Characterization of regulatory T cells in SARS-CoV-2 infected hemodialysis patients: relation to clinical and radiological severity.

BACKGROUND: Disordered Treg counts and function have been observed in patients with SARS-Cov-2 and are thought to contribute to disease severity. In hemodialysis patients, scarce data are available on the Treg response to SARS-CoV-2 or its relation to the clinical presentation. METHODS: A cross-sectional study included one hundred patients divided into three groups, thirty SARS-CoV-2-infected hemodialysis patients (COV-HD), and thirty confirmed SARSCoV-2 infected patients (COV), and forty non-infected hemodialysis patients (HD). Flow cytometric analysis of CD4, CD25, FoxP3, and CD39+ Tregs was done for all patients and tested for correlation to in-hospital mortality, clinical, radiological severity indices. RESULTS: COV-HD and COV patients had significantly lower Treg cell count than HD patients (Median value of 0.016 cell/ µl vs 0.28 cell/ µl, respectively- P: 0.001). COV-HD patients had higher CD39+ Tregs (median value of 0.006 cell/ µl vs 0.002 cell/ µl, respectively- P: 0.04). COV-HD patients had significantly lower hospital stay (median value of 3 vs 13 days, P:0.001), ICU admission rates (26.5% vs 46.7%, P:0.005) and in-hospital mortality (20.7% versus 43.3%, P:0.003) than COV patients. Treg and CD39 expressing Treg counts were not correlated to severity indices in both groups. A high neutrophil to lymphocyte ratio is strongly correlated to disease severity in COV-HD patients. CONCLUSIONS: This study provides evidence of T-cell, particularly T-regulatory cell decline in SARS-CoV-2 and suggests that hemodialysis per se does not distinctively impact the T-cell response. COV-HD patients exhibited a higher CD39+ Treg count and a better clinical profile, however, larger studies are needed to extrapolate on these findings.

Bacteriological and clinical assessment of tetracycline as root conditioning in adjunct to periodontal surgery.

The present study was conducted on 14 quadrants from seven solicited patients. After initial phase of plaque control, six different clinical parameters were recorded and scaling and root planning performed. In each of the seven patients two Modified Widman flaps were done. One served as a control and the other as experimental in which irrigation by Tetracycline-Hcl solution 100 mg/ml for 5 minutes was performed. On comparing the two treatment modalities the tetracycline-Hcl root conditioning showed a better improvement in all the clinical parameters tested. Tetracycline irrigation gave less bacterial counts than the control group right after irrigation, however after two weeks the bacterial counts increased again and were insignificantly different in the two groups.

Histologic study of the effects of short and long-term therapy of iodide administration on the periodontium of albino rats.

Iodine is a natural mineral essential for good health and highly concentrated in thyroid tissue. It is used for diagnostic purposes as well as for therapeutic means. The present study was conducted to evaluate the effect of a single dose of iodine administration and multiple doses of the drug for a short and long term therapy on the periodontium. Sixty male albino rats were participated in the study. Twenty rats were used as a control group, the rest of the animals were divided into two experimental groups. The first group received single dose (diagnostic dose) of iodine. The second experimental group was divided into two subgroups. The first subgroup received multiple doses of iodine for a short period of 15 days, while the second subgroup received the same multiple doses for one month. Three rats of the control group and four of each experimental group were sacrificed at the end of the first, second, third and fourth weeks from the beginning of the study. Maxillary and mandibular specimens were dissected, stained with H. & E. and examined microscopically. The results of the study revealed that single diagnostic dose of iodine has no effect on the periodontium while multiple doses of the drug used for therapeutic purposes caused degeneration of periodontal tissues. The effect increased when the drug is used for a long period, the effect of the drug may be related to the direct effect of iodine concentrated in saliva on living cells or indirectly through the effect of xerostomia induced by the drug.