Risk factors for recurrent wheezing after bronchiolitis

BACKGROUND

This study aimed to determine whether there was an association between certain factors in patients with bronchiolitis and recurrent wheezing in childhood.

METHOD

In 2021 we tracked children hospitalized for bronchiolitis at Chengdu Women's and Children's Central Hospital in 2017. The patients were classified into recurrent wheezing group (RWG) and non-recurrent wheezing group (NRWG). Possible risk factors including maternal age, school-age siblings, allergic history, atopic dermatitis, allergic rhinitis, atopic family history, severity of the condition, duration of hospitalization, nasopharyngeal secretions culture, blood eosinophil counts, FeNO and skin prick test were compared between the two groups. Continuous variables were analyzed by independent sample t-test for normal distribution and Mann-Whitney U-test for non-normal distribution. Categorical variables were tested using chi-square tests. Multifactor analysis was conducted by stepwise logistics regression analysis.

RESULTS

In total 167 participants were included, of which 26 and 141 were in RWG and NRWG respectively. In RWG children represented higher maternal age (P = 0.02) and greater probability of allergic history, atopic dermatitis, allergic rhinitis, atopic family history (odds ratio [OR] = 4.0,3.7, 7.8, 10.9 respectively, P < 0.01). However, school-age siblings, severity of the condition, duration of hospitalization, blood eosinophil counts, fractional exhaled nitric oxide and skin prick test results seemed unrelated to recurrent wheezing. In the subgroup analysis of nasopharyngeal secretion culture, there were more Moraxella catarrhalis-positive in RWG(P = 0.043). Atopic dermatitis, allergic rhinitis and atopic family history were identified as independent risk factors for recurrent wheezing.

CONCLUSION

Some children with bronchiolitis will develop recurrent wheezing, and the risk factors are allergic history, Moraxella catarrhalis infection or colonization, atopic dermatitis, allergic rhinitis and atopic family history; the latter three are independent risk factors.

Lysophosphatidic acid receptor 6 regulated by miR-27a-3p attenuates tumor proliferation in breast cancer

Purpose

Lysophosphatidic acid (LPA) is a bioactive molecule which participates in many physical and pathological processes. Although LPA receptor 6 (LPAR6), the last identified LPA receptor, has been reported to have diverse effects in multiple cancers, including breast cancer, its effects and functioning mechanisms are not fully known.

Methods

Multiple public databases were used to investigate the mRNA expression of LPAR6, its prognostic value, and potential mechanisms in breast cancer. Western blotting was performed to validate the differential expression of LPAR6 in breast cancer tissues and their adjacent tissues. Furthermore, in vitro experiments were used to explore the effects of LPAR6 on breast cancer. Additionally, TargetScan and miRWalk were used to identify potential upstream regulating miRNAs and validated the relationship between miR-27a-3p and LPAR6 via real-time polymerase chain reaction and an in vitro rescue assay.

Results

LPAR6 was significantly downregulated in breast cancer at transcriptional and translational levels. Decreased LPAR6 expression in breast cancer is significantly correlated with poor overall survival, disease-free survival, and distal metastasis-free survival, particularly for hormone receptor-positive patients, regardless of lymph node metastatic status. In vitro gain and loss-of-function assays indicated that LPAR6 attenuated breast cancer cell proliferation. The analyses of TCGA and METABRIC datasets revealed that LPAR6 may regulate the cell cycle signal pathway. Furthermore, the expression of LPAR6 could be positively regulated by miR-27a-3p. The knockdown of miR-27a-3p increased cell proliferation, and ectopic expression of LPAR6 could partly rescue this phenotype.

Conclusion

LPAR6 acts as a tumor suppressor in breast cancer and is positively regulated by miR-27a-3p.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12094-021-02704-8.

[Consistency of peripheral whole blood and venous serum procalcitonin in children: a multicenter parallel controlled study]

Objective: To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection. Methods: This multicenter cross-sectional parallel control study was conducted in 11 children's hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman's rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection. Results: A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum (r=0.97, P<0.01). The linear regression equation was PCT_{venous serum}=0.135+0.929×PCT_{peripheral whole blood}. However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods (r=0.51-0.92, all P<0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions: There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

[A comparative study of lacrimal magnetic resonance hydrography and lacrimal endoscopy examination in the diagnosis and treatment of lacrimal duct obstructive diseases]

OBJECTIVE

To evaluate the diagnostic value and treatment guidance of lacrimal magnetic resonance hydrography (LMRH) and lacrimal endoscopy examination in lacrimal duct obstruction.

METHODS

A retrospective analysis of clinical and imaging data of 59 patients with epiphora who had LMRH examination in Tongji Hospital during June 2013 and January 2014. Multiplanar reconstruction (MPR) and maximum intensity projection (MIP) were used to process the three dimensions T2-weighted images (T2WI). The size of lacrimal sac, lacrimal mucosal lesions and the obstructed plane of nasolacrimal duct were observed. The lacrimal irrigation results were used as gold standard. The sensitivity, specificity, accuracy of LMRH in diagnosis of lacrimal duct obstructive diseases and the consistency between the two methods were analyzed. In addition, 22 cases had lacrimal endoscopy examination in less than half month after MRD. The results of lacrimal endoscopy were compared with LMRH images. The treatment method was made according to the results of LMRH and lacrimal endoscopy.

RESULTS

According to the results of lacrimal irrigation, among 78 eyes of 59 patients, 2 eyes were diagnosed as lacrimal canalicular obstruction (2.6%, 2/78), 8 eyes were diagnosed as nasolacrimal duct stenosis (10.3%, 8/78), 24 eyes were diagnosed as nasolacrimal duct obstruction (30.8%, 24/78), 44 eyes were diagnosed as nasolacrimal duct obstruction accompanied with chronic dacryocystitis (56.4%, 44/78). The other 40 eyes were negative controls. LMRH had a high degree of consistency with lacrimal irrigation in diagnosis of lacrimal duct obstructive diseases. The value of Kappa was 0.963 (P= 0.026). The sensitivity of MRD in diagnosis of lacrimal duct obstructive diseases was 97.4%, the specificity was 100%, the accuracy was 98.3%, the positive predictive value was 100% and the negative predictive value was 95.2% . According to 40 eyes of the control group, the mean value of the maximum cross-sectional area of the lacrimal sac was: (10.9 ± 0.4) mm(2). Twenty-two eyes underwent lacrimal endoscopy examination and the endoscopic findings were consistent with LMRH diagnosis. The lesions in the lacrimal duct displayed more clearly and intuitively than the LMRH, while LMRH had its unique advantages in showing the size of lacrimal sac, the mucosal thickness of lacrimal duct, large foreign bodies and lesions around the lacrimal duct. According to the results of LMRH and lacrimal endoscopy, 2 eyes of canalicular obstruction, 8 eyes of nasolacrimal duct stenosis, 20 eyes of nasolacrimal duct obstruction underwent lacrimal probing and stent implantation. Four eyes of nasolacrimal duct obstruction had drug treatment under lacrimal endoscopy. Thirty-eight eyes of chronic dacryocystitis underwent endonasal dacryocystorhinostomy. The other 6 eyes of chronic dacryocystitis underwent stent removal combined with endonasal dacryocystorhinostomy.

CONCLUSIONS

LMRH is a noninvasive and reliable method to examine the lacrimal duct obstruction. It can better display the size of lacrimal sac, lacrimal mucosal thickness and surrounding soft tissues of lacrimal duct. It is also a good complementary method of lacrimal endoscopy and has guiding significance for individualized treatment in patients with lacrimal duct obstruction.

Metal artefact reduction in MRI at both 1.5 and 3.0 T using slice encoding for metal artefact correction and view angle tilting

OBJECTIVE

To compare metal artefact reduction in MRI at both 3.0 T and 1.5 T using different sequence strategies.

METHODS

Metal implants of stainless steel screw and plate within agarose phantoms and tissue specimens as well as three patients with implants were imaged at both 1.5 T and 3.0 T, using view angle tilting (VAT), slice encoding for metal artefact correction with VAT (SEMAC-VAT) and conventional sequence. Artefact reduction in agarose phantoms was quantitatively assessed by artefact volume measurements. Blinded reads were conducted in tissue specimen and human imaging, with respect to artefact size, distortion, blurring and overall image quality. Wilcoxon and Friedman tests for multiple comparisons and intraclass correlation coefficient (ICC) for interobserver agreement were performed with a significant level of p < 0.05.

RESULTS

Compared with conventional sequences, SEMAC-VAT significantly reduced metal artefacts by 83% ± 9% for the screw and 89% ± 3% for the plate at 1.5 T; 72% ± 7% for the screw and 38% ± 13% for the plate at 3.0 T (p < 0.05). In qualitative analysis, SEMAC-VAT allowed for better visualization of tissue structures adjacent to the implants and produced better overall image quality with good interobserver agreement for both tissue specimen and human imaging (ICC = 0.80-0.99; p < 0.001). In addition, VAT also markedly reduced metal artefacts compared with conventional sequence, but was inferior to SEMAC-VAT.

CONCLUSION

SEMAC-VAT and VAT techniques effectively reduce artefacts from metal implants relative to conventional imaging at both 1.5 T and 3.0 T.

ADVANCES IN KNOWLEDGE

The feasibility of metal artefact reduction with SEMAC-VAT was demonstrated at 3.0-T MR. SEMAC-VAT significantly reduced metal artefacts at both 1.5 and 3.0 T. SEMAC-VAT allowed for better visualization of the tissue structures adjacent to the metal implants. SEMAC-VAT produced consistently better image quality in both tissue specimen and human imaging.

Diffusion tensor imaging in evaluation of thigh muscles in patients with polymyositis and dermatomyositis

OBJECTIVE

To explore the diffusion tensor imaging (DTI) characteristics of thigh muscles in patients with polymyositis (PM) and dermatomyositis (DM).

METHODS

12 patients with known PM/DM and 10 healthy volunteers were enrolled in this study. Both DTI and conventional MR sequences were performed on both thighs of all subjects. Apparent diffusion coefficient (ADC), fractional anisotropy (FA) and three eigenvalues were compared between the PM/DM group and the healthy group. One-way analysis of variance and Student's t-test were used for statistical analyses with a significance of p < 0.05.

RESULTS

In the healthy group, the vastus intermedius muscle showed the highest ADC value and the gracilis (GA) muscle showed the lowest ADC value. These results were statistically significant when compared with other muscles (p < 0.05). The GA, semi-tendinosus and semi-membranosus muscles showed higher FA values than the other three thigh muscles (p < 0.05). The mean ADC value and three eigenvalues of oedematous muscles in the PM/DM group were higher on average and showed a statistically significant difference when compared with unaffected (non-oedematous muscles in patients) and normal muscles (p < 0.05). There was no statistical difference in the mean FA value between oedematous and normal muscles. The mean ADC, FA and three eigenvalues in unaffected muscles (in patients) showed no statistical differences from those in normal muscles (p > 0.05).

CONCLUSION

DTI can be used to quantitatively evaluate the anisotropic diffusion characteristics of muscles in patients with PM/DM.

ADVANCES IN KNOWLEDGE

A new application of DTI is proposed for inflammatory myopathies. The results show that ADC and the three eigenvalues were significantly different between diseased and normal muscles, a finding of potential value in both diagnosis and treatment monitoring of myopathies.

Assessment of coronary microvascular dysfunction in hypertrophic cardiomyopathy: first-pass myocardial perfusion cardiovascular magnetic resonance imaging at 1.5 T

AIM

To evaluate the integrity of the coronary microvasculature in patients with hypertrophic cardiomyopathy (HCM) using first-pass magnetic resonance perfusion imaging.

MATERIALS AND METHODS

Twenty-two patients with HCM and 13 healthy volunteers underwent cardiac magnetic resonance imaging (CMR) at rest. Imaging protocols included short axis cine, first-pass myocardial perfusion, and late-phase contrast-enhanced imaging. Left ventricular end-diastolic wall thickness (EDTH), myocardial thickening, maximal upslope of time-intensity curve (slopemax), and late myocardial gadolinium enhancement (LGE) were assessed for each myocardial segment. The differences in slopemax, myocardial thickening, and EDTH between healthy volunteers and HCM patients were evaluated as were differences among hypertrophic segments of different severities (mild, moderate, and severe hypertrophy) in a one-way analysis of variance analysis. The differences in slopemax, myocardial thickening, and EDTH between the segments with and without LGE were compared by independent-sample t-test. A Pearson correlation test was used to determine the relationships between slopemax, EDTH, and myocardial thickening.

RESULTS

Slopemax was statistically significantly less in HCM patients; the degree of myocardial thickening was also significantly reduced (p < 0.001). Slopemax and the degree of thickening statistically significantly decreased with increasing degrees of myocardial hypertrophy (p < 0.05). Differences in slopemax, myocardial thickening, and EDTH were observed between segments with and without LGE (p < 0.05). Slopemax and myocardial thickening were negatively correlated with EDTH.

CONCLUSION

First-pass myocardial perfusion CMR with slopemax measurements demonstrates microvascular coronary dysfunction in patients with HCM, a determination that may aid in risk stratification, therapeutic planning, and determination of prognosis for HCM.

Preparation and characterization of β-lactoglobulin hydrolysate-iron complexes

The purpose of this study was to determine the best preparation condition of β-lactoglobulin hydrolysate-iron complexes and characterize its structural transformation both before and after binding using the UV-visible absorption spectrum, Fluorescence spectrum, and Fourier transform infrared spectroscopy. Results showed that β-lactoglobulin hydrolysates obtained with alcalase after hydrolysis for 6h possessed the highest iron-binding capacity. The highest yield of complexes was obtained when the mass ratio between β-lactoglobulin hydrolysate and Fe(3+) reached 40:1, with the optimal pH value of 7.0. All of the spectra indicated that some sites such as amido bonds transformed during chelation, and nitrogen atoms could chelate with Fe(3+) to form coordinate bonds by offering electron pairs. Therefore, β-lactoglobulin hydrolysate-iron complexes may be good carriers for iron and possess great potential to be used as iron supplements.

Multi-targeted histone deacetylase inhibitors in cancer therapy

The heterogeneous nature of cancer requires a comprehensive approach for attacking the multiple mechanisms underlying the initiation and progression of cancers. Histone deacetylase inhibitors (HDACi) have emerged as a new class of anticancer agents, targeting the biological processes including cell cycle, apoptosis and differentiation. Studies have revealed that HDACi are synergistic with diverse classes of anticancer therapies including targeted therapeutics and conventional anticancer agents. Extensive medicinal chemistry efforts have yielded a wide range of chemical structures, indicative of the structural flexibility of HDACi. These findings have supported a strategy to generate multi-targeted HDACi by combining structural features from HDACi and other anticancer agents. HDACi can also be connected to a motif that allows for a selective delivery. Highlighting current examples, this brief review focuses on the rational design of multi-targeted inhibitors based on the examination and manipulation of chemical structures.

Diagnostic performance of CUBE MRI sequences of the knee compared with conventional MRI

AIM

To evaluate the efficacy and efficiency of three-dimensional (3D) fast spin-echo (FSE) with variable flip angle ("CUBE") magnetic resonance imaging (MRI) in knee imaging as compared with conventional MRI.

MATERIALS AND METHODS

Twenty-nine patients (single knee) with joint injuries of varying degrees were enrolled in this study between January, 2011 and December, 2011. All patients underwent conventional MRI and a fat-suppressed CUBE MRI sequence. All patients subsequently underwent knee arthroscopic surgery performed by an experienced orthopaedic surgeon within 2 weeks after the MRI examinations. With standard reference provided by arthroscopic results, the sensitivity, specificity, and accuracy of both the CUBE and conventional MRI techniques were calculated for detecting cartilage lesions, meniscus tears, and anterior cruciate ligament injuries, respectively. A chi-square test was used for statistical analysis with a level of significance of p < 0.05.

RESULTS

For the evaluation of articular cartilage lesions, the CUBE sequence had higher sensitivity (70.9% versus 50.6%, p < 0.01), higher specificity (72.6% versus 58.9%, p < 0.05), and higher accuracy (71.8% versus 55.2%, p = 0.001) than conventional MRI. For the evaluation of meniscus tears, CUBE and conventional MRI had similar sensitivity, specificity, and accuracy (p = 0.20-0.55). Similarly, there was no significant difference in sensitivity, specificity, or accuracy between CUBE imaging and conventional imaging in the detection of anterior cruciate ligament injuries (p = 0.13-0.65).

CONCLUSION

CUBE MRI has similar or superior sensitivity, specificity, and accuracy to a conventional imaging protocol in the comprehensive evaluation of knee joint injuries.

Highly efficient virus resistance mediated by artificial microRNAs that target the suppressor of PVX and PVY in plants

MicroRNAs (miRNAs) processed from nuclear-encoded transcripts control expression of target transcripts by directing cleavage or translational inhibition. Artificial miRNAs (amiRNAs) that exploit this endogenous gene silencing mechanism can be designed to target any gene of interest and provide a highly specific approach for effective post-transcriptional gene silencing (PTGS) in plants. Here, using Arabidopsis thaliana miR159a, miR167b and miR171a precursors as backbones, we designed two types of amiRNA targeting sequence that encode the silencing suppressor HC-Pro of Potato virus Y (PVY) and the TGBp1/p25 (p25) of Potato virus X (PVX). The detected amiRNAs efficiently inhibited HC-Pro and p25 gene expression and conferred highly specific resistance against PVY or PVX infection in transgenic Nicotiana tabacum; this resistance was also maintained under conditions of increased viral pressure. Moreover, resistance was strongly influenced by the complementarity between the target sequence and amiRNA, and was well correlated to amiRNA expression level; the expression level of amiRNAs was also well related to the precursor backbones. We further showed that transgenic N. tabacum developed highly effective resistance to both PVY and PVX through expression of a dimeric amiRNA precursor. Together, our findings indicate that transgenic plants with multiple virus-specific resistance can be obtained through co-expression of several amiRNAs targeting multiple viruses.

20p12.3 microdeletion predisposes to Wolff-Parkinson-White syndrome with variable neurocognitive deficits

BACKGROUND

Wolff-Parkinson-White syndrome (WPW) is a bypass re-entrant tachycardia that results from an abnormal connection between the atria and ventricles. Mutations in PRKAG2 have been described in patients with familial WPW syndrome and hypertrophic cardiomyopathy. Based on the role of bone morphogenetic protein (BMP) signalling in the development of annulus fibrosus in mice, it has been proposed that BMP signalling through the type 1a receptor and other downstream components may play a role in pre-excitation.

METHODS AND RESULTS

Using the array comparative genomic hybridisation (CGH), we identified five individuals with non-recurrent deletions of 20p12.3. Four of these individuals had WPW syndrome with variable dysmorphisms and neurocognitive delay. With the exception of one maternally inherited deletion, all occurred de novo, and the smallest of these harboured a single gene, BMP2. In two individuals with additional features of Alagille syndrome, deletion of both JAG1 and BMP2 were identified. Deletion of this region has not been described as a copy number variant in the Database of Genomic Variants and has not been identified in 13 321 individuals from other cohort examined by array CGH in our laboratory.

CONCLUSIONS

Our findings demonstrate a novel genomic disorder characterised by deletion of BMP2 with variable cognitive deficits and dysmorphic features and show that individuals bearing microdeletions in 20p12.3 often present with WPW syndrome.

[Studies on pharmacognosy of Echinacea purpurea]

Pharmacognostical studies of Echinacea purpurea were carried out by botanical analysis, microscopic analysis and physicochemical analysis. The detalied pharmacognostical characteristics of Echinacea purpurea were described respectively.

Successful radiofrequency current catheter ablation of accessory atrioventricular pathway after tricuspid replacement in Ebstein's anomaly

A 15-year-old female with Ebstein's anomaly was referred to hospital for radiofrequency (RF) current catheter ablation of her refractory paroxysmal supraventricular tachycardia (PSVT) after tricuspid valve replacement. A surface ECG showed ventricular preexcitation of type B Wolff-Parkinson-White (WPW) syndrome. In a baseline electrophysiological study, two types of PSVT with left and right bundle branch block (LBBB and RBBB) configurations were induced. The LBBB type was antidromic and the RBBB type was orthodromic atrioventricular reciprocating tachycardia (AVRT) with a right posterolateral accessory pathway. RF current was successfully delivered at the posterolateral site above the prosthetic valve (V-delta interval = -30 msec). The patient has been free from arrhythmias during a follow-up period of 9 months. RF current ablation seems to be useful for AVRT patients with corrected Ebstein's anomaly.

Accentuated antagonism by angiotensin II on guinea-pig cardiac L-type Ca-currents enhanced by beta-adrenergic stimulation

To examine mechanism(s) underlying the accentuated antagonism by angiotensin II (A-II) on twitch tension, we recorded L-type Ca2+ currents (ICa,L) using conventional patch-clamp techniques in single, guinea-pig, ventricular myocytes. ICa,L was recorded by a step-pulse protocol after eliminating K+ conductances (internal Cs+ plus tetraethylammonium chloride and K+-free extracellular solution). A-II (100 nM) did not affect basal ICa,L, but inhibited ICa,L that had been enhanced (approximately 200% of control) by (ISO, isoproterenol 100 nM). The inhibitory action of A-II was concentration dependent (concentration eliciting 50% inhibition 88+/-9 pM, n=41) and the ISO-enhanced component of ICa,L was completely blocked by A-II at concentrations above 10 nM. CV-11974 (500 nM), an A-II type-1 receptor (AT1) antagonist, prevented the inhibitory action of A-II. Pre-incubation with pertussis toxin (PTX) abolished the inhibitory effect of A-II. A-II also inhibited the ICa, L enhanced by histamine (500 nM) and forskolin (1 microM), but failed to affect ICa,L enhanced by intracellular cyclic adenosine monophosphate (1 mM). The inhibitory action of A-II may therefore involve AT1 receptors/PTX-sensitive, guanine nucleotide-binding (G) proteins (Gi)/adenylate cyclase and partially explains the A-II-dependent accentuated antagonism of inotropy.

Functional communication between cardiac ATP-sensitive K+ channel and Na/K ATPase

INTRODUCTION

Functional interaction between K(ATP) channel and Na/K ATPase was studied in single guinea pig ventricular myocytes because both membrane molecules are known to be involved in ischemic episodes.

METHODS AND RESULTS

K(ATP) channel currents were recorded at 36 degrees C by using whole cell, cell-attached, inside-out, and open cell-attached modes of patch clamp techniques on enzymatically isolated ventricular myocytes. In the whole cell mode, ouabain (1 microM) reversibly inhibited the K(ATP) currents induced by metabolic stress (ATP-free pipette solution and 1 mM NaCN), but not those activated by cromakalim (100 microM), a K(ATP) channel opener. In the cell-attached mode, ouabain concentration dependently inhibited K(ATP) channel opening induced by metabolic suppression (5.5 mM 2-deoxyglucose and 1 mM CN-). Half-inhibition concentration for ouabain was 21.0 +/- 5.5 nM and the Hill coefficient was 0.8 +/- 0.1 (n = 26). However, ouabain did not have an effect on the channel activity induced by cromakalim (100 microM). In the inside-out mode, ouabain applied to the internal side of membrane did not affect the channel. In the open cell-attached mode made by preincubation with streptolysin-O (0.08 U/mL), the K(ATP) channels were not activated by the metabolic inhibitors but were by reducing extracellular ATP concentrations, because subsarcolemmal ATP concentration could be controlled through tiny membrane holes. The channels thus activated were not suppressed by ouabain.

CONCLUSION

The inhibition of Na/K ATPase by ouabain appeared to block the K(ATP) channels by accumulating subsarcolemmal ATP caused by a decrease of the transition from ATP to ADP. In the presence of ischemic episodes, the administration of digitalis compounds may affect the opening of K(ATP) channels, which is primarily protective against the development of irreversible myocardial damage.

[Medicinal plant resources of Dipsacaceae in China]

Based on field investigation and taxonomic research on the medicinal plants of Dipsacaceae in China, eighteen species and four varieties of five genera in this family are reported. Among them, some new medicinal plant resources are supplemented, the Latin name of one species is revised, the distribution, habitats and medicinal uses of the species are spelled out and a key for the genus of Dipsacus is given.

Insulin secretion and its modulation by antiarrhythmic and sulfonylurea drugs

Cardiovascular drugs such as antiarrhythmic agents with Vaughan Williams class Ia action have been found to induce a sporadic hypoglycemia. Recent investigation has revealed that these drugs induce insulin secretion from pancreatic beta-cells by inhibiting ATP-sensitive K+ (KATP) channels in a manner similar to sulfonylurea drugs. The mechanism underlying block of KATP channels by antiarrhythmic drugs was different, however, from that of sulfonylureas: firstly, because binding of radioactive glibenclamide could not be inhibited by unlabelled antiarrhythmic agents, and vice versa; secondly, because the two compounds differ in the kinetics and sidedness of drug action-antiarrhythmic drugs act on the channel from the inner surface of the cell membrane, whereas glibenclamide binds through the intramembrane pathway; finally, it was shown that functional KATP channels in beta-cells are composed of two distinct molecules-a sulfonylurea receptor (SUR) and a channel pore-forming subunit, an inwardly-rectifying K channel with two transmembrane regions (Kir6.2). Antiarrhythmic drugs reversibly inhibit the K+ conductance displayed by the Kir6.1 (a putative KATP channel clone)-transfected NIH3T3 cells. Therefore they appear to interact directly with the pore-forming subunit, thereby inhibiting KATP channel currents and exerting an insulinotrophic effect.

Does gallstone formation after open cardiac surgery result only from latent hemolysis by replaced valves?

OBJECTIVES

To clarify the relationship between open heart surgery and gallstone formation.

METHODS

Fifty-one patients without gallstones (Group A) underwent cardiac surgery using a heart-lung machine and were followed for 24 months by ultrasonography. Blood tests of hemolysis markers were examined before, immediately after, and 3, 6, and 12 months after surgery. And 52 healthy candidates without gallstone (Group B) also were followed for 24 months.

RESULTS

The cumulative gallstone incidence in Group A was 15.7% at 3 months after surgery, 23.9% at 6 months, and 30.4% at and beyond 12 months and was significantly higher than that of Group B (p < 0.01). The stones showed a high dense pattern, indicative of pigment stones, in eight of the 10 patients assessed by CT. With respect to the type of surgery, latent hemolysis was seen only in patients who underwent mechanical valve replacement. However, there were no significant differences in the gallstone incidence between the patients who underwent mechanical valve replacement and those who underwent another cardiac surgery. The values of hemoglobin, haptoglobin, and lactate dehydrogenase showed abnormal values immediately after surgery, regardless of mechanical valve replacement or another cardiac surgery.

CONCLUSIONS

The use of a heart-lung machine, which produces hemolysis, appears to have a close relation to gallstone formation after open cardiac surgery.

[Correlative study on the storage time and quality of rhizoma Dryopteris crassirhizomae]

The contents of dryocrassin in Rhizoma Dryopteris Crassirhizomae were determined by TLC-scanning in a period of two years of storage. Phloroglucinol content was calculated by area normalization method. The results show that in contrast with the fresh crude drugs of Rhizoma Dryopteris Crassirhizomae, the contents of dryocrassin in the crude drugs of one year and two years of storage have reduced by 22% and 27% respectively, and phloroglucinol contents have reduced by 2% and 8% respectively.

Block of pancreatic ATP-sensitive K+ channels and insulinotrophic action by the antiarrhythmic agent, cibenzoline

1. We investigated the effect of cibenzoline (a class Ia antiarrhythmic drug) on basal insulin secretory activity of rat pancreatic islets and ATP-sensitive K+ channels (KATP) in single pancreatic beta cells of the same species, using radioimmunoassay and patch clamp techniques. 2. Micromolar cibenzoline had a dose-dependent insulinotrophic action with an EC50 of 94.2 +/- 46.4 microM. The compound inhibited the activity of the KATP channel recorded from a single beta-cell in a concentration-dependent manner. The IC50 was 0.4 microM in the inside-out mode and 5.2 microM in the cell-attached mode, at pH 7.4. 3. In the cell-attached mode, alkalinization of extracellular solution increased the inhibitory action of cibenzoline and the IC50 was reduced from 26.8 microM at pH 6.2 to 0.9 microM at pH 8.4. On the other hand, the action of cibenzoline in the excised inside-out mode was acute in onset with a small IC50, indicating that the drug attains its binding site from the cytoplasmic side of the cell membrane. 4. In the inside-out mode, micromolar ADP reactivated the cibenzoline-blocked KATP channels in a manner similar to that by which ADP restored ATP-dependent block of the channel. 5. The binding of [3H]-glibenclamide to pancreatic islets was inhibited by glibenclamide but not by cibenzoline. In contrast, the [3H]-cibenzoline binding was displaced by unlabelled cibenzoline but not by glibenclamide. It is concluded that cibenzoline blocks pancreatic KATP channels via a binding site distinct from the sulphonylurea receptor.

The triterpenes of Emmenospermum pancherianum

The free triterpenes identified as constituents of Emmenospermum pancherianum Baill. are ceanothic acid (wood), betulic acid (bark), and the new triterpene, 18α,24-dihydroxy-A(1)-norlupa-2,20(29)-diene-27,28- dioic acid 28-methyl ester 27,18α-lactone (1a) (bark); the structure of the last has been determined by spectroscopic analysis. Both wood and bark contained saponin which in each case on acid hydrolysis gave ebelin lactone, and two new sapogenins, 24,25-dihydroebelin lactone (9a)and the tetracarbocyclic triterpenoid (10a) possessing an aromatic ring D; all three sapogenins are secondary sapogenins. The primary sapogenins jujubogenin (11a) and dihydrojujubogenin (12a)have been obtained by degradation of the wood saponin, and dihydrojujubogenin has been shown to be the precursor of (9a) and (10a).