Phenazines with two cationic side chains as potential antimalarials

1,9-Phenazine-bis(dialkylaminocarboxamides) were prepared for screening as potential antimalarials. No significant activity against Plasmodium berghei was observed. The phenazine targets were prepared from 1,9-phenazinedicarboxylic acid by standard methods. The reaction between 1,9-phenazinedicarboxylic acid and thionyl chloride in the presence of dimethylformamide unexpectedly gave 4-chloro-1,9-phenazinedicarbonyl chloride.

"Dye/light" Dye-induced photosensitization of herpes virus. A clinical trial on humans

A series of 21 patients with herpetic corneal ulcers was treated by photodynamic inactivation (using a single application of neutral red 1 per cent solution followed by a 15-min exposure to a 40 watt light of 440--550 nm), carbolization, or idoxuridine (IDU) ointment. No significant difference was found in the number that healed, the mean healing time, or the number of recurrences after any of the three treatments.

Vulvar histology after neutral red photoinactivation of herpes simplex virus

The use of photodynamic dye and light inactivation for the treatment of genital herpes simplex virus infections has been associated with the risk of potential oncogenesis. Sixteen patients treated with neutral red and fluorescent light for documented herpetic infections were studied at intervals ranging from 9 to 52 months following treatment. Four patients treated with other modalities were included in the study. Biopsies of the treated areas were obtained, and 3925 tissue sections were examined. Mild atypical epithelial changes were focally present in most specimens regardless of therapy. Histologically identifiable premalignant change could not be demonstrated.

Photodynamic inactivation in recurrent infections with herpes simplex virus

Photodynamic inactivation with neutral red (a heterotricyclic dye) and light was evaluated in a placebo-controlled study of 170 episodes of recurrent infection with herpes simplex virus in 96 patients. The technique inactivated herpes simplex virus in vitro. However, no beneficial effect, either on the rate of resolution of herpetic lesions or on the interval to subsequent recurrences, was observed in treated patients. These negative results should not deter further investigation of photodynamic inactivation as a potential treatment for herpes simplex virus infections, but the clinical application of this form of therapy should be limited to properly controlled studies until its efficacy is proven.

In vitro and in vivo studies of the action of rifampicin, clofazimine and B1912 on Mycobacterium marinum

Rifampicin (RMP) and two riminophenazine compounds (B663 and B1912) suppressed the growth of Mycobacterium marinum in vitro and in a mouse footpad infection. At appropriate concentrations and dietary dosage, all three drugs showed bactericidal activity in vitro and in vivo. On the basis of minimum inhibitory concentration, RMP was considerably more active than the other two substances in vitro. However, the rate of bactericidal effect was similar for all three drugs. In vivo, the minimum bactericidal dietary dosages of RMP, B663 and B1912 were 0.03, 0.03 and less than or equal to 0.01%, respectively. Results suggest that these drugs may be of value for the treatment of clinical M. marinum infections.

Failure of neutral-red photodynamic inactivation in recurrent herpes simplex virus infections

Because photodynamic inactivation of herpes simplex virus infections may not be free of hazard, the efficacy of photodynamic inactivation with neutral red and light was evaluated in a placebo-controlled study of 170 episodes of recurrent herpes simplex virus infection in 96 patients. The preparation of neutral red that was used was shown to photoinactivate herpes simplex virus in vitro, but had no significant effect on the rate of resolution of herpetic lesions (P greater than 0.10) or on the frequency of subsequent recurrences (P greater than 0.10), except for orolabial lesions, in which an adverse effect on the rate of subsequent recurrences was observed (P less than 0.05). In the absence of demonstrated efficacy, the routine use of neutral red and light in patients with recurrent herpes simplex virus infections should be discontinued. Furthermore, other photoactive dyes should not be used until their efficacy has been demonstrated by suitably controlled clinical trials.

[The photodynamic effect in Herpes simplex: a review]

Photodynamic action is an extraordinarily potent physicochemical process which is dramatically lethal for herpesvirus and other organisms in vitro. Recent studies in animal models and man indicate that the process is effective against in vivo skin infections as well. Although a great deal is yet to be learned about the application of photodynamic action to clinical disease, current experience indicates that photodynamic action will find a permanent place in the physician's therapeutic armamentarium.

Acute abdomen in a patient treated with lamprene

Patients receiving Lamprene may develop acute abdominal symptoms which simulate an abdominal emergency. Withdrawal of the drug relieves these symptoms. The absorption of Lamprene can be increased and deposition in the reticuloendothelial system as crystals can be avoided if it is administered in an alcoholic medium.

Neutral red with photoinactivation in the treatment of herpes genitalis

A clinical trial was undertaken to compare the efficacy of neutral red photodynamic inactivation treatment of genital herpes infections with that of a non-photoactive dye, phenol red, as a control. In a series of nineteen patients with virologically proven herpes genitalis who were adequately followed, eleven were treated with neutral red, and eight with phenol red; no difference in response to therapy was found between the two groups, and it is concluded that under the conditions of this trial neutral red with photoinactivation was not effective in the treatment of acute genital herpes infections. Approximately 75 per cent. of those with vulval lesions also had concurrent cervical infection, so that an effective topical treatment would need to be applicable to both anatomical sites.

Photodynamic inactivation in experimental herpetic keratitis

The effect of photodynamic inactivation on experimental herpes simplex keratitis in rabbits was investigated using neutral red as a photosensitizing dye followed by exposure to light at 425nm. Combined dye application and light exposure early in the disease (two days following infection) reduced to a minimal extent the severity and duration of the acute epithelial infection. The effect on well-established keratitis (three days postinfection) was negligible as evaluated by clinical grading, viral recovery, and histopathological study. In initial experiments, it was found that the dye and light did not have any observable deleterious effect on intact corneas or cause any noticeable delay in healing of injured cornias. Further, when light or dye were utilized alone, neither changed the severity or duration of the keratitis. In vitro treatment of the virus with light and dye destroys its ability to produce experimental keratitis.

Genital herpes: Treatment with methylene blue and light exposure

Fifty-six patients with genital herpes were treated by photodynamic inactivation of herpesvirus by methylene blue (36 patients), proflavine (101 or neutral red (10). The first 35 patients were randomly selected for treatment with one of the three dyes. All the others were initially treated with methylene blue. The disease was temporarily eradicated in about 70% of instances by exposure of the lesions to light plus topically applied methylene blue, neutral red or proflavine. Relapses, however, were not prevented or appreciably reduced.

Thymus-dependent lymphocytes of peripheral blood in leprosy patients

Study of the numbers of thymus-derived lymphocytes by the rosette assay (T-RFC) in patients with leprosy reveals that lower than normal numbers of T-RFC are regularly seen in those patients with the active lepromatous form of this disease. Essentially normal numbers of T-RFC were found in inactive lepromatous, borderline, and indeterminate types of leprosy. The lowest percentages and lowest absolute numbers of T-RFC were encountered in patients with lepromatous leprosy resistant to chemotherapy. Patients with lepromatous leprosy complicated by erythema nodosum leprosum show numbers of T-RFC that are more nearly normal than the numbers of T-RFC in patients with uncomplicated lepromatous leprosy. These findings are discussed with respect to the pathogenesis of lepromatous leprosy and the T-RFC deficiency demonstrated in this disease. The possibility that transient defects in T-RFC numbers or function may predispose to lepromatous leprosy is proposed.