Destination and Specific Impact of Different Bile Acids in the Intestinal Pathogen Clostridioides difficile.

The anaerobic bacterium Clostridioides difficile represents one of the most problematic pathogens, especially in hospitals. Dysbiosis has been proven to largely reduce colonization resistance against this intestinal pathogen. The beneficial effect of the microbiota is closely associated with the metabolic activity of intestinal microbes such as the ability to transform primary bile acids into secondary ones. However, the basis and the molecular action of bile acids (BAs) on the pathogen are not well understood. We stressed the pathogen with the four most abundant human bile acids: cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA) and lithocholic acid (LCA). Thin layer chromatography (TLC), confocal laser scanning microscopy (CLSM), and electron microscopy (EM) were employed to track the enrichment and destination of bile acids in the bacterial cell. TLC not only revealed a strong accumulation of LCA in C. difficile, but also indicated changes in the composition of membrane lipids in BA-treated cells. Furthermore, morphological changes induced by BAs were determined, most pronounced in the virtually complete loss of flagella in LCA-stressed cells and a flagella reduction after DCA and CDCA challenge. Quantification of both, protein and RNA of the main flagella component FliC proved the decrease in flagella to originate from a change in gene expression on transcriptional level. Notably, the loss of flagella provoked by LCA did not reduce adhesion ability of C. difficile to Caco-2 cells. Most remarkably, extracellular toxin A levels in the presence of BAs showed a similar pattern as flagella expression. That is, CA did not affect toxin expression, whereas lower secretion of toxin A was determined in cells stressed with LCA, DCA or CDCA. In summary, the various BAs were shown to differentially modify virulence determinants, such as flagella expression, host cell adhesion and toxin synthesis. Our results indicate differences of BAs in cellular localization and impact on membrane composition, which could be a reason of their diverse effects. This study is a starting point in the elucidation of the molecular mechanisms underlying the differences in BA action, which in turn can be vital regarding the outcome of a C. difficile infection.

Love Death-A Retrospective and Prospective Follow-Up Mortality Study Over 45 Years.

BACKGROUND: Although sexual activity can cause moderate stress, it can cause natural death in individuals with pre-existing illness. The aim of this study was to identify additional pre-existing health problems, sexual practices, and potential circumstances that may trigger fatal events. METHODS: This medicolegal postmortem, retrospective, and prospective study is based on data of autopsies performed at the Institute of Legal Medicine of the University hospital, Goethe-University, Frankfurt/Main, Germany. OUTCOMES: Identification of pre-existing health problems, sexual practices, and potential circumstances than could trigger fatal events. RESULTS: From 1972 to 2016 (45 years) approximately 38,000 medicolegal autopsies were performed, of which 99 cases of natural death were connected to sexual activities (0.26%). Except for eight women, men represented most cases. The women's mean age was 45 years (median = 45) and the men's mean age was 57.2 years (median = 57). Causes of death were coronary heart disease (n = 28), myocardial infarction (n = 21) and reinfarction (n = 17), cerebral hemorrhage (n = 12), rupture of aortic aneurysms (n = 8), cardiomyopathy (n = 8), acute heart failure (n = 2), sudden cardiac arrest (n = 1), myocarditis (n = 1), and a combination of post myocardial infarction and cocaine intoxication (n = 1). Most cases showed increased heart weights and body mass indices. Death occurred mainly during the summer and spring and in the home of the deceased. If sexual partners were identified, 34 men died during or after sexual contact with a female prostitute, two cases at least two female prostitutes. Nine men died during or after sexual intercourse with their wife, in seven cases the sexual partner was a mistress, and in four cases the life partner. Five men died during homosexual contacts. Based on the situation 30 men were found in, death occurred during masturbation. Of the women, five died during intercourse with the life partner, two died during intercourse with a lover or friend, and in one case no information was provided. CLINICAL TRANSLATION: Natural deaths connected with sexual activity appear to be associated with male sex and pre-existing cardiovascular disorders. Most cases recorded occurred with mistresses, prostitutes, or during masturbation. If death occurs, the spouse or life partner might need psychological support. STRENGTH AND LIMITATIONS: To our knowledge, the present study contains the largest collection of postmortem data on natural deaths connected with sexual activities. However, the cases presented were of forensic interest; a larger number of undetected cases especially in the marital or stable relationship sector must be assumed. CONCLUSION: Patients should be informed about the circumstances that could trigger the "love death." Lange L, Zedler B, Verhoff MA, Parzeller M. Love Death-A Retrospective and Prospective Follow-Up Mortality Study Over 45 Years. J Sex Med 2017;14:1226-1231.

[Skull fracture or accessory suture in a child?]. / Schädelfraktur oder akzessorische Sutur bei einem Kind?

Differentiation between accessory sutures and fractures in the skull of an infant can be difficult. Apart from the regular sutures there is a multitude of variations that may be mistaken for a fracture line. Such variations include for instance the intraparietal suture between the two ossification centers of the parietal bone or the mendosal suture between the supraoccipital and interparietal bone of the occipital squama. The presented case refers to an approximately 20-month-old female child. During autopsy, a discontinuity in the right paramedian posterior cranial fossa parallel to the internal occipital crest with connection to the foramen magnum was observed. The macroscopic findings suggested a fracture line because of its course. However, neither a hemorrhage in the soft tissue nor callus formation was discernible. The discontinuity was preserved with the adjacent parts of the occipital bone for further histological examination. In the report of a cranial CT, which was carried out five days before the child's death, an accessory suture paramedially in the right posterior cranial fossa was described. When the clinical CT records were re-evaluated, a similar discontinuity at the corresponding position on the other side was detected, though of noticeably shorter length. Additionally, the preserved occipital bone fragment including the discontinuity was histologically processed. In the radiological literature, precise (radiological) criteria for differential diagnosis are indicated. A zigzag pattern with sclerotic borders and a bilateral and fairly symmetric occurrence indicate a suture, whereas a sharp lucency with non-sclerotic edges and a unilateral occurrence indicate a fracture. Taking all the findings into account, the depicted discontinuity was regarded as an accessory suture. This case demonstrates that differentiation between a fracture and an accessory suture may be difficult in the autopsy of a child and underlines the importance of a postmortem CT examination.