Clinical and electrophysiological course of acute syphilitic posterior placoid chorioretinitis.

BACKGROUND: Syphilis can affect the anterior as well as the posterior segment of the eye at any stage. HISTORY AND SIGNS: A 52-year-old man was referred to our clinic because of acute loss of his vision and hearing. Best corrected visual acuity (BCVA) was counting fingers (CF) right and 0.05 left eye, respectively. Fundoscopy revealed bilateral intraretinal macular haemorrhages and a large yellowish edematous lesion involving macula and midperipheral retina. Fluorescein angiography showed diffuse late edema. The visual field showed a defect corresponding to the edematous lesion. The "Ganzfeld" electroretinogram (ERG) was markedly reduced and the multifocal ERG in the affected area was not recordable. THERAPY AND OUTCOME: VDRL, FTA-Abs and TPHA tests in serum and cerebrospinal fluid were positive. Intravenous penicillin therapy was initiated. BCVA, visual field and ERG eventually recovered completely. CONCLUSIONS: Syphilis should be considered as a differential diagnosis in any unclear inflammatory ocular condition. Awareness of syphilitic posterior placoid chorioretinitis allows rapid diagnosis and therapy.

Role of antimutagens/anticarcinogens in cancer prevention.

Recently it has become increasingly clear that chemicals found in our foods and beverages can prevent the genetic damage that leads to cancer initiation. Such substances may also affect subsequent events in the pathways that lead to cancer, and may have the potential to inhibit the mutations that allow tumor cells to become resistant to antitumor agents. We describe here the antimutagenic potential of Glabrene analogs against EMS-induced mutations utilizing modified Ames tests in S. typhimurium TA 100 and E. coli JC 5088. Results of studies of the ability of well-known antioxidants such as EGCG and related compounds to prevent drug resistance mutations in microorganisms are described, and their possible significance in the prevention of chemotherapeutic drug-resistance in tumor cells is discussed.

Umbelliferone analogues and their potential to inhibit Benzo(a)pyrene- and hydrogen peroxide-induced mutations.

Following the natural product lead, farneciferol-D (kopetdaghin, 8), some ether analogues of umbelliferone were synthesized and assayed for their potential to be antimutagenic/anticarcinogenic against mutations induced by benzo(a)pyrene, a potent mutagen/carcinogen, and hydrogen peroxide, and for their ability to function as free radical scavengers. The "true" antimutagenic effect of these compounds was determined at half the nontoxic concentration in Salmonella typhimurium strains utilizing a modified Ames test protocol, and their free radical-scavenging ability was assayed utilizing a nonenzymatic phenazine methosulfate (PMS)-NADH system. Umbelliferone analogues 4 and 5 demonstrated good potential in preventing mutations induced by benzo(a)pyrene and hydrogen peroxide and also exhibited good superoxide scavenging ability in the PMS-NADH assay, suggesting that the antimutagenic activity of these analogues may be linked to their antioxidative properties.

Structure-antimutagenic activity relationship study of plicatin B.

A systematic structure-activity relationship study of plicatin B (1), an antimutagenic constituent of Psoralea juncea, was undertaken with a view toward elucidating its chemical mode of action and possibly optimizing its antimutagenic activity during the process. Compound 1 and its related analogues were examined for their antimutagenic activity against mutations induced by ethyl methanesulfonate, a direct acting mutagen and alkylating agent, in Salmonella typhimurium strain TA100, utilizing the modified Ames test protocol. The dihydro analogue 3 resulting from saturation of the conjugated alkene double bond of 1 was found to exhibit reduced cytotoxicity and enhanced efficacy relative to the parent compound. This result serves preliminarily to exclude a Michael acceptor role of the alpha,beta-unsaturated carbonyl moiety in connection with its antimutagenic activity.

Antimutagenic/antioxidant activity of green tea components and related compounds.

The ability of green tea components and other antioxidant compounds to function as antimutagens/antioxidants has been well established, and their role in cancer prevention is supported by numerous epidemiological studies. We have utilized modified Ames tests, superoxide scavenging assays, and assays for protection against DNA scissions to compare and contrast the protective effects of various teas and commercial and laboratory-isolated tea components to those produced by compounds such as resveratrol, selenium, curcumin, vitamins C and E, quercetin dihydrate, sulforaphane, ellagic acid dihydrate, glutathione reduced, trolox, butylated hydroxanisole (BHA), butylated hydroxytoluene (BHT), and N-acetyl-L-cysteine (NAC). In Ames tests, employing hydrogen peroxide as a mutagen, epigallocatechin gallate (EGCG) produced the highest level of protection of all antioxidants tested. Measurement of protection against DNA scissions produced results that again showed that EGCG produced the strongest protective effects. In scavenging assays using a xanthine-xanthine oxidase (enzymatic system), epicatechin gallate (ECG) showed the highest scavenging potential. In a nonenzymatic (phenazine methosulfate-NADH) oxidizing system, EGCG once again showed the strongest effects. The implications of these and similar results are discussed in relation to cancer prevention and prevention of drug/antibiotic resistance.

The search for orally active medications through combinatorial chemistry.

The literature of combinatorial chemistry is reviewed with particular attention paid to considerations of absorption, distribution, metabolism and excretion in the design and evaluation of libraries containing drug-like molecules. Published libraries are evaluated in particular for the likelihood that the products would possess oral bioavailability.

[Yellow discoloration of the lens in the diabetic patient]. / Die Gelbfärbung der Linse beim Diabetiker.

BACKGROUND: The yellowing is a precursor of the cataract. In the diabetic patient this phenomenon is established earlier than in normal control groups. In the literature the yellowing is explained by elevated glucose levels. Does the duration of diabetes play a key role for this phenomenon? MATERIALS AND METHODS: The yellowing of the lens can be very well detected by the ocular photometer. Using this device, 52 well regulated diabetics without retinopathy and 19 diabetics with mild background retinopathy were examined. We determined the contrast-transfer ratio of the lens, which has been correlated with the age, the duration of diabetes, the weight of the patient, the bodymass index and the hemoglobin a1c of the patient. RESULTS: Without retinopathy none of the introduced correlations were significant. If the diabetes is well regulated, even a long duration of diabetes does not cause any yellowing of the lens. With mild retinopathy the yellowing of the lens could not be detected because of the sites of measurement, which were changing. A high correlation between the duration of diabetes and the intensity of the macula and the excavation has been found. The macula gets darker and the excavation gets brighter. CONCLUSIONS: The yellowing of the lens does not depend on any of the presented parameters. In diabetics with mild background retinopathy the macula gets darker. This can be interpreted as an hyperemia of the choroid. Most probably this phenomenon is caused by the decline of sympathetic nerve fibers.