Prenatal exposure to PM2.5 components and the risk of different types of preterm birth and the mediating effect of pregnancy complications: a cohort study.

OBJECTIVES: This study aims to reveal the single and mixed associations of PM2.5 and its components with very, moderately, and late preterm births and to explore the potential mediating role of pregnancy complications in PM2.5-induced preterm birth. STUDY DESIGN: This was a retrospective cohort study. METHODS: We enrolled 168,852 mothers and matched the concentrations of PM2.5 and its five components (OM, SO42-, BC, NO3-, and NH4+) based on their geographical location. Next, we used generalized linear models, quantile g-computation, and mediation analysis to evaluate the associations of PM2.5 and its components with very, moderately, and late preterm births and the mediating role of pregnancy complications. RESULTS: Prenatal exposure to PM2.5 and its components was associated with preterm birth, and the association was strongest in the third trimester. Preterm birth was associated with co-exposure to a mixture of PM2.5 components in the third trimester, and the contributions of NO3-, NH4+, and BC to the risk of preterm birth were positive. Meanwhile, pregnancy complications mediated PM2.5-induced preterm birth. Moreover, very and moderately preterm births were associated with PM2.5 and its components in the second and third trimesters, and very and late preterm births were associated with co-exposure to a mixture of PM2.5 components in the third trimester. CONCLUSIONS: Later exposure to PM2.5 during pregnancy will cause earlier preterm birth. Targeted and positive interventions for anthropogenic sources of specific PM2.5 components and pregnancy complications are helpful for preterm birth prevention.

Upregulation of LINC00504 is associated with aggressive progression and poor prognosis in non-small cell lung cancer.

OBJECTIVE: Long noncoding RNA LINC00504 (LINC00504) has been demonstrated to be dysregulated in several tumors. However, its function in tumor progression remains largely unclear. The goal of our present study was to determine the expressions of LINC00504 in non-small cell lung cancer (NSCLC) and its clinical associations. PATIENTS AND METHODS: The expressions of LINC00504 were detected in 181 pairs of NSCLC specimens and adjacent normal tissues using qRT-PCR assays. Chi-square tests were applied to analyze the associations of LINC00504 expressions with various clinicopathological parameters of NSCLC specimens. The possible associations between LINC00504 expressions and overall survival were investigated using Kaplan-Meier assays. Univariate and multivariate assays were performed to further determine the prognostic value of LINC00504 levels in NSCLC patients. RESULTS: We showed that LINC00504 expressions were distinctly decreased in clinical NSCLC specimens compared to adjacent non-tumor specimens (p < 0.01). High LINC00504 expressions were strongly associated with TNM stage (p = 0.038) and lymph node status (p = 0.010). In addition, Kaplan-Meier analysis indicated that NSCLC patients with high LINC00504 expression tend to have shorter overall survival (p = 0.0036). More importantly, the results of multivariate analysis indicated LINC00504 as an independent prognostic marker (p = 0.0028). CONCLUSIONS: These findings revealed that LINC00504 might act as a prognostic biomarker for NSCLC patients.

Enhanced expression of circular RNA hsa_circ_000984 promotes cells proliferation and metastasis in non-small cell lung cancer by modulating Wnt/ß-catenin pathway.

OBJECTIVE: In recent years, several circular RNAs (circRNAs) have been identified to play important roles in human cancers. However, the exact effects and molecular mechanisms of circRNAs in non-small cell lung cancer (NSCLC) progression are still unknown. In this study, we aimed to investigate the effect of circular hsa_circ_000984 on NSCLC. PATIENTS AND METHODS: Quantitative real-time PCR was performed to detect the expression levels of hsa_circ_000984 in NSCLC tissues and cell lines. The associations between the expression of hsa_circ_000984 and clinicopathological parameters and patients' survival were analyzed. The cell growth was detected by CCK-8 assay and colony formation assay. Cell migration and invasion assays were used to study the changes in cell migration and invasion capacity. Western blot was performed to analyze the possible relationship between hsa_circ_000984 and the genes downstream of the Wnt/ß-catenin pathway. RESULTS: We found that hsa_circ_000984 was highly expressed in NSCLC tissues and cell lines and correlated with advanced TNM stage and lymph nodes metastasis. The clinical assays indicated that patients with high hsa_circ_000984 expression had shorter overall survival and disease-free survival. The functional investigations showed that the knockdown of hsa_circ_000984 suppressed NSCLC cells proliferation, migration, invasion, and EMT. Moreover, hsa_circ_000984 displayed its oncogenic roles by modulating the activation of Wnt/ß-catenin pathway, which was demonstrated by measuring the expression levels of, ß-catenin, c-myc, and cyclin D1. CONCLUSIONS: Our findings may facilitate a better understanding of hsa_circ_000984, and it might be a potential prognostic biomarker and treatment target for NSCLC patients.

[Research on the relationship between the daily mean temperature and the daily cases of varicella during 2008-2016 in Lanzhou, China].

Objective: To explore the effects of temperature on the daily cases of varicella. Methods: The data of daily cases of varicella was collected during 2008 to 2016 in Lanzhou from National Notifiable Disease Report System, and the meteorological data at the same period was integrated from Gansu Meteorological Administration. Distributed lag nonlinear model was fitted to reveal the relationship between the daily mean temperature and the daily cases of varicella and susceptible population. The minimum morbidity temperature was defined as the reference for the estimation of RRs in different temperature level (-5.2 ℃, 1.7 ℃, 20.1 ℃ and 25.4 ℃). Results: The total of 21 254 cases were reported from 2008 to 2016, of which the ratio of male to female was 1.28 (11 951/9 303) and people aged 6-14 years accounted for 52.87%. The relationship between the daily mean temperature and the daily cases of varicella was M type. For all subjects, the accumulative effects of temperature had statistical significance from lag 0-14 d when temperatures was at -5.2 ℃, 1.7 ℃ and 20.1 ℃,while the RRs (95%CI) were 1.87 (1.64-2.12) , 1.33 (1.10-1.62) ,1.60 (1.38-1.86) ,while from lag 0-7 d when temperatures was at 25.4 ℃,and the RR (95%CI) was 2.51 (1.93-3.27) . The RR value of accumulative effects was 6.23(95%CI: 4.38-8.86) on lag 7 d when temperatures was at -5.2 ℃, which was the highest value at different temperature during lag days. The cumulative effects trends of different temperatures were similar for different gender population or different age subjects. However, the cumulative effects of was highest for children aged 6-14 years among all subjects, and the value of RR was 6.12 (95%CI:3.71-10.10) on lag 5d when temperatures was at -5.2 ℃. Conclusion: We conclude that the increasing risk of varicella is associative with low and high temperature in Lanzhou. The effects of low temperature are stronger than those of high temperature. The children aged 6-14 years belong to the high-risk population of varicella.

Deferoxamine-activated hypoxia-inducible factor-1 restores cardioprotective effects of sevoflurane postconditioning in diabetic rats.

AIM: The cardioprotective effects of sevoflurane postconditioning (SpostC) are eliminated under diabetic conditions, and the underlying mechanism for this phenomenon remains unclear. Many studies have demonstrated that the hypoxia-inducible factor-1 (HIF-1) signalling pathway in the myocardium is impaired under diabetic conditions. This study was to investigate whether deferoxamine (DFO)-induced activation of HIF-1 signalling pathway can restore the cardioprotective effects of SpostC in diabetic rats. METHODS: A model of myocardial ischaemia/reperfusion (I/R) injury was induced via ligation of the left anterior descending artery. SpostC was conducted by administering 1.0 MAC sevoflurane. After inducing the I/R injury, the following parameters were measured: myocardial infarct size, cardiac function, myocardial ultrastructure, mitochondrial respiratory function, respiratory chain enzyme activity, rate of reactive oxygen species (ROS) generation, and protein expression of HIF-1α, vascular endothelial growth factor (VEGF), cleaved caspase-3, Bcl-2 and Bax. RESULTS: After DFO activated HIF-1 in the impaired myocardium of diabetic rats, SpostC significantly upregulated the protein expression of HIF-1α and its downstream mediator VEGF. This improved myocardial mitochondrial respiratory function and respiratory chain enzyme activity and reduced ROS generation as well as the protein expression of cleaved caspase-3 and Bax. As a result, myocardial infarct size decreased, and cardiac function and mitochondrial ultrastructure improved. CONCLUSION: This study demonstrates for the first time that abolishment of the cardioprotective effects of SpostC in diabetic rats is associated with impairment of the HIF-1 signalling pathway and that DFO can activate HIF-1 to restore these cardioprotective effects of SpostC in diabetic rats.

Karyotype analysis in large sample cases from Shenyang Women's and Children's hospital: a study of 16,294 male infertility patients.

To explore that it is necessary to routinely detect chromosomes in infertile patients, we investigated peripheral blood lymphocyte karyotype in 16,294 male infertile patients in the north-east of China and analysed the incidence and type of chromosomal anomaly and polymorphism. G-banding karyotype analysis of peripheral blood lymphocytes was performed in 16,294 cases. Semen analysis was performed three times in all the men. PCR and FISH confirmed the presence of the SRY gene. The rate of chromosomal anomaly in the 16,294 male infertile patients was 4.15% (677/16,294). The rates of chromosomal anomaly were 0.24% in normal semen group, 12.6% in light oligoasthenospermia group, 4.7% in moderate-to-severe oligoasthenospermia group and 9.59% in azoospermia group. There are two male infertile patients with 45,X chromosome karyotype. One X male patient had confirmed the presence of the SRY gene and FISH analysis demonstrated its location on the p arm of chromosome 13. The other X male patient had not found SRY gene in its whole-genome DNA. Meanwhile, sperm motility is slightly oligo-asthenozoospermic at the age of 35-39 and nearly azoospermic at the age of 40-45. As the rates of chromosomal anomaly are 0.24% and 12.6% even in normal semen group and light oligoasthenospermia group, the rates of chromosomal polymorphism are 5.36% and 25.51% in normal semen group and light oligoasthenospermia group, respectively; it is necessary to explore peripheral blood lymphocyte karyotype in all infertile couples. We mentioned that Y, 1, 2, 9 and 12 chromosomes were quite important about male infertility. These findings demonstrate that autosomal retention of SRY can be submicroscopic and emphasise the importance of PCR and FISH in the genetic workup of the monosomic X male. At the same time, it suggested that male infertility might be related to meiotic disturbances with spermatogenetic arrest in Y-autosome translocations, which could result in infertility by reduction of sperm production. Last but not least, ageing is one of the factors that could reduce sperm motility and quality.

High glucose concentration abrogates sevoflurane post-conditioning cardioprotection by advancing mitochondrial fission but dynamin-related protein 1 inhibitor restores these effects.

AIM: Hyperglycaemia-induced cell injury is a primary cause of cardiovascular complications in patients with diabetes. In vivo studies demonstrated that sevoflurane post-conditioning (SpostC) was cardioprotective against ischaemia/reperfusion injury, which was blocked by hyperglycaemia. This study investigated whether high glucose concentration abrogated SpostC cardioprotection in vitro by advancing mitochondrial fission and whether mitochondrial division inhibitor-1 (Mdivi-1) restored SpostC cardioprotection in cultured primary neonatal rat cardiomyocytes (NCMs). METHODS: Primary cultured NCMs in low and high glucose concentrations were subjected to hypoxia/reoxygenation (H/R) injury. SpostC was carried out by adding 2.4% sevoflurane to the cells at the beginning of reoxygenation for 15 min. Cell viability, lactate dehydrogenase (LDH) level, cell death, mitochondrial morphology, mitochondrial membrane potential and mitochondrial permeability transition pore (mPTP) opening level, as well as fission- and fusion-related proteins, were measured after H/R injury. Mdivi-1 treatment was performed 40 min before hypoxia to inhibit DRP1. RESULTS: SpostC protected cultured cardiomyocytes by increasing cell viability and reducing the LDH level and cell death following H/R, but high glucose concentration eliminated the cardioprotective effect. High glucose concentration abrogated SpostC cardioprotection via mitochondrial fragmentation (evidenced by decreased mitochondrial interconnectivity and elongation) and facilitation of mPTP opening. Decreased mitochondrial membrane potential was investigated with increased DRP1, FIS1 and MFN2 and decreased MFN1 and OPA1 expressions. Mdivi-1 (100 µmol L-1 ) inhibited excessive mitochondrial fission and restored the cardioprotective effect of SpostC in high glucose conditions. CONCLUSION: SpostC-induced cardioprotection against H/R injury was impaired under high glucose concentrations, but the inhibition of excess mitochondrial fission restored these effects.

Primary cilium is required for the stimulating effect of icaritin on osteogenic differentiation and mineralization of osteoblasts in vitro.

OBJECTIVE: Icaritin, one effective metabolite of Herba Epimedii-derived flavonoid icariin, has a strong osteogenic activity. However, its action mechanism remains unclear. Since primary cilia have been shown to play a pivotal role in regulating the osteogenesis, we hypothesized primary cilia are indispensable in mediating icaritin osteogenic effect. MATERIALS AND METHODS: Primary rat calvarial osteoblasts were transfected with siRNA1 targeting intraflagellar transport protein 88 (IFT88), a protein required for ciliogenesis, to prevent formation of primary cilium and were treated with 10-6 M icaritin. RESULTS: Alkaline phosphatase (ALP) activity was significantly increased after 3 days in cells transfected with scrambled siRNA control and treated by icaritin (SC+I group) compared to cells transfected with scrambled siRNA control only (SC group). ALP activity after IFT88 siRNA1 transfection and icaritin treatment (siRNA1+I group) was significantly lower than that of SC+I group. Formation of ALP positively stained colonies after 6 days, osteocalcin secretion after 9 days and formation of calcified nodules after 12 days displayed a similar tendency among the three groups. mRNA expression of osteogenesis-related genes ALP, BMP-2, COL1α, RUNX-2 and OSX after 24 h was significantly increased in SC+I group, but was not different with SC group in siRNA1+I group. Protein levels of BMP-2, COL1α, RUNX-2 and OSX after 48 h showed the similar tendency with gene expression. CONCLUSION: Primary cilia are important in mediating icaritin-stimulated osteogenic differentiation and may be a novel target for pharmacological therapies for bone loss.

Icariin attenuates hypoxia-induced oxidative stress and apoptosis in osteoblasts and preserves their osteogenic differentiation potential in vitro.

OBJECTIVES: Icariin, a prenylated flavonol glycoside isolated from traditional Chinese medicinal herb of the genus Epimedium, has been demonstrated to be a potential alternative therapy for osteoporosis, and its action mechanism so far has been mainly attributed to its phytoestrogenic property. As blood supply to bone is considerably reduced with ageing and by the menopause, we hypothesized that icariin treatment would reduce bone loss by preventing ischaemia-induced hypoxic damages to bone. MATERIALS AND METHODS: To investigate effects of icariin treatment on cultured rat calvarial osteoblasts exposed to hypoxic conditions (2% oxygen). RESULTS: Compared to normoxic control, cell viability decreased with time to 50% by 48 h in the hypoxic group, and icariin attenuated the reduction, dose dependently, with 10(-6) and 10(-5)  m concentrations showing significant protective effects. Icariin also inhibited increase of lactate dehydrogenase activity in culture media. Measurements on oxidative stress, cell cycling and cell survival indicated that icariin protected osteoblasts by reducing production of reactive oxygen species and malondialdehyde, increasing superoxide dismutase activity, arresting the cell cycle and inhibiting apoptosis. Icariin also preserved osteogenic differentiation potential of the hypoxic cells in a dose-dependent manner, compared to the hypoxia alone group, as revealed by increased levels of RUNX-2, OSX and BMP-2 gene expression, alkaline phosphatase activity, and formation of mineralized nodules. CONCLUSIONS: Our results demonstrated that icariin attenuated oxidative stress and apoptosis and preserved viability and osteogenic potential of osteoblasts exposed to hypoxia in vitro, and suggested that its anti-osteoporotic effect may be attributed to its anti-hypoxic activity and phytoestrogenic properties.

Blood loss after cardiopulmonary bypass, standard vs titrated protamine: a meta-analysis.

BACKGROUND: The aim of this meta-analysis was to determine whether standard or titrated dosing of protamine is more effective in facilitating haemostasis after cardiac surgery with cardiopulmonary bypass (CPB). METHODS: We searched MEDLINE, and Biomedical Central using the terms 'cardiopulmonary bypass and heparin and protamine'. Studies were included in the meta-analysis if they were randomised controlled trials (RCTs), controlled clinical studies, or cohort studies with designs comparing the postoperative volume of bleeding between the study group (titrated dose) and the control group (standard dose) for protamine reversal of surgical anticoagulation in CPB procedures. The primary outcome of interest was postoperative blood loss. RESULTS: There were 219 studies identified in the initial search; four of these were included in the meta-analysis. All studies were RCTs, involving a total of 507 patients. Postoperative blood loss was lower in the study group (range: 625-839 ml) compared with the control group (range: 765-995 ml) in all four studies. Transfusion of packed red blood cells was also lower in the study group compared with the control group in all four studies. There was no evidence of significant heterogeneity in postoperative blood loss among the four studies (Q=4.224, I2=28.98%, p=0.238); hence, a fixed-effects model of analysis was used. The overall/combined standardised difference in means of postoperative blood loss volume significantly favoured study treatment over control treatment (-0.562±0.322, p<0.001). CONCLUSION: These findings suggest that titrated protamine dosing is more effective than standard protamine dosing for reducing postoperative bleeding after CPB.

Icariin enhances the osteogenic differentiation of bone marrow stromal cells but has no effects on the differentiation of newborn calvarial osteoblasts of rats.

Since the total flavonoid extract (TFE) of Epimedium herb was found to prevent osteoporosis induced by ovariectomy in rats, we have been attempting to identify the exact compound responsible for the bone-strengthening activity. In this experiment, four flavonoid extracts were obtained from Epimedium sagittatum (Siebold & Zucc.) Maxim, which contained 25.3%, 51.2%, 82.3% and 99.2% icariin respectively. They were separately supplemented into the culture media of newborn rat calvarial osteoblasts (ROB) or primary rat bone marrow stroma cells (rMSCs) at 0.1, 1, 10 and 100 microg/ml respectively, in order to observe their effects on the cells. Not any appreciable effect was found on the differentiation of ROB, but an enhancing effect on the osteogenic differentiation of rMSCs was found, and the enhancing degree was icariin-dependent, that is, a higher concentration of icariin in the extract caused more mineralized bone nodules and higher calcium deposition levels. The gene expressions involved in osteogenesis were also improved which was revealed by RT-PCR, including alkaline phosphatase, bone matrix protein (osteocalcin, osteopontin, bone sialoprotein) and cytokines (TGF-beta1 and IGF-I). The effect of icariin on cell proliferation was assayed by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Icariin inhibited the proliferation of rMSCs and ROB when its concentration was higher than 10(-5) microM (6.7 microg/ml), no stimulative effect was found. The above results indicated that icariin may exert bone-strengthening activity by enhancing the osteogenic differentiation of MSCs, which partially explains the anti-osteoporosis action of Epimedium herb.

Comparison of lidocaine and bronchodilator inhalation treatments for cough suppression in patients with chronic obstructive pulmonary disease.

BACKGROUND: This study aimed to assess and compare the effectiveness of lidocaine and bronchodilator inhalation treatments for rapid cough suppression in patients with chronic obstructive pulmonary disease (COPD). METHODS: Prospective comparison study carried out in a tertiary emergency department. Consecutive COPD patients presenting with intractable cough were randomly assigned to receive lidocaine or terbutaline inhalation treatments for cough suppression. Patients with dyspnoea, unstable vital signs, and pneumonia or neoplasm on chest x ray were excluded. A subjective, 10 point questionnaire based cough severity score was used for assessing the outcome. RESULTS: The final study sample included 127 patients (mean (SD) age, 69.2 (12.1) years; 33.1% women) of whom 62 received nebulised lidocaine and 65 nebulised bronchodilator. The cough severity score was significantly reduced one hour after inhalation treatment with both lidocaine and bronchodilator, with no significant difference in efficacy. Common but mild side effects in the lidocaine group included oropharyngeal numbness and bitter taste, and, in the bronchodilator group, tremor and palpitation. Dyspnoea, dizziness, and nausea and vomiting were equally uncommon in both groups. None of these problems caused any of the patients to discontinue their treatments and no allergic reactions were reported. CONCLUSIONS: Both lidocaine and bronchodilator inhalation treatments are equally effective for short term cough suppression in patients with COPD.

Icariin, a flavonoid from the herb Epimedium enhances the osteogenic differentiation of rat primary bone marrow stromal cells.

The herb Epimedium has long been used in Traditional Chinese Medicine to treat bone fracture and prevent osteoporosis. Researchers believe that the flavonoids contained in the herb are the effective component for this activity. However, no single flavonoid has been studied for its effect on bone-related cells. In the present study, icariin, one of the major flavonoids of the herb, supplemented the primary culture medium of rat bone marrow stromal cells (rMSCs) at 0.1 microM , 1 microM and 10 microM respectively. It was found that icariin stimulated the proliferation of rMSCs and increased the number of CFU-F stained positive for alkaline phosphatase in a dose-dependent manner. Icariin also dose-dependently increased the alkaline phosphatase activity, osteoalcin secretion and calcium deposition level of rMSCs during osteogenic induction. The addition of 10 microM icariin caused four times more mineralized bone nodules to be formed by rMSCs than in the control. The results demonstrated that icariin should be an effective component for bone-strengthening activity, and one of the mechanisms is to stimulate the proliferation and enhance the osteogenic differentiation of MSCs.

Stachyose extract from Rehmannia glutinosa Libosch. to lower plasma glucose in normal and diabetic rats by oral administration.

The hypoglycemic effects of water extract and stachyose extract (Part III) from Rehmannia glutinosa Libosch. were investigated in this paper by oral administration to normal, glucose- and adrenaline-induced hyperglycemic and alloxan-induced diabetic rats. The results showed that Part III had the effect of lowering fasted plasma glucose level and partially preventing hyperglycemia induced by glucose (2.5 g x kg(-1), i.p.) and adrenaline (300 microg x kg(-1), i.p.), respectively, but no obvious dose-dependent effect was found when it was administered at the doses of 100, 200 and 400 mg x kg(-1) for 6 days, i.g. In alloxan-induced diabetic rats, Part III (200 mg x kg(-1) for 15 days, i.g.) gave a significant decrease in blood glucose level. The results suggested that Part III, which is mainly composed of stachyose from Rehmannia glutinosa Libosch., had a significant hypoglycemic effect in glucose- and adrenaline-induced hyperglycemic and alloxan-induced diabetic rats.

The serum of rats administered flavonoid extract from Epimedium sagittatum but not the extract itself enhances the development of rat calvarial osteoblast-like cells in vitro.

The flavonoid extract from Epimedium sagittatum (FES) has been found by us to be effective in preventing osteoporosis induced by ovariectomy in rats. In the present study, the effect of FES on the development of rat calvarial osteoblast-like (ROB) cells was investigated. No appreciable effect was observed when ROB cells were exposed to FES in vitro. However, serum isolated from rats administered FES orally was able to significantly stimulate the proliferation as well as the osteoblastic differentiation of ROB cells compared to serum from control rats. The results indicate that the serum of rats administered FES contains active metabolites ofFES that enhance the development of osteoblasts, while the original form of FES itself is inactive.

Preconsultation use of analgesics on adults presenting to the emergency department with acute appendicitis.

OBJECTIVE: 279 cases of appendicitis were reviewed and compared for the difference between those patients who received pain medication before consulting a surgeon and those who were not treated with analgesics. METHODS: All patients aged 15 years and older who underwent appendicectomy for appendicitis between 1 July 2001 and 30 June 2002 were divided into group 1 (those who received preconsultaion use of analgesics) and group 2 (those who were not treated with analgesics). The following measures were compared: age, sex, symptom duration, initial vital signs, white blood cell counts, frequency of imaging studies, time to operative intervention, and operative findings. Continuous and categorical variables were analysed using t and chi(2) tests, respectively. RESULTS: A total of 279 patients were included for analysis. Patient details (age, sex, symptom duration) of the two study groups were similar. There was no statistically significant difference between group 1 and group 2 with respect to vital signs (systolic blood pressure, pulse rate, respiratory rate, body temperature), white blood cell counts, and frequency of imaging studies (ultrasound, computed tomography). There was no significant difference in the rate of perforated appendicitis between the two study groups although a shorter median time to operative intervention has been found in the group who received analegesia. CONCLUSION: The preconsultation use of analgesics in ED patients with a final diagnosis of appendicitis is not associated with a longer delay to operative intervention and is not associated with an increased rate of perforated appendicitis.

Incomplete inactivation of voltage-dependent K+ channels in human B lymphoma cells.

The voltage-dependent K (KV) channel in Daudi human B lymphoma cells was characterized by using patch-clamp techniques. Whole-cell voltage-clamp experiments demonstrated that cell membrane depolarization induced a transient (time-dependent) outward current followed by a steady-state (time-independent) component. The time-dependent current resembled behavior of the type n channel, such as use dependence and a unique blockade by tetraethylammonium (TEA). Both time-dependent and time-independent currents were blocked by quinine with a similar IC50 (14.2 mM and 12.6 mM). Treatment with antisense oligonucleotide of human Kv1.3 gene significantly reduced both currents by 80%. Single-channel experiments showed that only one type of KV channel was recorded with a unitary conductance of approximately 19 pS. Consistent with whole-cell recordings, the channel activity in cell-attached patches remained in response to prolonged depolarization, and the remaining channel activity was blocked by quinine, but not TEA. Channel activity was scarcely seen in cell-attached patches after antisense treatment. Whole-cell current-clamp data showed that TEA, which blocks only the time-dependent current, caused a slight decrease in the membrane potential. In contrast, quinine and antisense, which block both time-dependent and -independent currents, strongly reduced the membrane potential. These data together suggest that the KV channel in Daudi cells does not completely inactivate and that the remaining channel activity due to this incomplete inactivation appears to be primarily responsible for maintaining the membrane potential.

Clinical application of DSA and evaluation of its methods: analysis of 160 cases and review of literature.

A total of 160 patients of two hospitals received 192 DSA examinations with different contrast administrations, and techniques of performing DSA were analyzed, compared, and evaluated with reference to the literature. It was concluded that (1) the peripheral injection of contrast material for IVDSA via cannula is simpler than that via a short catheter, but the incidences of contrast extravasation in both cases are higher than with central injection. (2) Both the lower part of the superior vena cava and the right atrial cavity are safe sites for central injection. With central injection for IVDSA, the arterial iodine concentration is approximately double that of peripheral injection, and consistent high quality examinations of the intracranial vessels may be obtained. However, neither peripheral nor central injections can visualize the small vessels clearly. (3) IVDSA may be substituted for conventional angiography only in examinations of the aorta and its main branches. (4) IADSA is becoming a superior angiographic technique and its clinical application is increasing. In addition, means of avoiding contrast extravasation during IVDSA and the main points of selecting the optimal technique for DSA are described in this paper.