The transcriptional and regulatory identity of erythropoietin producing cells.

Erythropoietin (Epo) is the master regulator of erythropoiesis and oxygen homeostasis. Despite its physiological importance, the molecular and genomic contexts of the cells responsible for renal Epo production remain unclear, limiting more-effective therapies for anemia. Here, we performed single-cell RNA and transposase-accessible chromatin (ATAC) sequencing of an Epo reporter mouse to molecularly identify Epo-producing cells under hypoxic conditions. Our data indicate that a distinct population of kidney stroma, which we term Norn cells, is the major source of endocrine Epo production in mice. We use these datasets to identify the markers, signaling pathways and transcriptional circuits characteristic of Norn cells. Using single-cell RNA sequencing and RNA in situ hybridization in human kidney tissues, we further provide evidence that this cell population is conserved in humans. These preliminary findings open new avenues to functionally dissect EPO gene regulation in health and disease and may serve as groundwork to improve erythropoiesis-stimulating therapies.

About the influence of environmental factors on the persistence of DNA - a long-term study.

DNA persistence and DNA transfer are important features in the assessment of a crime scene. The question how long DNA may persist at a certain location is similarly important as the one how the DNA has been transferred to this location. Depending on the source of the DNA as well as the conditions at the crime scene, the answer to this question is quite difficult. In this study, persistence of DNA from epithelial abrasions, blood cells, and saliva cells in indoor and outdoor scenarios has been investigated with regard to exposure time and exposure conditions including sunlight, temperature, and humidity in summer and winter scenarios. Overall, we generated 338 epithelial samples, 572 blood samples, and 572 saliva samples. A complete profile of the cell/DNA donor after exposure could be obtained in 47%, 65%, and 58% of epithelial abrasions, blood samples, and saliva samples, respectively. Regarding blood samples, there were no differences between supporting materials cloth and plastic; however, the percentage of complete profiles was higher for saliva samples on plastic and for epithelial samples on cloth. In indoor scenarios, complete profiles could be recovered from nearly all blood and saliva samples up to 9 months, whereas the amount of epithelial complete profiles already started to decline after 3 months. In outdoor scenarios, we observed a tipping point at an exposure time of 3 months. Blood and saliva samples collected after this period displayed complete profiles in less than 25% of samples. After 12 months, no outdoor sample showed a complete profile. The results of this study facilitate decisions on the relevance of recovered DNA from crime scenes.

Expression of Hsp27 and Hsp70 and vacuolization in the pituitary glands in cases of fatal hypothermia.

Hypothermia causes systemic cellular stress. The pituitary gland is an endocrine gland and plays an important role in thermoregulation. When the core body temperature drops, the pituitary gland is activated by stimulation of hypothalamic hormones. In this study, we investigated morphological alterations of the pituitary gland in cases of fatal hypothermia. Several morphological alterations of the anterior lobe of the pituitary gland, such as hemorrhage, vacuolization, and hyperemia, have been previously described in fatal hypothermia. However, the diagnostic value of these findings is controversial. We compared 11 cases of fatal hypothermia with 10 cases lacking antemortem hypothermic influences. In the presence of thermal cellular stress, the expression of heat shock proteins increases to protect cellular structures. Therefore, we immunohistochemically analyzed Hsp27 and Hsp70. Hsp27 expression was detected in 27.3% of the cases of fatal hypothermia and in 10.0% of the control cases, whereas Hsp70 expression was not detected in any case. Additionally, Sudan staining was performed to quantify fatty degeneration. A positive reaction was found in 45.5% of the study group and in 10.0% of the control group. This indicates that fatty degeneration might be a valuable marker when other macroscopic signs of hypothermia are absent.

Precision of estimating the time since death by vitreous potassium-Comparison of 5 different equations.

The precision of death time estimation by vitreous potassium using 5 different formulas is compared on a random sample of 600 cases. Mean differences, standard deviations and 95% limits of confidence between real and extrapolated time since death were calculated. The best results were obtained using equations with "mean" slopes of about 0,17 or 0,19mmol/l per hour. Equations with a steeper or flatter slope reveal already great mean deviations between real and extrapolated time since death and do not allow a reliable death time estimation.

Cerebrospinal fluid JC virus antibody index for diagnosis of natalizumab-associated progressive multifocal leukoencephalopathy.

OBJECTIVE: Progressive multifocal leukoencephalopathy (PML), caused by JC virus (JCV), can occur in patients receiving natalizumab for multiple sclerosis (MS). JCV detection by quantitative polymerase chain reaction (qPCR) in cerebrospinal fluid (CSF), or brain biopsy, is required for probable or definite diagnosis of PML. However, in some patients only low levels of JCV DNA (<100 copies/ml) are present in CSF, making the diagnosis challenging. Our objective was to assess the complementary value of a CSF JCV antibody index (AIJCV ) in the diagnosis of natalizumab-associated PML. METHODS: AIJCV was assessed in 37 cases of natalizumab-associated PML and 89 MS-patients treated with natalizumab without PML. Sera and CSF were tested in a capture enzyme-linked immunosorbent assay, using JCV-VP1 fused to glutathione S-transferase as antigen. Albumin levels and total immunoglobulin G concentration were determined by immunonephelometry, and the AIJCV was calculated as published. RESULTS: Twenty-six of 37 (70%) patients with natalizumab-associated PML exhibited an AIJCV > 1.5, whereas this was seen in none of the controls (p < 0.0001). At time of the first positive qPCR for JCV DNA, 11 of 20 (55%) patients with natalizumab-associated PML had an AIJCV > 1.5. JCV DNA levels of <100 copies/ml were seen in 14 (70%) of these 20 patients, of whom 8 (57%) demonstrated an AIJCV > 1.5. INTERPRETATION: Determination of the AIJCV could be an added tool in the diagnostic workup for PML and should be included in the case definition of natalizumab-associated PML.