Beam me up: A novel mass spectrometric ionization technique based on rapid evaporation of biological tissues (see picture) can be used to analyze vital tissues during surgical intervention as well as for processed tissue specimens. A tissue identification system based on principal‐component analysis was developed. The method differentiates malignant tumor cells from the surrounding healthy tissue.

Few reported inhibitors of secretory phospholipase A(2) enzymes truly inhibit the IIa human isoform (hnpsPLA(2)-IIa) noncovalently at submicromolar concentrations. Herein, the simple chiral precursor D-tyrosine was derivatised to give a series of potent new inhibitors of hnpsPLA(2)-IIa. A 2.2-A crystal structure shows an inhibitor bound in the active site of the enzyme, chelated to a Ca(2+) ion through carboxylate and amide oxygen atoms, H-bonded through an amide NH group to His48, with multiple hydrophobic contacts and a T-shaped aromatic-group-His6 interaction. Antiinflammatory activity is also demonstrated for two compounds administered orally to rats.

Laser desorption ionization-mass spectrometric (LDI-MS) analysis of vital biological tissues and native, ex vivo tissue specimens is described. It was found that LDI-MS analysis yields tissue specific data using lasers both in the ultraviolet and far-infrared wavelength regimes, while visible and near IR lasers did not produce informative MS data. LDI mass spectra feature predominantly phospholipid-type molecular ions both in positive and negative ion modes, similar to other desorption ionization methods. Spectra were practically identical to rapid evaporative ionization MS (REIMS) spectra of corresponding tissues, indicating a similar ion formation mechanism. LDI-MS analysis of intact tissues was characterized in detail. The effect of laser fluence on the spectral characteristics (intensity and pattern) was investigated in the case of both continuous wave and pulsed lasers at various wavelengths. Since lasers are utilized in various fields of surgery, a surgical laser system was combined with a mass spectrometer in order to develop an intraoperative tissue identification device. A surgical CO2 laser was found to yield sufficiently high ion current during normal use. The principal component analysis-based real-time data analysis method was developed for the quasi real-time identification of mass spectra. Performance of the system was demonstrated in the case of various malignant tumors of the gastrointestinal tract.

Direct combination of cavitron ultrasonic surgical aspirator (CUSA) and sonic spray ionization mass spectrometry is presented. A commercially available ultrasonic surgical device was coupled to a Venturi easy ambient sonic-spray ionization (V-EASI) source by directly introducing liquified tissue debris into the Venturi air jet pump. The Venturi air jet pump was found to efficiently nebulize the suspended tissue material for gas phase ion production. The ionization mechanism involving solely pneumatic spraying was associated with that of sonic spray ionization. Positive and negative ionization spectra were obtained from brain and liver samples reflecting the primary application areas of the surgical device. Mass spectra were found to feature predominantly complex lipid-type constituents of tissues in both ion polarity modes. Multiply charged peptide anions were also detected. The influence of instrumental settings was characterized in detail. Venturi pump geometry and flow parameters were found to be critically important in ionization efficiency. Standard solutions of phospholipids and peptides were analyzed in order to test the dynamic range, sensitivity, and suppression effects. The spectra of the intact tissue specimens were found to be highly specific to the histological tissue type. The principal component analysis (PCA) and linear discriminant analysis (LDA) based data analysis method was developed for real-time tissue identification in a surgical environment. The method has been successfully tested on post-mortem and ex vivo human samples including astrocytomas, meningeomas, metastatic brain tumors, and healthy brain tissue.

Increased mitochondrial reactive oxygen species (ROS), particularly superoxide have been suggested to mediate hypoxic pulmonary vasoconstriction (HPV), chronic hypoxia-induced pulmonary hypertension (PH) and right ventricular (RV) remodelling.We determined ROS in acute, chronic hypoxia and investigated the effect of the mitochondria-targeted antioxidant MitoQ under these conditions.The effect of MitoQ or its inactive carrier substance, decyltriphenylphosphonium (TPP), on acute HPV (1% O for 10 minutes) was investigated in isolated blood-free perfused mouse lungs. Mice exposed for 4 weeks to chronic hypoxia (10% O) or after banding of the main pulmonary artery (PAB) were treated with MitoQ or TPP (50 mg/kg/day).Total cellular superoxide and mitochondrial ROS levels were increased in pulmonary artery smooth muscle cells (PASMC), but decreased in pulmonary fibroblasts in acute hypoxia. MitoQ significantly inhibited HPV and acute hypoxia-induced rise in superoxide concentration. ROS was decreased in PASMC, while it increased in the RV after chronic hypoxia. Correspondingly, MitoQ did not affect the development of chronic hypoxia-induced PH, but attenuated RV remodelling after chronic hypoxia as well as after PAB.Increased mitochondrial ROS of PASMC mediate acute HPV, but not chronic hypoxia-induced PH. MitoQ may be beneficial under conditions of exaggerated acute HPV.