Structurally optimised BODIPY derivatives for imaging of mitochondrial dysfunction in cancer and heart cells

BODIPY based optical imaging agents with mitochondrial membrane potential dependent uptake are described.

Spontaneous cerebral gas embolism and pulmonary arteriovenous malformation: a case report

Pulmonary barotrauma can cause cerebral arterial gas embolism (CAGE) from pulmonary overdistension of alveoli forcing gas into the pulmonary vasculature. We report a case of CAGE in a man found to have occult pulmonary arteriovenous malformation (PAVM) and undiagnosed obstructive sleep apnea (OSA). A 46-year-old man was admitted to the hospital for an acute seizure and left-sided weakness, with telangiectasias on his lower lip and tongue. Brain-computed tomography (CT) showed gas emboli in the right hemisphere. Chest CT revealed a 1.8-cm PAVM in the posterior right costophrenic sulcus. A transthoracic echocardiogram showed no intracardiac shunt or patent foramen ovale. He was treated with phenytoin, lidocaine and hyperbaric oxygen. The PAVM was occluded with a detachable balloon followed by coil embolization. Polysomnography revealed severe obstructive sleep apnea, which was treated with CPAP. Seven years later, the patient was functioning at his pre-event baseline. We propose the CAGE was caused by high negative intrathoracic pressures while breathing against an obstructed upper airway, with air entrainment into the PAVM and subsequent arterialization.

Re and (99m)Tc complexes of BodP3--multi-modality imaging probes

A fluorescent tridentate phosphine, BodP3 (2), forms rhenium complexes which effectively image cancer cells. Related technetium analogues are also readily prepared and have potential as dual SPECT/fluorescent biological probes.

BR2BodPR2: highly fluorescent alternatives to PPh3and PhPCy2

The syntheses of highly fluorescent analogues of PPh₃and PhPCy₂based on the Bodipy chromophore are described.

Effects of caffeine on performance and mood depend on the level of caffeine abstinence

RATIONALE

Most studies of the effects of caffeine on performance have used regular caffeine consumers who are deprived at test. Thus the reported effects of caffeine could be explained through reversal of caffeine withdrawal.

OBJECTIVES

To test how preloading deprived caffeine consumers with 0, 1 or 2 mg/kg caffeine altered the subsequent ability of caffeine to modify mood and performance.

METHODS

Thirty moderate caffeine consumers were given a drink containing 0, 1 or 2 mg/kg caffeine at breakfast followed 60 min later by a second drink containing either 0 or 1 mg/kg caffeine. Performance on a measure of sustained attention and mood were measured before and after each drink.

RESULTS

Administration of both 1 and 2 mg/kg caffeine at breakfast decreased reaction time and 1 mg/kg caffeine also increased performance accuracy on the sustained attention (RVIP) task relative to placebo. Both breakfast doses of caffeine also improved rated mental alertness. Similarly, 1 mg/kg caffeine administered 60 min after breakfast decreased reaction time and increased rated mental alertness in the group who had not been given caffeine at breakfast. However, this second dose of caffeine had no effect on subsequent performance or mood in the two groups who had received caffeine at breakfast.

CONCLUSIONS

Caffeine reliably improved performance on a sustained attention task, and increased rated mental alertness, in moderate caffeine consumers who were tested when caffeine-deprived. However, caffeine had no such effects when consumers were no longer caffeine deprived. These data are consistent with the view that reversal of caffeine withdrawal is a major component of the effects of caffeine on mood and performance.

Urinary metabolites of a novel quinoxaline non-nucleoside reverse transcriptase inhibitor in rabbit, mouse and human: identification of fluorine NIH shift metabolites using NMR and tandem MS

1. The urinary metabolites of (S)-2-ethyl-7-fluoro-3-oxo-3,4-dihydro-2H-quinoxaline-carboxylic acid isopropylester (GW420867X) have been investigated in samples obtained following oral administration to rabbit, mouse and human. GW420867X underwent extensive biotransformation to form hydroxylated metabolites and glucuronide conjugates on the aromatic ring, and on the ethyl and isopropyl side-chains in all species. In rabbit urine, a minor metabolite was detected and characterized as a cysteine adduct that was not observed in mouse or man. 2. The hydroxylated metabolites and corresponding glucuronide conjugates were isolated by semi-preparative HPLC and characterized using NMR, LC-NMR and LC-MS/MS. The relative proportions of fluorine-containing metabolites were determined in animal species by 19F-NMR signal integration. 3. The fluorine atom of the aromatic ring underwent NIH shift rearrangement in the metabolites isolated and characterized in rabbit, mouse and human urine. 4. The characterization of the NIH shift metabolites in urine enabled the detection and confirmation of the presence of these metabolites in human plasma.

Urinary metabolites of a novel quinoxaline non-nucleoside reverse transcriptase inhibitor in dog, cynomolgus monkey and mini-pig

1. The metabolism of (S)-2-ethyl-7-fluoro-3-oxo-3,4-dihydro-2H-quinoxalinecarboxylic acid isopropylester (GW420867X) has been investigated following oral administration to dog, cynomolgus monkey and mini-pig. 2. The urinary metabolites were isolated and characterized using semi-preparative HPLC, NMR and LC-MS/MS. The relative proportions of fluorine-containing metabolites were determined for each species by 19F-NMR signal integration. 3. The metabolite profiles for each species were similar, although the proportion of individual components varied, suggesting that similar metabolic pathways are involved in the biotransformation of GW420867X in the species studied. 4. The urinary metabolites indicated that the major routes of biotransformation included hydroxylation and subsequent glucuronic acid conjugation on the aromatic ring, and on the ethyl and isopropyl side chains. A component was observed in mini-pig urine that corresponded to hydroxylation and glucuronidation accompanied by loss of the fluorine atom.

Distribution of membrane phospholipids in the rabbit neural retina, optic nerve head and optic nerve

Since diseases of the neural retina and optic nerve can result in alteration of biological membranes, this study determines similarities and differences in the membrane phospholipid content of the neural retina, optic nerve head, and optic nerve to serve as baseline data. Neural retina, optic nerve head, and optic nerve were dissected, isolated as 5 sets from 20 rabbits and frozen in liquid N2. Separate pooled-tissue extracts were prepared for each set of tissues and phosphorus-31 nuclear magnetic resonance (31P NMR) analyses performed. Ten phospholipids were quantified (respective neural retina, optic nerve head, and optic nerve mole % are given for the 5 major phospholipids detected): phosphatidylcholine (PC), 44.61, 27.67, 26.40; PC plasmalogen or alkylacyl PC (CPLIP); phosphatidylinositol (PI); sphingomyelin (SM); phosphatidylserine (PS), 12.63, 14.77, 15.09; phosphatidylethanolamine (PE), 21.21, 9.59, 8.69; PE plasmalogen (EPLAS), 11.07, 30.96, 33.93; an unidentified (unknown) phospholipid (U) at the chemical-shift value of 0.13 ppm; diphosphatidylglycerol (DPG); and phosphatidic acid (PA), 0.46, 2.92, 1.57. Significant differences between the various tissues were determined by the one-way analysis of variance, using a Scheffé range value of P < 0.05. The neural retina in all phospholipids detected except for the uncharacterized (unknown) phospholipid was significantly different from the optic nerve head tissue. The optic nerve head was significantly different from the optic nerve in PC, CPLIP, PE, EPLAS, U, DPG, and PA. The data provide a baseline for studies on pathologically changed neural retina, optic nerve head, and optic nerve.