Invasion of the mandible in gingivobuccal complex cancers: Histopathological analysis of routes of tumour entry and correlation with preoperative assessment.

OBJECTIVES: To determine the most accurate imaging modality predicting mandibular invasion in gingivobuccal (GB) complex cancers. To determine patterns of invasion and routes of tumour entry into the mandible by detailed histopathologic analysis. MATERIAL AND METHODS: Prospective observational study of GB Complex cancers juxtaposed with the mandible clinically necessitating some form of mandibular resection. Orthopantomogram (OPG), Multi Detector Computed Tomography (MDCT), DENTA scan and Single Photon Emission Computed Tomography scan (SPECT) were performed after which the patient was subjected to surgery. Histopathological assessment was systematically performed with serial cuts of the mandibular segment. RESULTS: Of 70 patients, MDCT was the most accurate with area under curve (AUC) of 0.833. OPG, DENTA and SPECT had AUC of 0.714, 0.786 and 0.738 respectively. Mean calculated difference of involved height was -0.025 cm by MDCT (p value 0.87), -0.2 cm by OPG (p value 0.09) and 0.12 by DENTA scan (p value 0.41). Mean difference of involved length was -0.51 cm (p value 0.08) and -1.02 cm (p value 0.04) for MDCT and OPG respectively. 50% of tumour invasion was through the occlusal route while large tumours demonstrated multiple routes of entry. CONCLUSION: -Gingivobuccal complex cancers are homogenous with respect to mandibular invasion, preferred route of tumour entry being the occlusal surface. -Multidetector CT scan is fairly accurate in detecting mandibular involvement and predicting extent of involvement. -Oncological safety can be achieved by positioning the bone cuts corresponding to the adjacent soft tissue margins in segmental mandibulectomy.

Deep brain stimulation for treatment-resistant depression: an integrative review of preclinical and clinical findings and translational implications.

Although deep brain stimulation (DBS) is an established treatment choice for Parkinson's disease (PD), essential tremor and movement disorders, its effectiveness for the management of treatment-resistant depression (TRD) remains unclear. Herein, we conducted an integrative review on major neuroanatomical targets of DBS pursued for the treatment of intractable TRD. The aim of this review article is to provide a critical discussion of possible underlying mechanisms for DBS-generated antidepressant effects identified in preclinical studies and clinical trials, and to determine which brain target(s) elicited the most promising outcomes considering acute and maintenance treatment of TRD. Major electronic databases were searched to identify preclinical and clinical studies that have investigated the effects of DBS on depression-related outcomes. Overall, 92 references met inclusion criteria, and have evaluated six unique DBS targets namely the subcallosal cingulate gyrus (SCG), nucleus accumbens (NAc), ventral capsule/ventral striatum or anterior limb of internal capsule (ALIC), medial forebrain bundle (MFB), lateral habenula (LHb) and inferior thalamic peduncle for the treatment of unrelenting TRD. Electrical stimulation of these pertinent brain regions displayed differential effects on mood transition in patients with TRD. In addition, 47 unique references provided preclinical evidence for putative neurobiological mechanisms underlying antidepressant effects of DBS applied to the ventromedial prefrontal cortex, NAc, MFB, LHb and subthalamic nucleus. Preclinical studies suggest that stimulation parameters and neuroanatomical locations could influence DBS-related antidepressant effects, and also pointed that modulatory effects on monoamine neurotransmitters in target regions or interconnected brain networks following DBS could have a role in the antidepressant effects of DBS. Among several neuromodulatory targets that have been investigated, DBS in the neuroanatomical framework of the SCG, ALIC and MFB yielded more consistent antidepressant response rates in samples with TRD. Nevertheless, more well-designed randomized double-blind, controlled trials are warranted to further assess the efficacy, safety and tolerability of these more promising DBS targets for the management of TRD as therapeutic effects have been inconsistent across some controlled studies.

Barriers in conducting clinical trials in oncology in the developing world: A cross-sectional survey of oncologists.

BACKGROUND: Several obstacles impede oncologists from performing clinical trials in the developing world. This study aimed to identify these barriers in order of importance and suggest possible remedial measures. MATERIALS AND METHODS: Design - cross-sectional survey. Two part questionnaire capturing experience of oncologists in practice and conducting trials (Part 1) and perceived barriers pertaining to investigator (training, time), patient (strict follow-up protocol), infrastructure (funds) and professional environment (encouragement from seniors) (Part 2) were administered to oncologists in two different settings: (1) Online portal (Survey Monkey) (2) In person during a national conference (Best of American Society of Clinical Oncology). Responses were captured on a Likert scale (1-5). RESULTS: (436/3021) 14.04% responded. A total of 313 (71.8%) had experience in conducting trials, but these were mainly industry-sponsored or small nonpractice changing studies. Lack of patient follow-up was the most significant barrier (inter quartile range [IQR] 4-5) followed by inadequate training, time and funds (IQR 2-5) and lack of encouragement (IQR 2-4) in decreasing order of frequency. Lack of adequate training was a barrier across all specialties (113 [71.97%] radiation oncologists, 71 [60.68%] medical oncologists and 73 [71.56%] surgical oncologists). More than half of the respondents without experience in clinical trials worked in academic institutions (50.48%). They perceived time constraint as a barrier more than their counterparts into private practice (175/242 [72.31%] vs. 119/177 [66.47%] respectively). CONCLUSION: Inability to maintain patient follow-up, lack of protected time and funds, inadequate training were the most significant barriers. Most of these can be addressed.

Nasal extranodal natural killer T cell lymphoma: an atypical presentation.

OBJECTIVE: We report two cases of nasal natural killer T cell lymphoma which presented atypically following surgical intervention. CASE REPORT: Two patients with a previous history of endoscopic nasal surgery presented with progressive facial swelling and necrosis. The histology of several nasal biopsies was suggestive of acute, necrotising inflammation. Considering these patients' midline destruction of the nose and face, and their inconclusive biopsies, immunohistochemical studies were undertaken, enabling the diagnosis of peripheral natural killer T cell lymphoma. CONCLUSION: Natural killer T cell lymphoma of the sinonasal tract is an important differential diagnosis of destructive lesions of the nose and midface. The definitive diagnosis is often delayed. Hence, this tumour should be considered in patients with atypical presentations of acute inflammation following surgical intervention; such patients should be thoroughly investigated. Early immunohistochemical investigation is needed to enable prompt diagnosis in suspicious cases.

Utility of PET in unknown primary with cervical metastasis: a retrospective study.

BACKGROUND: FDG-PET is recommended as an investigation in unknown primary tumors, but its definitive role and cost effectiveness are yet to be established. AIMS: dditional value of FDG-PET over conventional imaging in unknown primary tumors with cervical metastasis. SETTING AND DESIGN: Retrospective study in a tertiary level oncology centre. MATERIALS AND METHODS: A total of 112 patients were divided into three groups; 53 with conventional modalities (either computed tomography or magnetic resonance imaging) (group I), 59 with FDG-PET (group II), and group III (subgroup of group II) with both (40 patients). STATISTICAL ANALYSIS: Sensitivity and specificity of both conventional modality and PET were calculated. Association between neck nodes and distant metastasis was analysed using multivariate logistic regression analysis. RESULTS: Sensitivity and specificity for conventional modalities was 92.3% and 50% and sensitivity and specificity of FDG-PET was 92.8% and 71.4%, respectively. FDG-PET detected metastasis in 52.54% of patients. Multivariate logistic regression analysis showed statistically significant association between distant metastasis and multiplicity of nodes (N2b, N2c) (P = 0.007). Among all patients with low neck nodes in group II, FDG-PET detected primaries in 12 patients, 9 of which were infraclavicular (75%). FDG-PET added information to conventional imaging in 32.5% of patients and influenced an overall change in management in 38.9% of patients. CONCLUSIONS: FDG-PET is a valuable tool influencing change of management in unknown primary with cervical metastasis. It is recommended especially in the presence of low or multiple neck nodes in view of high incidence of infraclavicular primary and distant metastasis, respectively.

Self-inflicted injury in a case of Hallervorden-Spatz disease.

Hallervorden-Spatz disease (HSD) is a rare neurodegenerative disorder characterized by abnormally high deposits of iron in the brain. This report describes a child with HSD who presented with self-inflicted ulceration of the lip and tongue, which was initiated during periods of intense oro-facial spasms. Other findings included dental caries and trauma to the primary incisors. Comprehensive dental care was carried out under general anaesthesia. The self-mutilation of the oro-facial mucosa was eliminated by placement of upper and lower soft resin bite guards.

Alterations of KCl- and ATP-induced increase in [Ca2+]i in cardiomyocytes from vitamin B6 deficient rats.

Although vitamin B6 deficiency is related to coronary heart disease, no information regarding changes in myocardium due to vitamin B6 deficiency is available in the literature. In view of the critical role played by Ca2+ in cellular function, we investigated alterations in [Ca2+]i induced by KCI or ATP in vitamin B6 deficient and age-matched control rats. [Ca2+]i was measured in isolated cardiomyocytes by using the Fura-2 fluorescence technique. The KC1-induced increase in [Ca2+]i was augmented in vitamin B6 deficient cardiomyocytes, whereas the ATP-induced increase in [Ca2+]i was attenuated. The specific ATP binding to sarcolemma from hearts of vitamin B6 deficient rats was decreased. A single injection of vitamin B6 (10 mg/kg) to vitamin B6 deficient animals completely reversed the KC1- or ATP-induced changes in [Ca2+]i in cardiomyocytes as well as ATP binding with sarcolemma. These results regarding altered regulation of [Ca2+]i in cardiomyocytes and sarcolemmal ATP receptors indicate myocardial abnormalities due to vitamin B6 deficiency.