cell cancer (HNSCC) in a case-control study from North-East India. Methods: Expression of BRCA2, XPD and APE1 genes in the matched tumour, normal adjacent tissue (NAT) and blood of 12 HNSCC patients and blood of 8 age- and gender-matched controls was determined by quantitative real-time PCR. Results were validated by expression analysis of the corresponding proteins in the peripheral blood lymphocytes (PBLs) of 228 subjects (106 patients and 122 controls) by a slot-blot immunoassay. Findings: Expression of the BRCA2 and XPD genes in tumour tissue of HNSCC patients declined progressively as the cancer stage advanced, was reverse that of the NAT, but was mirrored by the expression in the blood. BRCA2 and XPD proteins were significantly (p < 0.0001) downregulated in the PBL of HNSCC patients to 71% and 77% the levels in controls, showing significant negative correlation with HNSCC stage (Spearman correlation coefficient (r s) of -0.9060, p < 0.0001 for BRCA2; r s of -0.8008, p < 0.01 for XPD). On the contrary, APE1 was significantly upregulated in PBL of HNSCC patients to 1.47 fold the level in controls, showing significant positive correlation with HNSCC stage (r s of 0.7023, p < 0.01). Classification and regression tree analyses predicted low levels of BRCA2 protein in PBL as the single most important risk factor for HNSCC, independent of gender. Smokers above 36 years of age with low level of BRCA2 appeared to exhibit a 1.78-fold increased risk for HNSCC (with a 1.78-fold increased risk for HNSCC (OR = 1.78, 95% confidence interval (CI) = 0.33-9.52) though this risk was not significant statistically. Similarly, low levels of BRCA2 appeared to indicate a moderate, but non-significant risk for HNSCC in non-smokers aged between 36 and 56 years (OR = 1.15, 95% CI = 0.21-6.37). Conclusions: Low level of BRCA2 protein in the peripheral blood indicates increased risk for HNSCC.

Comparative Study of Parathyroid Identification Techniques Using Zuckerkandl's Tubercle Versus Parathyroid Arterial Supply as Intra-Operative Markers.

Thyroid surgeons should be able to identify factors that prevent parathyroid damage. The aim of the study was (i) to compare the effectiveness of using Zuckerkandl's Tubercle (ZT) versus superior thyroid artery (STA) and inferior parathyroid artery (ITA) as markers for identification of superior and inferior parathyroid glands and (ii) to demonstrate a series of detailed, logical and orderly operative steps to identify ZT during thyroidectomy operation. This 1-year prospective observational study was carried out in the Department of Otolaryngology in a tertiary medical institute. Out of 36 cases of thyroidectomy, parathyroid identification in Group A was based on STA and ITA and in Group B was based on ZT. The surgical steps, parathyroid location, preservation and its anatomical relations were noted. The mean age in Group A and Group B was 38.8 years and 44.9 years respectively with 77.4 and 62.5% SPT identified above the intersection of RLN and ITA respectively. On left side 62.5% SPT were  located at 2 o'clock position and 50% at 10 o'clock location in right side. In Group A, 60.7% of IPT glands were related close to ITA while in Group B it was 44.4%. Group B reported a higher rate of successful identification and preservation (93.75%). ZT greatly improved the reliability for localising and preserving the parathyroid glands during thyroidectomy. SPT is usually found to lie cranial to ZT, above the intersection of RLN & ITA and behind RLN whereas IPT is variable and lies below the intersection.

Propagation-induced revival of entanglement in the angle-OAM bases.

Although the continuous-variable position-momentum entanglement of photon pairs produced by parametric down-conversion has applicability in several quantum information applications, it is not suitable for applications involving long-distance propagation. This is because entanglement in the position-momentum bases, as seen through Einstein-Podolsky-Rosen (EPR)-correlation measurements, decays very rapidly with photons propagating away from the source. In contrast, in this article, we show that in the continuous-variable bases of angle-orbital angular momentum (OAM), the entanglement, as seen through EPR-correlation measurements, exhibits a remarkably different behavior. As with the position-momentum bases, initially, the entanglement in the angle-OAM bases also decays with propagation, and after a few centimeters of propagation, there is no angle-OAM entanglement left. However, as the photons continue to travel further away from the source, the entanglement in the angle-OAM bases revives. We theoretically and experimentally demonstrate this behavior and show that angle-OAM entanglement revives even in the presence of strong turbulence.

Altered expression of junctional proteins as a potential biomarker in oral precancerous and cancerous patients.

Due to a lower survival rate in patients with advanced clinical stages of oral cancer, discovering a biomarker that could diagnose and predict disease progression is vital. Cell-cell junctional proteins play a crucial role in the maintenance of tissue architecture but are often deregulated in different cancer. The present study investigates the expression of cell-cell junctional proteins viz: e-cadherin (E-cad) and zonula occludens-1 (ZO-1) in oral precancerous (OED) and cancerous (OSCC) patients to monitor if they can serve as practicable molecular markers. The ultrastructural junctional complex was studied by transmission electron microscopy, and the expression of proteins was performed by immunohistochemistry. The relationship between the expression of protein and clinicopathological features of the patients was checked by Pearson's correlation test. Furthermore, the survival curve of the follow-up data was estimated by the Kaplan-Meier method. We observed a disrupted junctional complex and a significantly decreased immunoexpression of E-cad and ZO-1 in OED and OSCC when compared to the adjacent non-cancerous tissues. The expression of ZO-1 was associated with TNM stages, whereas E-cad was associated with histological grades as well as TNM stages. A positive correlation was observed between the expression of ZO-1 and E-cad proteins in OED and OSCC. Further, follow-up studies revealed that high ZO-1 and E-cad expressing patients survived longer than their low expressed counterparts. The present study shows disruption of junctional complex and alteration of junctional proteins expression that could draw the attention of health professionals to explore junctional proteins as a possible therapeutic target in oral cancer.

JunD accentuates arecoline-induced disruption of tight junctions and promotes epithelial-to-mesenchymal transition by association with NEAT1 lncRNA.

Head and neck cancers are highly prevalent in south-east Asia, primarily due to betel nut chewing. Arecoline, the primary alkaloid is highly carcinogenic; however its role in promoting tumorigenesis by disrupting junctional complexes and increasing risk of metastasis is not well delineated. Subsequently, the effects of low and high concentrations of arecoline on the stability of tight junctions and EMT induction were studied. A microarray analysis confirmed involvement of a MAPK component, JunD, in regulating tight junction-associated genes, specifically ZO-1. Results established that although arecoline-induced phosphorylation of JunD downregulated expression of ZO-1, JunD itself was modulated by the lncRNA-NEAT1 in presence of arecoline. Increased NEAT1 in tissues of HNSCC patients significantly correlated with poor disease prognosis. Here we show that NEAT1-JunD complex interacted with ZO-1 promoter in the nuclear compartment, downregulated expression of ZO-1 and destabilized tight junction assembly. Consequently, silencing NEAT1 in arecoline-exposed cells not only downregulated the expression of JunD and stabilized expression of ZO-1, but also reduced expression of the EMT markers, Slug and Snail, indicating its direct regulatory role in arecoline-mediated TJ disruption and disease progression.

Experimental demonstration of structural robustness of spatially partially coherent fields in turbulence.

Structured fields that are spatially completely coherent have been extensively studied in the context of long-distance optical communication, as the structure in the intensity profile of such fields is used for encoding information. This method of doing optical communication works very well in the absence of turbulence. However, in the presence of turbulence, the intensity structures of such fields start to degrade because of the complete spatial coherence of the field, and this structural degradation increases with the increase in turbulence strength. On the other hand, several theoretical studies have now shown that the structured fields that are spatially only partially coherent are less affected by turbulence. However, to the best of our knowledge, no such experimental demonstration has been reported until now. In this Letter, we experimentally demonstrate the structural robustness of partially coherent fields in the presence of turbulence, and we show that for a given turbulence strength, the structural robustness of a partially coherent field increases as the spatial coherence length of the field is decreased.

Joint detection of claudin-1 and junctional adhesion molecule-A as a therapeutic target in oral epithelial dysplasia and oral squamous cell carcinoma.

Abnormal expression of claudin-1 (CLDN-1) and junctional adhesion molecule-A (JAM-A) has been described in certain malignancies but their clinical relevance is poorly understood. The present study aims to elucidate the role of CLDN-1 and JAM-A in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Changes in the expression of these proteins were identified immunohistochemically on tissue sections from patients with OED and OSCC and compared with control. A correlation between the expression level of proteins and clinicopathological features was analyzed by Pearson's correlation χ2 test. The survival curve of the follow-up data was estimated by the Kaplan-Meier method followed by the log-rank test. CLDN-1 and JAM-A were highly expressed in OED and OSCC tissues when compared to control. Also, delocalization of CLDN-1 from the membrane to the cytoplasm to the nucleus was observed as the cell proceeds from normal to malignancy. Increased expression of CLDN-1 and JAM-A in both OED and OSCC were concomitant with histological grades. In addition, increased JAM-A was associated with perineural invasion of cancer cells. A positive correlation between the expression level of proteins was observed in OED (r = 0.733) and OSCC (r = 0.577). Kaplan-Meier analysis in patients with OSCC showed that the survival rate was lower in patients with high CLDN-1 and high JAM-A expression compared to low expressed patients. To conclude, the elevated level and delocalization of CLDN-1 and JAM-A suggest their use as tumor markers. A positive correlation between CLDN-1 and JAM-A suggests joint detection of these proteins as a future diagnostic tool in oral precancerous and cancerous conditions.

Correlation of serum lactate dehydrogenase and alkaline phosphatase in different histological grades of head and neck squamous cell carcinoma and premalignant lesions.

CONTEXT: Head neck cancer (HNCA) in North-East India accounts for 54.48% cancers at all sites, one of the highest in the country. Increased serum lactate dehydrogenase (LDH) activity is considered as a marker of cellular necrosis while serum alkaline phosphatase (ALP) is recognized as an important marker of induction of tumor cell differentiation. Considering the importance and need of biomarker in HNCA and there being no previous study on tumor markers from this highly prevalent region, we intended to examine the role of serum LDH and ALP in head and neck squamous cell carcinoma (HNSCC) and epithelial precursor lesions (EPLs) and also to find their correlation with the different histological grades of tumor. MATERIALS AND METHODS: This is a prospective observational study on patients with HNSCC and precancerous lesions attending Department of ENT of a Teaching Hospital. Serum LDH and ALP was measured in HNSCC, EPL and control groups and the results were statistically analyzed and compared using analysis of variance, Pearson correlation coefficient, and sensitivity-specificity analysis. RESULTS: Serum LDH was found to be a significant marker of HNSCC. Total serum LDH level was high in both premalignant and HNSCC cases. There was a significant correlation between serum LDH and grades of HNSCC showing highest levels of expression in moderately differentiated SCC. Elevated serum LDH was also seen in erythroleukoplakia, leukoplakia, and verrucous lesion, but serum ALP levels were not significant. CONCLUSIONS: This is the first study from this highly prevalent region of HNCA showing that serum LDH could be regarded as a biomarker for malignant and premalignant conditions of the head and neck.

Clinical-radiological correlation and role of computed tomography staging in chronic rhinosinusitis.

OBJECTIVE: This study aimed to determine whether there is a clinical-radiological correlation in chronic rhinosinusitis (CRS), to compare operative findings with those of computed tomography (CT) imaging, and to determine the importance of a CT score and staging in management of CRS. METHODS: This study is a prospective study. Adult patients meeting diagnostic criteria for CRS were prospectively studied using the Lund-Mackay (LM) symptom score and sinus CT scan. The symptom scores were correlated with CT stage according to the Kennedy and LM staging systems. Similarly, the intraoperative findings were correlated with the Kennedy staging system. The spectrum of anatomical variations in our study population was compared with the findings of symptomatic patients in various other studies. RESULTS: Thirty-four adult patients (13 females, 21 males, mean age: 33 years) met our inclusion criteria. Most of the patients presented with nasal obstruction, headache, and hyposmia. Nasal polyposis was the most common finding in CT scans, with many cases of retention cysts reported as polyps. In total, 50% of patients had a deviated septum. Concha bullosa was the most common finding among the various anatomical variations encroaching the ostiomeatal complex (OMC). In 60%-70% of cases, the CT scan grading correlated with operative findings. LM symptoms scores showed a poor correlation with both LM CT scores and the Kennedy stage. CONCLUSIONS: Although CT provided detailed information on sinus involvement; its relation with symptom severity is not reliable. The Kennedy CT staging system correlated better with CRS symptoms. Thus, use of Kennedy staging could be useful to endoscopic sinus surgeons as it provides an insight into the pathophysiology, can guide treatment, and facilitate prognosis prediction in CRS.

BRCA1 and MDM2 as independent blood-based biomarkers of head and neck cancer.

We investigated the role of BRCA1, MDM2, and p53 in the pathogenesis of head and neck cancer (HNC) and evaluated their potential utility as blood-based predictive biomarkers of HNC. Immunostaining of tissue biopsies and whole blood lymphocytes (WBL) of 36 HNC patients were evaluated by immunohistochemistry (IHC) and immunocytochemistry (ICC), respectively. The staining intensities of BRCA1 and MDM2 in matched tissue and blood samples were significantly associated with cancer stage. Furthermore, the cellular levels of BRCA1, MDM2, and p53 were evaluated in peripheral blood lymphocytes (PBL) of 134 HNC patients and 126 controls by slot blotting. Expression levels of all three proteins in PBL of HNC patients varied significantly with respect to those of controls (p < 0.0001) with BRCA1 downregulated to 75 % of control and MDM2 and p53 upregulated to 1.7- and 1.4-fold the control level, respectively. Moreover, positive correlation was observed between expression levels of BRCA1, MDM2, and p53 in matched tissue biopsies-WBL (r s = 0.840, 0.754, and 0.806, respectively), tissue biopsies-PBL (r s = 0.745, 0.736, and 0.776, respectively), and PBL-WBL (r s = 0.709, 0.758, and 0.740, respectively), validating the hypothesis that these proteins may serve as blood-based biomarkers of HNC. Bias-corrected and accelerated (BCa) bootstrap cross-validation estimation of receiver operating characteristics (ROC) analysis established BRCA1 (AUC = 0.726, sensitivity = 89 %, NPV = 82 %) and MDM2 (AUC = 0.827, sensitivity = 85 %, NPV = 81 %) as predictive biomarkers for HNC. In conclusion, this study suggests that BRCA1 and MDM2 play a crucial role in the pathogenesis of HNC and could be used independently as predictive biomarkers for HNC.

Nutritional Assessment of Patients with Head and Neck Cancer in North-East India and Dietary Intervention.

INTRODUCTION: Head and neck cancer (HNCA) patients have poor nutritional status which clearly bears a negative prognosis in cancer. There is no study and consensus on nutritional assessment tools and diet structure for such patients. This study intends to determine the prevalence of malnutrition and formulate a diet chart keeping in view the general food habit and economic condition of HNCA patients of North East (NE) region. AIM: To find out an affordable dietary intervention for HNCA patients based on dietary principles. To assess the role of nutritional assessment tools in these group of patients. MATERIALS AND METHODS: This is a 1-year prospective interventional study on HNCA patients attending the Dept of ENT of a teaching hospital. The outcome of the nutritional intervention using a specific diet were assessed using clinical, laboratory and anthropomorphic assessment tools and indices like Prognostic Nutritional Index (PNI) and Nutritional Assessment Index (NAI). RESULTS: The study diet provided appropriate amounts of nutrients to HNCA patients as evident from improvements in anthropomorphic parameters and nutritional indices. Clinically, Hemoglobin percentage (Hb%), Body Mass Index (BMI), Mid Arm Circumference (MAC) and triceps skin fold thickness (TST) were found to be reliable malnutrition markers. CONCLUSION: Nutritional Assessment Index has been found to be the best index to evaluate malnutrition. The daily requirement of nutrients for HNCA patients can be satisfactorily met by adopting specific diet chart presented in our study. As no structured diet plan are available in literature, our diet chart can act as a template diet appropriate for HNCA patients of this region.

MDM2 and TP53 Polymorphisms as Predictive Markers for Head and Neck Cancer in Northeast Indian Population: Effect of Gene-Gene and Gene-Environment Interactions.

BACKGROUND: Polymorphisms in the MDM2 309 (T>G) and TP53 72 (G>C) genes are reported to increase the susceptibility to head and neck cancer (HNC) in various populations. The risk for HNC is also strongly associated with etiologic habits such as smoking, alcohol consumption and/or chewing of betel quid (BQ). In a case-control study, we investigated the significance of the above polymorphisms alone, and upon interaction with one another as well as with various etiologic habits in determining HNC risk in a Northeast Indian population. MATERIALS AND METHODS: Genotyping at 309 MDM2 and 72 TP53 in 122 HNC patients and 86 cancer free healthy controls was performed by PCR using allele specific primers, and the results were confirmed by DNA sequencing. RESULTS: Individuals with the GG mutant allele of MDM2 showed a higher risk for HNC in comparison to those with the TT wild type allele (OR=1.9, 95%CI: 1.1-3.3) (p=0.022). The risk was further increased in females by ~4-fold (OR=4.6, 95% CI: 1.1-19.4) (P=0.04). TP53 polymorphism did not contribute to HNC risk alone; however, interaction between the TP53 GC and MDM2 GG genotypes resulted in significant risk (OR=4.9, 95% CI: 0.2-105.1) (p=0.04). Smokers, BQ- chewers and alcohol consumers showed statistically significant and dose- dependent increase in HNC risk, irrespective of the MDM2 genotype. CONCLUSIONS: MDM2 genotype could serve as an important predictive biomarker for HNC risk in the population of Northeast India.

XPD, APE1, and MUTYH polymorphisms increase head and neck cancer risk: effect of gene-gene and gene-environment interactions.

In the present study, we investigated the effect of the DNA repair gene polymorphisms XPD Asp312Asn (G>A), APE1 Asp148Glu (T>G), and MUTYH Tyr165Cys (G>A) on the risk for head and neck cancer (HNC) in association with tobacco use in a population of Northeast India. The study subjects comprised of 80 HNC patients and 92 healthy controls. Genotyping was performed using amplification refractory mutation system-PCR (ARMS-PCR) for XPD Asp312Asn (G>A) and PCR using confronting two-pair primers (PCR-CTPP) for APE1 Asp148Glu (T>G) and MUTYH Tyr165Cys (G>A). The XPD Asp/Asn genotype increased the risk for HNC by 2-fold (odds ratio, OR = 2.072; 95 % CI, 1.025-4.190; p < 0.05). Interaction between APE1 Asp/Asp and XPD Asp/Asn as well as MUTYH Tyr/Tyr and XPD Asp/Asn genotypes further increased the risk by 2.9 (OR = 2.97; 95 % CI, 1.16-7.61; p < 0.05) and 2.3 (OR = 2.37; 95 % CI, 1.11-5.10; p < 0.05) folds, respectively. The risk was further increased in heavy smokers with the XPD Asp/Asn genotype and heavy tobacco chewers with XPD Asn/Asn genotype by 7.7-fold (OR = 7.749; 95 % CI, 2.53-23.70; p < 0.05) and 10-fold (OR = 10; 95 % CI, 1.26-79.13; p < 0.05), respectively. We thus conclude that the XPD Asp312Asn and APE1 Asp148Glu polymorphisms increase the risk for HNC in association with smoking and/or tobacco chewing in the population under study.

Frontoethmoidal encephalomeningocoele with colpocephaly: case report and clinical review.

Frontoethmoidal encephalomeningocoele is a rare congenital disease in which an intracranial mass protrudes through a midline defect from the anterior cranial fossa into the facial skeleton. The condition affects patients in South East Asian countries, such as Thailand, Burma, Malaysia and Indonesia, with frequency of 1 in 5000. The pathogenesis of encephalocoeles may be regarded as a 'late' neurulation defect during the fourth gestational week. We present a case of frontoethmoidal encephalomeningocoele with corpus callosal agenesis and colpocephaly; this may well be the first report of this combination. The patient had a bulging mass in the middle frontonasal area, with broadening of the nasal bridge and hypertelorism. Computed tomography scans delineated the skull defect and associated brain anomalies. A one-stage, combined transfacial-transcranial approach, correctional procedure was performed. We present here a discussion of the findings, with special reference to the condition's pathogenesis, morphological classification and evolving surgical treatments. Early diagnosis and referral, involving multidisciplinary teamwork, are of paramount importance because of the distorting influence of the extruding mass on facial growth.

Prevalence of head and neck cancers in the north east-An institutional study.

In India, head and neck cancers (HNCA) account for 30-40% cancers at all sites. In North-eastern India, where this study was conducted, tobacco related oral cancer is very common which may be due to widespread habit of chewing tobacco. The lack of any study in this regard and alarmingly high prevalence of cancers of head and neck in this part of India has prompted us to take up this study. A retrospective study on prevalence of cancer in various head and neck regions like oropharynx, oral cavity, pharynx, larynx, oesophagus and nasal cavity was conducted in Department of Otolaryngology, Silchar Medical College and Hospital from 1993 to 2004.The prevalence is found to be significantly high at 54.48%, affecting males more than females in the age group of 40-69 years. HNCA of oropharynx and oral cavity constituted a major burden of total body cancer.This study hopes to quantify and analyze the spectrum of HNCA and should help as a starting point for a much needed population based study in this region. A comprehensive effort is needed to identify the cause of such high prevalence, generate awareness and treatment options suited to meet this challenge.

Deviated nasal septum in the newborn-A 1-year study.

A prospective study of 200 newborn babies was done at Silchar Medical College Hospital from September 2002 to August 2003. The babies aged from 0 to 4 days were taken in the study. They were examined for any signs of nasal obstruction, birth trauma, prolonged labour, mode of delivery (forceps/vaginal/caeserian section), intrauterine malposition, postmaturity, birthweight, cephalopelvic disproportion, parity of the mother and gestational period. The diagnosis was done by clinical examination, rhinometry, struts and applying cotton wool. In the study, the incidence was found to be 14.5% (29 cases). It was found that high-birth weight babies, delivered by vaginal route (55%), to a primi mother are more likely to have DNS after birth. Moreover, intrauterine malposition particularly breech (45%) and prolonged labour seemed to play a role in newborn DNS. More importantly, the present study seems to indicate that since a good percentage of such deformity originate at the gestational period, early detection at the neonatal age is vital to manage and also to prevent complications and sequelae in adult life. Therefore, a policy of routine screening in view of early correction is advocated to decrease the morbidity associated with nasal septal deviation in newborns.