Rotating night shift work and physical activity of nurses and midwives in the cross-sectional study in Łódź, Poland

Shift work have been thought to restrict participation in leisure time activities, but the knowledge about physical activity in rotating night shift nurses has been limited so far. We investigated the associations between the rotating night shift work and physical activity using data from a cross-sectional study among nurses and midwives. This study included 354 nurses and midwives (aged 40–60) currently working rotating night shifts and 371 ones working days only. The information on the work characteristics and potential covariates was collected via a personal interview. Weight and height were measured and BMI was calculated. Physical activity was assessed according to the international questionnaire on physical activity – IPAQ, and four domains: leisure time, occupational, transport related and household were analyzed. Women who reported none leisure time activity were defined as recreationally “inactive”. The associations were examined with multiple linear or logistic regression models adjusted for age, season of the year, number of full term births, marital status and BMI. Total and occupational physical activity was significantly higher among nurses working rotating night shifts. However, leisure time activity was significantly affected among rotating night shift nurses and midwives, compared to women working during the days only, with increased odds ratio for recreational “inactivity” (OR?=?1.57, 95% CI: 1.11–2.20). Rotating night shift work among nurses and midwives is associated with higher occupational physical activity but lower leisure time activity. Initiatives supporting exercising among night shift workers are recommended.     

The circadian disruption of night work alters gut microbiota consistent with elevated risk for future metabolic and gastrointestinal pathology

ABSTRACT

Day and night cycles are the most important cue for the central clock of human beings, and they are also important for the gut clock. The aim of the study is to determine the differences in the gut microbiota of rotational shift workers when working the day versus night shift. Fecal samples and other data were collected from 10 volunteer male security officers after 4 weeks of day shift work (07:00–15:00 h) and also after 2 weeks of night shift work (23:00–07:00 h). In total, 20 stool samples were collected for analysis of gut microbiota (10 subjects x 2 work shifts) and stored at ?80°C until analysis by 16 S rRNA sequencing. The relative abundances of Bacteroidetes were reduced and those of Actinobacteria and Firmicutes increased when working the night compared to day shift. Faecalibacterium abundance was found to be a biomarker of the day shift work. Dorea longicatena and Dorea formicigenerans were significantly more abundant in individuals when working the night shift. Rotational day and night shift work causes circadian rhythm disturbance with an associated alteration in the abundances of gut microbiota, leading to the concern that such induced alteration of gut microbiota may at least partially contribute to an increased risk of future metabolic syndrome and gastrointestinal pathology.     

Timing of food intake during simulated night shift impacts glucose metabolism: A controlled study

Eating during the night may increase the risk for obesity and type 2 diabetes in shift workers. This study examined the impact of either eating or not eating a meal at night on glucose metabolism. Participants underwent four nights of simulated night work (SW1–4, 16:00–10:00 h, <50 lux) with a daytime sleep opportunity each day (10:00–16:00 h, <3 lux). Healthy males were assigned to an eating at night (NE; n = 4, meals; 07:00, 19:00 and 01:30 h) or not eating at night (NEN; n = 7, meals; 07:00 h, 09:30, 16:10 and 19:00 h) condition. Meal tolerance tests were conducted post breakfast on pre-night shift (PRE), SW4 and following return to day shift (RTDS), and glucose and insulin area under the curve (AUC) were calculated. Mixed-effects ANOVAs were used with fixed effects of condition and day, and their interactions, and a random effect of subject identifier on the intercept. Fasting glucose and insulin were not altered by day or condition. There were significant effects of day and condition × day (both p < 0.001) for glucose AUC, with increased glucose AUC observed solely in the NE condition from PRE to SW4 (p = 0.05) and PRE to RTDS (p < 0.001). There was also a significant effect of day (p = 0.007) but not condition × day (p = 0.825) for insulin AUC, with increased insulin from PRE to RTDS in both eating at night (p = 0.040) and not eating at night (p = 0.006) conditions. Results in this small, healthy sample suggest that not eating at night may limit the metabolic consequences of simulated night work. Further study is needed to explore whether matching food intake to the biological clock could reduce the burden of type 2 diabetes in shift workers.     

A new highly sensitive chemiluminescent assay of alkaline phosphatase using lucigenin and its application to enzyme immunoassay

The chemiluminescent reaction of lucigenin with various reducing sugars and reducing compounds has been studied. It was found that dihydroxyacetone gave the most intense chemiluminescence (CL). We have developed highly sensitive chemiluminescent methods for alkaline phosphatase (ALP) based on the production of dihydroxyacetone using NADP⁺ or glycerol-3-phosphate as substrate. The detection limits for ALP using each substrate were 1.25 × 10^?19 mol/assay and 2.5 × 10^?19 mol/assay, and the coefficient of variation (n = 7) was 2.8% and 3.7%, respectively. We have also applied the method using NADP⁺ as substrate in enzyme immunoassays (EIA) for cholecystokinin (CCK) and human chorionic gonadotropin (hCG). CCK-8 (octapeptide sulphated form of a carboxy terminal fragment of CCK) concentrations released from alimentary canal of rat were assayed using the chemiluminescent EIA (CLEIA) and a fluorimtric EIA (ALP label). The correlation between CCK-8 values obtained by these methods was y = 1.04x + 18.21, r = 0.946, n = 28. hCG values in serum and in urine were measured. The correlation between hCG values in serum samples obtained using the CLEIA and a time-resolved fluoroimmunoassay (TR-FIA), and in urine samples obtained using the CLEIA and the fluorimetric EIA using ALP were satisfactory. The correlations were y = 1.00x ? 0.04, r = 0.997 (n = 51) and y = 1.00x ? 0.03, r = 0.999 (n = 10), respectively.     

Crucial role of alkaline sphingomyelinase in sphingomyelin digestion: a study on enzyme knockout mice

Alkaline sphingomyelinase (alk-SMase) hydrolyses sphingomyelin (SM) to ceramide in the gut. To evaluate the physiological importance of the enzyme, we generated alk-SMase knockout (KO) mice by the Cre-recombinase-Locus of X-over P1(Cre-LoxP) system and studied SM digestion. Both wild-type (WT) and KO mice were fed 3H-palmitic acid labeled SM together with milk SM by gavage. The lipids in intestinal content, intestinal tissues, serum, and liver were analyzed by TLC. In KO mice, nondigested 3H-SM in the intestinal content increased by 6-fold and the formation of 3H-ceramide decreased markedly, resulting in 98% reduction of 3H-ceramide/3H-SM ratio 1 h after gavage. The absorbed 3H-palmitic acid portion was decreased by 95%. After 3 h, a small increase in 3H-ceramide was identified in distal intestine in KO mice. In feces, 3H-SM was increased by 243% and ceramide decreased by 74% in the KO mice. The KO mice also showed significantly decreased radioactivity in liver and serum. Furthermore, alkaline phosphatase activity in the mucosa was reduced by 50% and histological comparison of two female littermates preliminarily suggested mucosal hypertrophy in KO mice. This study provides definite proof for crucial roles of alk-SMase in SM digestion and points to possible roles in regulating mucosal growth and alkaline phosphatase function.     

Interethnic variability in birth weight and genetic background: A study of placental alkaline phosphatase

The relationship between human placental alkaline phosphatase (PLAP) genotype and birth weight is investigated in a sample of white, black and Puerto-Rican new-born infants from New Haven, Connecticut (total 710 subjects). Black and Puerto-Rican infants show a higher incidence of growth retardation and a higher frequency of ALPp^*1/^*1 genotype as compared to whites. The proportion of newborns with a low birth weight (below the 10th percentile) is lower in infants with ALPp^*1/^*1 genotype than in those with other PLAP genotypes, especially among non-whites. It is argued that the higher frequency of ALPp^*1 allele among non-whites might be, at least in part, a consequence of their adaptation in the past to environmental conditions adverse to optimal intrauterine development. © 1996 Wiley-Liss, Inc.     

Energy intake of shift workers compared to fixed day workers: A systematic review and meta-analysis

Shift work is an established risk factor for a number of chronic conditions associated with excess energy intake including obesity, cardiovascular disease and type 2 diabetes. This systematic review investigated whether the 24 h energy intake of shift workers differs to that of fixed day workers. Included articles compared energy intake of shift workers (shift included midnight) with fixed day workers. There were 10 367 day workers and 4726 shift workers from 12 studies included in the qualitative analysis and meta-analyses. The standardised mean difference (95% CI) in energy intake between shift and day workers was ?0.04 (?0.11, 0.03); I² = 54%. Qualitative results on macronutrient intakes were conflicting. Reported energy intakes were not different between day workers and shift workers, suggesting that other factors such as circadian misalignment, meal timing, food choice and diurnal variation of energy metabolism at night may be responsible for the increased rates of obesity observed in shift workers. Guidance on health and well-being is required for this at-risk population group.     

The effects of extended nap periods on cognitive,physiological and subjective responses under simulated night shift conditions

Extended nap opportunities have been effective in maintaining alertness in the context of extended night shifts (+12?h). However, there is limited evidence of their efficacy during 8-h shifts. Thus, this study explored the effects of extended naps on cognitive, physiological and perceptual responses during four simulated, 8-h night shifts. In a laboratory setting, 32 participants were allocated to one of three conditions. All participants completed four consecutive, 8-h night shifts, with the arrangements differing by condition. The fixed night condition worked from 22h00 to 06h00, while the nap early group worked from 20h00 to 08h00 and napped between 00h00 and 03h20. The nap late group worked from 00h00 to 12h00 and napped between 04h00 and 07h20. Nap length was limited to 3 hours and 20 minutes. Participants performed a simple beading task during each shift, while also completing six to eight test batteries roughly every 2?h. During each shift, six test batteries were completed, in which the following measures were taken. Performance indicators included beading output, eye accommodation time, choice reaction time, visual vigilance, simple reaction time, processing speed and object recognition, working memory, motor response time and tracking performance. Physiological measures included heart rate and tympanic temperature, whereas subjective sleepiness and reported sleep length and quality while outside the laboratory constituted the self reported measures. Both naps reduced subjective sleepiness but did not alter the circadian and homeostatic-related changes in cognitive and physiological measures, relative to the fixed night condition. Additionally, there was evidence of sleep inertia following each nap, which resulted in transient reductions in certain perceptual cognitive performance measures. The present study suggested that there were some benefits associated with including an extended nap during 8-h night shifts. However, the effects of sleep inertia need to be effectively managed to ensure that post-nap alertness and performance is maintained.     

Coping with shift work-related circadian disruption: A mixed-methods case study on napping and caffeine use in Australian nurses and midwives

ABSTRACT

Introduction: Two of the most ubiquitous fatigue countermeasures used by shift-working nurses are napping and caffeine. This mixed-methods case study investigated the ways nurses and midwives utilised napping and caffeine countermeasures to cope with shift work, and associated sleep, physical health and psychological health outcomes.

Materials and Methods: N = 130 Australian shift-working nurses and midwives (mean age = 44 years, range = 21–67, 115F, 15M) completed the Standard Shiftwork Index. A sub-set of 22 nurses and midwives completed an in-depth interview.

Results: Nearly 70% of participants reported napping. Those who napped during night shifts had significantly less total sleep time before (F_2,75 = 5.5, p < 0.01) and between days off (F_2,82 = 3.9, p < 0.05). By the end of the night shift, average hours of time awake were significantly less for prophylactic and on-shift nappers compared to non-nappers (F_2,85 = 97.2, p < 0.001). Since starting shift work, the percentage of high caffeine consumers (>400 mg/day) increased from 15% to 33% of the sample and an average of 4 (SD = 2) caffeinated beverages per day was reported. Increased caffeine consumption was associated with greater sleep disturbance (r = 0.26, p < 0.05), psychological distress (r = 0.37, p < 0.001), abdomen pain (r = 0.27, p < 0.05) and weight gain since starting shift work (r = 0.25, p < 0.05). Interviews confirmed these relationships and revealed that caffeine consumption on night shift was common, whereas napping on night shift was dependent on a number of factors including ability to sleep during the day.

Conclusion: This study identified reasons shift workers chose to engage in or abstain from napping and consuming caffeine, and how these strategies related to poor sleep and health outcomes. Further research is required to help develop recommendations for shift workers regarding napping and caffeine consumption as fatigue countermeasures, whilst taking into account the associated hazards of each strategy.     

Purification and the immunological characterization of rat protein phosphatase 2A: enzyme levels in diabetic liver and heart

Summary Protein phosphatase 2A₁ was purified from rat skeletal muscle and used to produce antisera to the three subunits of the holoenzyme. Affinity purified antibodies specific for the subunits of the phosphatase enzyme were found to recognize the type 2A₁ and 2A₂ phosphatase from rat skeletal muscle, heart, liver, brain and erythrocytes and were used to investigate the effects of diabetes on the levels of this enzyme in liver and heart. Phosphorylase phosphatase assays coupled with immunoblot analysis of fractionated rat liver and heart cytosol from normal and diabetic animals show no apparent differences in the quantity or activity of these enzymes following the induction of alloxan diabetes. When considering these results and the normal physiological concentrations of known effectors of these enzymes, it is likely that protein phosphatase 2A₁ and 2A₂ are not responsible for the dephosphorylation of phosphorylase a under physiological conditions.     

Individual differences in the cortisol-awakening response during the first two years of shift work: A longitudinal study in novice police officers

Cortisol acts as a critical biological intermediary through which chronic stressors like shift work impact upon multiple physiological, neuro-endocrine and hormonal functions. Therefore, the cortisol awakening response (CAR) is suggested as a prime index of shift work tolerance. Repeated assessments of the CAR (calculated as MnInc) in a group of 25 young novice police officers showed that in the interval between about 4 and 14 months after transitioning from regular day work to rotating shift work, mean values began to rise from baseline to significantly higher levels at about 14 months after they commenced shift work. Visual inspection of the individual trends revealed that a subgroup of 10 subjects followed a monotonically rising trend, whereas another 14 subjects, after an initial rise from about 4–14 months, reverted to a smaller, baseline level cortisol response at about 20 months after the start of shift work. If the initial increase in the cortisol response marks the development of a chronic stress response, the subsequent reversal to baseline levels in the subgroup of 14 participants might be indicative of a process of recovery, possibly the development of shift work tolerance.     

Effect of circadian rhythm type on serum lipid levels in shift workers: A 5-year cohort study

We investigated how differences in circadian rhythm type affect the health of workers engaged in shift work. Employees, who were newly hired in a steel company between 2007 and 2011, received the Morningness–Eveningness Questionnaire (MEQ) survey. The target participants were 153 male shift workers who were not being treated with any antihyperlipidemic drugs and underwent periodic physical examinations including blood tests at least twice. According to the score of the MEQ at the time of joining the company, we classified the subjects into five types. Longitudinal changes in serum lipid level were estimated among the circadian rhythm types adjusted for age, BMI, and other covariates using a linear mixed model. The regression coefficient of total cholesterol level in the “definitely and moderately morning” group was ?17.83 (95% confidence interval (CI): ?33.42 to ?2.23), and in the “intermediate ‘group’ was ?16.84 [95% CI: ?30.40 to ?3.28], compared to the moderate evening type.” The total cholesterol level was higher in the moderately evening type than in any of the other groups. Between the Morningness–Eveningness (ME) type and Low-density lipoprotein (LDL) cholesterol levels, compared with the “moderately evening type” group, the regression coefficient in the “intermediate type” group was ?16.08 (95% CI: ?28.79 to ?3.37), and in the “definitely and moderately morning type” group was ?17.50 [95% CI: ?32.11 to ?2.88]. The “moderately evening type” group had a higher LDL cholesterol level than any of the other groups. Evening-type circadian rhythm type shift workers are more prone to elevated serum lipid levels.     

The effect of dim light at night on cerebral hemodynamic oscillations during sleep: A near-infrared spectroscopy study

Recent studies have reported that dim light at night (dLAN) is associated with risks of cardiovascular complications, such as hypertension and carotid atherosclerosis; however, little is known about the underlying mechanism. Here, we evaluated the effect of dLAN on the cerebrovascular system by analyzing cerebral hemodynamic oscillations using near-infrared spectroscopy (NIRS). Fourteen healthy male subjects underwent polysomnography coupled with cerebral NIRS. The data collected during sleep with dim light (10 lux) were compared with those collected during sleep under the control dark conditions for the sleep structure, cerebral hemodynamic oscillations, heart rate variability (HRV), and their electroencephalographic (EEG) power spectrum. Power spectral analysis was applied to oxy-hemoglobin concentrations calculated from the NIRS signal. Spectral densities over endothelial very-low-frequency oscillations (VLFOs) (0.003–0.02 Hz), neurogenic VLFOs (0.02–0.04 Hz), myogenic low-frequency oscillations (LFOs) (0.04–0.15 Hz), and total LFOs (0.003–0.15 Hz) were obtained for each sleep stage. The polysomnographic data revealed an increase in the N2 stage under the dLAN conditions. The spectral analysis of cerebral hemodynamics showed that the total LFOs increased significantly during slow-wave sleep (SWS) and decreased during rapid eye movement (REM) sleep. Specifically, endothelial (median of normalized value, 0.46 vs. 0.72, p = 0.019) and neurogenic (median, 0.58 vs. 0.84, p = 0.019) VLFOs were enhanced during SWS, whereas endothelial VLFOs (median, 1.93 vs. 1.47, p = 0.030) were attenuated during REM sleep. HRV analysis exhibited altered spectral densities during SWS induced by dLAN, including an increase in very-low-frequency and decreases in low-frequency and high-frequency ranges. In the EEG power spectral analysis, no significant difference was detected between the control and dLAN conditions. In conclusion, dLAN can disturb cerebral hemodynamics via the endothelial and autonomic systems without cortical involvement, predominantly during SWS, which might represent an underlying mechanism of the increased cerebrovascular risk associated with light exposure during sleep.     

The effects of long-term exposure to extremely low-frequency magnetic fields on bone formation in ovariectomized rats

The effects of long‐term extremely low‐frequency magnetic field (ELF‐MF) exposure on bone formation and biochemical markers were investigated in ovariectomized rats. Sixty mature female Sprague–Dawley rats were randomly divided into four different groups (n = 15): (i) unexposed control (CTL); (ii) ovariectomized only (OVX); (iii) non‐ovariectomized, exposed (SHAM + ELF‐MF); and (iv) ovariectomized, exposed (OVX + ELF‐MF). The third and fourth groups were exposed to 1.5 mT ELF‐MF for 4 h a day for 6 months. Bone mineral density (BMD) was determined using dual energy X‐ray absorption (DEXA) measurements. The formation and resorption of bone were evaluated using bone‐specific alkaline phosphatase (BAP), osteocalcin, osteoprotogerin, and N‐telopeptide. After 6 months of ELF‐MF therapy, BMD values were significantly lower in the OVX group and higher in the OVX + ELF‐MF and SHAM + ELF‐MF groups than they were before therapy (P < 0.001). Although there was no significant difference in BMD values among the groups before therapy, the BMD values increased significantly after 6 months in the OVX + ELF‐MF and SHAM + ELF‐MF groups and were reduced in the OVX group compared to the CTL group (P < 0.001). The concentrations of BAP, osteocalcin, osteoprotogerin, and N‐telopeptide in the three experimental groups also changed in a significant way compared to the CTL group. The results of the present study suggest that osteoporosis can be inhibited by ELF‐MF stimulation treatments. It was also concluded that ELF‐MF may be useful in the prevention of osteoporosis in ovariectomized rats. Bioelectromagnetics 33:543–549, 2012. © 2012 Wiley Periodicals, Inc.     

Associations between liver function and cerebrospinal fluid biomarkers of Alzheimer's disease pathology in non-demented adults: The CABLE study

Liver function has been suggested as a possible factor in the progression of Alzheimer's disease (AD) development. However, the association between liver function and cerebrospinal fluid (CSF) levels of AD biomarkers remains unclear. In this study, we analyzed the data from 1687 adults without dementia from the Chinese Alzheimer's Biomarker and LifestylE study to investigate differences in liver function between pathological and clinical AD groups, as defined by the 2018 National Institute on Aging-Alzheimer's Association Research Framework. We also examined the linear relationship between liver function, CSF AD biomarkers, and cognition using linear regression models. Furthermore, mediation analyses were applied to explore the potential mediation effects of AD pathological biomarkers on cognition. Our findings indicated that, with AD pathological and clinical progression, the concentrations of total protein (TP), globulin (GLO), and aspartate aminotransferase/alanine transaminase (ALT) increased, while albumin/globulin (A/G), adenosine deaminase, alpha-L-fucosidase, albumin, prealbumin, ALT, and glutamate dehydrogenase (GLDH) concentrations decreased. Furthermore, we also identified significant relationships between TP (β = −0.115, p_FDR < 0.001), GLO (β = −0.184, p_FDR < 0.001), and A/G (β = 0.182, p_FDR < 0.001) and CSF β-amyloid_1–42 (Aβ_1–42) (and its related CSF AD biomarkers). Moreover, after 10 000 bootstrapped iterations, we identified a potential mechanism by which TP and GLDH may affect cognition by mediating CSF AD biomarkers, with mediation effect sizes ranging from 3.91% to 16.44%. Overall, our results suggested that abnormal liver function might be involved in the clinical and pathological progression of AD. Amyloid and tau pathologies also might partially mediate the relationship between liver function and cognition. Future research is needed to fully understand the underlying mechanisms and causality to develop an approach to AD prevention and treatment approach.     

Effects of retinoic acid on the growth of cultured rabbit articular chondrocytes: Relation with alkaline phosphatase activity and beta receptor

The effects of retinoic acid (RA) on rabbit articular cartilage cells were studied for concentrations ranging from 5.10^-5 M to 10^-7 M; the treatment with RA over three days resulted in dose dependent inhibition of chondrocyte proliferation between 5.10^-5 and 10^-5 M with persistence of the inhibitory effect until 10^-6 M. RA until 10^-7 M induced a slight, but significant, enhancement of cell proliferation. This growth stimulating effect seems to be related to the Beta receptor system because Beta blockers, such as sotalol and DL propranolol, were able to suppress the stimulating action of agonist type isoprenaline. The activity of alkaline phosphatase (AP) was also determined. The highest dose of RA (5.10^-5 M) induced an increase (x 3) of AP activity, and 10^-7 M RA decreased it (x 0.4).     

Long-term exposure to outdoor VOCs and lung function in urban adults: a cross-sectional study in Tabriz an industrialized city in the northwest of Iran

Abstract

This study aimed to evaluate the effects of outdoor benzene, toluene, xylenes, and styrene (BTXS) on respiratory system performance in adults living in an industrialized city. The concentration of BTXS was measured in the three selected areas (low traffic, high traffic and industrial). Pulmonary function of totally 219 participants who have lived in the selected areas for at least five years, were evaluated through the spiromertry. Based on the results, significant differences were observed between the mean concentrations of BTXS (industrial area?>?high traffic area?>?low traffic area). Considerable decline of 0.46?L, 0.41?L, 2.99%, 0.9?L/min, and 0.59?L/s for Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV₁), FEV₁/FVC, Peak Expiratory Flow (PEF) and Forced Expiratory Flow between 25% and 75% of vital capacity (FEF_25–75%), respectively, were detected in industrial area residents compared to the low traffic region. In addition, some spirometric parameters were different between the other sampling sites. In conclusion, the results showed that the long term exposure to higher concentrations of BTXS increases respiratory dysfunction risks in industrial and high traffic areas respectively, as compared with living in the low traffic region.     

Effect of number of views on cross-sectional Compton imaging: A fundamental study with backprojection

IntroductionWe have been developing a medical imaging technique using a Compton camera, which is expected to reconstruct three-dimensional images. If the number of views is not sufficient, star-shaped artifacts (streak artifacts) could arise in cross-sectional images. Therefore, we estimated the point spread function (PSF) of cross-sectional Compton images and the effect of the number of views by Monte Carlo simulations and experimental studies.Materials and methodsA cross-sectional Compton image was reconstructed using a dataset comprising 719 view directions and PSF was analyzed using a radial distribution. The peak height, full width at half maximum (FWHM), background (BG), and residual sum of squares (RSS) were calculated from the obtained PSF. In addition, RSSs were plotted against the number of views to estimate the required number to suppress star-shaped artifacts.ResultsThere was no correlation found between the number of views and both FWHM (16 mm) and peak/BG ratio (∼1 × 10⁴). RSSs were reduced with the number of views and approached the minimum asymptotically. Correlation was observed between the required number of views and the number of Compton events used for image reconstruction.ConclusionWe determined the PSF of cross-sectional Compton images and the effect of the number of views on the images. The required number of views to suppress the star-shaped artifact is related to the square root of the number of Compton events used to reconstruct the image. From this study, we concluded that 21 or more views are required for clinical purposes.     

The gold nanoparticle size and exposure duration effect on the liver and kidney function of rats: In vivo

Nanoparticles (NPs) offer a great possibility for biomedical application, not only to deliver pharmaceutics, but also to be used as novel diagnostic and therapeutic approaches. Currently, there are no data available regarding to what extent the degree of the toxicity and the accumulation of gold nanoparticles (GNPs) are present in in vivo administration. This study aimed to address the GNP size and exposure duration effect on the liver and kidney function of rats: in vivo.MethodsA total of 30 healthy male Wistar-Kyoto rats of the same age (12 weeks old) and weighing 220–240 g of King Saud University colony were used. Animals were randomly divided into groups, two GNP-treated rat groups and one control group (CG). The 50 μl of 10 and 50 nm GNPs was intraperitoneally administered in rats for exposure duration of 3 days. Then, several biochemical parameters such as aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alanine transaminase (ALT), alkaline phosphatase (ALP), urea (UREA) and creatinine (CREA) were evaluated.ResultsIn this study, the AST values increased with the administration of 10 and 50 nm GNPs compared with the control. The AST values significantly increased with 10 nm GNPs compared with 50 nm GNPs and control. The GGT and ALT values decreased with the administration of 10 and 50 nm GNPs compared with the control. The GGT and ALT values significantly decreased with 50 nm GNPs compared with 10 nm GNPs and control. The ALP values significantly decreased with the administration of 10 and 50 nm GNPs compared with the control. The decrease in ALP values with 10 nm GNPs was higher than those compared with 50 nm GNPs. In this study, the levels of UREA and CREA values increased in a non significant manner after the administration of 10 and 50 nm GNPs compared with the control.ConclusionsThis study demonstrates that the increase in the enzymes AST and the decrease in ALP are smaller GNPs (10 nm) size-dependent for exposure duration of 3 days; while the decrease in the enzymes GGT and ALT are bigger GNPs (50 nm) size-dependent. The levels of UREA and CREA values indicated no significant changes with the administration of 10 and 50 nm GNPs for exposure duration of 3 days compared with the control. The administration of 10 and 50 nm GNPs for short exposure duration of 3 days induced only significant variations with some liver enzymes while kidney showed no significant variations. This study suggests that synthesis and metabolism of GNPs as well as the protection of the liver will be more important issues for medical applications of gold-based nanomaterials in future.     

The sex-specific effects of blood lead,mercury, and cadmium levels on hepatic steatosis and fibrosis: Korean nationwide cross-sectional study

AimThe potential effects of heavy metals on non-alcoholic fatty liver disease (NAFLD) remain unknown. We investigated the sex-specific relationships of blood lead (BPb), mercury (BHg), and cadmium (BCd) levels with hepatic steatosis (HS) and fibrosis (HF).MethodWe included 4420 participants from the 2016–2017 Korea National Health and Nutrition Examination Survey. High-risk alcoholics and patients with chronic hepatitis B or C infections or liver cirrhosis were excluded. We calculated the hepatic steatosis index (HSI) and fibrosis-4 index (FIB-4) values; we defined the presence of HS and HF as an HSI ≥ 36 and FIB-4 score >2.67, respectively. We adjusted for age, smoking and alcohol consumption statuses, hypertension, obesity, diabetes, hypertriglyceridemia, and BPb, BHg, and BCd levels.ResultIn males (n = 1860), the HSI was correlated negatively with the BPb level and positively with the BHg level (both p < 0.01). The FIB-4 score was correlated positively with the BPb and BCd levels (both p < 0.01). In females (n = 2560), the HSI and FIB-4 score were correlated positively with the BPb, BHg, and BCd levels (all p < 0.01). After adjustments, the BHg level increased the risk of HS in both males (OR = 1.065, p = 0.003) and females (OR = 1.061, p = 0.048), and the BCd level increased the risk of HF in females (OR = 1.668, p = 0.012).ConclusionBlood heavy metal levels were generally correlated positively with the HSI and FIB4 score, more so in females than males. The BHg level was associated with HS in males and females, and the BCd level was associated with HF in females. Further studies on NAFLD progression according to heavy metal status and sex are warranted.