Outcome of sentinel lymph node biopsy in early-stage squamous cell carcinoma of the oral cavity with methylene blue dye alone: a prospective validation study

Our aim was to evaluate the feasibility and role of sentinel lymph node (SLN) biopsy using methylene blue dye alone in identifying occult lymph node metastases in early oral cancer (cT1, T2, and cN0). The study was done from 2013–15 in 94 patients in a large cancer centre. The blue nodes were dissected and sent for frozen section, routine histopathological examination, and immunohistochemical testing for cytokeratin, and was followed by elective neck dissection in all patients. The identification rate was 93.61%. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for frozen section and haematoxylin and eosin (H&E) staining were 84.6%, 100%, 100%, 93.9% and 95.5%, respectively. Occult lymph node metastasis was seen in 27.6% cases. Biopsy of SLN with blue dye alone might be used successfully with good sensitivity and negative predictive value in countries with limited resources in the developing world. Immunohistochemistry contributes to it by increasing the sensitivity and NPV, and thereby improves the diagnostic value.     

P-glycoprotein (MDR 1 gene product) in cells of the immune system: Its possible physiologic role and alteration in aging and human immunodeficiency virus-1 (HIV-1) infection

P-glycoprotein, a 170-kd glycoprotein encoded by theMDR 1 gene, is a member of a highly conserved superfamily of ATP-binding cassette (ABC) transport proteins. It shares extensive homology with numerous bacterial and eukaryotic ABC transport proteins. P-glycoprotein acts as an energy-dependent efflux pump that appears to transport structurally diverse agents ranging from ions to peptides. P-glycoprotein (P-gP) has been implicated as playing a role in multidrug (MDR) resistance in cancer, chloroquine-resistantPlasmodium falciparum infection, and possibly human immunodeficiency virus-1 (HIV-1) resistance to nucleoside compounds. A number of normal tissues in humans and rodents have been shown to express high levels of P-gp. The expression and function of P-gp in cells of the immune system have been explored in the past 2 years. This review presents a state of the art regarding the expression, regulation, and function of Pgp in cells of the immune system. In addition, its alteration in aging and HIV-1 infection is reviewed. A possible physiologic role of P-gp in cytokine secretion, antigen processing/presentation, and effector functions is also discussed.     

Enzyme linked immunosorbent assay for the diagnosis of human neurocysticercosis: a preliminary report

The diagnostic efficacy of an indirect enzyme linked immunosorbent assay (ELISA) was evaluated in cases of neurocystecercosis. Subjects studied included 22 cases and 30 controls (comprising 12 cases of surgically confirmed hydatid disease, 5 cases each of tuberculoma and P.U.O. and 8 cases of pyogenic meningitis). A standard ELISA was performed using porcine cysticerci as antigen. Sensitivity and specificity of the test were calculated for serum and cerebrospinal fluid separately. The test was found to give a sensitivity of 68 and 33 per cent for serum and C.S.F. respectively. The specificity for confirmed case was found to be cent per cent for both with the criteria of reporting used. The sensitivity of the test may be increased by using purified specific antigen and/or sandwich ELISA instead of indirect ELISA technique.     

Long-term reproducibility of respiratory gas exchange measurements during exercise in patients with stable cardiac failure

Present-day technology has greatly facilitated the monitoring of respiratory gas exchange in the clinical exercise laboratory. Despite the growing use of these techniques to assess the severity and progression of disease or therapeutic response in patients with heart failure, the long-term reproducibility of oxygen uptake (VO2), carbon dioxide production, minute ventilation, heart rate (HR), and blood pressure at rest and during incremental exercise in such patients, to our knowledge, has not been evaluated. Therefore, the purpose of this study was to quantify the reproducibility of these variables along with exercise duration, maximum VO2 (VO2max) and anaerobic threshold in a group of 16 patients (61 +/- 7 years, 14 male) with chronic, stable cardiac failure of varying severity and etiology who had five or more incremental treadmill exercise tests over a period of time that ranged from 3 to 22 months. For each variable, reproducibility was represented by the coefficient of variation (CVAR). Except for exercise duration, CVAR was not a function of the severity of heart failure and, for all variables, patient-to-patient variation in CVAR was approximately 9 percent. The maximum CVAR for HR, systolic blood pressure, VO2, and VO2max was generally below 10.5 percent and for exercise duration and anaerobic threshold it was less than 12.5 percent. Based on this retrospective analysis, it is concluded that reproducible respiratory gas exchange and HR exercise responses are obtainable over extended periods of time in patients with stable, chronic cardiac failure. Exercise duration, however, is less reproducible in patients with moderate to severe failure.     

Can diffusion tensor metrics help in preoperative grading of diffusely infiltrating astrocytomas? A retrospective study of 36 cases

Introduction  

Diffusion weighted imaging and diffusion tensor imaging (DTI) give information about the amount and directionality of water diffusion occurring in a given tissue. Here we study the role of diffusion tensor metrics including fractional anisotropy (FA) and spherical anisotropy (CS) in preoperative grading of diffusely infiltrating astrocytomas.     

<Superscript>18</Superscript>F-FDG and <Superscript>18</Superscript>F-FLT PET/CT imaging in the characterization of mediastinal lymph nodes

Purpose

There is currently no single modality for accurate characterization of enlarged mediastinal lymph nodes into benign or malignant. Recently ¹⁸F-fluorothymidine (FLT) has been used as a proliferation marker. In this prospective study, we examined the role of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and ¹⁸F-FLT PET/CT in categorizing mediastinal lymph nodes as benign or malignant.

Materials and methods

A total of 70 consecutive patients with mediastinal lymphadenopathy detected on computed tomography (CT) or chest radiograph underwent whole body ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT (within 1 week of each other). Lymph nodal tracer uptake was determined by calculation of standardized uptake value (SUV) with both the tracers. Results of PET/CT were compared with histopathology of the lymph nodes.

Results

Histopathology results showed thirty-seven patients with sarcoidosis, seven patients with tuberculosis, nine patients with non-small cell lung cancer, five patients with Hodgkin’s lymphoma and twelve patients with non-Hodgkin’s lymphoma. The mean FDG SUV_max of sarcoidosis, tuberculosis, Hodgkin’s and non-Hodgkin’s lymphoma was 12.7, 13.4, 8.2, and 8.8, respectively, and the mean FLT SUV_max was 6.0, 5.4, 4.4, and 3.8, respectively. It was not possible to characterize mediastinal lymphadenopathy as benign or malignant solely based on FDG SUV_max values (p > 0.05) or FLT SUV_max values (p > 0.05). There was no significant difference in FDG uptake (p > 0.9) or FLT uptake (p > 0.9) between sarcoidosis and tuberculosis. In lung cancer patients, the FDG SUV_max and FLT SUV_max of those lymph nodes with tumor infiltration on biopsy was 6.7 and 3.9, respectively, and those without nodal infiltration was 6.4 and 3.7, respectively, and both the tracers were not able to characterize the nodal status as malignant or benign (p > 0.05).

Conclusion

Though ¹⁸F-FLT PET/CT and ¹⁸F-FDG PET/CT reflect different aspects of biology, i.e., proliferation and metabolism, respectively, neither tracer could provide satisfactory categorization of benign and malignant lymph nodes. The results of this study clearly suggest that differentiation of mediastinal nodes into benign and malignant solely based on SUV_max values cannot be relied upon, especially in settings where tuberculosis and sarcoidosis are common.

     

Comparison of intracerebral delivery of carboplatin and photon irradiation with an optimized regimen for boron neutron capture therapy of the F98 rat glioma

In this report we have summarized our studies to optimize the delivery of boronophenylalanine (BPA) and sodium borocaptate (BSH) for boron neutron capture therapy (BNCT) of F98 glioma bearing rats. These results have been compared to a chemoradiotherapeutic approach using the same tumor model. The best survival data from our BNCT studies were obtained using a combination of BPA and sodium borocaptate BSH administered via the internal carotid artery, in combination with blood–brain barrier disruption (BBB-D). This treatment resulted in a mean survival time (MST) of 140 d with a 25% cure rate. The other approach combined intracerebral administration of carboplatin by either convection enhanced delivery (CED) or Alzet pump infusion, followed by external beam photon irradiation. This resulted in MSTs of 83 d and 112 d, respectively, with a cure rate of 40% for the latter. However, a significant problem that must be solved for both BNCT and this new chemoradiotherapeutic approach is how to improve drug uptake and microdistribution within the tumor.     

CT patterns of nodal disease in pediatric chest tuberculosis

AIM:To highlight various patterns of nodal involvement and post treatment changes in pediatric chest tuberculosis based on contrast enhanced computed tomography(CECT) scans of chest.METHODS:This was a retrospective study consisting of 91 patients aged less than 17 years,who attended Paediatrics OPD of All India Institute of Medical Sciences with clinically diagnosed tuberculosis or with chest radiographs suggestive of chest tuberculosis.These patients had an initial chest radiograph as well as CECT of the chest and follow up imaging after 6 mo,and in some cases 9 mo,of completion of anti-tubercular treatment(ATT).CECT of these patients was reviewed for the location and extent of nodal involvement along with determination of site,size,enhancement pattern and calcification.RESULTS:Enlargement of mediastinal or hilar lymph nodes was found in 88/91 patients(96.7%),with the most common locations being paratracheal(84.1%),and subcarinal(76.1%).The most common pattern of enhancement was found to be inhomogenous.The nodes were conglomerate in 56.8% and discrete in 43.2%.In addition,perinodal fat was obscured in 84.1% of patients.In the post-treatment scan,there was 87.4% reduction in the size of the nodes.All nodes post-treatment were discrete and homogenous with perinodal fat present.Calcification was found both pre-and post-treatment,but there was an increase in incidence after treatment(41.7%).There was hence a reduction in size,change in enhancement pattern,and appearance of perinodal fat with treatment.CONCLUSION:Tubercular nodes have varied appearance and enhancement pattern.Conglomeration and obscuration of perinodal fat suggest activity.In residual nodes decision to continue ATT requires clinical correlation.