RESUMEN
We describe preparation and magnetic properties of an organic pi-conjugated polymer with very large magnetic moment and magnetic order at low temperatures. The polymer is designed with a large density of cross-links and alternating connectivity of radical modules with unequal spin quantum numbers (S), macrocyclic S = 2 and, cross-linking S = (1/2) modules, which permits large net S values for either ferromagnetic or antiferromagnetic exchange couplings between the modules. In the highly cross-linked polymer, an effective magnetic moment corresponding to an average S of about 5000 and slow reorientation of the magnetization by a small magnetic field (less than or equal to 1 oersted) below a temperature of about 10 kelvin are found. Qualitatively, this magnetic behavior is comparable to that of insulating spin glasses and blocked superparamagnets.
RESUMEN
BACKGROUND: The effects of extra-intestinal cancer on the course of inflammatory bowel disease (IBD) are poorly understood. AIM: To evaluate the impact of cancer and its management on IBD outcomes. METHODS: A total 80 IBD patients (51 Crohn's disease, 29 ulcerative colitis; 33 men, median age at cancer diagnosis 48yrs) diagnosed with extra-intestinal cancer were selected from a prospective database. IBD activity and therapeutic requirements (assessed year-by-year) were compared before and after cancer diagnosis, with a control group of patients without cancer matched for gender, birth date, date of IBD diagnosis and IBD phenotype. RESULTS: Paired comparisons of the consecutive periods before and after cancer diagnosis did not show significant changes in median (IQR) percentages of years with active disease (27% [0-50] vs. 19% [0-53]), while the proportion of patient-years on any immunosuppressant remained stable (26% vs. 28%). Chemotherapy had no significant effect on IBD activity. Compared to controls, patients with cancer had a similar IBD activity and use of anti-TNF, but less use of immunomodulators (19% vs. 25%, p<0,001) and an increased rate of surgery (4% vs. 2.5%, p<0,05). Individual variations in IBD activity after cancer diagnosis were not significantly different in patients with cancer and their matched controls. CONCLUSION: Occurrence of extra-intestinal cancer impacts IBD therapeutic management, with a trend towards less use of immunomodulators and more surgery. In the long-term, cancer diagnoses and treatments do not modify IBD outcomes.
Asunto(s)
Enfermedades Inflamatorias del Intestino/complicaciones , Neoplasias/complicaciones , Adulto , Estudios de Casos y Controles , Colitis Ulcerosa/complicaciones , Colitis Ulcerosa/tratamiento farmacológico , Enfermedad de Crohn/complicaciones , Enfermedad de Crohn/tratamiento farmacológico , Femenino , Humanos , Inmunosupresores/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Neoplasias/diagnóstico , Neoplasias/terapia , Resultado del TratamientoRESUMEN
BACKGROUND: Irritable bowel syndrome (IBS) is a multifactorial disease for which a dysbiosis of the gut microbiota has been described. Bile acids (BA) could play a role as they are endogenous laxatives and are metabolized by gut microbiota. We compared fecal BA profiles and microbiota in healthy subjects (HS) and patients with diarrhea-predominant IBS (IBS-D), and we searched for an association with symptoms. METHODS: Clinical features and stool samples were collected in IBS-D patients and HS. Fecal BA profiles were generated using HPLC coupled to tandem mass spectrometry. The fecal microbiota composition was assessed by q-PCR targeting dominant bacterial groups and species implicated in BA transformation. KEY RESULTS: Fourteen IBS-D patients and 18 HS were included. The two groups were comparable in terms of age and sex. The percentage of fecal primary BA was significantly higher in IBS-D patients than in HS, and it was significantly correlated with stool consistency and frequency. Fecal counts of all bacteria, lactobacillus, coccoides, leptum and Faecalibacterium prausnitzii were similar. There was a significant increase of Escherichia coli and a significant decrease of leptum and bifidobacterium in IBS-D patients. CONCLUSIONS & INFERENCES: We report an increase of primary BA in the feces of IBS-D patients compared to HS, correlated with stool consistency and frequency. A dysbiosis of different bacterial groups was detected, some of them involved in BA transformation. As the gut microbiota is the exclusive pathway to transform primary into secondary BA, this suggests a functional consequence of dysbiosis, leading to lower BA transformation.