Changes in tumor hypoxia measured with a double hypoxic marker technique

Purpose: Development of a double hypoxic cell marker assay, using the bioreductive nitroimidazole derivatives CCI-103F and pimonidazole, to study changes in tumor hypoxia after treatments that modify tumor oxygenation.

Methods and Materials: Both hypoxic markers were visualized by immunohistochemical techniques to detect changes in hypoxic fraction induced by carbogen breathing (95% O₂ and 5% CO₂) or hydralazine injection. The protocol was tested in a human laryngeal squamous cell carcinoma xenograft line. Quantitative measurements were derived from consecutive tissue sections that were analyzed by a semiautomatic image analysis system. Qualitative analysis was obtained by double staining of the two hypoxic markers on the same tissue section.

Results: A significant correlation between the hypoxic fractions for the two markers, CCI-103F and pimonidazole, was found in air breathing animals. After carbogen breathing, the hypoxic fraction decreased significantly from 0.07 to 0.03, and after hydralazine treatment, the hypoxic fraction increased significantly. Reduction of hypoxia after carbogen breathing was most pronounced close to well-perfused tumor regions.

Conclusions: With this method, employing two consecutively injected bioreductive markers, changes in tumor hypoxia can be studied. A significant reduction in hypoxia after carbogen breathing and a significant increase in hypoxia after hydralazine administration was demonstrated.     

Relapsing polychondritis studied by computed tomography

Computed tomographic findings in a patient with relapsing polychondritis are described. Collapse of the cartilage of the nose and calcification in cartilages of the ears were clearly demonstrated. CT scanning was also helpful in evaluating the tracheobronchial tree for airway compromise, which could prove fatal in this condition.     

Lung cancer audit in an Irish teaching hospital

Background Lung cancer is the most common cause of cancer-related death in Ireland. There are few complete data sets available as to the stage and cell type of lung cancers at time of presentation in Ireland. Aim To audit the lung cancers presenting to a large Dublin teaching hospital over a 12-month period. Method Prospective evaluation of all lung tumours presenting to our institution over a consecutive 12-month period. Results One hundred and ninety-eight lung cancers presented over the study period. There were 34 cases of small cell carcinoma and 150 cases of non-small cell carcinoma (NSCC). Fourteen patients were too ill or compromised at time of presentation for tissue confirmation. The most common cell type was squamous carcinoma. Eighty-four per cent of the NSCCs were either stage 3 or 4 at presentation. Conclusion Most lung cancers present late in the time course of the disease. Distribution of cell type and location are similar in Ireland and other developed countries.     

Olive oils high in phenolic compounds modulate oxidative/antioxidative status in men

The aim of the present study was to evaluate whether olive oils high in phenolic compounds influence the oxidative/antioxidative status in humans. Healthy men (n = 12) participated in a double-blind, randomized, crossover study in which 3 olive oils with low (LPC), moderate (MPC), and high (HPC) phenolic content were given as raw doses (25 mL/d) for 4 consecutive days preceded by 10-d washout periods. Volunteers followed a strict very low-antioxidant diet the 3 d before and during the intervention periods. Short-term consumption of olive oils decreased plasma oxidized LDL (oxLDL), 8-oxo-dG in mitochondrial DNA and urine, malondialdehyde in urine (P < 0.05 for linear trend), and increased HDL cholesterol and glutathione peroxidase activity (P < 0.05 for linear trend), in a dose-dependent manner with the phenolic content of the olive oil administered. At d 4, oxLDL after MPC and HPC, and 8-oxo-dG after HPC administration (25 mL, respectively), were reduced when the men were in the postprandial state (P < 0.05). Phenolic compounds in plasma increased dose dependently during this stage with the phenolic content of the olive oils at 1, 2, 4, and 6 h, respectively (P < 0.01). Their concentrations increased in plasma and urine samples in a dose-dependent manner after short-term consumption of the olive oils (P < 0.01). In conclusion, the olive oil phenolic content modulated the oxidative/antioxidative status of healthy men who consumed a very low-antioxidant diet.     

Clot penetration and fibrin binding of amediplase,a chimeric plasminogen activator (K2 tu-PA)

Amediplase (K(2) tu-PA) is a hybrid plasminogen activator, consisting of the kringle 2 domain of alteplase and the protease domain of urokinase. The objective of this study was to determine the in vitro clot penetration of amediplase in relation to its fibrin binding and to compare the properties with those of alteplase. The clot lysis activity of amediplase in internal clot lysis models (both purified system and plasma system) was about 10 times less than that of alteplase. The clot lysis activity of amediplase in an external clot lysis model (plasma system) was similar to that of alteplase at therapeutic concentrations around 1 micro g/ml. The fibrin-clot binding properties of amediplase and alteplase were studied in a purified system as well as in a plasma system. In both systems amediplase bound to fibrin although to a significantly lower extent than alteplase. The binding of amediplase or alteplase did not increase during plasmin-mediated degradation of fibrin. The binding of amediplase was fully inhibited by epsilon-aminocaproic acid, indicating that the observed binding was specific and occurred via the lysine binding site in the kringle of amediplase. Clot penetration was studied during pressure-driven fluid permeation using syringes containing plasma clots. Amediplase was able to enter the clot without significant hindrance, while alteplase was concentrated on the top of the plasma clot and hardly entered into the inner parts of the clot. Diffusion-driven clot penetration was studied during clot lysis using confocal microscopy. Alteplase was detected on or close to the clot surface, while two-chain urokinase, which has no affinity to fibrin, was also detected deep inside the clot. Amediplase showed a penetration behaviour, which was distinct from that of alteplase and similar to that of two-chain urokinase. We concluded that the fibrin binding of amediplase is moderate and does not hinder clot penetration under permeation-driven or diffusion-driven transport conditions. Enhanced clot penetration, especially in large clots, could allow a more efficient lysis during thrombolytic therapy.