[3 + 2] Cycloaddition Reaction of Vinylsulfonium Salts with Hydrazonoyl Halides: Synthesis of Pyrazoles.

An efficient [3 + 2] cycloaddition reaction between in situ generated nitrile imines from hydrazonoyl halides and vinylsulfonium salts is developed. The nitrile imines are demonstrated to be a new class of reaction partner for vinylsulfonium salts to conduct the [3 + 2] cycloaddition reaction. The process provides a concise and efficient method for the construction of pyrazole derivatives under mild reaction conditions with broad substrate scope, good product yields, and high regioselectivity.

Lead exposure disturbs ATP7B-mediated copper export from brain barrier cells by inhibiting XIAP-regulated COMMD1 protein degradation.

The brain barrier is an important structure for metal ion homeostasis. According to studies, lead (Pb) exposure disrupts the transportation of copper (Cu) through the brain barrier, which may cause impairment of the nervous system; however, the specific mechanism is unknown. The previous studies suggested the X-linked inhibitor of apoptosis (XIAP) is a sensor for cellular Cu level which mediate the degradation of the MURR1 domain-containing 1 (COMMD1) protein. XIAP/COMMD1 axis was thought to be an important regulator in Cu metabolism maintenance. In this study, the role of XIAP-regulated COMMD1 protein degradation in Pb-induced Cu disorders in brain barrier cells was investigated. Pb exposure significantly increased Cu levels in both cell types, according to atomic absorption technology testing. Western blotting and reverse transcription PCR (RT-PCR) showed that COMMD1 protein levels were significantly increased, whereas XIAP, ATP7A, and ATP7B protein levels were significantly decreased. However, there were no significant effects at the messenger RNA (mRNA) level (XIAP, ATP7A, and ATP7B). Pb-induced Cu accumulation and ATP7B expression were reduced when COMMD1 was knocked down by transient small interfering RNA (siRNA) transfection. In addition, transient plasmid transfection of XIAP before Pb exposure reduced Pb-induced Cu accumulation, increased COMMD1 protein levels, and decreased ATP7B levels. In conclusion, Pb exposure can reduce XIAP protein expression, increase COMMD1 protein levels, and specifically decrease ATP7B protein levels, resulting in Cu accumulation in brain barrier cells.

Cellular uptake of lead in the blood-cerebrospinal fluid barrier: Novel roles of Connexin 43 hemichannel and its down-regulations via Erk phosphorylation.

As the structural basis of blood-cerebrospinal fluid barrier (BCB), epithelial cells in the choroid plexus (CP) are targets for lead (Pb). Pb is known to accumulate in the CP; however, the mechanism of Pb uptake in the choroidal epithelial cells remains unknown. Recently, hemichannels of Connexin 43 (Cx43), the most ubiquitously expressed gap junction proteins in the CP, were found to be important pathways for many substances. This study was designed to investigate the roles of Cx43 in Pb uptake in the epithelial cells. Autometallography was used to outline Pb's subcellular location, and the characteristics of Pb transport into CP cells, including concentration- and time-dependence were analyzed by atomic absorption spectroscopy. Knockdown/overexpression of Cx43 with transient siRNA/plasmids transfections before Pb exposure diminished/increased the Pb accumulation. In the Z310 cell-based doxycycline-inducible Cx43 expression cell line (iZCx43), doxycycline induced a significant increase (3-fold) in Pb uptake, corresponding to the increased Cx43 levels. Activation of Cx43 hemichannels by reduced serum conditions caused an increase of Pb concentrations. Cx43-induced Pb uptake was attenuated after blockage of Cx43 hemichannels with its inhibitor, carbenoxolone. Additionally, down-regulation of Cx43 protein levels by Pb exposure paralleled cellular Pb concentrations in the time study. Concomitantly, expressions of phosphor-Src and phosphor-Erk were both significantly increased by Pb. However, inactivation of Erk, not Src pathway, reversed Pb-induced downregulation of Cx43. Taken together, these data establish that Pb can accumulate in the BCB and validate the role of Cx43 hemichannel in Pb uptake and its regulations through Erk phosphorylation.

Application of Femtosecond Laser + Piggyback Multifocal Intraocular Lens Implantation in Patients with Super-High Myopia Complicated with Cataract.

OBJECTIVE: To observe the clinical effect of piggyback multifocal intraocular lens (IOL) implantation in treating patients with high myopia complicated with cataract. METHODS: This was a prospective controlled study. We compared 32 eyes of 32 patients who underwent femtosecond laser-assisted cataract surgery with piggyback IOL implantation (two IOLs were implanted into the capsule) with 32 eyes of 32 patients who also underwent the same surgery (one IOL implanted into the capsule) due to high myopia complicated with cataract at the Wuhan Aier Eye Expert Hospital between January 2019 and October 2020. All patients were followed up for three months after surgery. Uncorrected distance visual acuity (UCDVA), uncorrected intermediate visual acuity (UCIVA), uncorrected near visual acuity (UCNVA), best-corrected distance visual acuity, distance-corrected intermediate visual acuity (DCIVA), distance-corrected near visual acuity (DCNVA), postoperative spectacle independence, postoperative visual interference, equivalent spherical lens, defocus curve, and IOL tilt and eccentricity were evaluated. RESULTS: Three months after surgery, the patients' UCIVA, UCNVA, DCIVA, and DCNVA were 0.49 ± 0.07, 0.38 ± 0.15, 0.47 ± 0.09, and 0.36 ± 0.12, respectively, in the research group and 0.56 ± 0.18, 0.72 ± 0.22, 0.55 ± 0.13, and 0.69 ± 0.15, respectively, in the control group; the differences between the two groups were statistically significant (P < .05). The spectacle independence rate was higher in the research group (93%) than in the control group (13%). The overall satisfaction regarding postoperative visual quality was also higher in the research group than in the control group. The absolute mean value of the spherical equivalents was 0.48 ± 0.28 D in the research group and 0.62 ± 0.33 D in the control group; the difference between the two groups was statistically significant (P < .05). CONCLUSION: Piggyback multifocal IOL implantation can expand the multifocal IOL application range, and satisfy the desire of patients with high myopia complicated with cataract to see both near and far.

Associations of E-proteinoid 3 receptor genetic polymorphisms with salt sensitivity, longitudinal blood pressure changes, and hypertension incidence in Chinese adults.

The E-proteinoid 3 receptor (PTGER3), a member of the prostaglandin E2 (PGE2) subtype receptor, belongs to the G-protein-coupled superfamily of receptors. Animal studies have demonstrated its involvement in salt sensitivity by regulating sodium reabsorption. This study aimed to investigate the association between genetic variants of PTGER3 and salt sensitivity, longitudinal blood pressure (BP) changes, and the incidence of hypertension in Chinese adults. A chronic salt intake intervention was conducted involving 514 adults from 124 families in the 2004 Baoji Salt-Sensitivity Study Cohort in northern China. These participants followed a 3-day regular baseline diet, followed by a 7-day low-salt diet (3.0 g/d) and a 7-day high-salt diet (18 g/d), and were subsequently followed for 14 years. The findings revealed a significant relationship between the single nucleotide polymorphism (SNP) rs17482751 of PTGER3 and diastolic blood pressure (DBP) response to high salt intervention. Additionally, SNPs rs11209733, rs3765894, and rs2268062 were significantly associated with longitudinal changes in systolic blood pressure (SBP), DBP, and mean arterial pressure (MAP) during the 14-year follow-up period. SNP rs6424414 was significantly associated with longitudinal changes in DBP over 14 years. Finally, SNP rs17482751 showed a significant correlation with the incidence of hypertension over 14 years. These results emphasize the significant role of PTGER3 gene polymorphism in salt sensitivity, longitudinal BP changes, and the development of hypertension in the Chinese population.

Non-high altitude methods for rapid screening of susceptibility to acute mountain sickness.

BACKGROUND: Acute mountain sickness (AMS) refers to the cerebral abnormalities typically triggered by exposure to hypobaric hypoxia at high altitude. Although AMS is not often life threatening, it can seriously impact health quality and decrease productivity. Thus, detection of potential susceptibility to AMS has become important for people arriving at high-altitude plateaus for the first time, including laborers and military staff. The aim of this review was to examine techniques which efficiently assess the susceptibility to AMS prior to exposure to high altitude. METHODS: By searching online databases, we retrieved studies with associations between AMS and methods to detect the susceptible people who were not exposed to high altitudes. Studies reporting significant correlation coefficients between screening methods and AMS scores were included. RESULTS: Several screening techniques of AMS susceptibility were found including cold pressor test, heart rate variability, and lung functions. Of these markers, heart rate variability was positively associated with AMS scores, while the rest were negatively associated with AMS scores. CONCLUSIONS: We identified three physiological markers that were significantly associated with the risk of AMS. Although it is well known that simple sea level tests are not really helpful in predicting AMS currently, these markers, to some degree, may be employed as references in predicting susceptibility.

Anti-inflammatory effect of miR-125a-5p on experimental optic neuritis by promoting the differentiation of Treg cells.

Methylprednisolone pulse treatment is currently used for optic neuritis. It can speed visual recovery, but does not improve the ultimate visual outcomes. Recent studies have reported that miR-125a-5p has immunomodulatory effects on autoimmune diseases. However, it remains unclear whether miR-125a-5p has effects on optic neuritis. In this study, we used adeno-associated virus to overexpress or silence miR-125a-5p in mice. We found that silencing miR-125a-5p increased the latency of visual evoked potential and aggravated inflammation of the optic nerve. Overexpression of miR-125a-5p suppressed inflammation of the optic nerve, protected retinal ganglion cells, and increased the percentage of Treg cells. Our findings show that miR-125a-5p exhibits anti-inflammatory effects through promoting the differentiation of Treg cells.

Association of high-normal albuminuria and vascular aging: Hanzhong adolescent hypertension study.

Normoalbuminuria has recently been associated with increased cardiovascular risk, and vascular aging is proposed as the early manifestation of cardiovascular disease. Here, the authors aimed to examine the association of high-normal albuminuria and vascular aging in a Chinese cohort. From our previously established cohort, 1942 participants with estimated glomerular filtration rate ≥60 mL/min/1.73 m2 or urinary albumin-creatinine ratio (UACR) <30 mg/g were enrolled. Brachial-ankle pulse wave velocity (baPWV) ≥1400 cm/s and/or carotid intima-media thickness (CIMT) ≥0.9 mm were used as indicators of vascular aging. Multivariate regression and receiving operating characteristic curve analysis were performed to examine the relationship between continuous and categorical UACR with vascular aging. We found an average UACR value of 8.08 (5.45-12.52) mg/g in this study. BaPWV and CIMT demonstrated positive correlations with lg-UACR (p < .05). High-normal albuminuria (10-29 mg/g) was significantly associated with the presence of vascular aging after adjusting for multiple cardiovascular confounders (OR = 1.540, 95% CI = 1.203-1.972, p = .001). In addition, a lg-UACR cutoff point of 0.918 lg(mg/g) (equal to UACR of 8.285 mg/g) was significantly associated with the presence of vascular aging and its components for all participants and those without hypertension or diabetes and without medication (p < .05). Briefly, high-normal albuminuria was significantly associated with vascular aging in this sample of Chinese adults. These findings implied the warning of elevated UACR even within normal range in clinical practice and the importance of UACR screening in normoalbuminuria for early detection and prevention of cardiovascular disease in otherwise healthy participants.

MiR-130/SNAP-25 axis regulate presynaptic alteration in anterior cingulate cortex involved in lead induced attention deficits.

Brain volume decrease in the anterior cingulate cortex (ACC) after lead (Pb) exposure has been linked to persistent impairment of attention behavior. However, the precise structural change and molecular mechanism for the Pb-induced ACC alteration and its contribution to inattention have yet to be fully characterized. The present study determined the role of miRNA regulated synaptic structural and functional impairment in the ACC and its relationship to attention deficit disorder in Pb exposed mice. Results showed that Pb exposure induced presynaptic impairment and structural alterations in the ACC. Furthermore, we screened for critical miRNA targets responsible for the synaptic alteration. We found that miR-130, which regulates presynaptic vesicle releasing protein SNAP-25, was responsible for the presynaptic impairment in the ACC and attention deficits in mice. Blocking miR-130 function reversed the Pb-induced decrease in the expression of its presynaptic target SNAP-25, leading to the redistribution of presynaptic vesicles, as well as improved presynaptic function and attention in Pb exposed mice. We report, for the first time, that miR-130 regulating SNAP-25 mediates Pb-induced presynaptic structural and functional impairment in the ACC along with attention deficit disorder in mice.

Early-Life Cardiovascular Risk Factor Trajectories and Vascular Aging in Midlife: A 30-Year Prospective Cohort Study.

BACKGROUND: Vascular aging, as assessed by structural and functional arterial properties, is an independent predictor of cardiovascular outcomes. We aimed to explore the associations of individual cardiovascular risk factors from childhood to midlife and their accumulation over a 30-year span with vascular aging in midlife. METHODS: Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, 2180 participants aged 6 to 18 years at baseline were followed for over 30 years. Distinct trajectories of systolic blood pressure (SBP), body mass index (BMI), and heart rate from childhood to midlife were identified by group-based trajectory modeling. Vascular aging was assessed by carotid intima media thickness or brachial-ankle pulse wave velocity. RESULTS: We identified 4 distinct SBP trajectories, 3 distinct BMI trajectories, and 2 distinct heart rate trajectories from childhood to midlife. Persistently increasing SBP, high-increasing BMI, and high-stable heart rate were all shown to have a positive association with brachial-ankle pulse wave velocity in midlife. For carotid intima-media thickness, similar associations were observed for persistently increasing SBP and high-increasing body mass index. After further adjustment for SBP, body mass index and heart rate at the time of vascular assessment in 2017, associations were also observed for cardiovascular risk factor trajectories accumulation with brachial-ankle pulse wave velocity (ß, 0.656 [95% CI, 0.265-1.047]) and with carotid intima media thickness (ß, 0.045 [95% CI, 0.011-0.079]) in adulthood. CONCLUSIONS: Longitudinal exposure to individual cardiovascular risk factors from childhood to midlife and cardiovascular risk factor accumulation were associated with an increased risk of vascular aging in midlife. Our study lends support for early targeting of risk factors in order to prevent cardiovascular disease later in life.

Associations of lipid accumulation product, visceral adiposity index, and triglyceride-glucose index with subclinical organ damage in healthy Chinese adults.

Background and aims: Obesity is an independent risk factor for cardiovascular disease development. Here, we aimed to examine and compare the predictive values of three novel obesity indices, lipid accumulation product (LAP), visceral adiposity index (VAI), and triglyceride-glucose (TyG) index, for cardiovascular subclinical organ damage. Methods: A total of 1,773 healthy individuals from the Hanzhong Adolescent Hypertension Study cohort were enrolled. Anthropometric, biochemical, urinary albumin-to-creatinine ratio (uACR), brachial-ankle pulse wave velocity (baPWV), and Cornell voltage-duration product data were collected. Furthermore, the potential risk factors for subclinical organ damage were investigated, with particular emphasis on examining the predictive value of the LAP, VAI, and TyG index for detecting subclinical organ damage. Results: LAP, VAI, and TyG index exhibited a significant positive association with baPWV and uACR. However, only LAP and VAI were found to have a positive correlation with Cornell product. While the three indices did not show an association with electrocardiographic left ventricular hypertrophy, higher values of LAP and TyG index were significantly associated with an increased risk of arterial stiffness and albuminuria. Furthermore, after dividing the population into quartiles, the fourth quartiles of LAP and TyG index showed a significant association with arterial stiffness and albuminuria when compared with the first quartiles, in both unadjusted and fully adjusted models. Additionally, the concordance index (C-index) values for LAP, VAI, and TyG index were reasonably high for arterial stiffness (0.856, 0.856, and 0.857, respectively) and albuminuria (0.739, 0.737, and 0.746, respectively). Lastly, the analyses of continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) demonstrated that the TyG index exhibited significantly higher predictive values for arterial stiffness and albuminuria compared with LAP and VAI. Conclusion: LAP, VAI, and, especially, TyG index demonstrated utility in screening cardiovascular subclinical organ damage among Chinese adults in this community-based sample. These indices have the potential to function as markers for early detection of cardiovascular disease in otherwise healthy individuals.

Ergosta-4,6,8(14),22-tetraen-3-one induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells.

BACKGROUND: Mushrooms have been used in Asia as traditional foods and medicines for a long time. Ergosta-4,6,8(14),22-tetraen-3-one (ergone) is one of the well-known bioactive steroids, which exists widely in various medicinal fungi such as Polyporus umbellatus, Russula cyanoxantha, and Cordyceps sinensis. Ergone has been demonstrated to possess cytotoxic activity. However, the molecular mechanisms by which ergone exerts its cytotoxic activity are currently unknown. METHODS: In the present study, ergone possessed a remarkable anti-proliferative activity toward human hepatocellular carcinoma HepG2 cells. We assayed the cell cycle by flow cytometry using PI staining; investigated the exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane by the FITC-annexin V/PI staining; observed the nuclear fragmentation by Hoechst 33258 staining and studied the protein expression of Bax, Bcl-2, p-53, procaspase-3, -8, -9, PARP and cleaved PARP by Western blotting analysis. RESULTS: Cells treated with ergone showed typical markers of apoptosis: G2/M cell cycle arrest, chromatin condensation, nuclear fragmentation, and phosphatidylserine exposure. Furthermore, PARP-cleavage; activation of caspase-3, -8, -9; up-regulation of Bax and down-regulation of Bcl-2 were observed in HepG2 cells treated with ergone, which show that both the intrinsic and extrinsic apoptotic pathways are involved in ergone-induced apoptosis in HepG2 cells. Ergosta-4,6,8(14),22-tetraen-3-one induces G2/M cell cycle arrest and apoptosis in HepG2 cells in a caspase-dependent manner. GENERAL SIGNIFICANCE: In this study, we reported for the first time that ergone-induced apoptosis through activating the caspase. These results would be useful for the further utilization of many medicinal fungi in cancer treatment.

Comparison of the actual diameter of capsulotomy and predicted diameter of capsulotomy after femtosecond laser-assisted capsulotomy.

PURPOSE: To compare the consistency between the actual diameter of capsulotomy (ADC) and the predicted diameter of capsulotomy (PDC) in femtosecond laser-assisted cataract surgery (FLACS) and analyze the factors that influence the deviation of the diameter of capsulotomy (DDC) between the actual and predicted. SETTING: Aier Eye Hospital of Wuhan University, China. DESIGN: Retrospective observational case series. METHODS: Patients who underwent FLACS from March 2020 to March 2021 were reviewed. The ADC in FLACS was measured and compared with the PDC. The effects of age, sex, and biometrics on DDC were analyzed. RESULTS: 412 eyes of 336 patients were included. The mean age was 53.0 ± 0.91 years (range 3 to 91 years). When the PDC was set to 4.50 mm, the results showed that the ADC was 5.21 ± 0.21 mm with a significant difference between them ( P &lt; .05). However, when the PDC was set to 5.2 mm, the ADC was 5.10 ± 0.38 mm without a significant difference between them ( P &gt; .05). No correlation ( P &gt; .05) was found between the DDC and the axial length, the DDC and the anterior chamber depth (ACD), and the DDC and the mean keratometry (Km), but a negative correlation was found between the DDC and the lens thickness (LT) ( r = -0.21; P &lt; .05) and the DDC with age ( r = -0.70; P &lt; .05). Using curvilinear regression analysis, a development of an age-depending correction formula was predicted: ADC = PDC + 1.23 - 0.30 ln (x) (x = age ≥3) ( R2 = 0.65; F = 752.39; P = .00). CONCLUSIONS: The consistency of the ADC and PDC was influenced by age and LT. For patients aged 40 years or younger, the younger the patient, the wider the DDC; for patients older than 40 years, the DDC was small. The thicker the LT, the smaller the DDC.

Early life body mass index trajectories and albuminuria in midlife: A 30-year prospective cohort study.

Background: Albuminuria is a marker of vascular dysfunction and is associated with chronic renal and cardiovascular diseases. Data on the association between the longitudinal patterns of weight change early in life and albuminuria later in life are limited. We aimed to identify the body mass index (BMI) trajectory across a 30-year span and evaluate its association with middle-age albuminuria. Methods: Of the 4623 participants aged 6-18-year-old recruited by Hanzhong Adolescent Hypertension Study cohort in northern China from March 10, 1987 to June 3, 2017, a total of 1,825 participants followed up with 6 visits over 30 years were enrolled. Group-based trajectory modeling was used to identify distinct BMI trajectories in longitudinal analyses. Albuminuria was defined as a urinary albumin-to-creatinine ratio (uACR) ≥ 30 mg/g. Findings: Three distinct BMI trajectories were identified: low-increasing (n = 671, 36.8%), moderate-increasing (n = 940, 51.5%), and high-increasing (n = 214, 11.7%); male participants exhibited a steeper increase in BMI than females. The uACR was increased linearly from the low- to high-increasing group. A total of 201 individuals developed albuminuria, with an incidence of 11.0%. Compared with the low-increasing group, the odds ratio (OR) of albuminuria in middle age was 2.13(95% confidence interval [CI]: 1.26 to 3.61) for the high-increasing group after full adjustment for age, sex, smoking, alcohol consumption, marital status, systolic blood pressure, diabetes, and hyperlipidemia. The unadjusted ORs of the high-increasing BMI group were 5.08 (2.76-9.37) for males and 3.45 (1.78-6.69) for females, and the association remained significant in males in the fully adjusted models. Interpretation: Higher BMI trajectories are associated with higher uACR and an increased risk of albuminuria in middle age, especially in males. Identifying long-term BMI trajectories from an early age may assist in predicting the risk of renal diseases and cardiovascular disease later in life. Funding: This work was supported by the National Natural Science Foundation of China (81600327, 82070437, 81870319, 82070549, and 82170437), Natural Science Basic Research Program of Shaanxi Province (2021JM-257 and 2021JM-588), Institutional Foundation of the First Affiliated Hospital of Xi'an Jiaotong University (2019QN-06 and 2021ZXY-14), the Clinical Research Award of the First Affiliated Hospital of Xi'an Jiaotong University of China (XJTU1AF-CRF-2019-004, XJTU1AF2021CRF-021, and XJTU1AFCRF-2017-021), Research Incubation Fund of Xi'an People's Hospital (FZ-61), Grants from the Major Chronic Non-communicable Disease Prevention and Control Research Key Project of the Ministry of Science and Technology of China (2017YFC1307604 and 2016YFC1300104).

Medical cost and healthcare utilization of amyotrophic lateral sclerosis in China: A cohort study based on hospital data from 2015 to 2018.

Amyotrophic lateral sclerosis (ALS), a specific neurodegenerative disease, imposed increased economic and utilizations burden on the healthcare system, especially with the progress of the diseases severity. However, the economic burden on Chinese ALS patients remained unclear. This study therefore was aimed to investigate medical cost and healthcare utilization for Chinese ALS patients.Longitudinal health data of over 20 million individuals, including military personnel and civilians, was collected from all Chinese military hospitals. We identified 480 patients with a first major diagnosis for ALS from 2015 to 2018, while matched 400 controlled patients on age, gender, ethnic group, geographic region, length of stay, year of diagnosis and comorbidity. Their medical cost and healthcare utilizations were then measured 1 year before, and 1 year after ALS diagnosis.The median annual medical cost of ALS patients was about 2-fold higher, 17,087 CNY during the index year than 1 year before, 7859 CNY. The highest increase in utilizations may account for medical costs on ALS patients, which was represented by hospitalizations (Odd Ratio (OR) = 4.26, 95% confidence interval (CI) 3.52, 5.15), electromyography (OR = 4.14, 95% CI 2.37, 7.22), nerve conduction velocity (OR = 3.26, 95% CI 2.23, 4.77).This study is the first one reporting direct economic burden on Chinese ALS patients. Efforts should be made to develop cost-effective diagnostic tools in order that sources of medical cost were more effectively allocated, and this disease was detected earlier.

Structural elucidation of high-molecular-weight alkaline degradation products of hexoses.

High-molecular-weight alkaline degradation products of hexoses (HMWHADPs) are colored substances in sugar solutions formed during sugar manufacturing process. These products may be occluded within sugar crystals and impart yellow or brown color to sucrose, thereby negatively affecting the quality of white sugar. Thus, the structural properties of HMWHADPs pose a significant scientific problem in the sugar industry. In the present study, the structural properties of HMWHADPs were investigated using nuclear magnetic resonance, zeta potential analyzer, energy-dispersive X-ray spectrometry, ultraviolet-visible spectra, and Fourier transform infrared spectroscopy. Results showed that HMWHADPs mainly contain carboxyl, aldehyde, alcoholic hydroxyl, conjugated double bonds, and saturated alkanes. Possible mechanisms of HMWHADP formation were proposed on the basis of structural property investigation. This study can be used as reference for future research and practice in developing effective methods for the removal of HMWHADPs from sugar solutions and prevention of their further formation in subsequent steps.

An efficient autometallography approach to localize lead at ultra-structural levels of cultured cells.

Understanding the precise intracellular localization of lead (Pb) is a key in deciphering processes in Pb-induced toxicology. However, it is a great challenge to trace Pb in vitro, especially in cultured cells. We aimed to find an innovative and efficient approach to investigate distribution of Pb in cells and to validate it through determining the subcellular Pb content. We identified its ultra-structural distribution with autometallography under electron microscopy in a choroidal epithelial Z310 cell line. Electron microscopy in combination with energy-dispersive X-ray spectroscope (EDS) was employed to provide further evidence of Pb location. In addition, Pb content was determined in the cytosol, membrane/organelle, nucleus and cytoskeleton fractions with atomic absorption spectroscopy. Pb was found predominantly inside the nuclear membranes and some was distributed in the cytoplasm under low-concentration exposure. Nuclear existence of Pb was verified by EDS under electron microscopy. Once standardized for protein content, Pb percentage in the nucleus fraction reached the highest level (76%). Our results indicate that Pb is accumulated mainly in the nucleus of choroid plexus. This method is sensitive and precise in providing optimal means to study the ultra-structural localization of Pb for in vitro models. In addition, it offers the possibility of localization of other metals in cultured cells. Some procedures may also be adopted to detect target proteins via immunoreactions.

Paradoxical sleep deprivation impairs spatial learning and affects membrane excitability and mitochondrial protein in the hippocampus.

Previous research has demonstrated that paradoxical sleep has a key role in learning and memory, and sleep deprivation interferes with learning and memory. However, the mechanism of memory impairment induced by sleep deprivation is poorly understood. The present study investigated the effect of paradoxical sleep deprivation (PSD) on spatial learning and memory using the Morris Water Maze. Effects of PSD on CA1 pyramidal neurons in hippocampus were also examined. PSD impaired spatial learning of rats. PSD induced translocation of Bax to mitochondria and cytochrome c release into the cytoplasm, and decreased the membrane excitability of CA1 pyramidal neurons, effects which may contribute to the deficits in learning behavior. These results may partially explain the mechanism of the effect of PSD on learning. Modulating the excitability of hippocampal neurons and protecting mitochondrial function are possible targets for preventing the effects of paradoxical sleep deprivation.

Low-level Gestational Lead Exposure Alters Dendritic Spine Plasticity in the Hippocampus and Reduces Learning and Memory in Rats.

Lead (Pb) is known to impair children's cognitive function. It has been previously shown that developmental Pb exposure alters dendritic spine formation in hippocampal pyramidal neurons. However, the underlying mechanism has not yet been defined. In this study, a low-level gestational Pb exposure (GLE) rat model was employed to investigate the impact of Pb on the spine density of the hippocampal pyramidal neurons and its regulatory mechanism. Pb exposure resulted in impaired performance of the rats in the Morris water maze tasks, and in decreased EPSC amplitudes in hippocampal CA3-CA1 regions. With a 3D reconstruction by the Imaris software, the results from Golgi staining showed that the spine density in the CA1 region was reduced in the Pb-exposed rats in a dose-dependent manner. Decreased spine density was also observed in cultured hippocampal neurons following the Pb treatment. Furthermore, the expression level of NLGN1, a postsynaptic protein that mediates synaptogenesis, was significantly decreased following the Pb exposure both in vivo and in vitro. Up-regulation of NLGN1 in cultured primary neurons partially attenuated the impact of Pb on the spine density. Taken together, our resultssuggest that Pb exposure alters spine plasticity in the developing hippocampus by down-regulating NLGN1 protein levels.