Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: comparison with intracoronary Doppler flow wire

OBJECTIVES

We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire.

BACKGROUND

Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method.

METHODS

Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty).

RESULTS

As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32.

CONCLUSIONS

Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.

Treatment tolerance of elderly cancer patients entered onto phase II clinical trials: an Illinois Cancer Center study

PURPOSE

Past research that has compared cancer treatment tolerance between elderly and nonelderly cancer patients has been contradictory. Some investigators concluded that there is no difference between the groups, while others demonstrated elderly patients experienced less tolerance to treatment. As a result, some physicians discriminate against elderly cancer patients by not entering them onto clinical trials out of a belief that they will not tolerate the therapy.

METHODS

An analysis was performed using the Illinois Cancer Center (ICC) data base, which contains treatment information for all patients registered onto phase II trials. A maximum of 672 cases was available for evaluation of 11 treatment-related variables.

RESULTS

The results demonstrated no significant differences between elderly and nonelderly patients for the following seven treatment-related variables: performance status (PS), number of dose reductions, number of treatment interruptions, total days of delay, best response, reason off-study, and number of grade 3 or greater toxicities. Minor differences were detected for number of courses and number of dose escalations.

CONCLUSION

Based on these results, elderly patients should not be denied access to cancer clinical trials relative to age alone.

Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

Work stress among six professional groups: the Singapore experience

Recent developments in stress research have called for attention to how social structures influence the stress and coping processes. This paper examines the experience of work stress among professionals in Singapore and argues that workers' experiences in the workplace are influenced not only by individual personality and job nature, but also by structural forces shaping the profession, the social organization of work institutions and the development of the economy. Data were collected from a survey of professionals in Singapore conducted in 1989-1990. The sample consisted of 2570 men and women from six different professions and para-professions, namely general practitioners, lawyers, engineers, teachers, nurses and life insurance personnel. Results showed that performance pressure and work-family conflicts were perceived to be the most stressful aspects of work. These two stressors also significantly contributed to the experience of overall work stress. Further, stress arising from work-family conflicts, performance pressure and poor job prospects was negatively associated with the level of work satisfaction. These findings were discussed in the contexts of increasing professionalization and de-professionalization and the growing emphases on productivity and efficiency in a quickly developing economy.

Recovery of white matter tracts in regions of peritumoral FLAIR hyperintensity with use of restriction spectrum imaging

BACKGROUND AND PURPOSE

DTI is being increasingly used to visualize critical white matter tracts adjacent to brain tumors before neurosurgical resection. However, brain tumors, particularly high-grade gliomas, are typically surrounded by regions of FLAIR hyperintensity that include edema, which increase isotropic diffusion, degrading the ability of standard DTI to uncover orientation estimates within these regions. We introduce a new technique, RSI, which overcomes this limitation by removing the spherical, fast diffusion component introduced by edema, providing better analysis of white matter architecture.

MATERIALS AND METHODS

A total of 10 patients with high-grade gliomas surrounded by FLAIR-HI that at least partially resolved on follow-up imaging were included. All patients underwent RSI and DTI at baseline (FLAIR-HI present) and at follow-up (FLAIR-HI partially resolved). FA values obtained with RSI and DTI were compared within regions of FLAIR-HI and NAWM at both time points.

RESULTS

RSI showed higher FA in regions of FLAIR-HI and NAWM relative to DTI, reflecting the ability of RSI to specifically measure the slow, restricted volume fraction in regions of edema and NAWM. Furthermore, a method by time interaction revealed that FA estimates increased when the FLAIR-HI resolved by use of standard DTI but remained stable with RSI. Tractography performed within the region of FLAIR-HI revealed the superior ability of RSI to track fibers through severe edema relative to standard DTI.

CONCLUSIONS

RSI improves the quantification and visualization of white matter tracts in regions of peritumoral FLAIR-HI associated with edema relative to standard DTI and may provide a valuable tool for neurosurgical planning.

CHEMOSENSORY RESPONSES TO AMINO ACIDS AND CERTAIN AMINES BY THE CILIATE TETRAHYMENA: A FLAT CAPILLARY ASSAY

An assay for chemosensory responses by the ciliate Tetrahymena thermophila is described that uses glass capillaries with a rectangular cross-section (inner dimensions, 20 x 2 x 0.2 mm). These have optical and geometrical properties permitting convenient observation of cell behavior within the capillaries. Washed cells, starved for 12 h, accumulated preferentially in capillaries containing L-methionine, L-leucine, L-cysteine, L-histidine, L-histamine, cimetidine, agmatine, and berenil at concentrations of 10^-3 M or less. They avoided capillaries containing tripelennamine, diphenhydramine, and pentamidine at these concentrations. It is argued that the actual response thresholds are much lower than the concentrations put into the capillaries, since cells respond to the gradient of the diffusing chemical. L-Isoleucine, itself inert, blocked the response to L-leucine but not to L-methionine, L-cysteine, or L-histidine. L-Ethionine and 1-homocysteine caused accumulation but not L-cysteine or DL-cystathionine. L-Cystine did not block the response to L-cysteine. Cells accelerated when entering a capillary where accumulation occurred. On reaching the interior they swam more slowly and uniformly, and with fewer turns or stops than in control capillaries lacking the chemical signal, or when outside of the capillaries. Cells were inhibited from leaving both control and test capillaries, possibly because of accumulated wastes or secretions in the surrounding medium.

Stress in the life course: a life history approach

This article examines the relationship between stress and distress in the life course, emphasizing the time elapsed between the event and measurement of psychological distress. Stressors are conceptualized as either distal or proximal based on how recently they occurred. Distal stressors are further classified as status changes or undesirable life changes. Using a life history calendar approach, we examine stressors occurring over a 15-year-period. We explore whether distal stressors affect current depressive symptomatology above and beyond the effect of more recent stressors and how these stressors vary in frequency and affect over 3 empirically defined age groups. While some events decrease in frequency over age, others occur consistently across age groups. Most important, distal stressors significantly impact current depressive symptomatology, independent of proximal stressors. Types of distal stressors affecting depression vary over age, indicating that the stage of life at which a stressor occurs is a significant determinant of the stressor's effect on depression.

Urban stress in China

The stress-distress model is examined in the context of a Chinese urban center, Tianjin. Conceptually, the relationship between stress (as reflected in life events) and distress (as reflected in depressed symptoms) is hypothesized to hold across societies. At the same time, the measures of stress must reflect the social reality of a particular community of society. In the case of urban China, the politically-imposed stratification system arranges individuals and family lives around work units. These work units dictate all aspects of the life of the worker and his or her family, ranging from housing, major purchases, access to local and distance facilities, schooling and employment for children, to retirement pension and funeral expenses. As a result, relationships in the work context are expected to produce stress-inducing conflicts. Results from a community survey of Tianjin residents in 1986 support both the generality of the stress-distress model and the specificity of the effects of work-related stressors.

Diagnostic Accuracy of PET, SPECT, and Arterial Spin-Labeling in Differentiating Tumor Recurrence from Necrosis in Cerebral Metastasis after Stereotactic Radiosurgery

BACKGROUND AND PURPOSE

Radiographic assessment of cerebral metastasis after stereotactic radiosurgery remains a major challenge in neuro-oncology. It is often difficult to distinguish tumor progression from radiation necrosis in this setting using conventional MR imaging. The objective of this study was to compare the diagnostic sensitivity and specificity of different functional imaging modalities for detecting tumor recurrence after stereotactic radiosurgery.

MATERIALS AND METHODS

We retrospectively reviewed patients treated between 2007 and 2010 and identified 14 patients with cerebral metastasis who had clinical or radiographic progression following stereotactic radiosurgery and were imaged with arterial spin-labeling, FDG-PET, and thallium SPECT before stereotactic biopsy. Diagnostic accuracy, specificity, sensitivity, positive predictive value, and negative predictive value were calculated for each imaging technique by using the pathologic diagnosis as the criterion standard.

RESULTS

Six patients (42%) had tumor progression, while 8 (58%) developed radiation necrosis. FDG-PET and arterial spin-labeling were equally sensitive in detecting tumor progression (83%). However, the specificity of arterial spin-labeling was superior to that of the other modalities (100%, 75%, and 50%, respectively). A combination of modalities did not augment the sensitivity, specificity, positive predictive value, or negative predictive value of arterial spin-labeling.

CONCLUSIONS

In our series, arterial spin-labeling positivity was closely associated with the pathologic diagnosis of tumor progression after stereotactic radiosurgery. Validation of this finding in a large series is warranted.

1,25-dihydroxyvitamin D3 inhibits nuclear factor kappa B activation by stabilizing inhibitor IκBα via mRNA stability and reduced phosphorylation in passively sensitized human airway smooth muscle cells

Excessive activation of nuclear transcription factor-κB (NF-κB) is involved in human airway smooth muscle cells (HASMCs) activities in asthma. We investigated the effects of 1,25 - dihydroxyvitamin D3 [1,25 - (OH) 2D3] on the NF- κB signaling pathway in passively sensitized HASMCs and the molecular mechanisms involved. HASMCs were treated with either healthy controls' serum, asthma patients' serum or pretreated with 1,25 - (OH) 2D3 prior to treatment with asthmatics' serum. At 1 h after serum treatment: electrophoretic mobility shift assay (EMSA) was used to detect NF-κB DNA binding activity; immunocytochemical staining was used to observe the nuclear translocation of NF-κB p65; Western blots were used for NF-κB p65, IκBα, and phospho-IκBα protein levels and the nuclear translocation of NF-κB p65; real-time quantitative PCR was used for NF-κB p65 and IκBα mRNA expressions; and actinomycin D treatment was used to determine IκBα mRNA stability. Our major findings were: (1) 1,25 - (OH) 2D3 significantly reduced asthma serum passively sensitized HASMCs NF-κB DNA binding activity and inhibited the nuclear translocation of NF-κB p65; (2) 1,25 - (OH) 2D3 increased the stability of IκBα mRNA with reduced IκBα phosphorylation in asthma serum passively sensitized HASMCs and significantly increased IκBα expression in these HASMCs. Inhibiting NF-κB signalling with 1,25 - dihydroxyvitamin D3 may be a therapeutic approach for controlling HASMC-related remodelling in asthma.

The role of immunohistochemistry in the diagnosis of hyalinizing clear cell carcinoma of the minor salivary gland: a case report

A case of hyalinizing clear cell carcinoma (HCCC) of the minor salivary glands of the oral cavity is reported. A 52- year-old woman presented with a growing mass at the base of the tongue. The patient underwent complete resection of the tumour. The histological picture was characterized by trabeculae or solid nests of proliferating cells with a clear cytoplasm, surrounded by a hyalinizing stroma. Tumour cells were immunoreactive for Cytokeratins 5, 6, 7, 8, 14, 17 and 18. No reactivity was observed for cytokeratin 20, vimentin, S- 100 protein, smooth-muscle actin, muscle-specific actin, and calponin. These findings confirmed the diagnosis of HCCC of minor salivary glands of the oral cavity. The clinical presentation, the immunohistochemical pattern and the role of cytokeratins in the differential diagnosis of HCCC are discussed with a review of the literature.

Perflubron emulsion reduces inflammation during extracorporeal circulation

The recovery from cardiac surgery and cardiopulmonary bypass can be complicated by an acute inflammatory response. Circulating blood through an extracorporeal circuit (ECC) contributes to this complication. Perfluorocarbon-based blood substitutes (PFCs) are under investigation for use as a component of the ECC "prime" solution, because PFCs increase the oxygen-carrying capacity of the diluted blood. Some PFCs may provide the additional benefit of attenuating the ECC-induced inflammatory response. Earlier, we reported that perflubron emulsion (PFE, Alliance Pharmaceutical Corp.) reduced neutrophil (PMN) activation in vivo. However, the potential of PFE to reduce ECC-induced PMN activation has not been investigated. In this study, we used a small-scale ECC model to quantify the extent of PMN activation during circulation and to examine if PFE treatment attenuated PMN activation. ECC circuits were filled with a mixture of blood and Plasmalyte. Two groups were studied: an untreated group containing blood plus PlasmaLyte and a treated group in which some of the Plasmalyte was substituted with PFE (4.5 g/100 ml). Hematology and measures of whole blood PMN activation were made from blood samples taken periodically throughout the 120-min ECC circulation period. We found, for the untreated group, a significant decrease in the number of circulating PMNs and an increase in PMN activation with time. PMN activation was demonstrated as a significant increase in the expression of the PMN adhesion protein CD11b (P < 0.05) and an increase in PMN oxygen free radical production (reactive oxygen species (ROS)). After 120 min of circulation, the PMNs remained capable of a significant response to a second inflammatory stimulus, but PFE treatment significantly attenuated the fMLP-induced increase in PMN ROS at t = 120 min (P < 0.05). These results suggest that PFE may have dual utility in cardiac surgery, to increase oxygen delivery and to serve as an antiinflammatory agent.

Three-dimensional reconstruction of electric-potential distribution in electron-holographic interferometry

A method of reconstructing the three-dimensional electric-potential distribution of a microscopic object with electron-holographic interferometry is presented. A sequence of processing techniques is developed to obtain the projected phase proportional to the potential distribution. A modified backprojection algorithm is used to reconstruct a three-dimensional potential distribution from the projected potentials obtained at different projection directions. In an experiment this method is applied to reconstruct three-dimensional latex particles.

Real-time electron-holographic interference microscopy with a liquid-crystal spatial light modulator

An electron-holographic interference microscope that produces a time-sequential interference micrograph at a TV rate is developed. In this system, the electron off-axis hologram detected with a TV camera is transferred to a liquid-crystal spatial light modulator as a video signal. The liquid-crystal spatial light modulator can function as a thin amplitude hologram or a thin phase hologram. Time-sequential interference micrograph is obtained at a TV rate by superimposition of a plane reference wave onto the reconstructed object wave. Experimental results for observing a dynamic domain-wall motion in thin Permalloy film are demonstrated.

Examining chronic kidney disease management in a single center

AIMS

The management of patients with chronic kidney disease in outpatient clinics was assessed for the ability to achieve targets of care advocated in clinical practice guidelines.

METHODS

272 records of outpatients with increased serum creatinine (> or = 1.5 mg/dl for women, > or = 2.0 mg/dl for men) were reviewed for details of their assessment and management. Prevailing data on blood pressure, anemia, bone disease and lipid status as well as therapeutic changes were evaluated.

RESULTS

The subjects were aged 64 +/- 18 years, serum creatinine 2.6 +/- 1.1 mg/dl, and calculated GFR (MDRD formula) 19.2 +/- 9.9 ml/min. Median UproV was 1.0 (0.024 - 12.4) g/day. Causes of CKD were diabetes (33.5%), HTN (8.8%), GN (19.5%), and adult PKD (3.3%). Treatment targets were BP < 130/85 mmHg, Hct > or = 36%, serum Ca++ > or = 8.5 mg/dl, serum Po4 < 4.5 mg/dl and cholesterol < 200 mg/dl. Of the patients with abnormal findings, mean values for SBP were 153 +/- 17 mmHg, DBP 93 +/- 6 mmHg, Hct 31.7 +/- 2.9%, Ca++ 8.0 +/- 0.7 mg/dl, PO4 5.6 +/- 1.0 mg/dl, and cholesterol 236 +/- 37 mg/dl. Only a minority of patients with abnormal values had their treatment altered. Furthermore, only 54% of patients with hypertension were treated with either ACEi or ARB therapy. Finally, only 6% of patients with hypercholesterolemia had fasting lipid levels measured.

CONCLUSION

This data suggests that treatment of patients with CKD has improved, but that many opportunities exist to optimize their care.

Method of compensating for aberrations in electron holography by using a liquid-crystal spatial-light modulator

A method for correcting the aberration of an electron-objective lens during the holographic reconstruction stage is proposed. In this method, a liquid-crystal spatial-light modulator is used as a computercontrolled phase plate on the Fourier plane of an optical reconstruction system. The effective refractive index of the liquid crystals changes with the applied electric field because of the crystals's birefringence. Thus the phase of light passing through the liquid-crystal spatial-light modulator can be flexibly modulated to compensate for wave aberration. Experimental results on adjusting the focus of the image wave reconstructed from an electron-image hologram of magnesium oxide particles are presented.

Use of the fast Fourier transform method for analyzing linear and equispaced Fizeau fringes

The Fourier transform method is applied to analyze the initial phase of linear and equispaced Fizeau fringes. We develop an algorithm for high-precision phase measurement by using the Fourier coefficient that corresponds to the spatial frequency of the Fizeau fringes, and we describe methods for determining the fringe carrier frequency. Errors caused by carrier frequency fluctuation and data truncation are studied theoretically and by computer simulation. To demonstrate the method we apply it to the real-time calibration of a piezoelectric transducer mirror in a Twyman-Green interferometer.

Phase-extraction technique for electron holography using a grating optical system

A description is made of a grating optical system for extracting phase distribution from electron holograms, that has an extremely high stability and can eliminate system aberrations. Phase measurement is achieved with phase-shifting interferometry by stepping the grating laterally. The system is used to extract the phase distribution of a magnesium oxide crystal from its electron hologram.