On the Relationship between Dynamic Contrast-Enhanced Ultrasound Parameters and the Underlying Vascular Architecture Extracted from Acoustic Angiography

Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA.     

New insights on COPD imaging via CT and MRI

Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD.     

Oxidative metabolism of lung macrophages exposed to sodium arsenite

Arsenic pollution has become increasingly severe. It occurs as the result of geological processes and different human activities. Arsenic toxicity at the respiratory level occurs mainly by inhalation of products of coal combustion. The aim of this study was to evaluate sodium arsenite (As³⁺) toxicity in murine alveolar macrophages (AMs) in vitro and its association with the alterations in cell metabolism.

No changes in viability, apoptosis or cell area were detected in AMs treated with As³⁺ concentrations up to 2 μM for 24–96 h. A marked decrease in these end-points was observed for As³⁺ concentrations ranging from 2.5 μM to 10 μM.

Regarding the dynamics of the endo-exocytic process triggered by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell incorporation, no variations were detected for As³⁺ concentrations lower than 2 μM while higher concentrations markedly modified this response.

MTT specific activity, as a measure of cell metabolic activity, was not modified irrespective of the As³⁺ concentration assayed. However, nitroblue tetrazolium (NBT) specific activity, as a measure of superoxide anion generation, is responsive but only to low As³⁺ doses.

Although this study focuses on lung macrophages, the effects of As³⁺ described herein may also apply to the response of macrophages residing in other organs.

Arsenite modifies the metabolic and the oxidative status of AMs in vitro. When macrophages are in an As³⁺ rich medium, they exhibit a reduction in respiratory burst levels and lose their intrinsic capacity to respond to toxicants.     

麦冬类中药组织切片计算机三维重建图鉴

利用计算机技术实现麦冬类中药组织连续切片三维重建与动态显示,为计算机辅助生药学鉴定和教学提供了新的三维图像技术和研究资料。     

Gastro-oesophageal reflux disease: Medical or surgical treatment? Report of an interactive workshop

Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.     

Usefulness of gallium 67 in research into the need for radical cervical lymph node dissection in patients with head and neck carcinomas

Fifty-nine patients with head and neck carcinoma were examined with 67Ga scintigraphy. All patients had undergone lymph node dissection of the neck. They were followed for a minimum of 2 years after the examination. The primary tumor, treated prior/contemporaneously to the lymph node dissection, did not evolve in this interval. Metastatic involvement of the lymph node capsule was observed in all 44 cases with metastatic lymph nodes; macroscopic radicality was surgically obtained since involvement of the capsule was only microscopic. Nevertheless, complementary radiotherapy was given. The whole of 17 recurrences in the soft tissues of the neck were found, within 2 years, in the group of 26 patients who had undergone dissection of lymph nodes with metastatic capsular involvement and whose postoperative 67Ga scintigraphy was positive. On the contrary, no recurrences in the soft tissues of the neck were observed in the group of 18 patients who had undergone dissection of lymph nodes with metastatic capsular involvement and whose scintigraphy was negative. This result proves (P less than 0.001) 67Ga capable of evidencing eventual microscopic diffusion. Such a possibility has not yet been realized in vivo with any other investigation technique. Scintigraphy was negative in a control group of 15 patients who had undergone lymph node dissection, and with nonmetastatic lymph nodes. This finding leads us to exclude that the use of 67Ga might result in misinterpreted findings in the exploration of relatively superficial tissues. In fact, the eventual accumulation of radioisotope in nonneoplastic pathologies is quite easily recognizable in the neck. We can therefore conclude that in those 9 cases with positive scintigraphy and in whom no recurrence was found, microscopic diffusion was probably present, but local recurrence of the disease was prevented by complementary radiotherapy.     

Microbial penetration of gloves following usage in routine dental procedures.

Unsterile polyvinyl, regular latex, and powder-free, modified latex examination gloves were evaluated following usage in routine dental procedures to assess their loss of integrity. Glove fingers were filled with a suspension of red-pigmented Serratia marcescens and drawn across the surface of tryptic soy agar plates. The appearance of red-pigmented Serratia colonies on the plates was used as an indication of glove defects. Unused, unwashed gloves taken at random from boxes served as controls. Of the gloves used in clinical procedures, 83.3% of the polyvinyl gloves, 35.0% of the regular latex gloves, and 7.5% of the powder-free, modified latex gloves allowed penetration of Serratia. Data thus suggest that advances in technology continue to develop a glove with more resistance than regular latex and vinyl gloves to routine clinical usage.     

Proteolytic activity of the purified hormone-binding subunit in the estrogen receptor.

The hormone-binding subunit of the calf uterus estradiol receptor was purified as a hormone-free molecule. Immunoaffinity chromatography with a specific monoclonal antibody was used as the final step. The purified subunit was specifically labeled by radioactive diisopropyl fluorophosphate. The diisopropyl fluorophosphate-labeled amino acid was serine. The purified receptor was able to release the fluorogenic or chromogenic group from synthetic peptides containing phenylalanine at the carboxyl terminus. This occurred only in the presence of estradiol and was hampered by aprotinin and diisopropyl fluorophosphate. Estradiol-dependent hydrolytic activity was also found in the eluate from gel slices after SDS/PAGE of purified receptor. This activity comigrated with the renaturable estradiol-binding activity. The estradiol antagonists 4-hydroxytamoxifen and ICI 164,384 as well as other steroid hormones were unable to activate this hydrolytic activity.