Impact of nepafenac 0.1% on macular thickness and postoperative visual acuity after cataract surgery in patients at low risk for cystoid macular oedema.

PURPOSE: To evaluate the use of topical nepafenac 0.1% after routine phacoemulsification in patients at low risk for cystoid macular oedema (CME) using optical coherence tomography (OCT) measurement of macular thickness. METHODS: Seventy-nine subjects with no risk factors for CME had uncomplicated bimanual micro-incision cataract surgery by an experienced surgeon. All subjects received preoperative nepafenac. Subjects were randomised to postoperative standard of care, consisting of a topical antibiotic for 10 days and topical corticosteroid for 1 month (control), or standard of care plus nepafenac for 1 month (treatment). OCT and ETDRS best-corrected visual acuity were measured preoperatively and 2 months postoperatively. Primary endpoints were comparison of changes in macular thickness between groups and the relationship of that change to postoperative vision. RESULTS: All subjects had excellent visual outcomes, with mean visual improvement of 15 letters. Cataract surgery was very efficient with a mean effective phaco time (EPT) of 4.99 and 6.90 s in the control and treatment groups, respectively. There were small increases in the central macular thickness in both the control (2.78 microm) and treatment (5.60 microm) groups. The change in macular thickness was statistically similar between groups and did not correlate with the final visual outcome. DISCUSSION: The small increase in macular thickness after routine cataract surgery is probably not clinically significant. In subjects undergoing routine cataract surgery, and at low risk for CME, the routine use of preoperative nepafenac may be all that is necessary to achieve excellent visual recovery.

Effects of high amphetamine dose on mood and cerebral glucose metabolism in normal volunteers using positron emission tomography (PET).

The effects of high euphorigenic doses of D-amphetamine (0.9-1.0 mg/kg p.o.) on regional cerebral glucose metabolism (rCMRglu) and psychological measures were investigated in 10 healthy human volunteers using a within-subject design and [F-18]-fluorodeoxyglucose positron emission tomography (FDG-PET) and a variety of psychological assessments. At the dose tested, D-amphetamine produced a mania-like syndrome concomitantly with a widespread increase in absolute cerebral metabolism, which was significant in the anterior cingulate cortex, caudate nucleus, putamen, and thalamus. An exploratory analysis revealed that: (1) certain aspects of this mania-like syndrome correlated positively with the metabolic changes seen in the frontal cortex, caudate nucleus and putamen; and (2) some of the amphetamine-induced changes in CMRglu correlated with D-amphetamine plasma levels. The present findings of cortical and subcortical increases in cerebral metabolism after D-amphetamine application in humans accord with previous studies in animals, demonstrating that relatively high doses of D-amphetamine (presumably at least 1 mg/kg) are needed to increase cerebral glucose metabolism.

Deaths and injuries as a result of lightning strikes to aircraft.

Aircraft are at risk of being struck by lightning or triggering lightning as they fly through clouds. Commercial and private airplanes have been struck, with resultant deaths and injuries to passengers and crew. We were interested in learning how large a problem existed to the American public from lightning strikes to airplanes. We analyzed data from the National Transportation Safety Board (NTSB) on lightning-related accidents in the United States from 1963-89. NTSB recorded 40 lightning-related aircraft accidents. There were 10 commercial airplane accidents reported, 4 of which were associated with 260 fatalities and 28 serious injuries. There were 30 private aircraft accidents that accounted for 30 fatalities and 46 serious injuries. While lightning remains a potential risk to aircraft passengers and crew, modern airplanes are better equipped to lessen the dangers of accidents due to lightning.

Pharmacodynamics and pharmacokinetics of khat: a controlled study.

OBJECTIVES: To show the subjective and cardiovascular effects of khat leaves having a standardized content of cathinone. BACKGROUND: The main effect of khat is an increase of energy and alertness. This effect is thought to be attributable to the phenylalkylamine cathinone, but no controlled clinical trials have been published. DESIGN: The design was balanced and double blind. Six drug-naïve volunteers received a single dose of khat corresponding to 0.8 mg/kg body weight, as well as alkaloid-free khat as a placebo. Psychologic effects were evaluated by the Addiction Research Center Inventory (ARCI) and visual analog scales. Physiologic measures were systolic blood pressure, diastolic blood pressure, and heart rate. Plasma concentrations of cathinone and its metabolites norephedrine and R,R-(-)norpseudoephedrine were determined by HPLC. RESULTS: Maximal plasma concentrations of cathinone (127 +/- 53 [SD] ng/ml) were attained after 127 +/- 30 minutes. The area under the plasma concentration-time curve from 0 to 9 hours was 415 +/- 207 ng/ml.hr, and the terminal elimination half-life was 260 +/- 102 minutes. An effect of khat was observed in the ARCI scales Abuse Potential (p < 0.01), Motor Stimulation (p < 0.02), Amphetamine-Like Effect (p < 0.005), and Stimulation-Euphoria (p < 0.005), as well as in the visual analog scales Excited-Calm (p < 0.001) and Energetic-Lethargic (p < 0.001). CONCLUSIONS: Our results provide objective evidence for the amphetamine-like stimulatory effects of khat leaves. These effects were closely similar to those observed after cathinone, 0.5 mg/kg body weight, although peak plasma concentrations of cathinone after khat were delayed.

Determination of (S)-(-)-cathinone and its metabolites (R,S)-(-)-norephedrine and (R,R)-(-)-norpseudoephedrine in urine by high-performance liquid chromatography with photodiode-array detection.

A high-performance liquid chromatographic (HPLC) procedure with photodiode-array detection (DAD) is described for the determination of (S)-(-)-cathinone (S-CA) and its metabolites (R,S)-(-)-norephedrine (R-NE) and (R,R)-(-)-norpseudoephedrine (R-NPE) in urine. Extraction and clean-up of 1-ml urine samples were performed on a cyano-bonded solid-phase column using (+/-)-amphetamine as internal standard. The concentrated extracts were separated on a 3-microns ODS-1 column with acetonitrile-water-phosphoric acid-hexylamine as the mobile phase. Peak detection was done at 192 nm. The detection limits for S-CA and R-NE/R-NPE in urine were 50 and 25 ng/ml, respectively. The differentiation of the enantiomers of cathinone and norephedrine was achieved by derivatization with (S)-(-)-1-phenylethyl isocyanate to the corresponding diastereomers followed by HPLC-DAD on a 5-microns normal-phase column. The R and S enantiomers of norpseudoephedrine were determined by gas chromatography-mass spectrometry after on-column derivatization with (S)-(-)-N-trifluoroacetylprolyl chloride. Following a single oral dose of 0.5 mg/kg of S-CA, the concentrations found in urine ranged from 0.2 to 3.8 micrograms/ml of S-CA, from 7.2 to 46.0 micrograms/ml of R-NE and from 0.5 to 2.5 micrograms/ml of R-NPE.

[Khat, a herbal drug with amphetamine properties]. / Khat, eine pflanzliche Droge mit Amphetaminwirkungen.

Because of their stimulating effect, leaves of the khat bush are chewed in several East African countries and in Yemen. Since only fresh leaves are active, this habit is almost unknown outside the regions where the plant grows. Recently, however, khat has made its appearance in the United States and in several European countries, while an import permit has been requested in Switzerland. These are reasons for making the practitioner familiar with the effects of this drug. During the last fifteen years, knowledge of khat and its constituents has made substantial progress. Today, the alkaloid cathinone is regarded as the main active principle of this drug, and this substance is held to be a natural amphetamine. This article summarizes knowledge of the pharmacology of khat.