Human Primary Intestinal Epithelial Cells as an Improved In Vitro Model for Cryptosporidium parvum Infection

The study of human intestinal pathogens has been limited by the lack of methods for the long-term culture of primary human intestinal epithelial cells (PECs). The development of infection models with PECs would allow a better understanding of host-parasite interactions. The objective of this study was to develop a novel method for prolonged in vitro cultivation of PECs that can be used to study Cryptosporidium infection. We isolated intact crypts from human intestines removed during weight loss surgery. The fragments of intestinal layers were cultivated with culture medium supplemented with growth factors and antiapoptotic molecules. After 7 days, the PECs formed self-regenerating cell clusters, forming villi that resemble intestinal epithelium. The PECs proliferated and remained viable for at least 60 days. The cells expressed markers for intestinal stem cells, epithelial cells, and mature enterocytes. The PECs were infected with Cryptosporidium. In contrast to older models in which parasite numbers decay, the burden of parasites increased for >120 h. In summary, we describe here a novel method for the cultivation of self-regenerating human epithelial cells from small intestinal crypts, which contain both intestinal stem cells and mature villus cells. We present data that suggest these cells support Cryptosporidium better than existing cell lines. PECs should provide an improved tool for studying host-parasite interactions involving Cryptosporidium and other intestinal pathogens.     

The tumor suppressor SirT2 regulates cell cycle progression and genome stability by modulating the mitotic deposition of H4K20 methylation

The establishment of the epigenetic mark H4K20me1 (monomethylation of H4K20) by PR-Set7 during G₂/M directly impacts S-phase progression and genome stability. However, the mechanisms involved in the regulation of this event are not well understood. Here we show that SirT2 regulates H4K20me1 deposition through the deacetylation of H4K16Ac (acetylation of H4K16) and determines the levels of H4K20me2/3 throughout the cell cycle. SirT2 binds and deacetylates PR-Set7 at K90, modulating its chromatin localization. Consistently, SirT2 depletion significantly reduces PR-Set7 chromatin levels, alters the size and number of PR-Set7 foci, and decreases the overall mitotic deposition of H4K20me1. Upon stress, the interaction between SirT2 and PR-Set7 increases along with the H4K20me1 levels, suggesting a novel mitotic checkpoint mechanism. SirT2 loss in mice induces significant defects associated with defective H4K20me1–3 levels. Accordingly, SirT2-deficient animals exhibit genomic instability and chromosomal aberrations and are prone to tumorigenesis. Our studies suggest that the dynamic cross-talk between the environment and the genome during mitosis determines the fate of the subsequent cell cycle.     

Influence of maturational status in the exercise-induced release of cardiac troponin T in healthy young swimmers

ObjectivesTo determine the influence of maturational status on the release of cardiac troponin T (cTnT) induced by a bout of 30 min, high-intensity, continuous exercise.DesignQuasi-experimental, cross-sectional study.MethodsSeventy male, young, well trained swimmers (age range 7–18 years, training experience 1–11 years) were classified by maturational stages: Tanner stage I (n = 14), II (n = 15), III (n = 15), IV (n = 13), and V (n = 13). Participants underwent a distance-trial of 30 min continuous swimming, and cTnT was measured before, immediately after and 3 h after exercise. Changes in cTnT over time were compared among groups, and associated with exercise load.ResultsBasal cTnT was higher in Tanner-V (3.8–8.1 ng/L) compared with I (1.5–5.5 ng/L, p < 0.001), II (1.5–4.5 ng/L, p < 0.001) and III (1.5–6.8 ng/L, p = 0.003), and in IV (1.5–6.3 ng/L) compared with II (p = 0.036). Maximal elevations of cTnT from baseline were notable (p < 0.001) and comparable among maturational stages (p = 0.078). The upper reference limit for myocardial injury was exceeded in 35.7% of the participants, without differences among groups (p = 0.18). Baseline cTnT correlated with participant characteristics, and maximal cTnT elevations from baseline with exercise internal load (%HRpeak, r_s = 0.34, p =  0.003; %HRmean, r_s = 0.28, p = 0.02).ConclusionsMaturational status influences positively absolute pre- and post-exercise cTnT but not its elevation after a bout of 30 min, high-intensity, continuous exercise.     

Psychosis and Dandy-Walker syndrome: a case report and review of the literature

Dandy-Walker syndrome (DWS) is a group of brain malformations which sometimes present with psychotic symptoms. We present the case of a patient diagnosed with Dandy-Walker variant who presented with schizophrenia-like psychosis. A man in his 30s was admitted to an acute psychiatric unit presenting with persecutory delusions, auditory hallucinations and violent behaviour. The MRI performed showed the typical alterations of Dandy-Walker variant: vermian hypoplasia and cystic dilatation of the fourth ventricle. He also suffered from mild intellectual disability. After being treated with olanzapine 10 mg/d for a month, his psychotic symptoms greatly improved and he was discharged. In conclusion, DWS may cause psychosis through a dysfunction in the circuit connecting prefrontal, thalamic and cerebellar areas. The association between these two conditions may contribute to the understanding of the aetiopathogenesis of schizophrenia.     

Prevalence and severity of atherosclerosis in different arterial territories and its relation with obesity

BackgroundThere is uneven association between obesity, traditional risk factors, and cardiovascular events. We aimed to analyze the relation between cardiovascular risk factors, including obesity, with the severity of atherosclerosis in different arterial territories.MethodsArteries from five territories (circle of Willis, carotids, coronaries, aorta, and renal) were taken from 185 persons, newborn to 90 years undergoing autopsy in the Forensic Medical Service in Mexico City, to determine atherosclerotic lesions by histopathological study. Lesions were classified according to the American Heart Association grading system as early (types I–III) and advanced (types IV–VI). The degree of atherosclerosis was correlated with arterial territories and risk factors.ResultsFrequencies of advanced lesions according to arterial territories were as follows: circle of Willis, 28%; right carotid, 36%; left carotid, 25%; right coronary, 71%; left coronary, 85%; right renal, 26%; left renal, 29%; and aorta, 52%; P=.0001, for all analyses. There was a higher risk for advanced lesions with increasing body mass index (BMI) (P=.004). However, after adjusting for age, gender, smoking status, hypertension, and diabetes mellitus, BMI was not independently associated with advanced lesions.ConclusionsCoronary arteries are significantly more affected than other arterial territories regardless of risk factors, showing the effect of local and systemic factors in the severity of atherosclerosis. We did not find an independent association between advanced atherosclerotic lesions and obesity.     

Metabolic syndrome and masticatory hypofunction: a cross-sectional study

Odontology - The objective of this paper is to clarify the rate of abdominal obesity (AO), waist-to-height ratio (WHtR), metabolic syndrome (MetS) and determine the relationship with the...