Correction: Sensitivity of self-reported opioid use in case-control studies: Healthy individuals versus hospitalized patients.

[This corrects the article DOI: 10.1371/journal.pone.0183017.].

Association of socioeconomic status with consumption of cigarettes, illicit drugs, and alcohol.

Introduction and Aims: Socioeconomic Status (SES) is considered as one of the important factors associated with use of various drugs. The present study aimed to investigate the effect of SES on cigarette smoking, alcohol use, drug use, and passive exposure to opium and cigarette smoke. Design and Methods: In this study, which is part of a multicenter case-control study, the research hypothesis was checked among controls who had referred to hospitals. Data were collected through a questionnaire and laboratory tests to determine the actual consumers of opium and other illicit drugs. Then, the data were analyzed using STATA 13. Result: This study was performed on 364 individuals within the age range of 30 to 75 years. More than 55% of the participants had a history of life-time consumption of cigarettes and hookah as well as alcohol and drugs. The results revealed an inverse relationship between SES and life-time consumption of hookah and alcohol. Furthermore, individuals with higher SES were more likely to deny their drug use. Discussion and Conclusions: The results revealed little robust evidence supporting the assumption that SES level can have an important effect on illicit drug use. On the other hand, the participants' characteristics could have a prominent effect on precise evaluation of the relationship between SES and drug use. Further multicenter studies are needed with samples diversified in terms of age and ethnicity to identify these confounding relationships.

More Protection of Lactobacillus acidophilus Than Bifidobacterium bifidum Probiotics on Azoxymethane-Induced Mouse Colon Cancer.

Based on the ability of the probiotics in the gut microflora modification, they can have the beneficial effects on diseases in the short and/or the long term. In previous study, we revealed that unlike Bifidobacterium bifidum, the amount of Lactobacillus acidophilus remained almost unchanged in mice gut microflora in the long term, indicating more stability of L. acidophilus than B. bifidum which can be used to prevent some incurable diseases such as cancer. Thirty-eight male BALB/c mice were divided into four groups, control, azoxymethane (AOM), L. acidophilus, and B. bifidum probiotics, to evaluate the protective effects of the probiotics on AOM-induced mouse colon cancer. Except for the control group, the rest of the animals were weekly given AOM (15 mg/kg, s.c) in three consecutive weeks. Colon lesion incidence was 74% in the AOM group in comparison with the control (0%) (P < 0.05). The lesions were varied from mild to severe dysplasia and colonic adenocarcinoma. Administration of the probiotics inhibited the incidence of colonic lesions by about 57% in L. acidophilus (P < 0.05) and 27% in B. bifidum (P > 0.05) compared to the AOM group. The serum levels of CEA and CA19-9 tumor markers were significantly decreased in L. acidophilus in comparison with the AOM group (P < 0.05). Moreover, the serum levels of IFN-γ and IL-10 and the number of CD4+ and CD8+ cells were significantly increased in L. acidophilus compared to AOM (P < 0.05). Our study highlighted the more potential effects of L. acidophilus probiotic than B. bifidum on mouse colon cancer.

Correction: Sensitivity of self-reported opioid use in case-control studies: Healthy individuals versus hospitalized patients.

[This corrects the article DOI: 10.1371/journal.pone.0183017.].

Sensitivity of self-reported opioid use in case-control studies: Healthy individuals versus hospitalized patients.

BACKGROUND: Several case-control studies have shown associations between the risk of different cancers and self-reported opium use. Inquiring into relatively sensitive issues, such as the history of drug use, is usually prone to information bias. However, in order to justify the findings of these types of studies, we have to quantify the level of such a negative bias. In current study, we aimed to evaluate sensitivity of self-reported opioid use and suggest suitable types of control groups for case-control studies on opioid use and the risk of cancer. METHODS: In order to compare the validity of the self-reported opioid use, we cross-validated the response of two groups of subjects 1) 178 hospitalized patients and 2) 186 healthy individuals with the results of their tests using urine rapid drug screen (URDS) and thin layer chromatography (TLC). The questioners were asked by trained interviewers to maximize the validity of responses; healthy individuals were selected from the companions of patients in hospitals. RESULTS: Self-reported regular opioid use was 36.5% in hospitalized patients 19.3% in healthy individuals (p-value> 0.001).The reported frequencies of opioid use in the past 72 hours were 21.4% and 11.8% in hospitalized patients and healthy individuals respectively. Comparing their responses with the results of urine tests showed a sensitivity of 77% and 69% among hospitalized patients and healthy individuals for self-reports (p-value = 0.4). Having corrected based on the mentioned sensitivities; the frequency of opioid regular use was 47% and 28% in hospitalized patients and healthy individuals, respectively. Regular opioid use among hospitalized patients was significantly higher than in healthy individuals (p-value> 0.001). CONCLUSION: Our findings showed that the level of opioid use under-reporting in hospitalized patients and healthy individuals was considerable but comparable. In addition, the frequency of regular opioid use among hospitalized patients was significantly higher than that in the general population. Altogether, it seems that, without corrections for these differences and biases, the results of many studies including case-control studies on opioid use might distort findings substantially.

Modifications of mice gut microflora following oral consumption ofLactobacillus acidophilus and Bifidobacterium bifidum probiotics.

BACKGROUND/AIM: Thirty male BALB/c mice were equally divided into three groups: control, L. acidophilus, and B. bifidum for the assessment of the probiotics' stability in the gut microflora. MATERIALS AND METHODS: First, the gut microflora of the mice was checked every 3 days (days 3, 6, 9, and 12) without probiotic consumption, and then the mice were daily given orally 1.5 g of probiotics in 30 cc of drinking water. The consumption of probiotics was then stopped for recovery and then the consumption continued for 5 months. RESULTS: On day 9 after the consumption of the probiotics, L. acidophilus and B. bifidum were significantly increased from 4% to 83% and from 1% to 61%, respectively. L. acidophilus count showed no significant decrease at the end of 5 months compared to day 9 of probiotic consumption (74%), but B. bifidum count was dramatically decreased to 45% and 36% at the end of 1 and 5 months, respectively. CONCLUSION: Our results revealed that, unlike B. bifidum, the amount of L. acidophilus remained almost unchanged in the long term, indicating more stability of L. acidophilus than B. bifidum in the gut microflora.

Survey of serum procalcitonin in cirrhotic patients.

Procalcitonin (PCT) is a prohormone that has been used as a marker for the diagnosis of bacterial infections. The aim of this study was to survey PCT levels in patients with cirrhosis. Sixty-four patients with hepatic cirrhosis and 32 healthy blood donors were enrolled in this study. Serum PCT levels was detected using immunoluminometric assay. The rate of positive PCT was higher in patients with hepatitis C cirrhosis (92.8%) than the other groups. Among other cirrhotic patients, positive PCT levels were 77% for hepatitis B, 70% for cancer and 53.3% for unknown groups respectively. Serum procalcitonin levels were significantly higher in cirrhotic patients with bacterial infection (2.65±1.11 ng/ml) than those without infection (0.59±0.16 ng/ml, P=0.0001). PCT assay in cirrhotic patients may help diagnosis of sepsis and reduce unnecessary antibiotic use.