A randomized double-blind placebo-controlled trial showing rifaximin to improve constipation by reducing methane production and accelerating colon transit: A pilot study

Objective

Gut microbe-derived methane may slow colon transit causing chronic constipation (CC). Effect of rifaximin on breath methane and slow-transit CC was evaluated.

Method

Bristol stool form, frequency, colon transit time (CTT), and breath methane were evaluated in 23 patients with CC (10 patients with constipation-predominant irritable bowel syndrome [IBS-C], 13 functional constipation, Rome III) and m-ethane production compared with 68 non-constipating IBS. Methane-producing CC (basal ≥?10 PPM and/or post-lactulose rise by >?10 PPM) was randomized (double-blind) to rifaximin (400-mg thrice/day, 2-weeks) or placebo. Stool forms, frequency, breath methane, and CTT were recorded afterward.

Results

CC patients tended to be methane producer more often (13/23 [56.5%] vs. 25/68 [36.5%], p?=?0.07) and had greater area under curve (AUC) for methane (2415 [435–23,580] vs. 1335 [0–6562.5], p?=?0.02) than non-constipating IBS. Methane producers (8/13 [61.5%]) and 5/10 (50%) non-producers had abnormal CTT (marker retention: 36-h, 53 [0–60] vs. 19 [8–56], p?=?0.06; 60-h, 16 [0–57] vs. 13 [3–56], p?=?0.877). Six and 7/13 methane producers were randomized to rifaximin and placebo, respectively. Rifaximin reduced AUC for methane more (6697.5 [1777.5–23,580] vs. 2617.5 [562.5–19,867.5], p?=?0.005) than placebo (3945 [2415–12,952.5] vs. 3720 [502.5–9210], p?=?0.118) at 1 month. CTT normalized in 4/6 (66.7%) on rifaximin (36-h retention, 54 [44–57] vs. 36 [23–60], p?=?0.05; 60-h, 45 [3–57] vs. 14 [11–51], p?=?0.09) but none on placebo (p?=?0.02) (36-h, 31 [0–60] vs. 25 [0–45], p?=?0.078; 60-h, 6 [0–54] vs. 12 [0–28], p?=?0.2). Weekly stool frequency (3 [1–9] and 7 [1–14], p?=?0.05) and forms improved with rifaximin than placebo.

Conclusion

Rifaximin improves CC by altering methane production and colon transit.

Trial registration

Clinical Trial Registry, India: REF/2012/01/003216

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Evaluation and characterization of tumor lysis syndrome before and after chemotherapy among pediatric oncology patients in Tikur Anbessa specialized hospital,Addis Ababa,Ethiopia

Background

Tumor lysis syndrome (TLS) is a life-threatening emergency disorder, caused by an abrupt release of intracellular metabolites after tumor cell death. It is characterized by a series of metabolic manifestations, especially hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia. The aim of this study was to evaluate and characterize the incidence of tumor lysis syndrome among pediatric oncology patients before and after treatment.

Methods

Hospital based prospective cohort study was conducted for 6 months on 61 newly diagnosed pediatric oncology patients. Socio-demographic data was collected by interview administered questionnaire. Patients were followed and the physical diagnosis, imaging and laboratory results were interpreted by senior physicians. Data was entered to and analyzed by SPSS version 23.

Results

Among 61 pediatric oncology patients 39(63.9%) were males. The mean (±SD) age of the pediatric patients was 6.39 (±?3.67) years ranging from 2 months to 14 years. 29.5% of patients were found to have TLS. There were 11.5% and 18.0% of laboratory TLS (LTLS) and clinical TLS (CTLS) cases respectively. There were72.2% spontaneous and 27.8% treatment induced TLS cases with 23% and 21.3% cases of hyperuricemia and 4.9% and 6.6% cases of hyperkalemia incidence before and after treatment respectively. Only two patients died, in the study period, due to TLS.

Conclusion

There was high incidence of TLS irrespective of socio-demographic variation among study participants, suggesting that children with cancer are at risk of developing TLS. As TLS is a life-threatening complication of malignancies, early identification of patients at risk and reducing morbidity and mortality is crucially important.

     

Non-suppressive regulatory T cell subset expansion in pulmonary arterial hypertension

Regulatory T cells (Tregs) have been reported to play a pivotal role in the vascular remodeling of pulmonary arterial hypertension (PAH). Recent studies have revealed that Tregs are heterogeneous and can be characterized by three phenotypically and functionally different subsets. In this study, we investigated the roles of Treg subsets in the pathogenesis of PAH in eight patients with PAH and 14 healthy controls. Tregs and their subsets in peripheral blood samples were analyzed by flow cytometry. Treg subsets were defined as CD4⁺CD45RA⁺FoxP3^low resting Tregs (rTregs), CD4⁺CD45RA^?FoxP3^high activated Tregs (aTregs), and CD4⁺CD45RA^?FoxP3^low non-suppressive Tregs (non-Tregs). The proportion of Tregs among CD4⁺ T cells was significantly higher in PAH patients than in controls (6.54 ± 1.10 vs. 3.81 ± 0.28 %, p < 0.05). Of the three subsets, the proportion of non-Tregs was significantly elevated in PAH patients compared with controls (4.06 ± 0.40 vs. 2.79 ± 0.14 %, p < 0.01), whereas those of rTregs and aTregs were not different between the two groups. Moreover, the expression levels of cytotoxic T lymphocyte antigen 4, a functional cell surface molecule, in aTregs (p < 0.05) and non-Tregs (p < 0.05) were significantly higher in PAH patients compared with controls. These results suggested the non-Treg subset was expanded and functionally activated in peripheral lymphocytes obtained from IPAH patients. We hypothesize that immunoreactions involving the specific activation of the non-Treg subset might play a role in the vascular remodeling of PAH.     

“Experience Keeps a Dear School”: the Effects of Ethnicity and Caregiving Experience on Hiring a Healthcare Advocate

In the present study, ethnic differences in evaluating the severity and associated needs of medical complications experienced by an elderly man and the likelihood of seeking professional assistance (i.e., hire a healthcare advocate [HCA]) to care for him, and for one’s own family or parent should they become ill, as a function of previous caregiving experience, were investigated. The 974 participants were White, Black, Hispanic, or Asian/Pacific Islander. They read a hypothetical vignette about a 75-year-old man, Daryl, who was experiencing health problems. Participants were instructed to imagine that they were James, Daryl’s son, and asked to indicate how severe his condition(s) were, how much medical assistance he would require, and how likely they would be to hire an HCA to assist him. They were also asked to report whether they previously had assisted a parent with activities of daily living (Assistance) and whether they would be likely to hire an HCA in the future if 1) a family member or 2) a parent, specifically, became ill. Two, 2 (Assistance) × 4 (Ethnicity) multivariate analyses of covariance (MANCOVA) were performed to assess differential responses among individuals of different ethnicities as a function of previous caregiver experience. A priori interaction contrasts were examined to determine whether Black, Hispanic, or Asian/Pacific Islander participants differed on the outcomes from White participants as a function of previous caregiver experience. There were no significant differences between Black or Asian/Pacific Islander and White participants, but Hispanic participants assigned significantly higher severity and need for medical assistance ratings and were significantly more likely to indicate that they would seek assistance from an HCA with respect to the vignette and for their own parents in the future if they had provided caregiving to a parent in the past, whereas White participants were less likely to seek assistance from an HCA if they had provided caregiving in the past to a parent. Although ethnic differences in evaluations of Daryl’s condition and in the reported likelihoods of hiring an HCA in various contexts as a function of previous caregiving experience were limited, there are important inter-cultural differences to recognize. It may be important in future research to assess ethnic differences in the expectations and experiences of caregiving.     

Functionally aberrant dendritic cell subsets and expression of DC-SIGN differentiate acute from chronic HBV infection

Background

Dendritic cells (DCs) promote pathogen recognition, uptake and presentation of antigen through DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and toll-like receptors (TLRs).

Aims and Objectives

We aimed to study temporal changes in DCs, TLRs and DC-SIGN during acute viral hepatitis B (AVHB) infection and compare them to chronic (CHB) and to investigate the earliest time point of activated pathogen recognition receptors in hepatitis B viral infection.

Methods

We measured the frequencies of circulating myeloid (mDC) and plasmacytoid (pDC) dendritic cells and IFN-α production along with the expression of DC-SIGN and Toll Like Receptors (TLR's) in HBV patients at different time points. Also investigated in healthy volunteers, the dynamic changes in TLRs expression after receiving hepatitis B vaccine.

Results

On follow-up of AVHB patients, we found the mDC population was significantly higher at week 4 and 6 (p < 0.02, 0.01), whereas the pDC population was unchanged at week 6 compared with week 0. Whereas frequencies of mDCs and pDCs were found to be elevated in AVHB and CHB patients than HC (p < 0.00 and 0.01, respectively) but was comparable among AVHB vs CHB. The DCs in CHB patients were functionally impaired with significantly low IFN-α production and low DCSIGN expression (p < 0.04 and 0.00, respectively). Even after stimulation by TLR agonists, no change was found in IFN-α production in CHB patients. MyD88 and IL-6, IFN-α mRNA levels were also found down-regulated. Interestingly, on follow-up after HBV vaccine, TLRs expression was found high at day 3 after vaccination.

Discussion

The initial events of immune activation might be responsible for modulating immune response. These novel observations would pave the way for the development of antiviral strategies for chronic HBV infection.

     

Influence of gender and age of onset on the outcome in children with systemic lupus erythematosus

The objective of our study was to determine the influence of gender and age of onset on the outcome in Saudi children with systemic lupus erythematosus (SLE). Medical records of children with SLE treated at King Faisal Specialist Hospital and Research Center were reviewed. Outcome measures included Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index score (SLICC/ACR), renal disease requiring dialysis, or transplant and death related to SLE. Patients were classified based on age at disease onset into early onset (<5 years) and late onset (>5 years). Data were analyzed, and comparison was made according to the gender and age groups. Eighty-nine patients (76 female and 13 male) were included. The median disease duration was 5 years. Twelve patients had early-onset disease. There was no difference in the mean age, age at diagnosis, disease duration, and follow-up between the different groups. Logistic regression analysis showed significant association of high SLICC/ACR score with early-onset disease and male gender, while renal disease requiring dialysis and renal transplant was associated significantly with male gender independently of age of disease onset. In contrast, death related to SLE was influenced by early-onset disease. Male children and early onset disease of this cohort had poorer outcome. This finding indicates that gender and early-onset disease influence the long-term outcome of SLE in children.     

Substitute Consent for Research Involving the Elderly: A Comparison Between Quebec and France

The authors first describe the rules enacted in Quebec and France to protect adults with decisional impairment who may be approached by investigators to participate in research protocols. They then present two consecutive postal surveys conducted among Quebec and French researchers in aging and designed to (1) assess their knowledge of the legal provisions implemented to protect decisionally incapable adults, (2) elicit their opinions regarding the person best suited to provide substitute consent for research participation, and (3) document their conduct related to obtaining consent for prospective subjects with impaired decisional capacity. Knowledge of the legislation governing substitute consent was poor, even more so among French than Quebec researchers (p < 0.001). In both samples, the majority of respondents felt that the substitute decision-maker does not have to be legally appointed when the study poses little risk to the participant. Practice data revealed a certain discrepancy between the conduct of researchers in aging and the legal provisions regarding consent for research purposes that prevail in their jurisdictions. These findings underscore the need to better educate clinical investigators about existing measures to protect prospective subjects who lack decisional capacity. They also provide some support for allowing close relatives to consent to research participation on behalf of older adults who are unable to consent by themselves and have not been appointed a legal representative.     

Carotid artery disease: Stenting versus endarterectomy

Atherosclerotic carotid artery stenosis is a major cause of disabling stroke or death. Although carotid endarterectomy (CEA) is currently considered to be the standard of care for patients with a severe symptomatic stenosis and selected patients with an asymptomatic carotid stenosis, carotid angioplasty and stenting (CAS) is increasingly being used as an alternative treatment modality. This article briefly summarizes the current trial data on CEA and CAS. More importantly, potential risk factors for CEA and CAS are reviewed and the complementary role of these techniques in the management of the individual patient is discussed.     

Nutritional status and serum zinc and selenium levels in Iranian HIV infected individuals

Background  

Human immunodeficiency virus infected individuals are prone to malnutrition due to increased energy requirements, enteropathy and increased catabolism. Trace elements such as zinc and selenium have major role in maintaining a healthy immune system. This study was designed to evaluate the nutritional status of Iranian subjects who were newly diagnosed with human immunodeficiency virus infection and to compare serum level of zinc and selenium in these patients with those of the sex and aged match healthy subjects.