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Der Freie Zahnarzt - Zauberer und Zahnarzt. Im neuen Teil unserer Serie „Zahnärzte mit außergewöhnlichen Hobbys“ geht es um Klaus Lennartz: Der Mönchengladbacher ist...     

Benign mesenchymal tumours and tumour‐like lesions in end‐stage renal disease

Aims: Mesenchymal neoplasms of the kidney are rare, and most represent sporadic angiomyolipomas. A few haemangiomas have been reported in end‐stage renal disease (ESRD) but, to date, no study has focused on the frequency and morphological spectrum of mesenchymal lesions in ESRD. Methods and results: We evaluated retrospectively 90 nephrectomy specimens with ESRD. Haemangiomas were detected in eight cases (8.8%; six males and two females; mean age: 55 years); four were multifocal and four had concurrent renal epithelial neoplasms. Lesions involved the medulla (three), cortex (two) or both (three), and the size range was 1–25 mm (mean 4.8 mm). Histologically, all were capillary haemangiomas with an at least focally detectable spleen‐like anastomosing pattern. All tumours stained positively for CD31 and FLI‐1, but none expressed pankeratin (KL‐1), podoplanin/D2‐40, HHV8 or GLUT‐1. Minute angiomyolipomas (mean size 2.3 mm) were detected in four patients (mean age 49.5 years). Tumour‐like smooth muscle proliferations were seen surrounding muscular arteries (eight), occasionally admixed with fat extending from the renal sinus mimicking angiomyolipoma. No similar tumours were found in 105 control kidneys. Conclusions: Benign haemangiomas are not uncommon in ESRD, but may be under‐recognized. They display distinctive morphology and should be distinguished from angiosarcomas and capillary‐rich renal cell carcinomas.     

Brief Report: Educational attainment does not influence brain aging

Education has been related to various advantageous lifetime outcomes. Here, using longitudinal structural MRI data (4,422 observations), we tested the influential hypothesis that higher education translates into slower rates of brain aging. Cross-sectionally, education was modestly associated with regional cortical volume. However, despite marked mean atrophy in the cortex and hippocampus, education did not influence rates of change. The results were replicated across two independent samples. Our findings challenge the view that higher education slows brain aging.     

Opening of ATP-sensitive potassium channels causes generation of free radicals in vascular smooth muscle cells

Recent evidence suggests that opening of mitochondrial K_ATP channels in cardiac muscle triggers the preconditioning phenomenon through free radical production. The present study tested the effects of K_ATP channel openers in a vascular smooth muscle cell model using the fluorescent probe MitoTracker (MTR) Red™ for detection of reactive oxygen species (ROS). Rat aortic smooth muscle cells (A7r5) were incubated with 1 μM reduced MTR (non-fluorescent) and the MTR oxidation product (fluorescent) was quantified. Thirty-minute pretreatment with either diazoxide (200 μM) or pinacidil (100 μM), both potent mitochondrial K_ATP channel openers, increased fluorescent intensity (FI) to 149 and 162 % of control (p < 0.05 for both), respectively, and the K_ATP channel inhibitor 5-hydroxydecanoate (5HD) blocked it. Valinomycin, a potassium-selective ionophore, raised FI to 156 % of control (p <: 0.05). However, 5HD did not affect the valinomycin-induced increase in FI. Inhibition of mitochondrial electron transport (myxothiazol) or uncoupling of oxidative phosphorylation (dinitrophenol) also blocked either valinomycin- or diazoxide-induced increase in FI, and free radical scavengers prevented any diazoxide-mediated increase in fluorescence. Finally the diazoxide-induced increase in fluorescence was not blocked by the PKC inhibitor chelerythrine, but was by HMR 1883, a putative surface K_ATP channel blocker. Thus opening of K_ATP channels increases generation of ROS via the mitochondrial electron transport chain in vascular smooth muscle cells. Furthermore, a potassium-selective ionophore can mimic the effect of putative mitochondrial KATP channel openers. We conclude that potassium movement through KATP directly leads to ROS production by the mitochondria. Received: 7 January 2002, Returned for revision: 31 January 2002, Revision received: 21 February 2002, Accepted: 14 March 2002     

PD1 expression and correlation with its ligands in oral cancer specimens and peripheral blood

ObjectivesThis study analyzed the expression of the PD1 receptor in tumor tissue and peripheral blood of oral squamous cell carcinoma (OSCC) patients, and correlated it with the PD1 ligands PD-L1 and PD-L2. The currently low response rates of checkpoint inhibitor treatment in OSCC could be increased by a better understanding of immune checkpoint biology. Despite evidence in the literature for upregulation of PD1 checkpoint ligands in OSCC tissue, there has been no correlation analysis of the PD1 receptor with its ligands in tissue specimens and peripheral blood of OSCC patients.Materials and methodsAn RT-qPCR analysis of PD1 mRNA expression was performed in oral cancer specimens, healthy mucosa, and corresponding blood samples. A cut-off point (COP) was determined and a chi-square (χ²) test was carried out. PD1 expression was correlated with previously reported PD-L1 and PD-L2 expression values using the Spearman test.ResultsTissue and blood specimens of 48 OSCC patients and 26 healthy individuals were analyzed. PD1 expression in OSCC specimens was significantly increased (p = 0.006) compared with healthy oral mucosa. PD1 overexpression in tissue samples showed a significant association with the presence of malignancy (p = 0.006). PD1 expression in tissue samples showed a significant positive correlation (p < 0.001) with the ligands PD-L1 and PD-L2. In contrast, there was no correlation between PD1 and its ligands in blood samples. However, there was a significant positive correlation (p < 0.001) between the ligands PD-L1 and PD-L2, both in tissue and blood samples.ConclusionsIncreased PD1 expression might be a manifestation of T-cell exhaustion in OSCC specimens, leading to immune tolerance. PD-L1/PD-L2-PD1 interaction may be a major mediator of local immunosuppression in OSCC, requiring advanced multimodal treatment protocols.     

The role of diabetes mellitus on the formation of severe odontogenic abscesses—a retrospective study

Objectives

To analyze the correlation of diabetes mellitus and hyperglycemia with severe odontogenic abscesses.

Materials and methods

Records of all patients in the Department of Oral and Maxillofacial Surgery of the Medical Center of the Johannes Gutenberg-University who underwent inpatient treatment for severe odontogenic abscesses between 2010 and 2016 were evaluated retrospectively regarding diabetes anamnesis, maximum and fasting blood sugar count, and duration until discharge. In order to compare the numbers to a general maxillofacial group, all patients who received inpatient treatment in 2013 for any diagnosis other than an abscess of the head and neck region were analyzed as well, and the numbers were correlated.

Results

In total, 977 abscess patients were found in the analyzed period. 7.0% of the patients had a known diagnosis of diabetes mellitus type II and 0.6% of type I. Correlation with the general group showed that abscesses were significantly more likely in diabetics as well as patients with abnormal maximum and fasting blood sugar counts. These patients also needed significantly longer inpatient treatment.

Conclusions

Diabetics and patients with abnormal glucose tolerance show significantly higher numbers of severe odontogenic abscesses and might therefore benefit from earlier escalation of antibiotic medication.

Clinical relevance

Severe odontogenic abscesses are one of the most frequent diagnoses in maxillofacial practice. Adjusting the therapeutic approach for diabetics or patients with abnormal blood sugar counts might help to prevent the development of abscesses.