Early therapy of feline leukemia virus infection (FeLV-FAIDS) with 9-(2-phosphonylmethoxyethyl)adenine (PMEA).

Cats infected with molecularly cloned FeLV-FAIDS develop an immunodeficiency syndrome characterized by persistent antigenemia, decline in circulating CD4+ T lymphocytes, and impaired T-cell-dependent immune responses and opportunistic infection. We evaluated the capacity of PMEA to inhibit the replication of FeLV-FAIDS in vitro and to inhibit the progression of FeLV-FAIDS infection in vivo. We found that PMEA inhibited replication of FeLV-FAIDS by greater than or equal to 50% at concentrations of greater than or equal to 0.5 microgram/ml (1.63 microM) in feline fibroblasts and prevented T lymphocyte killing at concentrations of 3 micrograms/ml. PMEA administered to cats at dosages of greater than or equal to 6.25 mg/kg/day from 0 to 49 days after FeLV-FAIDS infection prevented the development of persistent antigenemia and the induction of immunodeficiency disease. In contrast to placebo treated controls, cats successfully treated with PMEA contained viral infection, developed neutralizing antibody, and resisted a second virulent virus challenge without further therapy. Manifestations of PMEA toxicity produced by higher dosages (25 or 12.5 mg/kg/day) were anemia, leukopenia, and diarrhea. These results indicate PMEA to be a potent antiretroviral agent effective in aborting fatal progression of FeLV-FAIDS infection when therapy is initiated at the time of virus exposure.

Evaluation of 9-(2-phosphonylmethoxyethyl) adenine therapy for feline immunodeficiency virus using a quantitative polymerase chain reaction.

To determine the efficacy of 9-(2-phosphonylmethoxyethyl)adenine (PMEA) as a prophylactic chemotherapeutic agent for the treatment of lentivirus infections, three groups of specific pathogen free cats were treated with 0, 3, or 6 mg kg-1 twice daily doses of PMEA beginning 24 h prior to virus challenge with feline immunodeficiency virus Petaluma strain. Treatment was continued for 7 weeks post challenge. During this time cats were monitored for drug toxicity, virus specific antibody response, circulating viral antigen and infectious recoverable virus. To determine the long-term influence of PMEA therapy the cats were monitored for 1 year following the cessation of treatment. The low levels of infectious virus present in blood prompted the development of quantitative polymerase chain reaction assay to enumerate viral DNA burdens in the peripheral blood mononuclear cells of the infected cats and thereby assess drug efficacy. The results indicate that, although prophylactic PMEA did not prevent infection, it did substantially limit feline immunodeficiency virus replication. Furthermore, viral DNA levels remained low in the cats receiving drug a full year (the duration of the study) after cessation of treatment.

[Subgingival plaque due to gingivitis and inactive periodontitis sites in the adult periodontitis patient]. / Subgingivale Plaque aus Gingivitis- und inaktiven Parodontitisstellen beim erwachsenen Parodontitispatienten.

There are several discrepancies with respect to the composition of subgingival plaque in gingivitis and in inactive adult periodontitis (AP). In this study we compared subgingival plaque samples taken from gingivitis sites to those from inactive periodontitis sites of the same patients. Of 44 patients plaque samples from 86 gingivitis sites and 92 periodontitis sites were analysed. Darkfield microscopy showed a higher proportion of spirochetes and mobile rods in the periodontitis sites. Analysis of cultures revealed a higher and statistically significant number of anaerobes in the periodontitis sites (1.7 x 10(7) vs 3 x 10(6), p = 0.006). The following bacterial species were isolated more frequently from periodontitis sites than from gingivitis sites: Actinobacillus actinomycetemcomitans (18% vs 10%), as well as the black-pigmented Prevotella intermedia (68% vs 48%) and Porphyromonas gingivalis (48% vs 28%). On the one hand, these small differences in the bacteriological parameters can be explained by the fact that both gingivitis and periodontitis plaque samples were taken from the same periodontitis patients. An infection of the gingivitis sites from the parodontitis sites within the same patient could not be excluded. On the other hand, the mean probing depth of the gingivitis sites was relatively high, 3.6 mm (measuring point interdental plus pseudo-pocket) which may favor the growth of anaerobic bacteria.

Comparison of papilla healing following sulcular full-thickness flap and papilla base flap in endodontic surgery.

AIM: To compare the loss of papilla height when using the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full-thickness flap in cases with no evidence of marginal periodontitis. METHODOLOGY: Twelve healthy patients referred for surgical treatment of persisting apical periodontitis, who were free from periodontal disease and had intact interdental papillae, were included in the study. The preoperative papilla height was recorded by measuring the distance between a reproducible coronal point on the tooth and the most coronal point of the papilla. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space, and the PBI in the other interproximal space. The PBI consisted of a shallow first incision at the base of the papilla and a second incision directed to the crestal bone creating a split thickness flap in the area of the papilla base. Further, apically, a full-thickness flap was raised. In the other interproximal space, the buccal papilla was carefully incised and elevated completely. Following flap retraction, standard root-end resection and root-end filling were performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0) and the elevated papilla was reapproximated with vertical mattress sutures, which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1 month and at the 3-month recall, using plaster replicas. The loss of papilla height was measured using a laser scanner. Twelve papilla-paired sites were evaluated. The results were statistically analysed using the t-test. RESULTS: Complete closure of the wound was achieved in all treated sites followed by uneventful healing in all patients. The total mobilization of the papilla resulted in loss of papilla height of 1.10 +/- 0.71 mm at 1 month and 1.25 +/- 0.81 mm at the 3-month recall. At the 3-month recall, the retraction had increased in nine sites, whereas in three sites, the loss of height had slightly diminished compared to 1 month. In contrast, after the PBI, only minor changes could be detected: 0.07 +/- 0.09 mm at 1 month and 0.10 +/- 0.15 mm at 3 months. There was a significant difference between the two incision techniques studied (P < 0.007). CONCLUSIONS: In patients with healthy marginal periodontal conditions, the PBI allows rapid and predictable recession-free healing, whereas complete mobilization of the papilla led to a marked loss of the papilla height. In aesthetically relevant areas, the use of the PBI is recommended, to avoid opening of the interproximal space, when periradicular surgical treatment is necessary.

Comparison of long-term papilla healing following sulcular full thickness flap and papilla base flap in endodontic surgery.

AIM: To compare long-term loss of papilla height when using either the papilla base incision (PBI) or the standard papilla mobilization incision in marginal full thickness flap procedures in cases with no evidence of marginal periodontitis. METHODOLOGY: Twelve healthy patients, free of periodontal disease, who had intact interdental papillae were referred for surgical treatment of persisting apical periodontitis and included in the study. The flap design consisted of two releasing incisions connected by a horizontal incision. The marginal incision involved the complete mobilization of the entire papilla in one interproximal space but in the other interproximal space the PBI was performed. Further apically a full thickness flap was raised. Following flap retraction, standard apical root-end resection and root-end filling was performed. Flap closure was achieved with microsurgical sutures. The PBI was sutured with two to three interrupted sutures (size 7/0), the elevated papilla was reapproximated with vertical mattress sutures (size 7/0), which were removed 3-5 days after the surgery. The height of the interdental papilla was evaluated preoperatively and postoperatively after 1-, 3- and 12-month recall using plaster replicas. The loss of papilla height was measured using a laser scanner. Papilla paired sites were evaluated and statistically analysed. RESULTS: Most papilla recession took place within the first month after the surgery in the complete elevation of the papilla. Further small increase in loss of papilla height resulted at 3 months. After 1 year the loss of height diminished to 0.98 +/- 0.75 mm, but there was no statistical difference between the various recall intervals. In contrast, after PBI only minor changes could be detected at all times. There was a highly significant difference between the two incision techniques for all recall appointments (P < 0.001). CONCLUSIONS: In the short as well as long-term the PBI allows predictable recession-free healing of the interdental papilla. In contrast, complete mobilization of the papilla displayed a marked loss of the papilla height in the initial healing phase although this was less evident 1 year postoperatively. In aesthetically relevant areas the use of the PBI is recommended, to avoid opening of the interproximal space, when periradicular surgical treatment is necessary.