Microbial Sampling Using Interdental Brushes and Paper Points around Teeth and Implants: A Pilot Study for Comparison

Inflammatory periodontal and peri-implant diseases follow dysbiotic shifts in a susceptible host. A well-established tool for microbial sample collection is the use of paper points. The purpose of this pilot study was to evaluate the use of interdental brushes compared to paper points. Biofilm samples were collected with paper points and later interdental brushes from ten patients. Five patients were represented with a community periodontal index of treatment needs (CPITN) of 0–2 around the teeth and an implant with PPD ≤ 5 mm and no radiological bone loss. The remaining five patients had a CPITN ≥ 3 and one implant with peri-implantitis. Microbial samples were analyzed with quantitative polymerase chain reaction (qPCR) and next-generation sequencing (NGS). The results showed higher amounts of DNA in samples taken by interdental brushes but also higher Ct values. Both methods detected Filifactor alocis, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola in the majority of samples, while Aggregatibacter actinomycetemcomitans was rarely found. A microbial dysbiosis index showed comparable or higher values in sites with no periodontitis/peri-implantitis with interdental brushes. The results of this pilot study indicate that interdental brushes might be a valid technique for microbial sampling and particularly advantageous in the early detection of dysbiotic shifts around teeth and implants. Larger studies with more participants are needed to validate the proposed microbial sampling method with interdental brushes.

Longterm visual prognosis of patients with ocular Adamantiades-Behçet's disease treated with interferon-alpha-2a

OBJECTIVE

Relapsing ocular involvement is one of the major manifestations in Adamantiades-Behçet's disease (ABD). Combining systemic corticosteroids with cyclosporin A is currently the treatment of choice. Interferon-alpha (IFN-alpha) has proven to be effective in mucocutaneous ABD and has been reported to improve ocular lesions. We examined the longterm effects of IFN-alpha-2a in a case series of 45 patients with ocular involvement.

METHODS

Since 1988, 45 patients (79 eyes of 90 eyes) with ocular involvement in ABD have been treated with IFN-alpha (3 x 6-9 Mio IU per wk). In the initial acute phase of the disease, patients additionally received short-term corticosteroids (oral prednisolone 100 mg/day), tapered to a maintenance dose of 10 mg/day within 2 weeks. IFN-alpha-2a was administered as longterm therapy with a mean duration of 30 months (range 1.1-101 mo).

RESULTS

IFN-alpha-2a/prednisolone treatment was effective against vasculitis, optic nerve neuropathy, and iritis. Sixty-four eyes had no recurrence under therapy. To date, recurrences have been seen in 26 eyes under IFN-alpha treatment. Flu-like symptoms were recorded in nearly all patients (n = 43). Further side effects were dose-dependent reversible thrombocytopenia (n = 1), psychosis (n = 3), depression (n = 13), thyroiditis (n = 1), and reversible diffuse alopecia (n = 7). In our series, 92% of all eyes showed stable or improved visual acuity in longterm followup.

CONCLUSION

Longterm remission of ocular inflammation can be achieved with the combination of IFN-alpha and low-dose corticosteroids.

Direct observation of hole transfer through DNA by hopping between adenine bases and by tunnelling

The function of DNA during oxidative stress and its suitability as a potential building block for molecular devices depend on long-distance transfer of electrons and holes through the molecule, yet many conflicting measurements of the efficiency of this process have been reported. It is accepted that charges are transported over long distances through a multistep hopping reaction; this 'G-hopping' involves positive charges moving between guanines (Gs), the DNA bases with the lowest ionization potential. But the mechanism fails to explain the persistence of efficient charge transfer when the guanine sites are distant, where transfer rates do not, as expected, decrease rapidly with transfer distance. Here we show experimentally that the rate of charge transfer between two guanine bases decreases with increasing separation only if the guanines are separated by no more than three base pairs; if more bridging base pairs are present, the transfer rates exhibit only a weak distance dependence. We attribute this distinct change in the distance dependence of the rate of charge transfer through DNA to a shift from coherent superexchange charge transfer (tunnelling) at short distances to a process mediated by thermally induced hopping of charges between adenine bases (A-hopping) at long distances. Our results confirm theoretical predictions of this behaviour, emphasizing that seemingly contradictory observations of a strong as well as a weak influence of distance on DNA charge transfer are readily explained by a change in the transfer mechanism.