Label-free histological imaging of tissues using Brillouin light scattering contrast

Brillouin light scattering offers a unique label-free approach to measure biomechanical properties non-invasively. While this technique is used in biomechanical analysis of cells and tissues, its potential for visualizing structural features of tissues based on the biomechanical contrast has not been much exploited. Here, we present high-resolution Brillouin microscopy images of four basic tissue types: muscular, connective, epithelial, and nervous tissues. The Brillouin contrast distinguishes between muscle fiber cells and endomysium in skeletal muscle and reveals chondrocytes along with spatially varying stiffness of the extracellular matrix in articular cartilage. The hydration-sensitive contrast can visualize the stratum corneum, epidermis, and dermis in the skin epithelium. In brain tissues, the Brillouin images show the mechanical heterogeneity across the cortex and deeper regions. This work demonstrates the versatility of using the Brillouin shift as histological contrast for examining intact tissue substructures via longitudinal modulus without the need for laborious tissue processing steps.     

Mohs micrographic surgery for basal cell carcinomas: appropriateness of ‘Rotterdam’ criteria and predictive factors for three or more stages

Background In the Netherlands basal cell carcinomas (BCC) are eligible for Mohs microscopic surgery (MMS) if certain criteria are fulfilled. Objective To study the MMS indication criteria practised at the department of dermatology of the Erasmus University Medical Center, Rotterdam and to identify predictive factors for extensive subclinical tumour spread among BCCs eligible for MMS. Methods Pre‐operative patient and tumour characteristics were derived retrospectively between January 2nd 2006 and December 28th 2009 from 1174 patient records, accounting for 1464 BCCs. Multivariate logistic regression models were used to calculate crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) for one vs. two or more stages and for narrow (≤2 stages) vs. extensive subclinical spread (≥3 stages). Results H‐zone location [adjusted OR 1.51 (95% CI 1.16–1.96)], recurrent tumour [adjusted OR 1.50 (95% CI 1.11–2.02)], aggressive subtype [adjusted OR 1.25 (95% CI 1.01–1.56)] and tumour size ≥11 mm [adjusted OR 1.53 (95% CI 1.20–1.96)] were significantly associated with two or more stages. Predictive factors for extensive subclinical spread were recurrent tumour [adjusted OR 2.26 (95% CI 1.61–3.17)], tumour size ≥21 mm [adjusted OR 1.69 (95% CI 1.13–2.51)] and location in the H‐zone [adjusted OR 1.68 (95% CI 1.15–2.46)]. Conclusion ‘Rotterdam’ indication criteria used for MMS are appropriate. Predictors for extensive subclinical spread are important for patients’ and surgeons’ expectations prior to the operation about time span, defect size, reconstruction and possible associated morbidity.     

Endoluminal Nd:YAG laser application in ex vivo biliary porcine tissue

Adequate biliary drainage with endoscopic or percutaneous placement of self-expandable metal stents represents the goal of palliation in patients with inoperable malignant obstruction of the biliary tree. As an adjunct to stenting, various tissue ablation treatments have been proposed with conflicting results. The aim of this study was to test the effect on biliary tissue of a new ablation technique based on Nd:YAG laser light delivery. The study was conducted on ex vivo specimens of 18 healthy farm pigs, using cystic ducts that are the simplest biliary structures to isolate and cannulate ex vivo. A 22G cannula was positioned into the cystic duct and a quartz optical fibre, with a prototypal cooling system, was inserted into the cannula. Nd:YAG laser output powers of 10, 12, and 15 W were tested, with a total delivered energy of 1000 J in continuous mode in each case. After laser treatment, histological analysis was performed. At macroscopical examination, no lesions of the external wall of the cystic ducts were detected. At histopathological examination, a coagulative necrosis involving the entire mucosa up to the muscolaris propria without significant changes of periductal tissues was observed in all specimens. This study shows the possibility of using Nd:YAG laser on ex vivo porcine biliary ducts with the effect of obtaining a coagulative necrosis involving the whole mucosa.     

Recanting of life-time inhalant use: how big a problem and what to make of it

Aims   To establish the prevalence of recanting of life-time inhalant use, identify correlates of recanting to gain insight to its causes and develop a method for distinguishing recanters who truly are versus are not life-time users of inhalants.
Design and setting   Longitudinal survey data from students in 62 South Dakota middle schools who were participating in a field trial to evaluate a school-based drug prevention program.
Measurements   At grades 7–8, participants reported on their life-time inhalant use, other drug use and drug-related beliefs, attitudes and behaviors.
Findings   Forty-nine per cent of students who reported life-time inhalant use at grade 7 recanted their reports a year later. Comparison of students who recanted inhalant use with those who did or did not report inhalant use consistently on drug-related beliefs, attitudes and behaviors at grades 7 and 8 suggested that, whereas some inhalant use recanting reflects denial of past behavior, some reflects erroneous initial reporting. Based on a latent mixture model fitted to the multivariate distribution of grade 7 and grade 8 responses of recanters and consistent reporters, we calculated the probability that each recanter was, in fact, a life-time inhalant user. An estimated 67% of the recanters in our sample appear to be life-time inhalant users who admitted use in grade 7 and then denied that use at grade 8; 33% appear to be students who reported use incorrectly at grade 7 and then corrected that error at grade 8.
Conclusions   Inhalant use recanting is a significant problem that, if not handled carefully, is likely to have a considerable impact on our understanding of the etiology of inhalant use and efforts to prevent it.     

Relationship between plasma insulin and left ventricular mass in normotensive participants of the Gubbio Study

BACKGROUND: There is substantial but not conclusive evidence that insulin resistance is related to left ventricular mass (LVM) in hypertensive individuals. To what extent this association is mediated by the relationship between plasma insulin and body size and build is still debated, and is poorly explored in nonhypertensive people. OBJECTIVE: To explore the relationship between insulin or insulin resistance and LVM in a population-based sample of nonhypertensive participants of the Gubbio Study. METHOD: Echocardiographic LVM was determined in 91 nondiabetic, nonhypertensive individuals aged 45-54 years, participating in a population-based screening. LVM normalized for height2.7 was used in the analyses; LV hypertrophy was defined as a value of > or = 50 g/m2.7 in men or > or = 47 g/m2.7 in women. Fasting plasma insulin and glucose were measured and the Homeostasis Model Assessment (HOMA) index was used as a measure of insulin resistance. RESULTS: LVM was positively and significantly correlated with body mass index (BMI) (P < 0.01), waist circumference (P < 0.01) and HOMA index (P < 0.05), whereas correlations with plasma glucose and triglycerides did not reach statistical significance (P = 0.07 for both); all correlations were offset after adjusting for BMI. Fasting plasma insulin and HOMA index were not significantly different in subjects with or without LV hypertrophy (70.8 +/- 27.8 vs. 77.7 +/- 29.6 pmol/l and 2.2 +/- 1.0 vs. 2.6 +/- 1.4, respectively). Bivariate analysis performed stratifying participants above or below the 75th percentile of the sex-specific distribution for BMI (29.1 and 29.4 kg/m2 for males and females, respectively) and plasma insulin (84 pmol/l for either gender), did not result in appreciable differences in LVM due to insulin levels. Similar results were obtained replacing the HOMA index for insulin in the analysis. CONCLUSION: In nonhypertensive individuals left ventricular mass is not associated with plasma insulin independently of body mass index.     

Anemia in chronic congestive heart failure: frequency,prognosis, and treatment

Chronic heart failure (CHF) is a leading cause of morbidity and mortality. Although a precise definition for a cut-off value of hemoglobin level for anemia is still lacking, it has recently been found to be a common complication in CHF, occurring in 10-20% of patients. There are several possible pathogenetic mechanisms for anemia in CHF, and a precise underlying cause is found in only a minority of patients. In CHF, more than 50% of anemia cases are considered to be 'anemia in chronic illness'. In CHF patients, low hemoglobin values directly relate to poor peak oxygen consumption, disabling symptoms, and impaired survival. Recent pilot studies showed that correction of anemia with erythropoietin and iron may lead to improvement in symptoms and exercise capacity. These issues need to be tested in larger, double-blind, randomized, placebo-controlled trials before anemia treatment becomes routine in patients with CHF.     

Cycle-ergometry stress testing and use of chronotropic reserve adjustment of ST depression for identification of significant coronary artery disease in clinical practice

Diagnostic reliability of indexations of peak exercise ST segment depression (DeltaST) for heart rate reserve (HRi) or chronotropic reserve (CR) to identify significant coronary artery disease (CAD) by cycle-ergometer exercise testing has not been evaluated previously. Exercise testing by upright cycle-ergometer (25 W/3 min) were performed in consecutive patients in primary prevention with history of exercise-related chest discomfort and cardiovascular risk factors, or with overt peripheral artery disease, with or type-2 diabetes associated with two or more additional cardiovascular risk factors. Coronary angiography was performed after the test to assess significant CAD. Three different criteria for definition of inducible myocardial ischemia were tested versus significant CAD: peak DeltaST>or=100 microV, ST/HRi>1.69 microV/bpm or ST/CR>1.76 microV/%. Diagnostic accuracy vs. CAD of DeltaST>or=100 microV, of ST/HRi>1.69 microV/bpm, and of ST/CR>1.76 microV/% were 78%, 72%, and 89% respectively; sensitivity and specificity of the three criteria were 91% and 50%, 84% and 43%, 88% and 93%, respectively. Abnormal ST/CR predicted CAD independent of risk factors, pre-test probability, and more strongly than DeltaST. Combination of ST/HRi and ST/CR criteria did not improve CAD prediction. In conclusions, in clinical setting in patients in primary prevention but with moderate-to-high pre-test probability of CAD, exercise testing by cycle-ergometry and use of ST/CR>1.76 microV/% showed elevated sensitivity and specificity, and the best accuracy for diagnosis of significant CAD.     

Decreased treatment failure in recipients of HLA-identical bone marrow or peripheral blood stem cell transplants with high CD34 cell doses

We studied the association between CD34 cell dose and transplant outcomes in 359 bone marrow (BM) and 511 peripheral blood stem cell (PBSC) transplant recipients from human leucocyte antigen (HLA)-identical siblings, reported to the International Bone Marrow Transplant Registry (IBMTR). Transplants for leukaemia were performed between 1995 and 1998. Patients were divided into those receiving below or above the median CD34+ dose, for BM (3 x 106/kg) and PBSC (6 x 106/kg) grafts respectively. Cox proportional hazards regression was used to adjust for baseline patient-, disease- and transplant-related characteristics. Analysis of the BM recipients showed that high CD34 cell dose was associated with lower transplant-related mortality [relative risk (RR) = 0.60, P = 0.033] and treatment failure (inverse of leukaemia-free survival, RR = 0.69, P = 0.032). Among PBSC recipients, high CD34 dose was associated with faster recovery of neutrophils to > 0.5 x 109/l (RR = 1.38, P < 0.001) and platelets to > 20 x 109/l (RR = 1.34, P = 0.003), lower risk of relapse (RR = 0.62, P = 0.029) and treatment failure (RR = 0.74, P = 0.03). We conclude that higher CD34 cell doses decrease treatment failure in recipients of HLA-identical sibling BM and PBSC transplants.