Potassium affects the association between dietary intake of vitamin C and NAFLD among adults in the United States

INTRODUCTION

Although the association between nonalcoholic fatty liver disease (NAFLD) and vitamin C has been well studied, the effects of dietary potassium intake on this relationship are still unclear. Thus, this study aimed to determine the effects of dietary potassium intake on the association between vitamin C and NAFLD.

METHODS

We performed a cross-sectional learn about with 9443 contributors the usage of 2007-2018 NHANES data. Multiple logistic regression evaluation has been utilized to check out the affiliation of dietary vitamin C intake with NAFLD and advanced hepatic fibrosis (AHF). Subsequently, we plotted a smoothed match curve to visualize the association. Especially, the analysis of AHF was conducted among the NAFLD population. In addition, stratified evaluation used to be developed primarily based on demographic variables to verify the steadiness of the results. Effect amendment by way of dietary potassium intake used to be assessed via interplay checks between vitamin C and NAFLD in the multivariable linear regression.

RESULTS

In this cross-sectional study, we found that vitamin C was negatively related to NAFLD and AHF. The relationship between vitamin C and NAFLD was different in the low, middle and high potassium intake groups. Furthermore, potassium intake significantly modified the negative relationship between vitamin C and NAFLD in most of the models.

CONCLUSION

Our research showed that potassium and vitamin C have an interactive effect in reducing NAFLD, which may have great importance for clinical medication.

Comparison of outcomes between preservation or division of the uterine round ligament in laparoscopic groin hernia repair in females: a meta-analysis and trial sequential analysis

PURPOSE

The purpose of this study was to perform a meta-analysis comparing the short-term and long-term outcomes in laparoscopic groin hernia repair with or without preservation of the uterine round ligament (URL) in females.

METHODS

We searched several databases including PubMed, Web of Science, Cochrane Library, and and CNKI databases. This meta-analysis included randomized clinical trials, and retrospective comparative studies regarding preservation or division of the URL in laparoscopic groin hernia repair in females. Outcomes of interest were age, BMI, type of hernia, type of surgery, operating time, estimated blood loss, time of hospitalization, seroma, concomitant injury, mesh infection, recurrence, uterine prolapse, foreign body sensation, chronic pain, and pregnancy. Meta-analyses and trial sequential analysis were performed with Review Manager v5.3 and TSA software, respectively.

RESULTS

Of 192 potentially eligible articles, 9 studies with 1104 participants met the eligibility criteria and were included in the meta-analysis. There were no significant difference in age (MD-6.58, 95% CI - 13.41 to 0.24; P = 0.06), BMI (MD 0.05, 95%CI - 0.31 to 0.40; P = 0.81), blood loss (MD-0.04, 95% CI - 0.75 to 0.66; P = 0.90), time of hospitalization (MD-0.22, 95% CI-1.13 to 0.69; P = 0.64), seroma (OR 0.71, 95% CI 0.41 to 1.24; P = 0.23), concomitant injury (OR 0.32, 95% CI 0.01 to 8.24; P = 0.68), mesh infection (OR 0.13, 95% CI 0.01 to 2.61; P = 0.18), recurrence (OR 1.13, 95% CI 0.18 to 7.25; P = 0.90), uterine prolapse(OR 0.71, 95% CI 0.07 to 6.94; P = 0.77), foreign body sensation (OR 1.95, 95% CI 0.53 to 7.23; P = 0.32) and chronic pain(OR 1.03 95% CI 0.4 to 2.69; P = 0.95). However, this meta-analysis demonstrated a statistically significant difference in operating time (MD 6.62, 95% CI 2.20 to 11.04; P = 0.0003) between the preservation group and division group. Trial sequential analysis showed that the cumulative Z value of the operating time crossed the traditional boundary value and the TSA boundary value in the third study, and the cumulative sample size had reached the required information size (RIS), indicating that the current conclusion was stable.

CONCLUSION

In summary, laparoscopic groin hernia repair in women with the preservation of the round uterine ligament requires a longer operating time, but there was no advantage in short-term or long-term complications, and there was no clear evidence on whether it causes infertility and uterine prolapse.

Analysis of risk factors leading to multiple breast abscesses during lactation

We investigated 1805 cases of breast abscesses during lactation to estimate the risk factors for multiple breast abscesses during lactation. A total of 2000 cases of breast abscesses during lactation were investigated using an online questionnaire, and 1805 cases with complete data were analyzed. The survey response rate was 90%. According to the number of abscesses, the patients were divided into 2 groups: single breast abscess (number = 1298) and multiple breast abscess (number = 507). Pearson chi-square test was used to compare the 15 risk factors between the 2 groups. Risk factors with significant differences were substituted into a binary logistic regression model to analyze the independent risk factors associated with multiple breast abscesses during lactation. There were significant differences between the 2 groups in (1) weeks postpartum, (2) separated from the baby, (3) breastfeeding exclusivity, (4) nipple inversion, (5) fever, (6) breast redness/swelling, (7) nipple pain, (8) breast massage by nonmedical staff, with (1), (5), (6), and (8) being independent risk factors. Patients under 6 weeks postpartum, separated from the baby, not exclusively breastfeeding, having an inverted nipple on the affected side, fever, breast skin redness and swelling on the affected side, nipple pain, and having undergone a breast massage by nonmedical staff are more likely to develop multiple breast abscesses.

Clinical characteristics of lactational breast abscess caused by methicillin-resistant Staphylococcus aureus: hospital-based study in China

Background

This study aimed to identify the differences in clinical characteristics, puncture efficacy, antibiotic use, treatment duration, breastfeeding post-illness, and recurrence of patients with breast abscesses caused by methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA) infection during lactation.

Methods

The clinical data of patients with breast abscesses during lactation who were treated from January 2014 to February 2017 at Haidian Maternal and Child Health Hospital, Beijing, were reviewed. According to bacterial culture results, they were divided into MRSA (n = 260) and MSSA (n = 962) groups. Hospitalization (whether or not the patients were hospitalized), postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, frequency of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration, cessation of breastfeeding and recurrence were compared between the two groups using a t-test and a chi-squared test.

Results

We noted that only the cessation of breastfeeding was statistically significantly different between the two groups (P = 0.018). Hospitalization, postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, number of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration and recurrence showed no statistically significant differences (P = 0.488, P = 0.328, P = 0.494, P = 0.218, P = 0.088, P = 0.102, P = 0.712, P = 0.336, P = 0.512, P = 0.386 and P = 0.359, respectively).

Conclusions

There was no difference in clinical characteristics between breast abscesses infected by MRSA and those infected by MSSA. Ultrasound-guided needle aspiration could be the first choice for MRSA-infected breast abscess treatment. There is no need to increase antibiotic use because of MRSA infection, unless it is necessary. The reason why more patients with MRSA infected breast abscesses terminated breastfeeding is unclear from this study.

Lactational Breast Abscesses Caused by Methicillin-Resistant or Methicillin-Sensitive Staphylococcus aureus Infection and Therapeutic Effect of Ultrasound-Guided Aspiration

Background and Objective: We investigated whether (1) there are any differences in lactational breast abscesses between patients from whom methicillin-resistant Staphylococcus aureus (MRSA) and those from whom methicillin-sensitive S. aureus (MSSA) were isolated from pus samples and (2) there are differences in the effects of ultrasound-guided aspiration. Materials and Methods: The clinical data of 171 patients with lactational breast abscesses treated by ultrasound-guided aspiration in Beijing from January to July 2018 were retrospectively analyzed. The patients were divided into MSSA infection (N = 132) and MRSA infection (N = 39) groups according to their bacterial culture results. Abscess cavity location, abscess cavity number, maximum abscess cavity size, antibiotic utilization rate, and cure rate were compared between the groups. Cure rate refers to the proportion of the total number of cases remaining after the elimination of failed cases. The number of ultrasound-guided aspiration procedures performed for healing between the two groups was also compared. Results: There were no significant differences in abscess cavity location, abscess cavity amount, and abscess cavity size between both groups. The antibiotic utilization rate of the two groups were 58.3% (MSSA, 77/132) and 69.2% (MRSA, 27/39), respectively, and there were no significant differences between both groups. The cure rates of ultrasound-guided aspiration of the two groups were 97.7% (MSSA, 129/132) and 92.3% (MRSA, 36/39), and there were no significant differences between both groups. There were also no significant differences in the median number of aspiration performed for cure between the MRSA infection group (median = 3, range = 1-10) and the MSSA infection group (median = 3, range = 1-14). Conclusion: Lactational breast abscesses are the same irrespective of the type of S. aureus infection. Treatment by ultrasound-guided aspiration for patients with MRSA infection can achieve the same effect as that for those with MSSA infection.

[Neck lymphatic metastasis, surgical methods and prognosis in early tongue squamous cell carcinoma]

Objective: To investigate the different pattern of neck lymph node metastasis, the choice of surgical methods and prognosis in early tongue squamous cell carcinoma. Methods: A total of 157 patients with early oral tongue squamous cell carcinoma were included in this study. Statistical analysis was performed to identify the pattern of lymph node metastasis, to determine the best surgical procedure and to analyze the prognosis. Results: The occurrence of cervical lymph node metastasis rate was 31%(48/157). Neck lymphatic metastasis was significantly related to tumor size (P=0.026) and histology differentiation type (P=0.022). The rate of metastasis was highest in level Ⅱ [33% (16/48)]. In level Ⅳ, the incidence of lymph node metastasis was 5%(7/157), and there was no skip metastases. The possibility of level Ⅳ metastasis was higher, when level Ⅱ (P=0.000) or Ⅲ (P=0.000) involved. The differentiation tumor recurrence, neck lymphatic metastasis and adjuvant radiotherapy were prognostic factors (P<0.05). Multivariate analyses revealed histology differentiation type, neck lymphatic metastases and adjuvant radiotherapy were the independent prognostic factors. Conclusions: Neck lymphatic metastasis rate is high in early tongue squamous cell carcinoma, simultaneous glossectomy and neck dissection should be performed. Level Ⅳ metastasis rate is extremely low, so supraomohyoid neck dissection is sufficient for most of the time. The histology differentiation type, neck lymphatic metastasis and adjuvant radiotherapy are independent prognostic factors.

Expression of eag1 channel associated with the aggressive clinicopathological features and subtype of breast cancer

BACKGROUNDS

Expression of eag1 channel (Eag1) is associated with cell malignant transformation, tumor cell metastasis and poor prognosis of the patient. This study aimed at examining whether expression of the Eag1 associated with aggressive clinicopathological feature and the molecular subtype of breast cancer.

MATERIALS AND METHODS

109 patients who received breast cancer operation during January 2009 to December 2010 in Chinese-Japanese Friendship Hospital of Jilin University were recruited. We investigated the association of the Eag1 with clinicopathological features and molecular subtype of in triple negative breast cancer (TNBC) by univariate or multivariate analysis in a cross-section study.

RESULTS

The positive rate of Eag1 was 18.5% higher in TNBC compared with non-triple negative breast cancer (Non-TNBC) (P = 0.012, OR = 2.83, 95% CI = 2.16-3.47). Compared with the Eag1 negative group, the expression of Eag1 was linked to the larger tumor size (P = 0.002), advanced TNM stage (P = 0.029), high proportion of positive lymph node (87.6% vs. 65%, P = 0.014) and invasive ductal carcinoma (91% vs. 75%, P = 0.046).

CONCLUSIONS

The expression of Eag1 may be partially explained the aggressive behavior of TNBC in the breast cancer tissue.

Synthesis and molecular characterization of acrylate liquid crystalline resin monomers (ALCRM)

A novel biocompatible resin monomer 4&mdash;3&mdash;(acryloyloxy)&mdash;2&mdash;hydroxypropoxy) phenyl 4&mdash;(3&mdash;(acryloyloxy)&mdash;2&mdash;hydroxypropoxy) benzoate, as an oral restorative &mdash; acrylate liquid crystalline resin monomer (ALCRM) was synthesized. The intermediate product and the final product were characterized by differential scanning calorimetry (DSC), polarized optical microscope (POM), and nuclear magnetic resonance (NMR). A resin matrix which has a potential application in dental composites was prepared by photopolymerizing ALCRM and triethylene glycol dimethacrylate (TEGDMA) as a primary and diluted monomer with a photosensitizer of camphorquinone (CQ) and 2&mdash;(Dimethylamino)ethyl methacrylate (DMAEMA) mixture. The molar ratio of ALCRM and TEGDMA was 7:3. The properties such as the curing depth, curing time, and the volumetric shrinkage of the resin matrix were investigated and compared with a traditional composite resin matrix Bis&mdash;GMA. After photocuring polymerization, the conversion degree of the resin matrix is 68.06%, higher than Bis&mdash;GMA/TEGDMA; the curing time is 4.08±0.20min, the curing depth is 2.10±0.17mm, and the volumetric shrinkage is 3.62%±0.26%. All the properties exhibit a better performance of the prepared resin matrix than Bis&mdash;GMA.

Transfection of hairpin small interfering RNA expression vector targeting rat nuclear factor (NF) (κB) inhibits rat cell proliferation induced by NF-κB signal pathway activation

OBJECTIVE

The aim of this work was to construct one small interfering RNA (siRNA) eukaryotic expression vector targeting rat nuclear factor (NF)κB p65 and identify its inhibition effect on cell proliferation according to its down-regulation of NF-κB pathway.

METHODS

The p65siRNA expression vector "pGenesil-1.2-p65siRNA" and negative control plasmid "HK" were transfected into the cultured rat cells. After transfection, cells were divided into 4 treatment groups: 1) control cells cultured in complete. Dulbecco modified Eagle medium; 2) lipopolysaccharide (LPS) (1 μg/mL); (3) LPS (1 μg/mL) + HK-transfected; 4) LPS (1 μg/mL) + p65siRNA (pGenesil-1.2-p65siRNA). Thereafter, the protein levels of NF-κB p65 in the cells were detected by Western blotting at 72 hours after LPS stimulation. Furthermore, to observe cell proliferation, the proliferative rate of the cell growth was evaluated by the methylthiazolyl tetrazolium assay (at 24, 48, and 72 hours). The cell cycle distribution at 72 hours was detected by flow cytometry.

RESULTS

p65siRNA effectively down-regulated the protein level of p65 (P < .05). Meanwhile, the proliferation of cells transfected with p65siRNA expression vector was significantly inhibited (P < .05), the ratio of cells at G(0)/G(1) stage markedly increased, and the proportion of cells at S stage was significantly decreased among transfected compared with control cells (P < .05).

CONCLUSIONS

p65siRNA effectively suppressed NF-κB, expression, inhibiting rat cell proliferation induced by NF-κB signal pathway activation.

The proteasome inhibitor bortezomib inhibits intimal hyperplasia of autologous vein grafting in rat model

OBJECTIVE

Increasing evidence indicates that inflammation plays an important role in intimal hyperplasia (IH) induced by autologous vein grafts. The proteasome inhibitor bortezomib shows anti-inflammatory effects, so we used an autologous vein transplantation model to test whether bortezomib inhibits neointimal formation in transplant-induced vasculopathy.

MATERIALS AND METHODS

We subjected 88 rats to autologous external jugular vein grafting surgery randomly assigned to be treated with bortezomib or vehicle. After 24 or 72 hours, rats were humanely killed and vein grafts processed for real-time RT-PCR (24 and 72 hours), ELISA (24 hours), or neutrophil chemotaxis assay (24 hours). Subsequently, rats were humanely killed at 1 and 2 weeks after grafting with samples processed for morphometric analysis.

RESULTS

Bortezomib significantly inhibited IH at 2 weeks compared with untreated controls (P < .05). Expression of mRNA for vascular cell adhesion molecule-1, intercellular adhesion molecule-1, cytokine-induced neutrophil chemoattractant 2beta, monocyte chemoattractant-1, interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha markedly increased in injured vessels during the first day after surgery declining over the following 3 days. Bortezomib significantly attenuated gene expression and protein levels of most inflammatory mediators (P < .05), simultaneously inhibiting neutrophil chemotactic activity of vessel homogenates.

CONCLUSIONS

Bortezomib inhibited neointimal formation at least partially by attenuating the inflammatory response in transplant-induced vasculopathy. It may become a novel vasoprotective agent in the clinical field.

Investigation of Lpin1 as a candidate gene for fat deposition in pigs

Lpin1 deficiency prevents normal adipose tissue development and remarkably reduces adipose tissue mass, while overexpression of the Lpin1 gene in either skeletal muscle or adipose tissue promotes adiposity in mice. However, little is known about the porcine Lpin1 gene. In the present study, a 5,559-bp cDNA sequence of the porcine Lpin1 gene was obtained by RT-PCR and 3'RACE. The sequence consisted of a 111-bp 5'UTR, a 2,685-bp open reading frame encoding a protein of 894 amino acids and a 2,763-bp 3'UTR. Semi-quantitative RT-PCR analysis revealed that Lpin1 had a high level of expression in the liver, spleen, skeletal muscle and fat, a low level of expression in the heart, lung and kidney. The porcine Lpin1 gene was assigned to 3q21-27 by using the somatic cell hybrid panel (SCHP) and the radiation hybrid (IMpRH) panel. One C93T single nucleotide polymorphism (SNP) was identified and genotyped using the TaqI PCR-RFLP method. Association analysis between the genotypes and fat deposition traits suggested that different genotypes of the Lpin1 gene were associated with percentage of leaf fat and intramuscular fat.

[Randomized controlled multi-central study on acupuncture at Tanzhong (CV 17) for treatment of postpartum hypolactation]

OBJECTIVE

To study on clinical role of acupuncture at Tanzhong (CV 17) for treatment of postpartum hypolactation and to provide clinical basis for indications of acupoints.

METHODS

This was a single blind randomized controlled multi-center study by Beijing obstetrical and gynecological hospital, Beijing Mother and Child health institute and Haidian Mother and Child health institute, 276 cases of postpartum hypolactation were randomly divided into an acupuncture group and a Chinese drug group. The acupuncture group were treated with acupuncture at Tanzhong (CV 17) and the Chinese drug group with traditional drug Tongre Decoction. Degree of breast engorge, lactating volume, prolactin, neonate body weight, artificial feeding frequency and volume, urination frequency and crying time of neonate were recorded for comparison of therapeutic effects.

RESULTS

After treatment, degree of breast engorge, lactating volume, neonate body weight, artificial feeding frequency and volume, urination frequency and crying time of neonate were significantly improved in the two groups, with no significant difference between the two groups.

CONCLUSION

Acupuncture at Tanzhong (CV 17) can effectively promote lactation with a same therapeutic effect as the traditional Chinese drug Tongru Decocnon.

Effect of new O-superfamily conotoxin SO3 on sodium and potassium currents of cultured hippocampal neurons

The effects of a new O-superfamily conotoxin SO3 on sodium and potassium currents were examined in cultured rat hippocampal neurons using the whole-cell patch clamp technique. SO3 caused a concentration-dependent, rapidly developing and reversible inhibition of sodium currents (I(Na)). The IC(50) value for the blockage of I(Na) was calculated to be 0.49 and the Hill coefficient was 1.7. Using electrophysiological and pharmacological protocols, transient A-type potassium currents (I(A)) and delayed rectifiers potassium currents (I(K)) were isolated. SO3 caused a concentration-dependent, and reversible inhibition of I(K). The IC(50) value for the blockage of I(K) was calculated to be 1.6 and the Hill coefficient was 0.6, with no significant effect on I(A). These results indicate that SO3 can selectively inhibit neuronal sodium and potassium currents.

Effects of the Superoxide Anionic Radicals to the Cultured Cerebral Cortex Neuron of Newborn Rat

The effect of the superoxide anionic radicals to the cultured cerebral cortex neuron of newborn rat was investigated by using xanthine oxidase/xanthine. The results are as follows. The growth of neuron was inhibited ATPase activity decreased to 4.223 &mgr;mol/(mg.min(-1))(Pr) total cellular carbonyl increased to 295.40 &mgr;mol/g wet weight lipid peroxides(LPO) increased to 4.87 nmol/g(Pr) membrane lipid fluidity decreased (P value 0.398) in nuclear DNA, thesingle strand breaks(SSB) increased in the single cell gel assay(SCG), DNA migration was 7.35 mm ݣ subcellular structures of the neuron changed (mitochondria were swelling, etc.) and SOD gene expression of the neuron increased (the SOD activity and the SOD content increased, SOD mRNA content increased). These suggest that the superoxide anionic radicals could damage proteins, nucleic acids, lipids and subcellular structures in neurons.

Regulation of neuromuscular synapse development by glial cell line-derived neurotrophic factor and neurturin

Glial cell line-derived neurotrophic factor (GDNF) is known for its potent effect on neuronal survival, but its role in the development and function of synapses is not well studied. Using Xenopus nerve-muscle co-cultures, we show that GDNF and its family member neurturin (NRTN) facilitate the development of the neuromuscular junction (NMJ). Long-term application of GDNF significantly increased the total length of neurites in the motoneurons. GDNF also caused an increase in the number and the size of synaptic vesicle clustering, as demonstrated by synaptobrevin-GFP fluorescent imaging, and FM dye staining. Electrophysiological experiments revealed two effects of GDNF on synaptic transmission at NMJ. First, GDNF markedly increased the frequency of spontaneous transmission and decreased the variability of evoked transmission, suggesting an enhancement of transmitter secretion. Second, GDNF elicited a small increase in the quantal size, without affecting the average rise and decay times of synaptic currents. Imaging analysis showed that the size of acetylcholine receptor clusters at synapses increased in muscle cells overexpressing GDNF. Neurturin had very similar effects as GDNF. These results suggest that GDNF and NRTN are new neuromodulators that regulate the development of the neuromuscular synapse through both pre- and postsynaptic mechanisms.

Expression of neuropsin in oligodendrocytes after injury to the CNS

Proteases are involved in a variety of processes including demyelination after injury to the central nervous system. Neuropsin is a serine protease, which is constitutively expressed in the neurons of the limbic system. In the present study, intrahippocampal kainate injection and enucleation were performed on adult mice. Neuropsin mRNA and protein expression was detected by in situ hybridization and immunohistochemistry. Double in situ hybridization confirmed that the mRNA expression was induced in oligodendrocytes. One day after kainate injection to the hippocampus, neuropsin mRNA was expressed, peaking 4-8 days postoperatively and disappearing at 14 days. Immunohistochemistry and immunoelectron microscopy revealed that neuropsin was expressed in the cell body of oligodendrocytes and myelin. To see if neuropsin degrades myelin protein, purified myelin was incubated with recombinant neuropsin. A decrease in the intensity of the bands of myelin basic protein was observed. These results indicate that neuropsin is involved in demyelination.

Autoimmunity to munc-18 in Rasmussen's encephalitis

Rasmussen's encephalitis (RE) is a rare disease of the central nervous system characterized by severe epileptic seizures, progressive degeneration of a single cerebral hemisphere, and autoimmunity directed against glutamate receptor subunit, GluR3. We report here the identification of high-titer autoantibodies directed against munc-18 in the serum of a single patient with RE previously shown to have anti-GluR3 antibodies. Munc-18 is an intracellular protein residing in presynaptic terminals, which is required for secretion of neurotransmitters. These findings are consistent with the possibility of intermolecular epitope spreading between GluR3, a postsynaptic cell surface protein, and munc-18, a presynaptic intracellular protein. Immune attack on these two proteins, which participate at distinct steps of synaptic transmission, could act in an additive or synergistic manner to impair synaptic function and lead to seizures and neuronal death.

Blocking effect of tricyclopinate on nicotinic receptors in cultured sympathetic neurons

AIM

To investigate the mechanism of tricyclopinate, an antagonist of nicotinic receptor, on neuronal nicotinic acetylcholine receptors (nAChR).

METHODS

A tight seal whole-cell recording patch-clamp technique was performed to record nicotine-evoked currents in the cultured sympathetic neurons from neonatal rat superior cervical ganglia (SCG).

RESULTS

Tricyclopinate inhibited the nicotine-induced currents competitively and the inhibition was voltage-independent. The decay of the nicotine-induced current was accelerated significantly in the presence of tricyclopinate.

CONCLUSION

Tricyclopinate inhibits neuronal nAChR by interacting with the allosteric sites rather than the open ionic channels or acetylcholine recognition site of the receptor.

Neostigmine competitively inhibited nicotinic acetylcholine receptors in sympathetic neurons

The present experiment investigates the effect of neostigmine on nicotinic acetylcholine receptors (nAChRs) in the cultured neurons from neonatal rat superior cervical ganglia (SCG). Using whole-cell patch clamp techniques, we found that the amplitudes of the currents induced by 50 microM dimethylphenylpiperazinium (DMPP) were 21.5+/-10.7%, 52.9+/-9.2% and 86.9+/-4.9% depressed at the increased concentrations of neostigmine 100, 200 and 400 microM, respectively. The inhibition of neostigmine decreased gradually with the increased concentration of nicotine from 10 to 160 microM. Lineweaver-Burk's double-reversible plot illustrated that neostigmine blocked neuronal nAChRs in a competitive manner. Hyperpolarization of membrane potential from -40 mV to -100 mV did not significantly influence the blockade of neostigmine. Neostigmine could not accelerate the decay of the DMPP-induced currents, neither evoke any detectable currents in SCG neurons. The results indicate that neostigmine depress neuronal nAChRs in a competitive, concentration-dependent and voltage-independent manner, and can not facilitate desensitization of the receptors. The present data suggest that neostigmine blocks neuronal nAChRs by interacting with the ACh binding sites of the receptors.

Glutamate receptor GluR3 antibodies and death of cortical cells

Rasmussen's encephalitis (RE), a childhood disease characterized by epileptic seizures associated with progressive destruction of a single cerebral hemisphere, is an autoimmune disease in which one of the autoantigens is a glutamate receptor, GluR3. The improvement of some affected children following plasma exchange that removed circulating GluR3 antibodies (anti-GluR3) suggested that anti-GluR3 gained access to the central nervous system where it exerted deleterious effects. Here, we demonstrate that a subset of rabbits immunized with a GluR3 fusion protein develops a neurological disorder mimicking RE. Anti-GluR3 IgG isolated from serum of both ill and healthy GluR3-immunized animals promoted death of cultured cortical cells by a complement-dependent mechanism. IgG immunoreactivity decorated neurons and their processes in neocortex and hippocampus in ill but not in healthy rabbits. Moreover, both IgG and complement membrane attack complex (MAC) immunoreactivity was evident on neurons and their processes in the cortex of a subset of patients with RE. We suggest that access of IgG to epitopes in the central nervous system triggers complement-mediated neuronal damage and contributes to the pathogenesis of both this animal model and RE.

Physostigmine blocked nicotinic acetylcholine receptors in rat sympathetic ganglion neurons

AIM

To study the blocking mechanism of physostigmine (Phy) on nicotinic acetylcholine receptors (NAChR) in sympathetic neurons.

METHODS

The whole-cell patch-clamp technique was used to observe the effects of Phy on NAChR in the cultured sympathetic neurons from neonatal rat superior cervical ganglia (SCG).

RESULTS

Phy 5 -20 mumol.L-1 inhibited neuronal NAChR in a concentration-dependent manner and accelerated the desensitization of NAChR. Changing the membrane potential from -50 to -90 mV did not affect the blocking effect of Phy. Phy 200 mumol.L-1 did not induce any noticeable response in SCG neurons.

CONCLUSION

Phy blocked NAChR in the sympathetic ganglion neurons by interacting with the allosteric sites out of the binding sites and the open ionic channels of the receptors. Phy did not possess excitative effect on NAChR in SCG neurons.

Kinetic properties of nicotinic receptors in cultured rat sympathetic neurons from superior cervical ganglia

AIM

To analyze the kinetic properties of the effect of nicotine on nicotinic acetylcholine receptors (nAChR) in the cultured sympathetic neurons from neonatal rat superior cervical ganglia (SCG).

METHODS

The whole-cell recording method of patch-clamp technique was used to record the currents induced by different concentrations of nicotine. The concentration-response of nicotine was fitted with Clark equation.

RESULTS

Hill coefficient (1.097) was determined by fitting the nicotine responses of neuronal nAChR with Clark equation. The theoretical values of nicotine effect, calculated with Clark equation with H = 1, were basically identical with the practically recorded currents.

CONCLUSIONS

Interaction of nicotine and nAChR in rat SCG fits a single binding site model.

[Opposite actions of ACh on excitatory and inhibitory synaptic transmission in cultured rat cortical neurons]

Effect of ACh on spontaneous EPSC and IPSC in cultured postnatal rat cortical neurons was studied using whole-cell voltage-clamp technique. EPSC was blocked by a non-NMDA glutamate receptor antagonist DNQX, while IPSC was blocked by a GABAA receptor antagonist bicuculline. When ACh (10-100 mumol/L) was applied by puff pipettes to the cells recorded, the frequency of EPSC was enhanced greatly, but the amplitude distribution was not changed significantly. However, the frequency of IPSC was attenuated by ACh even at a quite low concentration (1 mumol/L). The effect of ACh on EPSC and IPSC could be blocked by M type ACh receptor antagonist atropine (1 mumol/L). ACh had no significant effect on whole-cell currents activated by glutamate and GABA. The above results provide evidence that ACh has opposite effects on excitatory and inhibitory synaptic transmission in rat cortex by acting at presynaptic sites. It is also suggested that ACh plays an important role in the maintenance of excitability of cortical neurons.

[Nicotinic currents of cultured rat superior cervical ganglion neurons and use-dependent block by mecamylamine]

AIM

Comparison of action of nicotinic agonists and antagonists on nicotinic acetylcholine receptor (nAChR) in superior cervical ganglion (SCG) neurons.

METHODS

Whole-cell recordings were made from cultured neonatal rat SCG neurons. Cholinergic drugs were applied by local pressure perfusion.

RESULTS

The neurons were activated by nicotinic agonists and peak current were acetylcholine (ACh), 443 +/- 183 pA; nicotine, 1175 +/- 377 pA; dimethylphenylpiperazinium (DMPP), 2946 +/- 358 pA, respectively. The nicotinic responses were blocked by mecamylamine (Mec), hexamethonium and curare, the efficacies were 435 +/- 154 pA, 725 +/- 320 pA, 887 +/- 214 pA, but not by alpha-bungarotoxin. The block by Mec was use-dependent, i.e., it was dependent on repeated presentation of the agonists. The first 6 peak currents were expressed as percentage of the first response as following: 100, 64 +/- 3, 50 +/- 3, 41 +/- 4, 32 +/- 3%.

CONCLUSION

The present data suggest that nAChR of SCG neurons have different pharmacological characteristics from that of muscle or central neurons.

[Whole cell recording of sodium, potassium and calcium currents of cultured neonatal rat sympathetic neurons]

Na, K and Ca currents and other electrophysiological characteristics of cultured neonatal rat superior cervical sympathetic neurons were studied using whole cell clamp technique. The mean passive and active membrane properties measured are as follows: resting membrane potential, -51 +/- 6 mV; input resistance, 1432 +/- 389 M omega; time constant, 130 +/- 32 ms; amplitude of action potential, 96 +/- 10 mV; overshoot, 42 +/- 6 mV. Na, K and Ca currents were isolated upon pharmacological manipulations. The predominant type of K current was a noninactivating delayed rectifier. Voltage-clamp studies also showed the presence of a high voltage-activated sustained inward Ca current, while low voltage could not elicit any transient Ca current.

[High-dose cytarabine as intensive postremission therapy in acute myelogenous leukemia: effect on long-term disease-free survival]

In an attempt to increase the proportion of patients with acute myelogenous leukemia (AML) remaining in long-term disease-free survival (DFS). 37 patients with AML in complete remission (CR) received HD-Ara-C (1.0 g/m2) as intensive postremission therapy. The results were compared with those of 28 patients who did not receive HD-Ara-C therapy (control group) during the same period. With a median follow-up of 21.7 months (6.9-77.3), median CR duration was 16.0 months for HD-Ara-C group and 10.0 months (2.0-75.2) for the control group. Relapse rates were 48.6% (18/37) and 75% (21/28), respectively. The actuarial 3 and 5 years DFS was 50.2% and 43% for HD-Ara-C group versus 31% and 16.7% for the control group. There was significant difference (P < 0.05). This result suggested that HD-Ara-C could prolong DFS and reduce relapse in patients with AML.

Nuclear export of signal recognition particle RNA is a facilitated process that involves the Alu sequence domain

The signal recognition particle is a cytoplasmic RNA-protein complex that mediates translocation of secretory polypeptides into the endoplasmic reticulum. We have used a Xenopus oocyte microinjection assay to determine how signal recognition particle (SRP) RNA is exported from the nucleus. Following nuclear injection, SRP RNA accumulated in the cytoplasm while cytoplasmically injected SRP RNA did not enter the nucleus. Cytoplasmic accumulation of SRP RNA was an apparently facilitated process dependent on limiting trans-acting factors, since nuclear export exhibited saturation kinetics and was completely blocked either at low temperature or by wheat germ agglutinin, a known inhibitor of nuclear pore-mediated transport. At least one target for trans-acting factors that promote nuclear export of SRP RNA appears to be the Alu element of the molecule, since a transcript consisting of only the Alu sequence was exported from the nucleus in a temperature-dependent manner and the Alu transcript competed in the nucleus for transport with intact SRP RNA. Although the identities of trans-acting factors responsible for SRP RNA transport are at present unknown, we suggest that proteins contained within the cytoplasmic form of SRP are candidates. Consistent with this idea were the effects of a mutation in SRP RNA that prevented binding of two known SRP proteins to the Alu sequence.

The effects of glutamate and GABA (gamma-amino-butyric-acid) on spontaneous acetylcholine release at the neuromuscular junction in Xenopus laevis embryo cell cultures

The miniature endplate currents (MEPC's) were recorded at the neuromuscular junction of Xenopus laevis embryo neuron-muscle co-cultured cells. These MEPC's were due to the spontaneous release of acetylcholine from the nerve terminal. After perfusion with glutamate (10 mumol/L), both frequency and amplitude of the MEPC's increased. After washing away of glutamate, this effect persisted. We named this phenomena "Long-Term Facilitation". GABA (20 mumol/L) on the other hand had an inhibitory effect on both frequency and amplitude of the MEPC's. After washing away of GABA, the MEPC frequency and amplitude increased. We named this effect "Post-Potentiation". Local perfusion experiments furthermore indicated that the effect of glutamate was restricted to the neuromuscular junction, the effect of GABA was restricted to the soma.

[Blocking effect of anisodamine on acetylcholine receptor channels]

Anisodamine, an analog of atropine, was isolated first in China. Patch-clamp technique was used to study the inhibitory effect of anisodamine (Ani) on acetylcholine receptor on the membrane of muscle innervated by neuron. Neural tube in embryo of Xenopus laevis were cultured. By whole-cell clamp and outside-out patch, we found that the inhibitory effect of Ani was obvious on both miniature end-plate currents (MEPC) and single channel. This effect was reversible and the minimal concentration for complete inhibition was 60 mumol.L-1, vs 1 and 0.5 mmol.L-1 for atropine and scopolamine, respectively. Our results indicate that Ani blocks both M-ACh and N-ACh receptors.

Characterization of dynorphin-containing neurons on dissociated dentate gyrus cell cultures

In the dentate gyrus, the synthesis of the opioid peptide, dynorphin, is modulated by a variety of stimuli. In order to elucidate the cellular and molecular mechanisms regulating the synthesis of dynorphin in the hippocampus, we have established a routine primary cell culture of dentate granule neurons and identified granule-like neurons by a characteristic marker, dynorphin, in these cultures. Cultures were prepared from 7-day-old rat pups and maintained in medium with 2% fetal bovine serum. These cultures contained approximately 20% neurons and survived for over 4 weeks. After 2 weeks in culture, neurons expressing dynorphin-A and its messenger RNA were detected using immunocytochemistry and in situ hybridization, respectively. In dentate cultures, enkephalin-, cholecystokinin-, neuropeptide Y- and substance P-positive cells were observed in addition to dynorphin-positive cells with immunocytochemistry. The results suggest that dentate gyrus cell cultures provide a valid in vitro model for studying molecular mechanisms regulating prodynorphin gene expression.

Dopamine stimulates [3H]phorbol 12,13-dibutyrate binding in cultured striatal cells

The effect of dopamine (DA) on the binding of [3H]phorbol 12,13-dibutyrate ([3H]PdBu) in cultured rat striatal cells was examined. DA maximally increased specific [3H]PdBu binding by 70 +/- 10%, an increase comparable to that observed with norepinephrine (NE). This finding suggests that DA activates protein kinase C in cultured striatal cells, because increases in [3H]PdBu binding reflect translocation of protein kinase C. Half-maximal stimulation was observed with 10(-6) M DA. The peak response was observed at 2-3 min after addition of 10(-4) M DA, but [3H]PdBu binding was still increased above basal at 30 min. DA was not acting via an adrenergic receptor. Prazosin (10(-6) M) blocked the response to NE, suggesting mediation by an alpha 1-adrenergic receptor, but had little effect on the response to DA. Conversely, the D1 receptor antagonist SCH-23390 (10(-6) M) blocked the response to DA, but only partially inhibited the response to NE. Morphine (10(-6) M) inhibited the response to DA by 46 +/- 14%, but did not affect significantly the response to NE. The DA effect on [3H]PdBu binding is apparently independent of the increase in cyclic AMP seen on D1 receptor activation. Forskolin, apomorphine, and the D1 agonist SKF-38393 all increased cyclic AMP in striatal cells, but were less effective than DA in stimulating [3H]PdBu binding. The D2 agonist quinpirole was ineffective in stimulating either cyclic AMP or [3H]PdBu binding.

[Changes of releases of beta-endorphin-like immunoreactive substances and noradrenaline in rabbit's preoptic area during acupuncture analgesia]

RIA and HPLC-ECD were used respectively to detect beta-endorphin-like immunoreactive substances (beta-EPIS), noradrenaline and 3-methoxy-4-hydroxyphenyloglycol (MHPG), a noradrenaline metabolite, in the perfusate from the rabbit's preoptic area before and after 10 min of electroacupuncture (EA). It was found that, the content of beta-EPIS in the perfusate increased during acupuncture analgesia, while those of noradrenaline and MHPG decreased. A negative correlation (r = -0.831; P less than 0.05) was shown between the changes of beta-EPIS and MHPG contents during acupuncture analgesia, indicating that beta-endorphin may be related to the inhibition of noradrenaline release during acupuncture analgesia.

[Effect of electroacupuncture on electroconvulsive shock--an autoradiographic study for opioid receptors]

Radioreceptor-binding assay combined with autoradiography technique in the brain slices of rats was used to investigate cerebral areas related to electroconvulsive shock (ECS) and to analyze changes of opioid receptors of these areas in electroacupuncture (EA) anticonvulsion. The results from image processing and detection of optic density (O.D.) showed that repeated ECS resulted in an increase of opioid receptor densities in the caudate nucleus, hippocampus, habenulae nucleus and amygdala. In the group of EA plus ECS, however, the opioid receptor densities in the hippocampus, habenula nucleus and amygdala decreased as compared with that in ECS group. In addition, the receptor density in the caudate nucleus showed a decrease tendency. The results provided morphological evidence of the involvement of opioid receptors in these cerebral areas in the process of ECS and EA anticonvulsion.

[Change of preoptic opiate receptors after injection of 6-OHDA into sublocus coeruleus in the rabbit]

The formaldehyde histofluorescence method and receptor autoradiography were respectively used to investigate the distribution and densities of the catecholamine (CA) terminals and [3H]-etorphine binding sites, after 20 days of injection of 6-hydroxydopamine (6-OHDA) into N. subcoerulens of the rabbit. The results showed that both CA terminals and [3H]-etophine binding sites in the preoptic area, especially in the medial preoptic area, were reduced in 6-OHDA pretreated animals, thus suggesting the possible location of opioid receptors on the CA terminals.

[Effect on electroacupuncture on experimental epilepsy--power spectrum analysis of EEG]

The present study was undertaken to investigate the effect of electroacupuncture (EA) on electroconvulsive shock (ECS) and penicillin-induced convulsions in rats, using power spectrum analysis technique. Under quiet state, delta and theta bands were found to be predominant in the power spectrum of spontaneous EEG's with the peak of the main power in the delta band. During ECS and penicillin-induced convulsions, the power percentage of the delta band decreased, while those of alpha and beta bands increased. The bands with the peak of the main power shifted to the right, and the total power was distinctly enhanced. No marked change in background EEG activity was observed during EA stimulation. In the case of EA plus ECS or penicillin-induced convulsions, the power percentage of the delta band increased, while those of alpha and beta bands decreased. The peak of the main power returned to the delta band with a decreased total power. The compressed power spectrum array showed distinct suppression of convulsions by EA audio-visually. These results suggest that EA enables the EEG to synchronize and enhances the inhibitory process of the brain, thereby plays its anticonvulsant role.

Change of Leu-enkephalin- and B-endorphin-like immunoreactivity in the hippocampus after electroconvulsive shock and electroacupuncture

To determine whether the effect of electroacupuncture (EA) on electroconvulsive shock (ECS) was through affecting endogenous opioid peptidergic system in the hippocampus, we used radioimmunoassay (RIA) to measure leu-enkephalin- and beta-endorphin-like immunoreactivity (L-E-LI and Beta-E-LI) in the hippocampal perfusate after ECS and EA treatments. Wistar rats were given ECS stimulation, which caused behavioral and electroencephalogram (EEG) convulsions. However, EA could suppress ECS-elicited convulsions (including both behavioral and EEG abnormalities). The results of RIA showed that after repeated ECS treatments, the contents of L-E-LI and Beta-E-LI increased significantly by 136% and 157%, respectively. In contrast, EA treatment depleted alterations of L-E-LI and Beta-E-LI induced by ECS, depleting L-E-LI by 32% and Beta-E-LI by 85%. These observations suggest that anticonvulsive action of EA is related to the release of L-E and Beta-E in hippocampus, probably through decreasing their release, thus to exert EA action.

The analgesic and respiratory depressant actions of metorphamide in mice and rabbits

Metorphamide (MET) elicited a potent, dose-dependent analgesia and respiratory depression in mice and rabbits. MET induced-analgesia was naloxone reversible and potentiated by bestatin. Naloxonazine, a relatively selective mu 1 blocker, at certain dosage (50 micrograms per rabbit, icv), could abolish the analgesia but not the respiratory inhibition produced by MET. Our result indicates that mu 1 receptors mediate the MET induced-analgesia but not its respiratory effect. Since MET is a mu- and kappa-ligand with very low delta activity, the MET induced respiratory depression may be mediated by mu 2 or kappa binding sites.