The effect of obesity phenotype changes on cardiovascular outcomes in adults older than 40 years in the prospective cohort of the Tehran lipids and glucose study (TLGS): joint model of longitudinal and time-to-event data

BACKGROUND

Obesity is a worldwide health concern with serious clinical effects, including myocardial infarction (MI), stroke, cardiovascular diseases (CVDs), and all-cause mortality. The present study aimed to assess the association of obesity phenotypes and different CVDs and mortality in males and females by simultaneously considering the longitudinal and survival time data.

METHODS

In the Tehran Lipid and Glucose Study (TLGS), participants older than three years were selected by a multi-stage random cluster sampling method and followed for about 19 years. In the current study, individuals aged over 40 years without a medical history of CVD, stroke, MI, and coronary heart disease were included. Exclusions comprised those undergoing treatment for CVD and those with more than 30% missing information or incomplete data. Joint modeling of longitudinal binary outcome and survival time data was applied to assess the dependency and the association between the changes in obesity phenotypes and time to occurrence of CVD, MI, stroke, and CVD mortality. To account for any potential sex-related confounding effect on the association between the obesity phenotypes and CVD outcomes, sex-specific analysis was carried out. The analysis was performed using packages (JMbayes2) of R software (version 4.2.1).

RESULTS

Overall, 6350 adults above 40 years were included. In the joint modeling of CVD outcome among males, literates and participants with a family history of diabetes were at lower risk of CVD compared to illiterates and those with no family history of diabetes in the Bayesian Cox model. Current smokers were at higher risk of CVD compared to non-smokers. In a logistic mixed effects model, odds of obesity phenotype was higher among participants with low physical activity, family history of diabetes and older age compared to males with high physical activity, no family history of diabetes and younger age. In females, based on the results of the Bayesian Cox model, participants with family history of diabetes, family history of CVD, abnormal obesity phenotype and past smokers had a higher risk of CVD compared to those with no history of diabetes, CVD and nonsmokers. In the obesity varying model, odds of obesity phenotype was higher among females with history of diabetes and older age compared to those with no history of diabetes and who were younger. There was no significant variable associated with MI among males in the Bayesian Cox model. Odds of obesity phenotype was higher in males with low physical activity compared to those with high physical activity in the obesity varying model, whereas current smokers were at lower odds of obesity phenotype than nonsmokers. In females, risk of MI was higher among those with family history of diabetes compared to those with no history of diabetes in the Bayesian Cox model. In the logistic mixed effects model, a direct and significant association was found between age and obesity phenotype. In males, participants with history of diabetes, abnormal obesity phenotype and older age were at higher risk of stroke in the Bayesian Cox model compared to males with no history of diabetes, normal obesity phenotype and younger persons. In the obesity varying model, odds of obesity phenotype was higher in males with low physical activity, family history of diabetes and older age compared to those with high physical activity, no family history of diabetes and who were younger. Smokers had a lower odds of obesity phenotype than nonsmokers. In females, past smokers and those with family history of diabetes were at higher risk of stroke compared to nonsmokers and females with no history of diabetes in the Bayesian Cox model. In the obesity varying model, females with family history of diabetes and older ages had a higher odds of obesity phenotype compared to those with no family history of diabetes and who were younger. Among males, risk of CVD mortality was lower in past smokers compared to nonsmokers in the survival model. A direct and significant association was found between age and CVD mortality. Odds of obesity phenotype was higher in males with a history of diabetes than in those with no family history of diabetes in the logistic mixed effects model.

CONCLUSIONS

It seems that modifications to metabolic disorders may have an impact on the heightened incidence of CVDs. Based on this, males with obesity and any type of metabolic disorder had a higher risk of CVD, stroke and CVD mortality (excluding MI) compared to those with a normal body mass index (BMI) and no metabolic disorders. Females with obesity and any type of metabolic disorder were at higher risk of CVD(, MI and stroke compared to those with a normal BMI and no metabolic disorders suggesting that obesity and metabolic disorders are related. Due to its synergistic effect on high blood pressure, metabolic disorders raise the risk of CVD.

The association between ambient air pollution and migraine: a systematic review

Some studies have shown the effect of air pollution on migraine. However, it needs to be confirmed in larger-scale studies, as scientific evidence is scarce regarding the association between air pollution and migraine. Therefore, this systematic review aims to determine whether there are associations between outdoor air pollution and migraine. A literature search was performed in Scopus, Medline (via PubMed), EMBASE, and Web of Science. A manual search for resources and related references was also conducted to complete the search. All observational studies investigating the association between ambient air pollution and migraine, with inclusion criteria, were entered into the review. Fourteen out of 1417 identified articles met the inclusion criteria and entered the study. Among the gaseous air pollutants, there was a correlation between exposure to nitrogen dioxide (NO2) (78.3% of detrimental relationships) and carbon monoxide (CO) (68.0% of detrimental relationships) and migraine, but no apparent correlation has been found for sulfur dioxide (SO2) (21.2% of detrimental relationships) and ozone (O3) (55.2% of detrimental relationships). In the case of particulate air pollutants, particulate matter with a diameter of 10 μm or less (PM10) (76.0% of detrimental relationships) and particulate matter with a diameter of 2.5 μm or less (PM2.5) (61.3% of detrimental relationships) had relationships with migraine. In conclusion, exposure to NO2, CO, PM10, and PM2.5 is associated with migraine headaches, while no conclusive evidence was found to confirm the correlation between O3 and SO2 with migraine. Further studies with precise methodology are recommended in different cities around the world for all pollutants with an emphasis on O3 and SO2.

Association between metabolic syndrome and myocardial infarction among patients with excess body weight: a systematic review and meta-analysis

BACKGROUND

Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality worldwide. Controversial views exist over the effects of metabolically unhealthy obesity phenotypes on CVDs. This study aimed to perform a meta-analysis to assess the association between metabolic syndrome and myocardial infarction (MI) among individuals with excess body weight (EBW).

METHODS

We searched PubMed/Medline, Scopus, and Web of Science databases as of December 9, 2023. Cohort studies involving patients with overweight or obesity that reported the relevant effect measures for the association between metabolic syndrome and MI were included. We excluded studies with incomplete or unavailable original data, reanalysis of previously published data, and those that did not report the adjusted effect sizes. We used the Newcastle Ottawa Scale for quality assessment. Random-effect model meta-analysis was performed. Publication bias was assessed by Begg's test.

RESULTS

Overall, nine studies comprising a total of 61,104 participants were included. There was a significant positive association between metabolic syndrome and MI among those with obesity (hazard ratio (HR): 1.68; 95% confidence interval (CI): 1.27, 2.22). Subgroup analysis showed higher HRs for obesity (1.72; 1.03, 2.88) than overweight (1.58; 1.-13-2.21). Meta-regression revealed no significant association between nationality and risk of MI (p = 0.75). All studies had high qualities. There was no significant publication bias (p = 0.42).

CONCLUSIONS

Metabolic syndrome increased the risk of MI in those with EBW. Further studies are recommended to investigate other risk factors of CVDs in EBW, in order to implement preventive programs to reduce the burden of CVD in obesity.

Cosmetic use and serum level of lead (not cadmium) affect bone mineral density among young Iranian women

Bone mineral density is a crucially important index for skeletal health. A low amount of bone density (osteoporosis) is a common health problem among men and especially women. Among different parts of the body, women's face is the area on which many types of (facial) cosmetics are routinely applied. The aims of this study were to measure the association of cosmetic use with BMD of the lumbar spine and femoral neck among young female students. This is a cross-sectional study on 65 female students in the 2017 academic year. The study participants were students at Shiraz University of Medical Sciences who were selected randomly using phone directory sampling method. Based on the results of multiple linear regression, adjusted for several important covariates, cosmetic use is inversely associated with the BMD z-scores. Lead was significantly associated with trochanteric z-score (B = -0.002 to 95% CI = -0.004 to -0.0003, p = 0.02) and total lumbar z-score (B = -0.002 to 95% CI = -0.004 -0.0005, p = 0.01). In the present study, duration of using cosmetics was significantly associated with BMD of key skeletal regions. The big market of cosmetics in many countries especially those in the Middle East is highly a vastly neglected health issue. Many more observational prospective or interventional studies are required to understand the benefits and hazards caused by cosmetics in women.

Serum level of lead and cadmium is linked to facial cosmetics use among Iranian young women

Cosmetics are applied widely by women and men for different proposes mainly beauty and skin care. However, the biologically active substances which are used in these products and their health effects are not fully known. The aims of this study were, first, to estimate the prevalence of cosmetics use, and second, to examine if any association exists between cosmetic use and serum levels of lead and cadmium (two heavy metals with major health effects) among young women. This is a cross-sectional study conducted on 65 female students during the first semester of 2017 academic year. Study sample was selected randomly using phone numbers. About 70% of the study participants started using cosmetics under age 20 years (about 14% under 15), and 50% were using the products on a daily base. After adjusting for possible confounders, significant associations were found between the participants age (B = - 0.0008, CI = - 0.001 to - 4.71, P = 0.03) and duration of using cosmetics (B = 0.0006, CI = 0.0001 to 0.115, P = 0.01) with the level of cadmium in their serum samples. Duration of using cosmetics (B = 0.008, CI 0.001 to 0.01, P = 0.01) was the only variable which was significantly associated with serum level of lead in the participants. According to the results of the present study, most Iranian girls start using cosmetics at a very young age making them more vulnerable to the potential hazards of the ingredients of cosmetic products including heavy metals and preservatives. The association between duration of using cosmetics and serum level of lead and cadmium may cause serious health problems for women at young ages and their fetus or children via placenta and breast milk. The big market of cosmetics in many countries especially Middle East is highly important.

Letter to the editor. Concerning the article entitled ''Guillain Barre syndrome associated with COVID-19 infection: A case report"

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A novel coronavirus (COVID-19) was detected in Wuhan City, Hubei Province of China.

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The most symptoms of disease have reported fever, cough, dyspnea, myalgia, headache, and diarrhea.

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We followed up GBS symptoms in one infected patient with COVID-19.

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The limbs weakness of patient completely improved after treatment with IVIG.

Guillain Barre syndrome associated with COVID-19 infection: A case report

Novel outbreak with coronavirus 2019 began since 31 December 2019. Coronaviruses can cause multiple systemic infections that respiratory complications are the most obvious symptoms. In this report, we describe the symptoms of Guillain Barre syndrome (GBS) in one infected patient with COVID-19, for the first time. We reported a 65-years- old male patient with complaints of acute progressive symmetric ascending quadriparesis. Two weeks prior to hospitalization, the patient suffered from cough, fever, and RT-PCR was reported positive for COVID-19 infection. The electrodiagnostic test showed that the patient is an AMSAN variant of GBS. COVID-19 stimulates inflammatory cells and produces various inflammatory cytokines and as a result, it creates immune-mediated processes. GBS is an immune-mediated disorder and molecular mimicry as a mechanism of autoimmune disorder plays an important role in creating it. It is unclear whether COVID-19 induces the production of antibodies against specific gangliosides. Further investigations should be conducted about the mechanism of GBS in patients with COVID-19, in the future.

Correction to: Scintigraphic evaluation of remote perconditioning protection against unilateral renal ischemia/reperfusion injury in rats: a longitudinal study

The original article was published with incorrect article title.

Scintigraphic evaluation of remote pre-conditioning protection against unilateral renal ischemia/reperfusion injury in rats: a longitudinal study

PURPOSE

To determine the role of remote perconditioning (RPeC) on renal function and histology in an animal model of unilateral renal ischemia and reperfusion (IR) injury.

METHODS

Rats were subjected to 60 min unilateral renal ischemia. RPeC protocol was the application of four cycles of 5 min IR of left femoral artery during renal ischemia. Assessments of histological changes and renal function were made 24 h, 1 week, or 3 weeks later. 99mTc-DMSA scan was performed using a small-animals SPECT system.

RESULTS

24-h reperfusion decreased the 99mTc-DMSA uptake in the left kidney compared to the intact kidney of control animals. RPeC group has higher uptake compared to the IR group. After 1 week and 3 weeks, uptakes were gradually increased in both groups and no differences were observed. Severe morphological changes in the ischemic kidneys of both groups were observed after 24 h which attenuated after 1 week and 3 weeks. Moreover, no differences in creatinine and BUN levels between IR-treated and intact animals were observed.

CONCLUSION

These data suggest that RPeC exerts a partially transient improvement in the renal function in the first day after reperfusion. However, long-term follow-up study showed no beneficial effects of RPeC. Moreover, noninvasive 99mTc-DMSA scan revealed a suitable tool in the follow-up evaluation of recovery process in the unilateral renal IR injury models.

Inducible and endothelial nitric oxide synthase distribution and expression with hind limb per-conditioning of the rat kidney

INTRODUCTION

We recently reported that a series of brief hind limb ischemia and reperfusion (IR) at the beginning of renal ischemia (remote per-conditioning - RPEC) significantly attenuated the ischemia/reperfusion-induced acute kidney injury. In the present study, we investigated whether the nitric oxide synthase (NOS) pathway is involved in the RPEC protection of the rat ischemic kidneys.

MATERIAL AND METHODS

Male rats were subjected to right nephrectomy and randomized as: (1) sham, no additional intervention; (2) IR, 45 min of renal ischemia followed by 24 h reperfusion; (3) RPEC, four 5 min cycles of lower limb IR administered at the beginning of renal ischemia; (4) RPEC+L-NAME (a non-specific NOS inhibitor, 10 mg/kg, i.p.) (5) RPEC + 1400W (a specific iNOS inhibitor, 1 mg/kg, i.p.). After 24 h, blood, urine and tissue samples were collected.

RESULTS

The protective effect of RPEC on renal function, oxidative stress indices, pro-inflammatory marker expression and histopathological changes of kidneys subjected to 45 min ischemia were completely inhibited by pretreatment with L-NAME or 1400W. It was accompanied by increased iNOS and eNOS expression in the RPEC group compared with the IR group.

CONCLUSIONS

These findings suggest that the protective effects of RPEC on renal IR injury are closely dependent on the nitric oxide production after the reperfusion and both eNOS and iNOS are involved in this protection.

Family and social predictors of substance use disorder in Iran: a case-control study

BACKGROUND

The problem of substance use disorder in Iran is of great national concern. The aim of this study was to measure the association between substance use disorder and demographic, social and behavioral factors in Yasuj city, located at southwest of Iran.

METHODS

As the second phase of a previously published study, this case-control study was conducted in 2015-2016 on 362 addicted participants and 207 controls (with no history of substance use disorder). The control group was selected from male hospital visitors in Yasuj city during the same period of selection of the case group. The required information was collected via a self-administered questionnaire.

RESULTS

Based on the results of multivariate analysis, significant associations were found between the number of sisters (OR = 0.82, 95%CI = 0.68 to 0.99, P = 0.04), history of smoking (ORyes/no = 19.89, 95%CI = 10.02 to 39.49, P < 0.001), leisure time activity (ORwith friends/home = 8.98, 95%CI = 3.99 to 20.19, P < 0.001) and substance use disorder.

CONCLUSION

This study introduced smoking, number of sisters, education and way of spending leisure time as predictors of substance use disorder. Among these factors, smoking was the most powerful risk factor and spending leisure time with family and having sister were the most powerful preventive factors for substance use disorder.

Withdrawing attempt and its related factors among Iranian substance users: a case-control study

Background

Substance dependence is considered as an important health disorder with a wide and serious range of psychosocial effects. With regard to the large number of people with substance dependency in Iran and high failure rate of quitting attempts, the aim of this study was to identify contributing factors to quitting substance dependency among patients in Yasuj the capital of Kohgilooyeh and Boyerahmad province.

Methods

This case-control study was conducted on 150 current substance users (as control group) and 187 patients who voluntarily introduced themselves to governmental and private residential treatment camps (as case group). The participants in the case group were selected via two stage cluster sampling among those admitted to residential treatment camps. Those in the control group were selected via snowball sampling among current substance users.

Results

Based on the results from multiple logistic regression analysis, significant associations were observed between attempting to withdraw substance use and father’s education (OR _{high school or university /illiterate} = 0.36, 95%CI: 0.18 to 0.72, P = 0.004) and smoking (OR _yes/no = 4.26, 95%CI = 1.90 to 9.57, P < 0.001) were identified.

Conclusions

This study introduced father’s education as an obstacle to attempting to quit substance dependency. This finding can be justified by easier access to money and therefore less financial pressure in providing drugs among those with wealthier families. Also, smoking was more common among those who registered with the camps. This is possibly due to the quitters attempt to replace the drugs with cigar smoking as an alternative. Training families in helping their members in preventing or quitting substance dependency is a potentially useful approach. Studies are needed to define whether the common belief that smoking helps in withdrawing substance use is helpful.

Harmful Outcome of Occupational Exposure to Petrol: Assessment of Liver Function and Blood Parameters among Gas Station Workers in Kermanshah City, Iran

Background:

Petrol is an integral ingredient in industrial world. According to the US Agency for Toxic Substances and Disease Registry, there are typically more than 150 chemicals in petrol, including small amounts of benzene, toluene, xylene, ethyl benzene, and trace amounts of some contaminants, such as lead. The aim of this study was to measure the possible deleterious effect of long-term exposure to petrol on blood parameters and liver function.

Methods:

This is a case–control study conducted on 160 participants. Among them, 80 participants worked in a gas station for at least 4 years and 80 participants appeared with no history of occupational exposure to petrol. Blood sample was taken at the time of admonition to the tardive office at each station at 10 AM to measure the association of number of total and differential leukocyte and liver functions.

Results:

Based on the results, significant reduction in total leukocyte numbers was found in exposed group compared to unexposed group (1347 ± 4.59, <0.001). However, there was a significant increase in neutrophil (75.9 ± 3.50 in exposed group compared with 58.9 ± 3.15 among unexposed group, P < 0.001). However, no significant difference was found in liver enzymes between both groups.

Conclusions:

Long-term exposure to petrol fumes has deleterious effect on white blood cells. A significant reduction in the number of total and differential lymphocyte seems to be attributed to the toxic effect of petrol ingredients.

Hypertension, risk factors and coronary artery stenosis: A case-control study

Although hypertension is introduced as a major risk factor for cardiovascular diseases (CVDs), our knowledge about the nature of the association is hindered. The aim of this study was to assess the concurrent associations of several factors including serologic, anthropometric and coronary artery stenosis (CAS) with blood pressure. This is a case-control study on 163 hypertensive patients (SBP > 140 mmHg or DBP > 80 mmHg) and 227 healthy participants. All participants underwent angiography due to classic symptoms of CVDs. Controlling for other study variables, significant associations between CAS (OR yes/no = 1.99, 95%CI: 1.18-3.34 P = 0.006), BMI (kg/m2) (OR = 1.08, 95%CI: 1.03-1.14, P = 0.002) and age (year) (OR = 1.03, 95%CI = 1.005-1.05, p = 0.01) with hypertension were found. However, according to the results of the stratified analysis, no such associations were found among those with significant CAS. BMI and age were the only significant predictors of hypertension among participants with no CAS. Abdominal obesity was not remained in the final model regardless of the presence or absence of stenosis. As expected, stenosis itself was significantly associated with hypertension. This study suggested that BMI and age are the most powerful predictors of hypertension among those without CAS. As the result, it can be concluded that CAS alters the association between several factors and hypertension.

Under-ascertainment, under-reporting and timeliness of Iranian communicable disease surveillance system for zoonotic diseases

OBJECTIVES

The important steps in controlling infectious diseases are fast detection, proper treatment and on-time reporting of cases to the appropriate authorities. This study was conducted to evaluate the quality of Iranian communicable diseases surveillance system (CDSS) for zoonotic diseases in rural areas of Fars province (Iran's third largest province).

STUDY DESIGN

The three most important evaluation indices of CDSS, namely under-ascertainment, under-reporting and timeliness, for the three most common zoonotic diseases were measured using independent data source obtained from door-to-door interviews and patients' medical records.

METHODS

Interviews were conducted with 48,771 households in rural areas of Fars province from April 2014 to March 2015. The medical and registration data were obtained from the CDSS and medical or health centres.

RESULTS

Under-ascertainment, total under-reporting and timeliness (delay from the time of onset of symptoms to the time of visiting a medical or health centre, to the time of reporting visited cases to the highest level of CDSS) for leishmaniasis were 19.6%, 42.5% and 81.61 days (48.95 due to system delay), respectively. The corresponding indices for brucellosis were 0%, 41.8% and 56.5 days (22 due to system delay), respectively. For animal bite, the corresponding indices were 7.83%, 13.07% and less than 72 h, respectively (no system delay).

CONCLUSIONS

Although the status of case reporting and timeliness of surveillance system in public sectors providing medical services are clearly better than those of the private sectors, the indices are far from the level needed by CDSS to be able to detect and handle epidemics on time. Training health personnel, especially physicians, from public and private sectors to secure their cooperation along with routine and indebt evaluation are necessary to improve CDSS in Iran.

Evaluation of environmental heat stress on physiological parameters

BACKGROUND

Thermal component of the atmospheric environment is an important issue which is related to human's health. Thermal environment includes both heat exchange conditions (stress) and the physiological response (strain). The aim of this study was to measure the association of heat indices (PSI, HSI, Humidex) especially subjective one (STI) with some physiological parameters (Blood pressure, pulse rate and skin temperature).

METHODS

This is a cross-sectional study conducted on 387 male farmers on Boukan, West Azerbaijan, Iran in 2016. Sampling was conducted on the hottest days in summer on July based on the meteorological report. Heat parameters was measured 3 times in each session.

RESULTS

Direct associations were found between heat indices and physiological parameters except systolic BP. However, invers associations were found between blood pressure, skin and core body temperature, pulse rate with all heat indices. Based on the results of linear regression analysis, significant association was found between WBGT and skin temperature (B = 0.31, CI: 0.02, 0.61, P = 0.03). Results also showed significant association between Humidex and skin temperature (B = 0.21, CI: -0.03, 0.40, P = 0.02). However, no significant associations were found between other heat stress indices including UTCI, PHS, HIS, STI and Humidex with all study physiological parameters (core body temperature, systolic and diastolic blood pressure and also pulse rate).

CONCLUSION

As expected, farmer's health is affected by physiological parameters. Moreover, among assessed types of heat stress indices WBGT and Humidex were more powerful to show better the association with mentioned physiological parameters.

Risk factors for being the at-fault driver: A case-control study

OBJECTIVE

It is estimated that road traffic accidents are globally responsible for approximately 1.2 million deaths and 20 to 50 million injuries. About 70% of traffic incidences (TIs) occur in developing countries and among countries with high TI rates; Iran is the first. The aim of this study was to measure the association between being responsible for a traffic accident and some vehicle, human; and environmental related factors in Yasuj, a city with a high incidence of road traffic injuries and deaths in Iran.

METHODS

This is a time-, date-, and place-matched case-control study conducted in 2015 using all traffic accidents registered and investigated by police during 2012. In total, 194 drivers were considered the at-fault driver in a traffic accident and the 194 drivers in the same collisions were included in the analysis.

RESULTS

Based on the results from multivariate conditional logistic regression, significant associations between vehicle maneuver (OR_{Turn to right or left/Moving forward} = 11.10, 95% confidence interval [CI], 1.77-69.58, P = .01) and age (odds ratio [OR] = 1.11, 95% CI, 1.004-1.22, P = .04) and the chance of being an at-fault driver were found.

CONCLUSION

Driver behavior-related interventions including training and law enforcement seem to be more effective in reducing road traffic accidents in Iran.

Involvement of neuronal pathways in the protective effects of hindlimb perconditioning during renal ischemia

Remote ischemic perconditioning (RPEC) is a therapeutic intervention that has been demonstrated to reduce renal ischemia/reperfusion (I/R) injury. However, the underlying renal protective mechanism remains unclear. The present study hypothesized that RPEC may utilize neural pathways to transfer the protective signal from the perconditioned hindlimb to the kidney. Following a right nephrectomy, rats were randomly allocated into five groups (n=6). The sham group underwent the surgical protocol only. In all other groups, the left renal pedicle was clamped for 45 min and reperfused for 24 h. The I/R control group then underwent 45 min ischemia and 24 h reperfusion (I/R) with no more intervention but the I/R-NR control group underwent the ischemia and reperfusion followed by left femoral nerve (FN) and sciatic nerve (SN) resection. The RPEC group underwent ischemia and reperfusion followed by four cycles of 5 min occlusions of the left femoral artery and 5 min reperfusion. Finally, the RPEC-NR group underwent ischemia and reperfusion followed by left FN and SN resection. Following 24 h, renal functional indices, plasma blood urea nitrogen (BUN) and creatinine (Cr) levels, urinary N-acetyl-β-glucosaminidase (NAG) release and histopathological changes were assessed. Compared with the sham group, ischemia and reperfusion in the sham and I/R control groups resulted in renal dysfunction, indicated by significantly increased levels of BUN and Cr. This was accompanied by increased urinary NAG activity and morphological damage observed in control groups. In the RPEC group, renal histology and function were significantly improved compared with the control groups. However, FN and SN resection eliminated the protection of the kidney, which was induced by RPEC. In conclusion, remote hindlimb ischemic perconditioning reduced renal I/R injury in the rat kidney in a manner that potentially involves a neural pathway.

Factors associated with work ability index (WAI) among intensive care units' (ICUs') nurses

Objectives:

Work ability is a crucial occupational health issue in health care settings where a high physical and psychosocial work capacity is required and a high risk of disabling injuries and illnesses is predictable. This study aims to examine the association between the work ability index (WAI) and individual characterizations, workload, fatigue, and diseases among intensive care units' (ICUs') nurses.

Methods:

The study sample included 214 nurses selected by a random sampling method from a target population consisting of 321 registered nurses working in eight ICUs. Multiple linear regression analysis was used to test the association between WAI scores and each of the independent variables.

Results:

Results of multivariate analysis revealed a strong and negative association between WAI scores and diseases (B=-5.82, 95% CI=-7.16, -4.48, P<0.001). Among the studied individual characterizations, body mass index (BMI) was significantly and inversely associated with WAI scores. A significant and negative association was also found between WAI scores and dimensions of MFI-20, such as general fatigue (B=-0.31, 95% CI=-0.53, -0.09, P=0.005) and physical fatigue (B=-0.44, 95% CI=-0.65, -0.23, P<0.001). From dimensions of workload, frustration (B=-0.04, 95% CI=-0.07, -0.02, P<0.001) and temporary demand (B=-0.04, 95% CI=-0.08, -0.0001, P=0.04) showed a negative and significant association with WAI scores, while performance showed a positive and significant association (B=0.04, 95% CI=0.01, 0.07, P=0.005).

Conclusions:

Based on the study findings, development of health care programs with the aim of setting up a healthy work environment characterized by a well-structured preventive attitude toward controlling diseases, and a well-designed organizational framework toward increasing the level of performance and motivation, reducing the level of fatigue, as well as reducing the workload, is necessary to promote work ability among ICUs' nurses.

Hind limb perconditioning renoprotection by modulation of inflammatory cytokines after renal ischemia/reperfusion

Purpose Renal ischemia/reperfusion (I/R) injury is a common clinical problem associated with significant mortality and morbidity. One newly described strategy to reduce this damage is remote perconditioning (RPEC), in which short-time ischemia of a limb during renal ischemia reduces the I/R-induced kidney injury. This study aimed to assess whether RPEC confer protection through changes in pro-inflammatory mediators. Methods Rats were subjected to right nephrectomy and randomized into: sham (no intervention), I/R (subjected to 45-min left renal ischemia) and RPEC group (subjected to four cycles of 5-min I/R of the femoral artery administered during renal ischemia). After 24-h, blood, urine, and kidney samples were collected. Biochemical indicators of renal dysfunction were measured in the cases of Neutrophil gelatinase-associated lipocalin (NGAL), and N-acetyl-B-diglucosaminidase (NAG) activity. Inflammatory cytokines [interleukin (IL)-6 and tumor necrosis factor-alpha, TNF-α] expression in the renal tissues as well as Periodic acid-Schiff stained histological sections were evaluated. Results I/R resulted in renal dysfunction, as evidenced by higher renal NGAL expression and urinary NAG activities. This was accompanied by increased TNF-α and IL-6 expressions as well as histological changes in this group. However, RPEC improved renal histology and function compared with the I/R group. Furthermore, the RPEC group showed decreases in TNF-α and IL-6 expression. Conclusions These results suggest that RPEC reduces the dysfunction and injury associated with I/R of the kidney. This technique reduced the pro-inflammatory cytokine in the kidney. RPEC could be a promising strategy against I/R-induced acute kidney injury partly by down-regulation of inflammatory mediators.

Postconditioning is protective in renal reperfusion injury only in male rats. A gender difference study

PURPOSE

We investigated the impact of sex on the protective effect of postconditioning (POC), a series of brief ischemia-reperfusion (IR) cycles at the reperfusion onset, as a recently described novel approach to attenuate renal IR injury. In this study, the left renal pedicles of uni-nephrectomized male and female rats were clamped for 45 minutes followed by 24 hours of reperfusion as IR groups. Uni-nephrectomized, sham-operated male and female rats served as control groups. Ischemic postconditioning was performed using 4 cycles of 10 seconds of IR of renal pedicle at the end of the ischemia. Twenty-four hours later, BUN (blood urea nitrogen), plasma creatinine (Cr), and renal histological changes, as well as kidney levels of MDA (malondialdehyde) and SOD (superoxide dismutase) as oxidative stress markers were evaluated to detect the protective effect of POC against IR injury in rats.

RESULTS

Induction of IR resulted in significant reduction in renal function, demonstrated by increase in plasma Cr and BUN, histological changes and oxidative stress in both genders. Application of POC afforded significant protection against these injuries in male rats, namely decreased levels of BUN and Cr, histological improvements and less oxidative damages. However, there were no significant differences in the above-mentioned parameters in female rats.

CONCLUSION

While POC is shown to be beneficial against renal IR injury in male rats, it did not show any protective effect in female rats.

Hepatoprotective effects of remote perconditioning during renal ischemia

BACKGROUND

Novel treatment strategies are required to reduce the development of hepatic injury during surgical procedure in which renal ischemia/reperfusion (IR) is inevitable. Remote perconditioning (rPeC) has been proved to reduce the extent of kidney damages induced by renal IR injury. The aim of this study was to determine the protective effect of rPeC against hepatic injury caused by renal ischemia.

METHODS

Male rats were subjected to the right nephrectomy and randomized as: sham, no additional intervention; IR, 45 min of left renal pedicle occlusion; rPeC, four cycles of 5-min limb IR administered at the beginning of renal ischemia. After 24-h of reperfusion, the plasma and tissue samples were taken.

RESULTS

A significant improvement in hepatic functional injury and oxidative damages were observed in the rPeC group compared to the IR group. However, histological evaluation and plasma levels of TNF-α revealed no significant difference among groups.

CONCLUSIONS

It is concluded that rPeC exerted protective effects on renal IR-induced hepatic injury as a remote organ. The protection may be a consequence of the reduction in oxidative stress in the liver. This simple approach may be a promising strategy against IR-induced remote organ damages in the clinical practice (Fig. 4, Ref. 23).

Generalized lock-in detection for interferometry: application to phase sensitive spectroscopy and near-field nanoscopy

A generalized lock-in detection method is proposed to extract amplitude and phase from optical interferometers when an arbitrary periodic phase or frequency modulation is used. The actual modulation function is used to create the reference signals providing an optimal extraction of the useful information, notably for sinusoidal phase modulation. This simple and efficient approach has been tested and applied to phase sensitive spectroscopy and near-field optical measurements. We analyze the case where the signal amplitude is modulated and we show how to suppress the contribution of unmodulated background field.

Remote preconditioning reduces oxidative stress, downregulates cyclo-oxygenase-2 expression and attenuates ischaemia-reperfusion-induced acute kidney injury

Remote preconditioning (rPeC) is a phenomenon by which short-time intermittent ischaemia-reperfusion (I/R) of a remote organ during ischaemia protects other organs from I/R injury (IRI). The aim of the present study was to investigate the protective effect of rPeC on renal IRI in rats. Rats were subjected to right nephrectomy and randomized as into a sham group (no additional intervention), an I/R group (subjected to 45 min left renal pedicle occlusion) and an rPeC group (subjected to four cycles of 5 min I/R of the left femoral artery administered at the beginning of renal ischaemia). After 24 h, blood, urine and tissue samples were collected. Compared with the sham group, I/R resulted in renal dysfunction, as evidenced by significantly lower creatinine clearance (CCr; 0.52 ± 0.06 vs 0.11 ± 0.02 mL/min, respectively) and higher fractional excretion of sodium (FE(Na) ; 0.80 ± 0.07% vs 2.46 ± 0.20%, respectively). This was accompanied by decreased superoxide dismutase (SOD; 6.9 ± 1.7 vs 26.7 ± 2.7 U/g tissue) and catalase (CAT; 20.2 ± 8.8 vs 32.2 ± 8.7 K/g tissue) activity in the I/R group, as well as decreased levels of reduced glutathione (GSH; 21.7 ± 8.1 vs 81.2 ± 20.2 μmol/g tissue) and increased malondialdehyde levels (MDA; 1.2 to 0.1 vs 0.5 ± 0.2 μmol/100 mg), cyclo-oxygenase (COX)-2 expression and histological damage. In the rPeC group, renal histology and function were significantly improved (CCr 0.32 ± 0.02 mL/min; FE(Na) 1.33 ± 0.12%) compared with the I/R group. Furthermore, compared with the I/R group, the rPeC group exhibited increases in SOD and CAT activity (22.8 ± 3.8 U/g tissue and 21.7 ± 8.6 K/g tissue, respectively), increased GSH levels (74.0 ± 4.9) and decreased MDA levels (1.1 ± 0.3 μmol/100 mg) and COX-2 expression. In conclusion, rPeC appears to exert protective effects against renal IRI. This protection may be a consequence of reductions in lipid peroxidation, intensification of anti-oxidant systems and downregulation of COX-2 expression. A simple approach, rPeC may be a promising strategy for protection against IRI in clinical practice.

Thermochemical growth of Mn-doped CdS nanoparticles and study of luminescence evolution

We report a new method of growing Mn-doped CdS (CdS:Mn) nanoparticles in an aqueous solution at boiling temperature. The idea is to use precursors that react only at high temperature, in order to gain crystalline luminescent nanoparticles. CdSO(4), Mn(NO(3))(2) and Na(2)S(2)O(3) were used as the precursors, and thioglycerol was employed as the capping agent and also the reaction catalyst. Na(2)S(2)O(3) is thermally sensitive and it releases S(2-) ions upon heating. The CdS:Mn nanoparticles obtained are about 4 nm in size and show both cubic and hexagonal crystalline phases with a ratio of 35% to 65%. The luminescence of nanoparticles contains a peak at 580 nm, which is related to Mn(2+) ions. Prolonged reaction time results in a decrease of the Mn luminescence peak to about 35% of the maximum value. We discuss the possible causes of the Mn peak reduction and attribute it to preferential dissolution of Mn ions into the solution due to shape reconfiguration of the nanoparticles.