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Biomedical subjects

R J Klein

Publications and source records attributed to R J Klein.

61 records · Page 4Linked to original sources
PubMed1974

Treatment of poxvirus infections in rabbits with 9-beta-D-arabinofuranosyladenine.

The antiviral efficacy of 9-beta-d-arabinofuranosyladenine (ara-A) was evaluated in localized lesions produced by the intradermal inoculation of rabbits with vaccinia virus (VV) and rabbit Shope fibroma virus (SFV). Ara-A administered intraperitoneally suppressed or significantly reduced the cutaneous pustular lesions produced by VV as well as the benign skin tumors caused by the SFV. With a daily dose of 300 mg/kg given for 5 days starting at the time of infection, or with 600 mg/kg daily starting 3 days after inoculation, we were able to suppress completely the formation of tumors induced by the SFV. The appearance of pustular lesions induced by VV was completely suppressed by a dose of 600 mg of ara-A per kg given for 3 days when the treatment was initiated at the time of infection, but a significant reduction in the number of pustular lesions was obtained with a single dose of 600 mg/kg, or with five doses of 300 mg/kg starting 24 h after inoculation. No toxic effect of ara-A was noted in the treated rabbits.

Animals↗
PubMedDate not supplied

Effect of a thymidine kinase inhibitor (L-653,180) on antiviral treatment of experimental herpes simplex virus infection in mice.

Thymidine kinase (TK) inhibitors can block the activity of TK-dependent antiviral drugs in vitro. We have examined the ability of the TK inhibitor (+/-)-9-([(Z)-2-(hydroxymethyl)cyclohexyl] methyl)guanine (L-653,180) to prevent the therapeutic effect of acyclovir (ACV) in experimental herpes simplex virus type 1 (HSV) skin infections of mice. The results showed that ACV given in the drinking water prevents, in a dose-dependent way, the evolution of the viral infection, and that L-653,180 can reverse some of the therapeutic effects of the antiviral drug. Among the parameters used to evaluate the effect of the TK inhibitor mortality was increased compared to ACV treatment alone, only in the presence of low doses of ACV, whereas the establishment of latent infections in sensory ganglia was significantly increased compared to ACV treatment alone, even when high doses of ACV were administered together with L-653,180.

Acyclovir↗
PubMedDate not supplied

Initiation and maintenance of latent herpes simplex virus infections: the paradox of perpetual immobility and continuous movement.

During the acute phase of infection, herpes simplex virus (HSV) is taken up by nerve endings and travels, probably as a noninfectious nucleocapsid, toward the neurons of sensory ganglia. Infectious virus can be detected in ganglia for a limited period, after which the virus enters into a latent phase. It appears that synthesis of deoxyribonucleic acid is not required and that an early viral protein and at least one additional late virus gene product are involved in the establishment of latency. The distinction between a "static" and a "dynamic" form of latency depends on the ability to detect viral activities in neurons and on whether these observed activities are expressed continuously or intermittently. The development of recurrent lesions following virus reactivation is an occasional event and is controlled by inducing agents and the state of the organism. The maintenance of latency depends on the number of neurons that become latently infected after the primary episode, the number of neurons in which reactivation takes place, the fate of the neuron after virus reactivation, and the possibility of renewed neuronal infections after each recurrent episode. Exogenous reinfections may also contribute to the maintenance of latency since they can lead to latent infections in nearby or distantly located sensory ganglia. Multiple latent infections may result also from a single primary infection by dissemination of the virus to distantly located ganglia.

Animals↗
PubMedDate not supplied

Photorefractive keratectomy for hyperopic and mixed astigmatism.

BACKGROUND: The correction of astigmatism with photorefractive keratectomy has been recommended in simple and myopic astigmatism. Therefore in this study the excimer laser was used to correct compound hyperopic and mixed astigmatism. METHODS: We present a prospective clinical study of photorefractive keratectomy in 30 eyes of 24 patients with compound hyperopic astigmatism with a mean spherical equivalent of +4.30 D and mean astigmatism of 2.33 D (group I) and in 17 eyes of 15 patients with mixed astigmatism with a mean spherical equivalent refraction of +0.46 D and mean astigmatism of 4.75 D (group II). The excimer laser used in this study was an MEL 60 (Aesculap-Meditec). In both groups an 18-month follow-up study was performed. RESULTS: In the compound hyperopic astigmatism group after 18 months, 14 of 17 treated eyes (82.3%) were within +/-1.00 D, and 11 (64.7%) were within 60.50 D of the intended correction. In the mixed astigmatism group after 18 months, 10 of 11 eyes (90.9%) were within +/-1.00 D, 8 eyes (72.7%) were within +/-0.50 D of the intended correction. In regard to the stability the 1 year regression of spherical equivalent in the compound hyperopic astigmatism group is 0.78 D and in the mixed astigmatism group 0.37 D. At 18 months, spectacle corrected visual acuity in the compound hyperopic astigmatism group was unchanged or improved in 14 eyes (87.5%); 2 eyes (12.5%) had lost one line. In the mixed astigmatism group at 18 months, spectacle corrected visual acuity was unchanged or improved in 9 eyes (81.8 %); 2 eyes (18.1%) lost one line. Preoperatively, the mean uncorrected visual acuity was 20/100 in the compound hyperopic astigmatism group and the mixed astigmatism group. At 18 months, 14 eyes (93.3%) in the compound hyperopic astigmatism group had an uncorrected visual acuity of 20/40 or better; 4 (26.6%) eyes had an uncorrected visual acuity of 20/20 or better. In the mixed astigmatism group, 9 (81.8%) eyes had an uncorrected visual acuity of 20/40 or better; 4 (36.3%) eyes had an uncorrected visual acuity of 20/20 or better. CONCLUSION: Photorefractive keratectomy is an efficient and relatively safe procedure for reducing or eliminating compound hyperopic and mixed astigmatism up to 6.00 D.

Adult↗