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Objective: To assess the utility of visual electrophysiological methods, visual evoked potentials (VEPs) and pattern electroretinograms (PERGs) were recorded for the detection of subclinical optic nerve and retinal involvement in patients with diabetes mellitus. Subjects and Methods: The data of 63 patients (126 eyes) with no vascular retinopathy or optic neuropathy were retrospectively analyzed. The patients were divided into polyneuropathic/nonpolyneuropathic groups to differentiate between early and late subclinical stages. The recorded parameters were compared with local reference values. Results: 116 eyes (92%) had VEP and 76 (60%) had PERG abnormalities. The most frequent alteration was latency delay, but waveform and amplitude irregularities were also observed. The simultaneous use of the two methods allowed us to differentiate abnormal VEPs of purely optic nerve origin from those reflecting retinal involvement. Conclusions: We suggest that regular electrophysiological screening should receive more attention in the ophthalmological care of diabetic patients.

Purpose: To compare the interocular amplitude differences of the multifocal electroretinograms (mfERGs) evoked by either monocular or binocular stimulation in healthy subjects with good vision. Methods: Thirty-five subjects were included in the study. A Roland Consult RETIscan system was used. DTL electrodes were employed. First, the right and left eyes were stimulated separately, then, binocular stimulation was applied. The amplitudes of the scalar products were averaged over five concentric retinal regions (rings). Results: The interocular amplitude differences were 21.55% (SD: ±12.72) under monocular conditions and 18.69% (SD: ±11.64) under binocular conditions. No significant differences were found between the amplitudes and variability values obtained under either monocular or binocular stimulation. Conclusions: Our results provided no evidence for the advantage of either binocular or monocular stimulating conditions in obtaining mfERGs. A considerable side difference was found between the mfERGs of ...

A novel cascade condensation-intramolecular acylation process for the synthesis of the title compounds from anthranilic acid derivatives is developed.

The reaction of various anthranilic acid derivatives or their esters with 4-oxotetrahydrothiophene-3-carbonitrile 2, 2-oxocyclopentanecarbonitrile (9, n = 1) or 2-oxocyclohexanecarbonitrile (9, n = 2) in ethanol under reflux conditions giving rise the formation of single products isolated in each case after simple filtration. The products were characterized as pyrazolo[1,5-a]quinazolin-5-ones 4 instead of the expected pyrazol-3-amines 3. These cascade condensation–intramolecular acylation processes generated in one-step reactions from simple starting materials novel heterocyclic scaffolds ready for further functionalization. The present synthetic protocol provides acceptable yields of new tetracyclic products in high purity.

A new two-step synthesis of pyrrole-2-carboxylic acids, steps via 1,3 dipolar cycloaddition of azomethine ylides to nitro-styrenes and oxidation of the resulting pyrrolidines with alkaline hydrogen peroxide is described. The oxidation of cycloadducts 3 by the means of MnO2 under different conditions also has been examined.

a,b;g,d-Unsaturated nitrile oxides 6, 13 have been prepared from the corresponding aldehydes via sequential oxime formation, chlorination, and dehydrochlorination. These nitrile oxides show unexpected stability, presumably due to delocalisation, and can be isolated. 2,6-Diphenylbenzonitrile oxide 13b was particularly stable and a single crystal X-ray structure was obtained. 3,3-Diphenylpropenitrile oxide 6 was also isolated but could be dimerized, to give a 1,4,2,5-dioxadiazine 7 or furoxan 8, via slight modifications to the conditions employed. The corresponding nitrones 14, 17 have also been prepared, via the reaction of the a,b;g,d-unsaturated aldehydes 10a,b with substituted hydroxylamines, isolated and trapped.

We have studied the behaviour of 2-acetoxy-nitroethane derivatives in the presence of triethylamine and of an azomethine ylide generated also by the action of this base in the same reaction mixture. Under these conditions the nitro-olefins are generated and react in situ with the corresponding dipoles, giving pyrrolidine derivatives in moderate to good yields.

The simple γ-pyranones 4, 5, and 6 undergo 4π + 2π cycloaddition reactions with Danishefsky’s diene 8 and azomethine ylides 12, 16, and 25 to give a range of cycloadducts. The position of the electron-withdrawing group is the decisive factor in these reactions, with the 2-substituted derivatives 5 and 6 being less reactive than the 3-substituted γ-pyranone 4. The esters, 4 and 5, react via addition across the 2,3-CC bond of the pyranone ring, whilst the aldehyde 6 reacts via addition across the CO of the carbaldehyde group.

The tricyclic core of the martinellines has been synthe- sised stereoselectively in two steps, using 1,3-dipolar cycloaddition of azomethine ylides as a key step.