FoxA1/2-dependent epigenomic reprogramming drives lineage switching in lung adenocarcinoma

The ability of cancer cells to alter their identity is essential for tumor survival and progression. Loss of the pulmonary lineage specifier NKX2-1 within KRAS-driven lung adenocarcinoma (LUAD) enhances tumor progression and results in a pulmonary-to-gastric lineage switch that is dependent upon the activity of pioneer factors FoxA1 and FoxA2; however, the underlying mechanism remains largely unknown. Here, we show that FoxA1/2 reprogram the epigenetic landscape of NKX2-1-negative LUAD to facilitate a gastric identity. After Nkx2-1 deletion, FoxA1/2 mediate demethylation of gastric-defining genes through recruitment of TET3, an enzyme that induces DNA demethylation. H3K27ac ChIP-seq and HiChIP show that FoxA1/2 also control the activity of regulatory elements and their 3D interactions at gastric loci. Furthermore, oncogenic KRAS is required for the FoxA1/2-dependent epigenetic reprogramming. This work demonstrates the role of FoxA1/2 in rewiring the methylation and histone landscape and cis-regulatory dynamics of NKX2-1-negative LUAD to drive cancer cell lineage switching.

FoxA1 and FoxA2 control growth and cellular identity in NKX2-1-positive lung adenocarcinoma

Changes in cellular identity (also known as histologic transformation or lineage plasticity) can drive malignant progression and resistance to therapy in many cancers, including lung adenocarcinoma (LUAD). The lineage-specifying transcription factors FoxA1 and FoxA2 (FoxA1/2) control identity in NKX2-1/TTF1-negative LUAD. However, their role in NKX2-1-positive LUAD has not been systematically investigated. We find that Foxa1/2 knockout severely impairs tumorigenesis in KRAS-driven genetically engineered mouse models and human cell lines. Loss of FoxA1/2 leads to the collapse of a dual-identity state, marked by co-expression of pulmonary and gastrointestinal transcriptional programs, which has been implicated in LUAD progression. Mechanistically, FoxA1/2 loss leads to aberrant NKX2-1 activity and genomic localization, which in turn actively inhibits tumorigenesis and drives alternative cellular identity programs that are associated with non-proliferative states. This work demonstrates that FoxA1/2 expression is a lineage-specific vulnerability in NKX2-1-positive LUAD and identifies mechanisms of response and resistance to targeting FoxA1/2 in this disease.

Inhibition of UDP-Glucuronosyltransferase Enzymes by Major Cannabinoids and Their Metabolites

The UDP-glucuronosyltransferase (UGT) family of enzymes play a central role in the metabolism and detoxification of a wide range of endogenous and exogenous compounds. UGTs exhibit a high degree of structural similarity and display overlapping substrate specificity, often making estimations of potential drug-drug interactions difficult to fully elucidate. One such interaction yet to be examined may be occurring between UGTs and cannabinoids, as the legalization of recreational and medicinal cannabis and subsequent co-usage of cannabis and therapeutic drugs increases in the United States and internationally. In the present study, the inhibition potential of the major cannabinoids Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN), as well as their major metabolites, was determined in microsomes isolated from HEK293 cells overexpressing individual recombinant UGTs and in microsomes from human liver and kidney specimens. The highest inhibition was seen by CBD against the glucuronidation activity of UGTs 1A9, 2B4, 1A6, and 2B7, with binding-corrected IC50 values of 0.12 ± 0.020 µM, 0.22 ± 0.045 µM, 0.40 ± 0.10 µM, and 0.82 ± 0.15 µM, respectively. Strong inhibition of UGT1A9 was also demonstrated by THC and CBN, with binding-corrected IC50 values of 0.45 ± 0.12 μM and 0.51 ± 0.063 μM, respectively. Strong inhibition of UGT2B7 was also observed for THC and CBN; no or weak inhibition was observed with cannabinoid metabolites. This inhibition of UGT activity suggests that in addition to playing an important role in drug-drug interactions, cannabinoid exposure may have important implications in patients with impaired hepatic or kidney function. SIGNIFICANCE STATEMENT: Major cannabinoids found in the plasma of cannabis users inhibit several UDP-glucuronosyltransferase (UGT) enzymes, including UGT1A6, UGT1A9, UGT2B4, and UGT2B7. This study is the first to show the potential of cannabinoids and their metabolites to inhibit all the major kidney UGTs as well as the two most abundant UGTs present in liver. This study suggests that as all three major kidney UGTs are inhibited by cannabinoids, greater drug-drug interaction effects might be observed from co-use of cannabinods and therapeutics that are cleared renally.

On the geometric ergodicity of hybrid samplers

In this paper, we consider the random-scan symmetric random walk Metropolis algorithm (RSM) onℝd. This algorithm performs a Metropolis step on just one coordinate at a time (as opposed to the full-dimensional symmetric random walk Metropolis algorithm, which proposes a transition on all coordinates at once). We present various sufficient conditions implyingV-uniform ergodicity of the RSM when the target density decreases either subexponentially or exponentially in the tails.

Efficacy of amine-based disinfectant KENO™COX on the infectivity of Cryptosporidium parvum oocysts

Cryptosporidium parvum is a zoonotic protozoan parasite that may cause severe neonatal diarrhoea or even mortality in newborn ruminants: its oocysts are extremely resistant to normal environmental conditions and to most common disinfectants. KENO™COX, a patent pending amine-based formula, was tested for its ability to inactivate C. parvum oocysts. The Daugschies assay (2002), a standardized assay for chemical disinfection initially described for Eimeria spp., was adapted for C. parvum oocysts. KENO™COX diluted in water at 2% and 3% concentration and incubated with oocyst suspensions for 2h, allowed a significant reduction in viability, lysing 89% and 91% of oocysts respectively. Infectivity of the remaining C. parvum oocysts was assessed by inoculation to C57 Bl/6 neonatal mice. Each mouse received 2.5 μl of a suspension initially containing 500,000 oocysts before contact with KENO™COX. Six days post inoculation, the intestinal parasite load was significantly reduced by 97.5% with KENO™COX 2% compared to that of the mice inoculated with untreated parasites. KENO™COX 3% completely eliminated infectivity of oocysts. The number of oocysts remaining infectious in the inoculum treated with KENO™COX 2% was calculated from an inoculated dose-response curve: it was estimated at about 48.6 oocysts among the 500,000 oocysts initially treated corresponding to 99.99% of inhibition. These results demonstrate the high efficacy of KENO™COX against C. parvum oocysts. Combined with an appropriate method of cleaning, the application of KENO™COX may be a useful tool to reduce cryptosporidial infectious load on farm level.

Effects of whole wheat feeding on the development of coccidial infection in broiler chickens

A complete ground and pelleted feed was compared to free choice feeding of whole wheat and a pelleted protein concentrate during three experimental infections with coccidia in broiler chickens. At 22 d of age birds were inoculated with different doses of sporulated oocysts of a cecal species (Eimeria tenella) in experiment 1 or intestinal species E. maxima or E. acervulina in experiments 2 and 3, respectively. The effects of diets were assessed on weight gain, hematocrit (during cecal coccidiosis), serum coloration (during intestinal coccidiosis), oocyst excretion, and lesion score until 7 d post-inoculation. In experiment 1 before inoculation, the birds fed whole grain had more beneficial microflora with lower counts of coliform bacteria. As shown by oocyst output and lesion score, whole wheat feeding increased parasite development during infection with the cecal parasite E. tenella. This led to significantly lower weight gain with whole wheat than with ground wheat from 5 to 6 d post-inoculation and to lower hematocrit at the highest infective dose. Parasite development in experiments 2 and 3 was similar among diets, during intestinal infection with E. maxima and E. acervulina, respectively, with no significant differences in lesion score. During the acute phase (4 to 7 and 3 to 5 d post-inoculation), when a difference appeared between diets, whole wheat fed-birds were always more affected than ground diet-fed birds in terms of serum coloration and weight gain. These results might be explained by modifications of digestive physiology and intestinal microflora by whole wheat.

Effective suppression of vancomycin-resistant Enterococcus species in asymptomatic gastrointestinal carriers by a novel glycolipodepsipeptide, ramoplanin

Nosocomial bloodstream infections due to vancomycin-resistant enterococci (VRE) are associated with increased morbidity rates, mortality rates, and hospitalization costs. Gastrointestinal carriage of VRE is an important risk factor for subsequent infections. This 3-arm, phase II, double-blinded, randomized, multicenter, placebo-controlled study evaluated the safety and efficacy of oral ramoplanin (a novel, nonabsorbed glycolipodepsipeptide) versus placebo for suppression of gastrointestinal VRE colonization. Sixty-eight patients who were colonized with VRE were enrolled and received 2 daily doses of ramoplanin (100 mg or 400 mg) or placebo orally for 7 days. The primary end point was the proportion of persons per group from whom VRE were not recovered (VRE-free) on days 7, 14, and 21 after screening. After treatment, VRE-free status was as follows: day 7, none of the 20 patients in the placebo group, and 17 of 21 (P<.001) and 18 of 20 (P<.001) in the 100-mg and 400-mg ramoplanin groups, respectively; on day 14, 2 of 20 patients in the placebo group, and 6 of 21 (P=.134) and 7 of 17 (P=.028), in the 100-mg and 400-mg ramoplanin groups, respectively. By day 21, there were no differences between treatment groups. Adverse events were similar for all treatment groups. Ramoplanin was safe and effective in temporarily suppressing gastrointestinal VRE carriage.

Kinetics of specific immunoglobulin A, M and G production in the duodenal and caecal mucosa of chickens infected with Eimeria acervulina or Eimeria tenella

The development and appearance of antibody was studied in the intestine and serum from histocompatible GB1 chickens orally infected with oocysts of Eimeria acervulina (restricted to the duodenum) or Eimeria tenella (restricted to the caeca). The local immune response was measured as the specific antibody levels in the supernatants of intestinal fragments (duodenum and caecum) maintained in culture for 16 h at 41 degrees C, 5% CO2, 95% air. Specific IgM was detected 1 week after E. acervulina infection, and the specific IgA and IgG contents of the duodenum and caecum were significantly elevated (P < 0.001) after 2 weeks. The intestinal specific IgG content was raised. E. tenella infection resulted in specific IgA only in the parasitized area during the second week post-infection (P < 0.05). Specific IgM and IgG were both detected in the duodenum and caecum, respectively, 1 and 2 weeks p.i. Production of parasite-specific immunoglobulins was always significantly higher in the parasitized than in the unparasitized areas (caeca for E. acervulina, duodenum for E. tenella). This ex vivo culture assay of intestinal fragments used to measure the mucosal immune response of intestinal areas showed a significant production of specific IgA and IgM. In addition, high levels of IgG were also measured. The role of this specific IgG in Eimeria infection remains to be determined.

Receptivity and susceptibility of the domestic duck (Anas platyrhynchos), the Muscovy duck (Cairina moschata), and their hybrid, the mule duck, to an experimental infection by Eimeria mulardi

The receptivity and susceptibility of the Muscovy duck, the domestic duck, and their hybrid, the mule duck, toward an experimental infection by Eimeria mulardi were studied. To appraise their susceptibility, female ducklings were infected with a dose of 75,000 oocysts per duckling (bringing about a clinical coccidiosis). In another group, to compare the multiplication rates of the parasite in the three species of ducks, thus assessing their receptivity, an infection with 750 oocysts per duckling was realized. Eimeria mulardi develops in the three species of ducks. In each case, a significant decrease in growth in the contaminated group vs. the control group was noted, even though the Muscovy and the mule ducks were more susceptible to the contamination.

Publications from the Caribbean in the health sciences

The investigation reported here examined scientific publications from Barbados, Jamaica, and Trinidad and Tobago over the period 1976-1990. Its purpose was to provide new information about Caribbean research in the health field through assessment of published works. To this end a broad array of journal subject categories was examined using SCISEARCH, an international index of medical and scientific literature. In all, 1,712 titles (articles, editorials, reviews, letters, meeting abstracts, and notes) were selected for analysis. This analysis indicated that Jamaica accounted for about three-quarters of the titles and that there had been a steady increase in the number of titles published over the study period that was most marked in Barbados. Most of the principal authors were affiliated with the University of the West Indies, and nearly one-third of the titles were published in the West Indian Medical Journal, the sole publication from the three study countries that SCISEARCH listed. Most of the subjects covered fell within the area of "general medicine" rather than experimental medicine or public health. However, of the 383 titles dealing with experimental medicine, nearly all (331) originated in Jamaica. In contrast, less than half of the 262 titles in the public health field came from Jamaica, a relatively large number (106) originating in Trinidad and Tobago. Most of the 1,712 titles (63.8%) dealt with topics outside the priority areas identified by the Caribbean Ministers of Health as part of the Caribbean Cooperation in Health (CCH) Initiative.

Histopathology of the small intestinal mucosa in Nematodirus spathiger infection in rabbits

Rabbits were experimentally infected with two levels (5000 and 17,000) infective larvae of Nematodirus spathiger. Histological (villus length, mucosa to serosa ratio, crypt surface) and biochemical (protein content, alkaline phosphatase and leucine aminopeptidase activities) measurements relating to the small intestinal mucosa were examined along the entire length of the organ. In the proximal intestine, the presence of worms was associated with villus abrasion, increased crypt surface and decreased alkaline phosphatase and leucine aminopeptidase activities. Conversely, beyond the main site of infection in the distal small intestine, some signs of hypertrophied villi and crypts were noted without any changes in enzyme activities. These distal variations were similar to those previously described in experimental Trichostrongylus colubriformis infections of rabbits. These results tend to confirm the use of the rabbit as an experimental model to study Nematodirus infection. They also suggest that the distal adaptive process in the nematode-parasitized small intestine could occur independently of the worm species.

Causes of death in persons with human immunodeficiency virus infection

PURPOSE

Pneumocystis carinii pneumonia (PCP) was reported to be the predominant cause of human immunodeficiency virus (HIV)-related deaths prior to 1988, the year that effective prophylaxis against PCP entered routine use. Our study was performed to study the causes of HIV-related death since January 1988 in a region where patient tracking is virtually complete.

PATIENTS AND METHODS

We surveyed physicians associated with the Brown University Acquired Immunodeficiency Syndrome (AIDS) Program who cared for greater than 95% of known HIV-positive patients in Rhode Island. These physicians identified all those HIV-infected persons who had died under their care between January 1988 and July 1990, and determined these patients' causes of death by chart review. For comparison, death certificates of identified persons were also reviewed at the Rhode Island Department of Vital Statistics.

RESULTS

Among 126 deaths since January 1988, bacterial infections were the most common cause of death (30%), whereas PCP was responsible for only 16% of deaths. Persons not receiving any form of PCP prophylaxis were more likely to die from PCP than were those who received prophylaxis (26% versus 11% [p = 0.04]). Cause of death as recorded on actual death certificates was imprecise, although bacterial infections were again the most common cause indicated. Only one death occurred in a patient with a CD4 count greater than 200/mL, and this was not HIV-related.

CONCLUSION

PCP has not been the leading cause of death in our region since January 1988. Bacterial infections contribute substantially to mortality, and this may influence future prophylactic regimens. HIV-related deaths in patients with CD4 counts greater than 200/mL are unusual.

Experimental infections with Nematodirus spathiger in rabbits

The feasibility of infecting laboratory rabbits experimentally with the ovine nematode Nematodirus spathiger was examined. Eight-week-old rabbits were dosed either with 5000 or with 17,000 third-stage larvae and killed on days 10, 21 or 42 post-infection. With the lower dose, 20 to 40% of the inoculum were recovered at necropsy. Similar values were observed with the 17,000 dose on days 10 and 21 post-infection, but on day 42 the worm population was residual (0.6%). With both dose levels, during the course of infection, the worm populations were mainly composed of fourth-stage larvae and worm egg excretion was low. N. spathiger mainly inhabited the proximal jejunum. The results were compared with N. spathiger infection in sheep to assess the usefulness of the rabbit as an experimental model for Nematodirus infection.

Effects of human serum and plasma on development of mouse embryos in culture media

Mouse embryos were cultured in Ham's F-10 medium (unsupplemented) and Ham's F-10 medium supplemented with either 15% fetal cord serum, 15% fetal cord plasma, 15% maternal serum, or 15% maternal plasma. None of the blood supplements significantly increased the numbers of embryos that developed to blastocysts, and the last three of the blood supplements inhibited embryo development. The cause of the inhibition was not identified. Estradiol concentrations of blood samples used as media supplements were found not to correlate with inhibition of embryo.