Meta-analysis of the efficacy and safety of Ginkgolide Meglumine Injection combined with Butylphthalide in the treatment of Acute Ischemic Stroke

OBJECTIVE

To evaluate the efficacy and safety of Ginkgolide Meglumine Injection (GMI) combined with Butylphthalide in the treatment of Acute Ischemic Stroke (AIS), and provide reference for rational clinical medication.

METHODS

PubMed, Embase, Web of science, CNKI, Wanfang, VIP and other databases were searched for published studies on the treatment of AIS with GMI combined with Butylphthalide in both Chinese and English. The search period was from the establishment of the database to July 2023. The included studies that met the inclusion criteria were analyzed using RevMan 5.3 software for Meta-analysis.

RESULTS

A total of 25 studies involving 2362 patients (experimental group = 1182, control group = 1180) were included. The results of meta-analysis showed that the overall effective rate of the experimental group was significantly higher than that of the control group [RR = 1.21, 95% CI (1.16, 1.26), P< 0.00001]. In addition, compared with the control group, the experimental group showed significant improvement in NIHSS score [SMD = -1.59, % CI (-2.00-1.18), P< 0.00001] and ADL score [SMD = 2.12, 95% CI (1.52, -2.72), P<0.00001], significant decrease in CRP [SMD = -2.24, 95% CI (-3.31, -1.18), P<0.0001] and TNF-α [SMD = -2.74, 95% CI (-4.45, -1.03), P< 0.005] levels, and improvement in plasma viscosity [SMD = -0.86, 95% CI (-1.07, -0.66), P< 0.00001]. However, the influence on homocysteine level remains inconclusive. Furthermore, there was no significant difference in the incidence of adverse reactions between the two groups [SMD = 0.95, 95% CI (0.71, 1.28), P> 0.05].

CONCLUSION

GMI combined with Butylphthalide shows good clinical application effects and good safety in the treatment of AIS. However, more large-sample, multicenter, randomized controlled are needed to confirm these findings.

Combining stable isotope, multielement and untargeted metabolomics with chemometrics to discriminate the geographical origins of ginger (Zingiber officinale Roscoe)

Ginger (Zingiber officinale Roscoe) is a high-value food and herb worldwide. The quality of ginger is often related to its production regions. In this study, stable isotopes, multiple elements, and metabolites were investigated together to realize ginger origin traceability. Chemometrics showed that ginger samples could be preliminarily separated, and 4 isotopes (δ13C, δ2H, δ18O, and δ34S), 12 mineral elements (Rb, Mn, V, Na, Sm, K, Ga, Cd, Al, Ti, Mg, and Li), 1 bioelement (%C), and 143 metabolites were the most important variables for discrimination. Furthermore, three algorithms were introduced, and the fused dataset based on VIP features led to the highest accuracies for origin classification, with predictive rates of 98% for K-nearest neighbor and 100% for support vector machine and random forest. The results demonstrated that isotopic, elemental, and metabolic fingerprints were useful indicators for the geographical origins of Chinese ginger.

Stimulating factors for regulation of osteogenic and chondrogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells (MSCs), distributed in many tissues in the human body, are multipotent cells capable of differentiating in specific directions. It is usually considered that the differentiation process of MSCs depends on specialized external stimulating factors, including cell signaling pathways, cytokines, and other physical stimuli. Recent findings have revealed other underrated roles in the differentiation process of MSCs, such as material morphology and exosomes. Although relevant achievements have substantially advanced the applicability of MSCs, some of these regulatory mechanisms still need to be better understood. Moreover, limitations such as long-term survival in vivo hinder the clinical application of MSCs therapy. This review article summarizes current knowledge regarding the differentiation patterns of MSCs under specific stimulating factors.

Headspace GC/MS and fast GC e-nose combined with chemometric analysis to identify the varieties and geographical origins of ginger (Zingiber officinale Roscoe)

Food authenticity regarding different varieties and geographical origins is increasingly becoming a concern for consumers. In this study, headspace gas chromatography-mass spectrometry (HS-GC-MS) and fast gas chromatography electronic nose (fast GC e-nose) were used to successfully distinguish the varieties and geographical origins of dried gingers from seven major production areas in China. By chemometric analysis, a distinct separation between the two varieties of ginger was achieved based on HS-GC-MS. Furthermore, flavor information extracted by fast GC e-nose realized the discrimination of geographical origins, and some potential flavor components were selected as important factors for origin certification. Moreover, several pattern recognition algorithms were compared in varietal and regional identification, and random forest (RF) led to the highest accuracies for discrimination. Overall, a rapid and precise method combining multivariate chemometrics and algorithms was developed to determine varieties and geographical origins of ginger, and it could also be applied to other agricultural products.

[Advice on the rationalized layout of outpatient clinics in a wound repair department]

According to a document issued by the General Office of National Health Commission, "one person, one diagnosis, and one room" is required in the process of outpatient consultation. However, the patient will need to go to another room for dressing change after the doctor checks the wound if sticking to the conventional layout of current wound repair specialist outpatient clinic in hospitals and following the regulation of "separation of diagnosis and treatment". To allow a patient walking back and forth with the exposed wounds to different clinics or going to another clinic for dressing change with the original dressing reapplied to the wound is against the regulation of nosocomial infection control and the principle of sterility. To ensure that the layout of the outpatient clinic in the wound repair outpatient department not only conforms to the principle of "one person, one diagnosis, and one room", but also meets the characteristics of the diagnosis and treatment process of chronic wounds, this paper proposes the layout of "large space and small partition" in the wound repair clinic.

Virtual touch imaging quantification shear-wave elastography for breast lesions: the diagnostic value of qualitative and quantitative features

AIM

To investigate the value of the qualitative and quantitative features of Virtual Touch imaging quantification (VTIQ) shear-wave elastography in the characterisation of breast lesions.

MATERIALS AND METHODS

Conventional ultrasound (US) and VTIQ were performed in 148 solid breast lesions in 148 women. During qualitative analysis, patterns of VTIQ were categorised into two patterns, 1 and 2. During quantitative analysis, the mean SWV (SWVmean) and the maximum SWV (SWVmax) of each lesion were used. The sensitivity, specificity, and the areas under the receiver operating characteristic (ROC) curve (Az value) were calculated for conventional US, VTIQ, and combined conventional US and VTIQ.

RESULTS

Malignant lesions were more likely to show VTIQ pattern 2 than the benign lesions (p<0.001). There was no significant difference in the Az values between SWVmean (0.907) and SWVmax (0.902; p=0.572). There was no significant difference in the Az values between the VTIQ pattern (0.884) and SWVmax (p=0.572). The combined conventional US and VTIQ pattern carried a similar Az value (0.949) as compared with the combined conventional US and SWVmax, which yielded an Az value of 0.952 (p=0.683).

CONCLUSION

The combination of either VTIQ pattern or SWVmax and conventional US may be helpful in the characterisation of benign and malignant breast lesions.

Interobserver variability between experienced radiologists in evaluating the number of abnormal lymph nodes seen on preoperative axillary ultrasound

AIM

To determine the interobserver variability of experienced radiologists in evaluating the number of suspicious lymph nodes (LNs) seen on axillary ultrasound (AUS) examination, and to evaluate the effects of clinicopathological features on the discordance.

MATERIAL AND METHODS

A prospective non-randomised triple-blind study was conducted from July 2016 to December 2017 at Shanghai Ruijin Hospital. Three experienced radiologists performed AUS on 462 patients (469 axillae) with invasive breast cancer independently and assessed the number of abnormal LNs during the real-time AUS examination. Interobserver agreement was determined according to the kappa statistic.

RESULTS

The mean numbers of metastatic LNs on final histology study were 0.35, 0.98, 3.05 and 4.70 for patients with 0, 1, 2 and >2 abnormal nodes on preoperative AUS. When the cut-off (the number of abnormal LNs seen on AUS was >1) at which the maximal sum of sensitivity and specificity for diagnosis of ≥3 tumour-involved LNs was achieved was applied, the Az values ranged from 0.776 to 0.811. When the number of abnormal LNs was grouped into two-category classification (0-1 versus ≥2 abnormal LNs detected by AUS), good interobserver agreement (kappa: 0.601-0.687) was found, and disagreement between the radiologists was more frequently found in patients with T2-stage tumour and in those with one or two tumour-involved nodes.

CONCLUSION

Abnormal LN count according to two-category classification (0-1 versus ≥2 abnormal LNs detected by AUS) was a feasible method with good accuracy and high repeatability to select patients with heavy nodal disease in the post-Z0011 trial era.

Reconstructing the Perceived Faces from Brain Signals without Large Number of Training Samples. Annu Int Conf IEEE Eng Med Biol Soc 2020;2020:1108-1111. [PMID: 33018180 DOI: 10.1109/embc44109.2020.9176684]

Reconstructing the perceived faces from brain signals has become a promising work recently. However, the reconstruction accuracies rely on a large number of brain signals collected for training a stable reconstruction model, which is really time consuming, and greatly limits its application. In our current study, we develop a new framework that can efficiently perform high-quality face reconstruction with only a small number of brain signals as training samples. The framework consists of three mathematical models: principle component analysis (PCA), linear regression (LR) and conditional generative adversarial network (cGAN). We conducted a functional Magnetic Resonance Imaging (fMRI) experiment in which two subjects' brain signals were collected to test the efficiency of our proposed method. Results show that we can achieve state-of-the-art reconstruction performance from brain signals with a very limited number of fMRI training samples.

[Pay attention to the exposure risk of patients with chronic wounds on the way to hospital during coronavirus disease 2019 epidemic prevention and control]

Statistics show that 76.74% (4 688) of 6 109 patients with chronic wounds are over 50 years of age; the proportion of patients with underlying diseases in all age groups above 50 years ranges from 78.25% to 100.00%. Among the underlying diseases of chronic wound patients, the top four diseases are diabetes mellitus, cardiovascular and cerebrovascular diseases, hypertension, and respiratory diseases. The above underlying diseases and ages of patients are the susceptibility factors of coronavirus disease 2019 released by National Health Commission of China. It is an unavoidable fact that the patients with chronic wounds have to go to the hospital for treatment prescribed by the physician. At the same time, we found that quite a few patients preferred going far afield in choosing hospital for treatment due to various reasons. During the prevention and control of coronavirus epidemic, this " go far afield" style of seeking medical treatment may increase the exposure risk during travelling. Accordingly, we convened 36 wound care clinics in different regions in Shanghai to implement the " Five Measures" encouraging the patients with chronic wounds to seek medical treatment nearby. The principle of this operation is that when seeking medical treatment, patients with chronic wounds should try their best to reduce the travel distance as much as possible to minimize the exposure risk during the epidemic period, which will in turn support the campaign of epidemic prevention and control.

General characteristics, economic burden, causative drugs and medical errors associated with medical damage litigation involving severe cutaneous adverse drug reactions in China

WHAT IS KNOWN AND OBJECTIVE

To investigate the general characteristics, economic burden, causative drugs and medical errors associated with litigation involving severe cutaneous adverse drug reactions (SCADRs) in China, with the aims of improving rational medication use and reducing the extent of damage from SCADRs.

METHODS

This study analysed 150 lawsuit judgements involving SCADRs from 2005 to 2019, collected from China Judgments Online.

RESULTS AND DISCUSSION

In total, 50% of lawsuits stemmed from SCADRs occurring in general hospitals. The average time elapsed from the date of occurrence of the SCADRs to the end of litigation procedures was 1055 days. Of the patients involved, 51% were female and more than two thirds (69%) were under 60 years old. The most common outcome of SCADRs was death (39%), followed by disabilities (30%). The average responsibility of the medical provider was 48 ± 29%. The average amount of compensation was $43 424. Of the cases studied, 51% of SCADRs were Stevens-Johnson syndrome or toxic epidermal necrolysis, which together accounted for 75% of cases with known clinical subtype. The overall average economic burden of SCADRs was $99 178, of which indirect costs made up the largest proportion (more than 60%). The most common causative drug groups were antimicrobial drugs (49%), Chinese patent medicine and Chinese herbal medicine (17%), and antipyretic analgesics (16%). Finally, 61% of medical errors were found to stem from violation of duty of care, 20% from violation of informed consent and 18% from violations related to the medical record writing and management system.

WHAT IS NEW AND CONCLUSION

Severe cutaneous adverse drug reactions not only severely affect patient survival and quality of life, but also impose a heavy economic burden in terms of health care and societal costs. Medical providers should be better educated on strategies to reduce risk to patients and establish mechanisms of risk sharing and management.

A novel T-C3N and seawater desalination

A structurally stable stacked multilayer carbonitride is predicted with the aid of ab initio calculations. This carbonitride consists of C3N tetrahedra, and is similar to T-carbon and thus named T-C3N. Its 2-dimensional (2D) monolayer is also carefully investigated in this work. The studies on electronic properties reveal that bulk and 2D T-C3N are insulators with a 5.542 eV indirect band gap and a 5.741 eV direct band gap, respectively. However, the monolayer T-C3N exhibits an excellent uniform porosity. Its 5.50 Å pore size is perfect for water nanofiltration. The adsorption and permeation of water molecules on the monolayer T-C3N are investigated. Its promising potential application in highly efficient nanofiltration membranes for seawater desalination is discussed.

Antidepressant effect of taurine in chronic unpredictable mild stress-induced depressive rats

Depression, a psychiatric and dysthymic disorder, severely affects the learning, work and life quality. The main pathogenesis of depression is associated with central nervous system (CNS) dysfunction. Taurine has been demonstrated to exert protective effects on the brain development and can improve learning ability and memory. Our study investigated the antidepressant-like effects of taurine pre-treatment by examining the changes in depression-like behavior, hormones, neurotransmitters, inflammatory factors and neurotrophic factors in the hippocampus of a chronic unpredictable mild stress (CUMS)-induced depressive rat model. Taurine was found to inhibit the decrease of sucrose consumption and prevent the deficiency of spatial memory and anxiety in rats exposed to CUMS, suggesting a preventive effect of taurine on depression-like behavior. Furthermore, the decreased levels of 5-hydroxytryptamine, dopamine, noradrenaline; the increased levels of glutamate, corticosterone; and the decreased expressions of fibroblast growth factor-2, vascular endothelial growth factor and brain derived neurotrophic factor in depressive rats were hindered by taurine pre-administration. However, tumor necrosis factor-α and interleukin-1β levels were not significantly changed by taurine. The results demonstrated that the anti-depressive effect of taurine may be involved in the regulation of hypothalamic-pituitary-adrenal (HPA) axis and the promotion of neurogenesis, neuronal survival and growth in the hippocampus.

Impact of human activities on subaqueous topographic change in Lingding Bay of the Pearl River estuary, China, during 1955-2013

Estuaries have been sites of intensive human activities during the past century. Tracing the evolution of subaqueous topography in estuaries on a decadal timescale enables us to understand the effects of human activities on estuaries. Bathymetric data from 1955 to 2010 show that land reclamation decreased the subaqueous area of Lingding Bay, in the Pearl River estuary, by ~170 km² and decreased its water volume by 615 × 10⁶ m³, representing a net decrease of 11.2 × 10⁶m³ per year and indicating the deposition of approximately 14.5 Mt/yr of sediment in Lingding Bay during that period. Whereas Lingding Bay was mainly governed by natural processes with slight net deposition before 1980, subsequent dredging and large port engineering projects changed the subaqueous topography of the bay by shallowing its shoals and deepening its troughs. Between 2012 and 2013, continuous dredging and a surge of sand excavation resulted in local changes in water depth of ± 5 m/yr, far exceeding the magnitude of natural topographic evolution in Lingding Bay. Reclamation, dredging, and navigation-channel projects removed 8.4 Mt/yr of sediment from Lingding Bay, representing 29% of the sediment input to the bay, and these activities have increased recently.

[Clinical effect of compound internal fixations in treating extreme distal radial fractures]

Objective: To investigate the clinical character and treating strategy of extreme distal radial fractures. Methods: From June 2012 to May 2014, 12 patients who suffered from extreme distal radial fractures were treated in Department of Orthopedics, Tongji Hospital, Tongji University. According to AO/OTA classification, there were 4 cases of type 23B1, 3 cases of 23B2, 3 cases of 23C1 and 2 cases of 23C3.When classified by morphological features, there were 4 of simple styloid process fracture, 3 of simple extreme distal radial fracture without articular surface involved, 3 of styloid process fracture combined with distal radial articular fracture, and 2 of articular surface splintered or collapse fracture. According to the fracture features that radiographic exams showed, different surgical paths and fixation methods were chosen in order to protect soft tissues to the best advantage. To those patients with simple styloid process fracture, screw alone, Kirschner-wire or styloid plate were used for fixation. To the other types of fracture, open reduction and compound internal fixation with low-notch volar plate, dorsal or volar mini-plate, screw or Kirschner-wire was applied to ensure the stability of fixation, and maximally protect soft tissues like tendons, ligaments and neurovascular bundles, counting on the "stuffing-squeezing" effects after reduction or reconstruction of the articular surface. Situation of the wound and soft tissue were mainly checked in the first 2 weeks, and in the 3rd month post-operatively, fracture reduction and internal fixation were evaluated by radiographic methods like X-ray and CT scan. When 12 months post-operatively, not only radiographic follow-up such as fracture reduction, internal fixation and osteoarthritis were taken, but also some other evaluation, such as pain of wrist, rotation range of forearm, grip strength, and function of wrist according to DASH scores. Results: All of the 12 cases were followed up for at least 1 year. The wound healed well in all cases 2 weeks post-operatively, and no soft tissue infections, necrosis or neurovascular complications occurred. All fractures healed and no loss of reduction occurred 3 months post-operatively. Internal fixations were at good condition except in 2 cases, whose Kirschner-wire had been removed 2.5 and 2.8 months after the operation due to loosening and partly backing out on dorsal side. When followed up at 12 months post-operatively, one from these 2 patients suffered from a mild pain of wrist, and grip strength together with the function of the affected wrist dramatic declined when compared to the unaffected side. With the help of radiograph, local collapse on the articular surface was found, which meant to be traumatic arthritis. There were no pain in the rest 11 cases, and flexion-extension range of the wrist, rotation range of forearm and grip strength of the affected side recovered to over 80% of the unaffected side, with a DASH score was from 7 to 15 points(average 11.9 points)below 15 points. Conclusions: Traditional volar plates can not be used for extreme distal radial fractures. It may be an effective way to treat extreme distal radial fractures with compound internal fixation on the basis of morphological feature of fractures and the situation of soft tissue because of vivid of the fixation, reducing damage of soft tissue and early functional training.

Investigation of single nucleotide polymorphisms in phosphodiesterase 4D gene in Mongol and Han patients with ischemic stroke in Inner Mongolia

We investigated single nucleotide polymorphisms (SNP) at 87 sites of the phosphodiesterase 4D (PDE4D) gene in Mongol and Han patients with ischemic stroke in Inner Mongolia. SNPs in 226 patients with ischemic stroke (case group, 110 Mongol patients, 116 Han patients) and 220 patients without neurological disease (control group, 102 Mongol patients, 118 Han patients) were detected by polymerase chain reaction-restriction fragment length polymorphism and gene sequencing. The genotype and allele frequencies of all groups were compared. There were no statistically significant differences in genotypes in the PDE4D gene at 87 sites between the case and control groups (P > 0.05). The C allele frequency in the case group was significantly higher than that in the control group (P < 0.05). The CC genotype and C allele frequencies in the Mongol case subgroup were higher than those in the Mongol control subgroup (P < 0.05). The CC genotype and C allele frequencies in the Han case subgroup were higher than those in the Han control subgroup (P < 0.05). In the case group, there were no significant differences at 87 sites for genotypes and allele frequencies between the Mongol and Han subgroups. In the control group, there were no significant differences at 87 site genotypes and allele frequencies between the Mongol and Han subgroups. The increase in the C allele frequency at 87 SNP sites in PDE4D may increase ischemic stroke risk. We found no differences in the risk between Mongol and Han populations in Inner Mongolia.

Evaluating the association between pathological myopia and SNPs in RASGRF1. ACTC1 and GJD2 genes at chromosome 15q14 and 15q25 in a Chinese population

BACKGROUND

This study investigated the association of the 27 SNPs located in RASGRF1. GJD2, and ACTC1 genes with pathological myopia in a Chinese Han population.

METHODS

Myopia patients were stratified according to whether they did (n = 274) or did not (n = 131) have myopic macular degeneration (MMD). The SNPbrowser software was used to identify specific SNPs for analysis and minimal allele frequency of >20%, and a pairwise r(2) < 0.85 were genotyped using MALDI-TOF mass spectrometry.

RESULTS

Before controlling for false discovery rate, the frequency of the rs1867315 C/C genotype compared with healthy controls was lower in the myopia group (p = 0.006) and in myopia patients without macular degeneration (p = 0.019). The frequency of the rs670957A/A genotype was also lower in patients without MMD compared with controls (p = 0.045). For rs2070664, the frequency of the A allele was higher in the patients with MMD compared to those without MMD (p = 0.032). After controlling for a false discovery rate of 5%, there was no significant difference in genotype and allele frequencies between these groups.

CONCLUSION

In this study, there was no association of the analyzed SNPs located in RASGRF1. GJD2, and ACTC1 with pathological myopia, suggesting that SNPs included in our study have no or a limited role in causing pathologic myopia in this Chinese Han population.

Monocyte/macrophage β2-AR as a target of antisympathetic excitation-induced atherosclerotic progression

The aim of this study was to determine whether monocyte/macrophage β2-AR could act as the therapeutic target of antisympathetic excitation-induced atherosclerotic progression. Cultivated human THP-1 cells were divided into different groups and incubated with isoprenaline, metoprolol, propranolol or β2-AR blocker for 24 h, together with oxidized low-density lipoprotein (ox-LDL). Afterwards, each group was analyzed for C-C chemokine receptor type 2 (CCR2) expression, monocyte chemotactic protein 1 (MCP-1) release into medium and cell migration ability. In the isoprenaline group, CCR2 protein level was increased, as well as the secretion of MCP-1, and cell motility was enhanced, in a concentration-dependent manner. Propranolol and ICI 118,551 significantly reversed the stimulatory effect of isoprenaline on THP-1 cells induced by ox-LDL, but only high concentrations of metoprolol interfered significantly with the action of isoprenaline (P < 0.05). Isoprenaline or a β-AR blocker could mediate through β2-AR, affecting MCP-1 secretion, CCR2 protein expression and cell migration capacity of THP-1 cells. Therefore, monocyte-macrophage β2-AR may act as a target of antisympathetic excitation-induced atherosclerotic progression.

Maximal, minimal, and mean pulsed Doppler parameters: which should be utilized in the diagnosis of thyroid nodules?

AIM

To compare the diagnostic efficacy of the maximal, minimal, and mean pulsatility index (PI) and resistance index (RI) and determine which should be utilized in the evaluation of thyroid nodules.

MATERIALS AND METHODS

A total of 224 consecutive patients with thyroid nodules were included in this prospective study. Doppler signals from three different nodular arteries were obtained and six Doppler parameters were used for final analysis: maximal PI (PImax), minimal PI (PImin), mean PI (PImean), maximal RI (RImax), minimal RI (RImin), and mean RI (RImean).

RESULTS

Eighty-five patients had malignant and 139 cases had benign thyroid nodules. All three sets of PI and RI parameters were significantly higher in malignant than in benign thyroid nodules (p = 0.000 for all). The area under the receiver operating characteristic (ROC) curve (Az) of PImax was significantly higher than that of PImin (p = 0.046) and higher than that of PImean (p = 0.161). The Az value of RImax was higher than that of RImean and RImin; however, the differences were not significant (p = 0.403, and p = 0.058, respectively). The Az values of the three sets of PI parameters (PImax, PImin, and PImean) were significantly higher than those of the corresponding sets of RI parameters (p = 0.005, p = 0.003, and p = 0.003, respectively).

CONCLUSION

Maximal pulsed Doppler parameters should be utilized in the evaluation of thyroid nodules. PI parameters were superior to the RI parameters in determining malignant nodules.

Optimization of hollow waveguides as absorption cells for spectroscopic gas sensing

Flexible and low-loss hollow waveguide has many advantages as an absorption cell for spectroscopic gas sensing. The characteristics of the sensing system are dependent on the parameters of the hollow waveguide cell. In this paper, a mathematical model was proposed to analyze the waveguide cell by considering waveguide loss, effective optical path length, and signal-to-noise ratio of the system. Simulation results show that the gas absorption intensity and system sensitivity are dependent not only on the waveguide length but also on the bore-diameter, signal-to-noise ratio, and the concentration of the target gases. The results provide optimizing methods for the sensing system and algorithms for error compensation. Preliminary experiments on concentration detection of methane gas were carried out and measured data showed good agreements with the simulation results.

An integrated lab-on-a-disc for automated cell-based allergen screening bioassays

We have utilized various valving scheme to leverage purely rotation-regulated flow control to enable comprehensive cell-based bioassays (CBBs) on centrifuge-based lab-on-a-disc (LOAD). A LOAD has been developed to examine allergic degranulation from live basophils for allergens screening for the first time, which can also be adjusted to suit a wide range of CBBs. In this system, controlled allergic reaction together with mediator separation from basophils using siphon valving and centrifugal sedimentation are realized inside microstructured network. The entire degranulation analysis process including on-demand release of samples, reaction and degranulation, allergic mediator separation and detection is executed in an automatic sequence within a single run. To validate our cell-based approach, detection of degranulation mediated by known secretagagues, ionomycin or chemotatic peptide formyl-methionine-leucine-pheylalanine (fMLP), is first demonstrated. Further experiments using real allergens house dust mite protein (Der p1) and its corresponding human serum IgE also show positive results. The overall efficiency of the assay is 80.6%, which is comparable to other conventional methods. With 4 identical units on a disc running in a parallel format, the device offers the possibility of single-step, multiplexed allergens screening. The device is capable of reporting a result within 30 min. It has many desirable merits including fast and multiplexed analysis, low cost, single-step operation, minimal sample volume, less discomfort and most importantly increased safety as patients are no longer susceptible to possible anaphylactic shock reactions induced by the common skin-prick-test. The flexibility of the flow control within the device makes it suitable to a wide range of CBBs.

Photonic-assisted microwave frequency measurement with higher resolution and tunable range

A photonic-assisted approach to microwave frequency measurement is proposed based on frequency-to-power mapping with the help of the so-called amplitude comparison function. The key component is a dual-output Mach-Zehnder modulator (MZM) working at chirped modulation. The proposed scheme is characterized as having simplicity, higher resolution, and tunable measurement range. Owing to experimental constraint, an equivalent experiment has been carried out using a common single-output MZM at different bias points to prove the concept.

[Surgical exploration of the sentinel lymph nodes in the papillary thyroid carcinoma]

OBJECTIVE

To study the technique of sentinel lymph node mapping in the papillary thyroid carcinoma and its evaluation in the search for cervical metastases.

METHOD

Exploration of the sentinel lymph nodes of the papillary thyroid carcinoma by injection of methylene blue around the tumour among 25 patients during surgery. The nodes which stained blue and the other nodes removed by functional neck dissection were examined histologically after staining with hematoxylin-eosin-saffron (HES). We have evaluated the predictive value of the technique in mapping the cervical metastases in the sentinel lymph node.

RESULTS

Among the 25 patients, 22 patients presented sentinel lymph nodes (blue-stained), that is to say a rate of identification of 88%. At histological examination, 19 of the 22 patients had positive sentinel lymph nodes, of which 13 had also positive nodes not coloured with blue. The histological examination of patients without sentinel lymph node was negative.

CONCLUSION

The technique of the sentinel lymph node has a strong positive predictive value in the search for cervical node metastases in the papillary thyroid carcinoma.

Spectral-resolved backreflection measurement of polarization mode dispersion in optical fibers

An improved backreflection technique is proposed to perform the spectral-resolved measurement of polarization mode dispersion (PMD) in optical fibers. This technique is based on the PMD dynamical equation and realized by measuring the polarization state evolutions of the reflected signal in both frequency and time domains. Two experimental setups, employing the far-end Fresnel reflection, are constructed to verify this technique. The agreement between the results of the proposed backreflection technique and the conventional forward technique is observed.

An evaluation of para toluene-sulfonamide metabolism and effect with regard to CYP isoforms, P-glycoprotein, and drug interactions

Aim of this study was to investigate liver metabolism of with regard to para toluene-sulfonamide (PTS), CYP isoforms, P-glycoprotein (P-gp), and drug interactions. Known substrates, inducers and inhibitors of CYP and inhibitor of P-gp were employed and metabolites were determined with HPLC. Male Wistar rats were pretreated with ip phenobarbital (PB), ketoconazole (Ket), or verapamil (Ver) for 3 days and in situ liver perfusion of PTS was conducted in a recirculation system. Rats were also pretreated with ip PTS (33 mg x kg(-1) x d(-1) or PTS 99 mg x kg(-1) x d(-1)) for 4 days before liver perfusions with dextromethorphan (Dex) and phenacetin (Phe) preparations were conducted. Microsome incubation was used to investigate PTS effect on five CYP isoforms and PTS-drug interactions probability with phyllotoxin and 5-fluorouracil (5-FU) in vitro. PTS at 60 min perfusates had areas of 61.4% and 133.6% of the blank control in PB group and Ket group, respectively. The result that PTS metabolism was enhanced by PB and inhibited by Ket treatments suggested liver CYP was attributed to PTS metabolism. PTS 99 mg x kg(-1) x d(-1) pretreatment slowed down the metabolism of Dex and Phe while in vitro incubations did not show a PTS (0-160 micromol/L) effect on CYP activities. PTS metabolite formation when co-incubated with phyllotoxin was 50.7% of the negative control. The potent inhibitory ability of phyllotoxin to PTS requires further clinical investigation regarding in concomitant administration.

Generalized Mueller matrix method for polarization mode dispersion measurement in a system with polarization-dependent loss or gain

A generalized Mueller matrix method (GMMM) is proposed to measure the polarization mode dispersion (PMD) in an optical fiber system with polarization-dependent loss or gain (PDL/G). This algorithm is based on the polar decomposition of a 4X4 matrix which corresponds to a Lorentz transformation. Compared to the generalized Poincaré sphere method, the GMMM can measure PMD accurately with a relatively larger frequency step, and the obtained PMD data has very low noise level.

Quasi-monochromatic fiber depolarizer and its application to polarization-dependent loss measurement

We theoretically derive the relationship between the degrees of polarization (DOPs) of input and output for an optical component with polarization-dependent loss (PDL) and birefringence. Based on the theoretical result, we propose a novel depolarizer for quasi-monochromatic light that can depolarize a fully polarized light with a 50 MHz linewidth to less than 0.2% in the DOP The depolarized light is then used to measure PDL in a single-mode optical fiber link. To the best of our knowledge, our new PDL measurement method is significantly faster than all known methods. Experimental results show excellent agreement with other methods.

The Saccharomyces Pif1p DNA helicase and the highly related Rrm3p have opposite effects on replication fork progression in ribosomal DNA

Replication of Saccharomyces ribosomal DNA (rDNA) proceeds bidirectionally from origins in a subset of the approximately 150 tandem repeats, but the leftward-moving fork stops when it encounters the replication fork barrier (RFB). The Pif1p helicase and the highly related Rrm3p were rDNA associated in vivo. Both proteins affected rDNA replication but had opposing effects on fork progression. Pif1p helped maintain the RFB. Rrm3p appears to be the replicative helicase for rDNA as it acted catalytically to promote fork progression throughout the rDNA. Loss of Rrm3p increased rDNA breakage and accumulation of rDNA circles, whereas breakage and circles were less common in pif1 cells. These data support a model in which replication fork pausing causes breakage and recombination in the rDNA.

The small subunit is required for functional interaction of DNA polymerase delta with the proliferating cell nuclear antigen

DNA polymerase delta is usually isolated as a heterodimer composed of a 125 kDa catalytic subunit and a 50 kDa small subunit of unknown function. The enzyme is distributive by itself and requires an accessory protein, the proliferating cell nuclear antigen (PCNA), for highly processive DNA synthesis. We have recently demonstrated that the catalytic subunit of human DNA polymerase delta (p125) expressed in baculovirus-infected insect cells, in contrast to the native heterodimeric calf thymus DNA polymerase delta, is not responsive to stimulation by PCNA. To determine whether the lack of response to PCNA of the recombinant catalytic subunit is due to the absence of the small subunit or to differences in post-translational modification in insect cells versus mammalian cells, we have co-expressed the two subunits of human DNA polymerase delta in insect cells. We have demonstrated that co-expression of the catalytic and small subunits of human DNA polymerase delta results in formation of a stable, fully functional heterodimer, that the recombinant heterodimer, similar to native heterodimer, is markedly stimulated (40- to 50-fold) by PCNA and that the increase in activity seen in the presence of PCNA is the result of an increase in processivity. These data establish that the 50 kDa subunit is essential for functional interaction of DNA polymerase delta with PCNA and for highly processive DNA synthesis.

Purification and characterization of the catalytic subunit of human DNA polymerase delta expressed in baculovirus-infected insect cells

The catalytic subunit of human DNA polymerase delta has been overexpressed in insect cells by a recombinant baculovirus. The recombinant protein has a Mr = approximately 125,000 and is recognized by polyclonal antisera against N-terminal and C-terminal peptides of the catalytic subunit of human DNA polymerase delta. The recombinant protein was purified to near homogeneity (approximately 1200-fold) from insect cells by chromatography on DEAE-cellulose, phosphocellulose, heparin-agarose, and single-stranded DNA-cellulose. The purified protein had both DNA polymerase and 3'-5' exonuclease activities. The properties of the recombinant catalytic subunit were compared with those of the native heterodimeric DNA polymerase delta isolated from fetal calf thymus, and the enzymes were found to differ in several respects. Although the native heterodimer is equally active with either Mn2+ or Mg2+ as divalent cation activator, the recombinant catalytic subunit is approximately 5-fold more active in Mn2+ than in Mg2+. The most striking difference between the two proteins is the response to the proliferating cell nuclear antigen (PCNA). The activity and processivity of native DNA polymerase delta are markedly stimulated by PCNA whereas it has no effect on the recombinant catalytic subunit. These results suggest that the small subunit of DNA polymerase delta is essential for functional interaction with PCNA.

Exposure of rat muscle phosphoglycerate kinase to a nonenzymatic MFO system generates the old form of the enzyme

The occurrence of age-related modifications in enzymes is a well-established symptom of aging that has been explained by several possible mechanisms including the oxidation of amino acid residues by mixed-function oxidation (MFO) systems. In the present study native old phosphoglycerate kinase was compared with young enzyme which had been modified by oxidation with ascorbate: FeCl3 followed by reduction. The comparison was done by monitoring the rates of heat denaturation of these enzyme forms, as well as their inactivation by trypsin. A remarkable similarity between the old and treated young enzyme was revealed, while native young phosphoglycerate kinase was inactivated with a different rate. Extensive unfolding followed by refolding converted both old and MFO-treated young phosphoglycerate kinase to species which greatly resemble the native young enzyme in their heat inactivation kinetics. These results demonstrate that the exposure of phosphoglycerate kinase to the mixed-function oxidation system introduces some modifications which are not reversed by subsequent enzyme reduction and which resemble those found in the native old enzyme. This mechanism, therefore, may account for the aging of phosphoglycerate kinase in vivo.

Endurance-training induced changes in skeletal muscle phosphoglycerate kinase of old Wistar rats

Sufficiently intense, long-term, endurance training has been shown in several studies to induce a variety of adaptations in skeletal muscle, including a substantial restoration of the activities of several muscle enzymes which are known to be modified during biological aging. This activity-restoration may reflect either an increase in the amounts of enzyme proteins or an enhancement of the specific activities of these molecules. The present study examined the effect of long-term endurance training on the status of phosphoglycerate kinase in skeletal muscle of old rats, as compared with the enzyme isolated either from non-trained old or young animals. The kinetics of heat inactivation, which differ markedly between young and old forms of phosphoglycerate kinase, were used as a sensitive probe for the status of the enzyme. The results reveal a remarkable similarity between the heat inactivation patterns of phosphoglycerate kinase from the muscle of old, exercise-trained rats and enzyme purified from young animals, while enzyme samples isolated from sedentary old animals are significantly more heat-stable. Adaptation to endurance-training is thus evident at the molecular level, and maintains phosphoglycerate kinase in its young form. The aging of this enzyme has been previously shown to involve only conformational changes, which develop following a reversible partial oxidation of reactive cysteine residues. Whether the adaptation of the enzyme to endurance-training results from enhancement in its turnover rate (i.e., dwell time in the cell becoming too short for modifications to develop) or is due to increased protection against oxidation (being the first step in the enzyme's aging) remains to be studied.

[Effect of expression of exogenous PDGF-A chain on growth and transformation of CHO cells]

CHO cells were transfected with plasmid pSV2-PDGF-A (containing human PDGF-A cDNA) by calcium phosphate method. Twenty transfected cell lines were obtained after G418 selection. The selected 2 cell lines At1 and Aot7), with prominent changes in morphology and growth behaviour, showed transcription of PDGF-A chain mRNA much higher than CHO cells, strong fluorescent PDGF-specific reaction, appearing that PDGF-like proteins were synthesized in cytoplasm of these cells. At1 and Aot7 cells not only had increased growth rate, but also formed large colonies in soft agar and grew into fibrosarcomas in nude mice. These results suggested that the expression of exogenous PDGF-A gene might cause the uncontrolled growth and malignant transformation of CHO cells.

Earthworm muscle preparation for studying several potent compounds--the possible existence of a "Soman receptor."

A new model of earthworm (Eisenia foedida) dorsal muscle preparation was studied. It is a specific preparation for testing GABA and its agonist muscimol. The response of muscle could be recorded through mechanical functional changes instead of potential variations. Thus, it is a direct and simple means for measuring GABA activity. ChE-deactivated preparation was suggested for this purpose. By mild membrane modifications of earthworm muscle preparation, it was possible to remove or inactivate GABA, glutamic acid or Soman combining protein. In conjunction with superfusion of Ach-receptor antagonist (alpha-Bungaratoxin) or GABA antagonist (picrotoxin, isopropylbicyclophosphate), we could differentiate Soman receptor from Ach and GABA receptor. The possible existence of a Soman receptor in the earthworm muscle was therefore proposed.