Short-term effects of air pollution on hospital admissions of respiratory diseases in Hamadan, Iran, 2015 to 2021

The short-term effects of air pollution on respiratory diseases have been reported in many countries. Urban areas are most affected because of the many sources of pollution and the large number of people living there. This study aims to investigate the effect of short-term exposure to air pollutants on respiratory hospital admissions in the city of Hamadan. In this ecological study, daily hospital admission data were collected from Shahid Beheshti Hospital in Hamadan. Daily information on air pollutants (CO, SO2, NO2, O3, PM2.5 and PM10) from Hamadan Department of Environment (DoE) organization and of climate factors from Hamadan Meteorological Office were collected. A negative binomial regression model was used to examine the effect of air pollution on daily respiratory hospitalizations. The effect of exposure to pollutants was measured whit different time lags (0-7 days). Furthermore, the effect of meteorological variables was controlled. Subgroup analyses were performed by sex and age group. A total of 12,454 hospitalizations for respiratory diseases were recorded. Results showed a strong and immediate effect of CO on respiratory hospital admissions with highest association at lag 7 (relative risk (RR) = 1.38, 95% CI: 1.33, 1.42). The effects of CO and SO2 on respiratory hospitalizations are greater for men than women. Regarding the short-term effects of PM2.5, SO2 and O3, adults (aged less than 65) were more prone to hospitalization for respiratory diseases. These results show that exposure to air pollution, particularly CO, may increase hospital admissions due to respiratory illness. So reducing the concentration of these pollutants can reduce the number of hospital admissions.

The spectrum of ATM gene mutations in Iranian patients with ataxia-telangiectasia

BACKGROUND

Ataxia-telangiectasia (A-T) is a rare genetic disorder characterized by a distinct range of clinical manifestations, including progressive ataxia, immunodeficiency, and radiosensitivity.

METHODS

Clinical data, laboratory results, and genetic data were collected from forty-three A-T patients. Whole-exome sequencing and Sanger sequencing were done for the patients clinically diagnosed as suffering from A-T. Based on the phenotype severity of the disease, patients were divided into severe and mild subgroups.

RESULTS

The median (IQR) age of diagnosis in this cohort was 5 (3-7) years, and various types of clinical manifestations, including fever (P =.005), lower respiratory tract infection (P = .033), diarrhea (P = .014), and hepatosplenomegaly (P = .032), were significantly higher among patients diagnosed with the severe phenotype. Our results showed a correlation between phenotype severity and mutation type. The chance of having severe phenotype in patients who have severe mutations, including frameshift and nonsense, was 7.3 times higher than in patients who were categorized in the mild genotype group (odds ratio = 7.3, P = .006). Thirty-four types of mutations including 9 novel mutations were observed in our study.

CONCLUSION

Molecular analysis provides the opportunity for accurate diagnosis and timely management in A-T patients with chronic progressive disease, especially infections and the risk of malignancies. This study characterizes for the first time the broad spectrum of mutations and phenotypes in Iranian A-T patients, which is required for carrier detection and reducing the burden of disease in the future using the patients' families and for the public healthcare system.

Clinical, immunological and genetic findings in patients with UNC13D deficiency (FHL3): A systematic review

BACKGROUND

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare autosomal recessive immune disorder that is caused by mutations in 6 different genes related to the formation and function of secretory lysosomes within cytotoxic T lymphocytes and natural killer (NK) cells. Thus, defect in these genes is associated with the accumulation of antigens due to defective cytotoxic function. FHL type 3 (FHL3) accounts for nearly 30-40% of FHL, and its underlying reason is mutation in UNC13D gene which encodes Munc13-4 protein.

METHODS

For the first time, we aimed to systematically review clinical features, immunologic data, and genetic findings of patients with FHL3. We conducted electronic searches for English-language articles in PubMed, Web of Science, EMBASE, and Scopus databases to collect comprehensive records related to patients with UNC13D mutations.

RESULTS

A total of 279 abstracts were initially reviewed for inclusion. Among them, 57 articles corresponding to 322 individual FHL3 patients fulfilled our selection criteria. Finally, 73 and 249 patients were considered as severe and mild feature groups, respectively. Our results confirmed that fever, hepatosplenomegaly, and hemophagocytosis are common clinical features in the disease. Moreover, reduced fibrinogen and NK cell activity, as well as increased ferritin and triglycerides, are important markers for early diagnosis of the FHL3 disease. Investigation of genotype showed that the most prevalent type and zygosity of UNC13D are splice-site errors and compound heterozygous, respectively.

CONCLUSION

FHL3 patients have a wide range of clinical manifestations, which makes it difficult to diagnose. Therefore, it seems that the sequencing of the entire UNC13D gene (coding and non-coding regions) is the most appropriate way to accurate diagnosis of FHL3 patients.

Evaluation of prognostic factors effect on survival time in patients with colorectal cancer, based on Weibull Competing-Risks Model

AIM

The aim of this study was to assess the association between survival of patients with colorectal cancer and prognostic factors in a competing risk parametric model using Weibull distribution.

BACKGROUND

The prognosis of colorectal cancer is relatively good in terms of survival time. In many prognostic studies, patients may be exposed to several types of competing events. These different causes of death are called competing risks.

METHODS

Data was recorded from 372 patients with colorectal cancer who registered in the Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences (Tehran, Iran) from 2004 to 2015 in a retrospective study. Analysis was performed using competing risks model and Weibull distribution. Software used for data analysis was R, and significance level was regarded as 0.05.

RESULTS

The result indicated that, at the end of follow-up, 111 (29.8%) deaths were from colorectal cancer and 14 (3.8%) deaths were due to other diseases. The average body mass index (BMI) was 24.61(SD 3.98). The mean survival time for a patient in 372 was 62.05(SD 48.78) month with median equals to 48 months. According to competing-risks method, only stageIII (HR, 1.69; 95% CI, 1.246-2.315 ), stageIV( HR, 4.51; 95% CI,2.91-6.99 ) and BMI( HR, 0.96; 95% CI, 0.96-0.975) have a significant effect on patient's survival time.

CONCLUSION

This study indicated pathologic stage (III,IV) and BMI as the prognosis, using a Weibull model with competing risks analysis, while other models without the competing events lead to significant predictors which may be due to over-estimation.