N6022 attenuates cerebral ischemia/reperfusion injury-induced microglia ferroptosis by promoting Nrf2 nuclear translocation and inhibiting the GSNOR/GSTP1 axis

Stroke poses a significant risk of mortality, particularly among the elderly population. The pathophysiological process of ischemic stroke is complex, and it is crucial to elucidate its molecular mechanisms and explore potential protective drugs. Ferroptosis, a newly recognized form of programmed cell death distinct from necrosis, apoptosis, and autophagy, is closely associated with the pathophysiology of ischemic stroke. N6022, a selective inhibitor of S-nitrosoglutathione reductase (GSNOR), is a "first-in-class" drug for asthma with potential therapeutic applications. However, it remains unclear whether N6022 exerts protective effects in ischemic stroke, and the precise mechanisms of its action are unknown. This study aimed to investigate whether N6022 mitigates cerebral ischemia/reperfusion (I/R) injury by reducing ferroptosis and to elucidate the underlying mechanisms. Accordingly, we established an oxygen-glucose deprivation/reperfusion (OGD/R) cell model and a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to mimic cerebral I/R injury. Our data, both in vitro and in vivo, demonstrated that N6022 effectively protected against I/R-induced brain damage and neurological deficits in mice, as well as OGD/R-induced BV2 cell damage. Mechanistically, N6022 promoted Nrf2 nuclear translocation, enhancing intracellular antioxidant capacity of SLC7A11-GPX4 system. Furthermore, N6022 interfered with the interaction of GSNOR with GSTP1, thereby boosting the antioxidant capacity of GSTP1 and attenuating ferroptosis. These findings provide novel insights, showing that N6022 attenuates microglial ferroptosis induced by cerebral I/R injury through the promotion of Nrf2 nuclear translocation and inhibition of the GSNOR/GSTP1 axis.

Therapeutic strategies targeting the NLRP3‑mediated inflammatory response and pyroptosis in cerebral ischemia/reperfusion injury (Review)

Ischemic stroke poses a major threat to human health. Therefore, the molecular mechanisms of cerebral ischemia/reperfusion injury (CIRI) need to be further clarified, and the associated treatment approaches require exploration. The NOD‑like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome serves an important role in causing CIRI, and its activation exacerbates the underlying injury. Activation of the NLRP3 inflammasome triggers the maturation and production of the inflammatory molecules IL‑1β and IL‑18, as well as gasdermin‑D‑mediated pyroptosis and CIRI damage. Thus, the NLRP3 inflammasome may be a viable target for the treatment of CIRI. In the present review, the mechanisms of the NLRP3 inflammasome in the intense inflammatory response and pyroptosis induced by CIRI are discussed, and the therapeutic strategies that target the NLRP3‑mediated inflammatory response and pyroptosis in CIRI are summarized. At present, certain drugs have already been studied, highlighting future therapeutic perspectives.

[Efficacy of different regimens and prognostic factors in patients with first relapsed multiple myeloma treated after front-line bortezomib, cyclophosphamide, and dexamethasone]

Objective: To analyze the efficacy of second-line regimens and prognostic factors in patients with first-relapsed multiple myeloma (MM) treated with bortezomib, cyclophosphamide, and dexamethasone (BCD). Methods: A retrospective cohort study. Clinical data were collected in first-relapsed MM patients after BCD treatment from three tertiary hospitals in north China from July 2009 to October 2022. Patients were classified according to the second-line regimen into the immunotherapy group, single novel agent group [either proteasome inhibitor (PI) or immunomodulatory drug (IMiD)], combination treatment group (both PI+IMiD), and traditional treatment group. Responses to second-line regimens and survival data were analyzed. The Kaplan-Meier method was used for survival analysis and the Cox proportional risk model was used for univariate and multivariate analyses. Results: A total of 217 patients were enrolled including 8.8% (19/217) in the immunotherapy group, 48.4% (105/217) in the PI/IMiD group, 29.9% (65/217) in the PI+IMiD group, and 12.9% (28/217) in the traditional treatment group. The median age was 62 years (range 31-83 years) and 56.2% (122/217) were males. The overall response rates (ORRs) in the four groups were 94.7% (18/19) vs. 56.2% (59/105) vs. 73.8% (48/65) vs. 32.1% (9/28) (χ2=24.55; P<0.001), respectively. The progression-free survival (PFS) of the second-line regimens (2ndPFS) was 17.7 vs. 9.0 vs. 9.2 vs. 4.6 months (χ2=22.74; P<0.001), respectively, among which patients in the PI/IMiD and PI+IMiD groups had comparable 2ndPFS (χ2=1.76; P=0.923). Patients with high-risk cytogenetic abnormalities (HRCAs) achieved the longest 2ndPFS of 22.0 months in the immunotherapy group (χ2=15.03; P=0.002). Multivariate analysis suggested that immunotherapy (HR=0.11, 95%CI 0.05-0.27), achievement of efficacy of partial response or better (HR=0.47, 95%CI 0.34-0.66), and non-aggressive relapse (HR=0.25, 95%CI 0.17-0.37) were independent prognostic factors of 2ndPFS. Conclusion: In this real-world study, immunotherapy was associated with a more favorable efficacy and PFS for first-relapsed MM patients after BCD treatment, with similar outcomes in patients with HRCAs.

[Analysis of the efficacy and influencing factors of sodium channel blockers in the treatment of focal epilepsy in infants under 6 months of age]

Objective: To analyze the efficacy and safety of the sodium channel blockers (SCB) antiseizure medication in the treatment of focal epilepsy in infants under 6 months of age. Methods: This was a case series study. Infants with focal epilepsy with onset within 6 months of age and treated with SCB attending the Department of Neurology of Beijing Children's Hospital from June 2016 to April 2022 were collected. The clinical data, auxiliary examinations, SCB application, efficacy, adverse reactions, and prognosis were analyzed retrospectively. Patients were grouped according to type of seizure and epileptic syndrome, age of onset and etiology. Chi square test and Fisher exact test were used to analyze the differences between groups statistically. Results: A total of 118 infants were enrolled, 65 males and 53 females, with an age of epilepsy onset of 56 (4, 114) days. Developmental and epileptic encephalopathy was diagnosed in 60 infants, 39 had self-limited neonatal and (or) infantile epilepsy, and 19 had non-syndromic focal epilepsy. Application of SCB: 106 used oxcarbazepine, 2 used lacosamide, 9 switched from oxcarbazepine to lacosamide or a combination of 2 SCB, and 1 used oxcarbazepine, lacosamide, and lamotrigine successively; oxcarbazepine was the first choice in 46 cases. The age at which SCB was applied was 103 (53, 144) days. The children were followed up for 6 months to 6 years. SCB was effective in 89 cases (75.4%), including 70 cases (59.3%) who achieved seizure freedom. The seizure-free rate was higher in the focal epilepsy only group than in the group with other seizure types (64.4% (65/101) vs. 4/17, χ²=9.99, P<0.05). The responder and seizure-free rates were all higher in the group with the onset age of >3-6 months than the group >1-3 months (84.4% (38/45) vs. 62.5% (20/32), 73.3% (33/45) vs. 46.9% (15/32), χ²=4.85 and 5.58, both P<0.05). With the exception of variants in the PRRT2 gene, those with variants in sodium or potassium channels had higher responder and seizure-free rates than those with variants in other genes(86.2% (25/29) vs. 45.5% (10/22), 62.1% (18/29) vs. 22.7% (5/22), χ²=9.65 and 7.82,both P<0.05). The most common adverse event was transient hyponatremia, which happened in 66 cases (55.9%). There were 9 cases of rash, which subsided in 6 cases after discontinuing oxcarbazepine and switching to lacosamide, and 7 cases of electrocardiogram abnormalities, which improved after withdrawing oxcarbazepine and changing to lacosamide in 1 case. Conclusion: SCB are effective and tolerable in the treatment of focal epilepsy in infants under 6 months of age, with better efficacy in patients with genetic variants of the sodium or potassium channel, focal seizures only, and seizure onset >3-6 months of age.

Pharmacokinetics and Bioequivalence of Abiraterone Acetate Tablets in Healthy Chinese Volunteers: An Open, Randomized, Single-Dose, Three-Period, Three-Sequence Crossover Study

BACKGROUND AND OBJECTIVE

Abiraterone acetate tablet is an inhibitor of androgen synthesis, primarily for the treatment of metastatic castration-resistant prostate cancer (mCRPC). This study evaluated the bioequivalence and pharmacokinetics of the reference and test formulations of abiraterone acetate tablets in healthy Chinese volunteers.

METHODS

A single-center, open, single-dose, randomized, three-period, three-sequence, semi-repeat (only repeated reference formulations), and reference formulation-corrected fasting reference-scaled average bioequivalence test was conducted in 36 healthy volunteers included in this study. Volunteers were randomly assigned to one of three groups in a 1:1:1 ratio. There was a minimum 7-day washout period between each dose. Blood samples were collected at prescribed time intervals, the plasma concentration of abiraterone acetate tablets was determined by liquid chromatography-tandem mass spectrometry, and adverse events were recorded.

RESULTS

Under fasting conditions, the maximum plasma concentration (C_max) was 27.02 ± 14.21 ng/mL, area under the concentration-time curve from time zero to time t (AUC_t) was 125.30 ± 82.41 h·ng/mL, and AUC from time zero to infinity (AUC_∞) was 133.70 ± 83.99 h·ng/mL. The 90% confidence intervals (CIs) of the geometric mean ratio (GMR) of AUC_t and AUC_∞ were in the range of 0.8000-1.2500, and the coefficient of variation (CV_WR) of C_max was more than 30%. The Critbound result was - 0.0522, and the GMR was between 0.8000 and 1.2500.

CONCLUSION

Both test and reference formulations of abiraterone acetate tablets were bioequivalent in healthy Chinese subjects under fasting conditions.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04863105, registered 26 April 2021-retrospectively registered ( https://register.

CLINICALTRIALS

gov/prs/app/action/SelectProtocol?sid=S000ARAA&selectaction=Edit&uid=U00050YQ&ts=2&cx=-vbtjri.

[Pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies]

Objective: To investigate the pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies. Methods: Sputum samples were collected from 967 patients with hematological malignancies and lower respiratory tract infections in Department of Hematology,the Second Hospital of Shanxi Medical University from January 2017 to July 2020. The pathogens and drug sensitivity reports were carried out by automatic bacterial identification instruments. WHONET 5.6 and SPSS 20.0 softwares were used for statistical analysis. Results: A total of 961 strains of pathogens were isolated, 516 (53.7%) pathogens were Gram-negative bacteria, mainly 118 strains of Klebsiella pneumonia (12.3%), 68 strains of Pseudomonas aeruginosa (7.1%), 67 strains of Acinetobacter baumannii (7.0%),52 strains of Stenotrophomonas maltophilia (5.4%), 43 strains of Escherichia coli (4.5%), and 42 strains of Enterbacter cloacae (4.4%). There were 171 (17.8%) strains of Gram-positive bacteria and 274 (28.5%) fungi. The drug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem were 22.1%-31.3%. Stenotrophomonas maltophilia was sensitive to levofloxacin, compound sulfamethoxazole and minocycline. The antimicrobial resistance rates of these three enterobacteria to carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam were low (<10%). The resistant Gram-positive bacteria to ticoplanin, vancomycin and linazolamide were not detected. Conclusion: The major pathogens related to lower respiratory tract infections in patients with hematological malignancies are gram-negative bacteria in our centre. Different pathogens appear different characteristics of antimicrobial resistance.

Pharmacokinetics and Bioequivalence of Cefprozil for Suspension and Granule Formulation in Healthy Chinese Volunteers: Two Single-Dose Crossover Studies

INTRODUCTION

Cefprozil, an oral second-generation semi-synthetic cephalosporin, possesses a broad spectrum of antimicrobial activity. A granule formulation has been developed to improve medication adherence of the patients. This study was conducted to assess the bioequivalence of the granule formulation to a dry suspension in healthy Chinese volunteers and estimate the pharmacokinetic (PK) profiles of cefprozil.

METHODS

An open-label, randomized, single-dose, two-period, two-group, crossover study was conducted in 60 healthy Chinese volunteers under fasted or fed conditions (30 volunteers for each condition) to assess the bioequivalence between two formulations of cefprozil. Blood samples were collected at specified time intervals, and the plasma concentrations of cis- and trans-cefprozil were determined by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. PK and bioavailability parameters were estimated via non-compartmental methods. Adverse events (AEs) were also recorded.

RESULTS

Under fasted conditions, the mean Cmax was (3534.70 ± 634.67) ng/ml, Tmax was (0.98 ± 0.25) h, t1/2 was (1.37 ± 0.13) h and AUC0-t was (9302.86 ± 1618.39) ng·h/ml, respectively, after a single dose of 125 mg cefprozil for suspension. Under fed conditions, the mean Cmax was (2438.80 ± 493.78) ng/ml, Tmax was (1.66 ± 0.76) h, t1/2 was (1.36 ± 0.24) h and AUC0-t was (9332.36 ± 1373.61) ng·h/ml, respectively. The PK parameters of the granule formulation of cefprozil were similar to those of the suspension. The 90% CI values of the GMRs of Cmax, AUC0-t and AUC0-∞ under both fasted and fed conditions were within the prespecified bioequivalence range (80.00-125.00%).

CONCLUSIONS

According to the criteria for bioequivalence, the test granule formulations of cefprozil and "Cefprozil for Suspension®" were determined to be bioequivalent whether under fasted or fed conditions by measurement of cis-, trans- and total cefprozil.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04414254.

[Clinical characteristics of patients with ankylosing spondylitis and inflammatory bowel disease]

Objective: To analyze the clinical characteristics of patients with ankylosing spondylitis (AS) with inflammation bowel disease (IBD). Methods: AS patients fulfilling the 1984 modified New York diagnostic criteria were recruited in Chinese AS Prospective Imaging Cohort (CASPIC) consecutively from April 2016 to June 2017 in Chinese People's Liberation Army General Hospital by using smart management system for spondyloarthritis (SpAMS). The diagnosis of IBD was confirmed by tissue pathology via ileocolonoscopy. Demographic, clinical and biochemical data were collected. Results: In total, 893 patients with AS were recruited with the mean age 30.8 years. The majority were men (739, 82.8%). There were 64 (7.2%) patients concomitant with IBD. The mean age [(34.5±7.5) years vs. (30.5±8.8) years, P<0.001] was older and the disease duration [(10.8±6.9) years vs. (8.1±5.9) years, P=0.001] was longer in patients with IBD than patients without. Compared with patients without IBD, patients with IBD had more frequent involvement of the cervical spine [(21.9% (14/64) vs. 10.5% (87/829), P=0.006) and thoracic spine [29.7% (19/64) vs. 12.3% (102/829), P<0.001]. Uveitis [28.1% (18/64) vs. 16.4% (136/829), P=0.017] and psoriasis [7.8% (5/64) vs. 2.3% (19/829), P=0.009] were also more common in patients concomitant with IBD. In addition, patients with IBD had significantly higher scores in BASDAI (3.3±2.1 vs. 2.4±1.8, P<0.001), BASFI [2.2 (1.0,3.3) vs. 1.1(0.2,2.4), P<0.001)] and ASAS HI (7.1±4.3 vs. 5.3±3.7, P= 0.001) than patients without IBD. Conclusions: Compared with patients without IBD, AS patients concomitant with IBD have more severe disease activity and organ dysfunction. Furthermore, the uveitis and psoriasis are more frequently accompanied in AS patients with IBD.

Genomic regions under selection in the feralization of the dingoes

Dingoes are wild canids living in Australia, originating from domestic dogs. They have lived isolated from both the wild and the domestic ancestor, making them a unique model for studying feralization. Here, we sequence the genomes of 10 dingoes and 2 New Guinea Singing Dogs. Phylogenetic and demographic analyses show that dingoes originate from dogs in southern East Asia, which migrated via Island Southeast Asia to reach Australia around 8300 years ago, and subsequently diverged into a genetically distinct population. Selection analysis identifies 50 positively selected genes enriched in digestion and metabolism, indicating a diet change during feralization of dingoes. Thirteen of these genes have shifted allele frequencies compared to dogs but not compared to wolves. Functional assays show that an A-to-G mutation in ARHGEF7 decreases the endogenous expression, suggesting behavioral adaptations related to the transitions in environment. Our results indicate that the feralization of the dingo induced positive selection on genomic regions correlated to neurodevelopment, metabolism and reproduction, in adaptation to a wild environment.

Recognizing basal cell carcinoma on smartphone-captured digital histopathology images with a deep neural network

BACKGROUND

Pioneering effort has been made to facilitate the recognition of pathology in malignancies based on whole-slide images (WSIs) through deep learning approaches. It remains unclear whether we can accurately detect and locate basal cell carcinoma (BCC) using smartphone-captured images.

OBJECTIVES

To develop deep neural network frameworks for accurate BCC recognition and segmentation based on smartphone-captured microscopic ocular images (MOIs).

METHODS

We collected a total of 8046 MOIs, 6610 of which had binary classification labels and the other 1436 had pixelwise annotations. Meanwhile, 128 WSIs were collected for comparison. Two deep learning frameworks were created. The 'cascade' framework had a classification model for identifying hard cases (images with low prediction confidence) and a segmentation model for further in-depth analysis of the hard cases. The 'segmentation' framework directly segmented and classified all images. Sensitivity, specificity and area under the curve (AUC) were used to evaluate the overall performance of BCC recognition.

RESULTS

The MOI- and WSI-based models achieved comparable AUCs around 0·95. The 'cascade' framework achieved 0·93 sensitivity and 0·91 specificity. The 'segmentation' framework was more accurate but required more computational resources, achieving 0·97 sensitivity, 0·94 specificity and 0·987 AUC. The runtime of the 'segmentation' framework was 15·3 ± 3·9 s per image, whereas the 'cascade' framework took 4·1 ± 1·4 s. Additionally, the 'segmentation' framework achieved 0·863 mean intersection over union.

CONCLUSIONS

Based on the accessible MOIs via smartphone photography, we developed two deep learning frameworks for recognizing BCC pathology with high sensitivity and specificity. This work opens a new avenue for automatic BCC diagnosis in different clinical scenarios. What's already known about this topic? The diagnosis of basal cell carcinoma (BCC) is labour intensive due to the large number of images to be examined, especially when consecutive slide reading is needed in Mohs surgery. Deep learning approaches have demonstrated promising results on pathological image-related diagnostic tasks. Previous studies have focused on whole-slide images (WSIs) and leveraged classification on image patches for detecting and localizing breast cancer metastases. What does this study add? Instead of WSIs, microscopic ocular images (MOIs) photographed from microscope eyepieces using smartphone cameras were used to develop neural network models for recognizing BCC automatically. The MOI- and WSI-based models achieved comparable areas under the curve around 0·95. Two deep learning frameworks for recognizing BCC pathology were developed with high sensitivity and specificity. Recognizing BCC through a smartphone could be considered a future clinical choice.

[Comparison of clinical manifestations according to HLA-B(27) genotype in ankylosing spondylitis patients: real-world evidence from smart management system for spondyloarthritis]

Objective: The aim of this study was to set up a large, longitudinal and prospective database to compare the clinical manifestations in human leucocyte antigen (HLA)-B(27) positive and negative patients with ankylosing spondylitis(AS) based on real-world evidence in Chinese population. Methods: A total of 897 outpatients with confirmed AS were recruited consecutively by smart management system for spondyloarthritis (SMSP) from April 13, 2016 to June 6, 2017 in Chinese PLA General Hospital from 30 provinces and autonomous regions. 801 patients with HLA-B(27) data were included in the analysis. Demographic and clinical parameters including Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), ankylosing spondylitis disease activity score (ASDAS), arthritis, enthesitis, Bath ankylosing spondylitis metrology index (BASMI), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were compared between HLA-B(27) positive and negative groups. Results: A total of 801 patients were included in the analysis with an average age of (30.7±8.8) years. There were 659 males and 142 females and HLA-B(27) was present in 88.0%(705/801). Males were significantly more in HLA-B(27) positive patients [83.3%(587/705) vs. 75.0%(72/96); P=0.047].The average age at disease onset was (22.3±7.6)years in HLA-B(27) positive patients and (24.4±8.7) years in HLA-B(2)7 negative ones (P=0.028).There was significant difference in diagnose delay between two groups [14.3(2.5,43.6)months in HLA-B(27) positive patients vs. 20.3(5.0,67.4) months in HLA-B(27) negative ones, P=0.041]. Anterior uveitis was found to be significantly more common in HLA-B(27) positive patients [18.9% (133/705)vs.7.3%(7/96),P=0.005], and knee involvement less common in HLA-B(27) positive patients [4.0%(27/682) vs.10.0%(9/90), P=0.010], conversely. CRP[6.5(3.0, 16.4)mg/L vs. 3.5(1.6, 12.3)mg/L] and ESR[11.0(4.0, 24.0)mm/1h vs. 7.0(3.0, 16.0)mm/1h] were significantly higher in HLA-B(27) positive patients(P=0.005,0.013, respectively).But no differences in BASDAI,ASDAS,BASFI and BASMI were obtained between two groups. Conclusions: HLA-B(27) positive patients had a higher proportion of males, a younger age of onset and a greater risk for occurrence of anterior uveitis, suggesting a poorer prognosis.

The geographical distribution of grey wolves (Canis lupus) in China: a systematic review

The grey wolf (Canis lupus) is one of the most widely distributed terrestrial mammals, and its distribution and ecology in Europe and North America are largely well described. However, the distribution of grey wolf in southern China is still highly controversial. Several well-known western literatures stated that there are no grey wolves in southern China, while the presence of grey wolf across China has been indicated in A Guide to the Mammals of China, published by Princeton University Press. It is essential to solve this discrepancy since dogs may have originated from grey wolfs in southern China. Therefore, we systematically investigated Chinese literatures about wild animal surveys and identified more than 100 articles and books that included information of the distribution of grey wolves in China. We also surveyed the collections of three Chinese natural museums and found 26 grey wolf skins specimens collected across China. Moreover, we investigated the fossil records of wolf in China and identified 25 archaeological sites with wolf remains including south China. In conclusion, with the comprehensive summary of Chinese literatures, museum specimens and fossil records, we demonstrate that grey wolves does distribute across all parts of the Chinese mainland, including the most southern parts of China.

[Dynamin-1-related infantile spasms: a case report and review of literature]

Objective: To analyze the clinical and gene mutation characteristics of dynamin-1 (DNM1)-related infantile spasms. Method: Clinical, laboratory and genetic data of one case of DNM1-related infantile spasms diagnosed by Xiangya Hospital in September 2015 were analyzed.Through taking "Dynamin-1" "DNM1" as key words to search at CNKI, Wanfang, PubMed and OMIM to date (April 2016), the clinical characteristics of 9 reported cases of DNM1-related epileptic encephalopathy in international literature with our case were reviewed. Result: The boy is the second child of healthy and nonconsanguineous parents.At 7 months, he started to have seizures with head dropping, and he was brought for the first time to our hospital at the age of 17 months.The patient presented with severe psychomotor retardation, epilepsy, muscular hypotonia, and electroencephalography showed hypsarhythmia.He received 28 days of adrenocorticotropic hormone (ACTH) therapy.After that, his seizures were improved with valproic acid and levetiracetam, and disappeared between 3 years and 5 months to 5 years and 5 months of age on treatment with valproic acid only.Exome-sequencing study (trios) identified novel heterozygous mutation c. 443A>G (p.Glu148Arg) in DNM1. Up to now, 9 cases of epileptic encephalopathy (infantile spasms or Lennox-Gastaut syndrome) associated with de novo DNM1 gene mutations have been reported. Conclusion: The main clinical features of DNM1 mutations include intractable seizures, intellectual disability, developmental delay, hypotonia, and developmental delay before the onset of seizures.

Mitochondrial DNA sequence variation in Iranian native dogs

The dog mtDNA diversity picture from wide geographical sampling but from a small number of individuals per region or breed, displayed little geographical correlation and high degree of haplotype sharing between very distant breeds. For a clear picture, we extensively surveyed Iranian native dogs (n = 305) in comparison with published European (n = 443) and Southwest Asian (n = 195) dogs. Twelve haplotypes related to haplogroups A, B and C were shared by Iranian, European, Southwest Asian and East Asian dogs. In Iran, haplotype and nucleotide diversities were highest in east, southeast and northwest populations while western population had the least. Sarabi and Saluki dog populations can be assigned into haplogroups A, B, C and D; Qahderijani and Kurdi to haplogroups A, B and C, Torkaman to haplogroups A, B and D while Sangsari and Fendo into haplogroups A and B, respectively. Evaluation of population differentiation using pairwise F_ST generally revealed no clear population structure in most Iranian dog populations. The genetic signal of a recent demographic expansion was detected in East and Southeast populations. Further, in accordance with previous studies on dog-wolf hybridization for haplogroup d2 origin, the highest number of d2 haplotypes in Iranian dog as compared to other areas of Mediterranean basin suggests Iran as the probable center of its origin. Historical evidence showed that Silk Road linked Iran to countries in South East Asia and other parts of the world, which might have probably influenced effective gene flow within Iran and these regions. The medium nucleotide diversity observed in Iranian dog calls for utilization of appropriate management techniques in increasing effective population size.

Analysing codon usage bias of cyprinid herpesvirus 3 and adaptation of this virus to the hosts

The codon usage patterns of open reading frames (ORFs) in cyprinid herpesvirus 3 (CyHV-3) have been investigated in this study. The high correlation between GC12 % and GC3 % suggests that mutational pressure rather than natural selection is the main factor that determines the codon usage and base component in the CyHV-3, while mutational pressure effect results from the high correlation between GC3 % and the first principal axis of principle component analysis (Axis 1) on the relative synonymous codon usage (RSCU) value of the viral functional genes. However, the interaction between the absolute codon usage bias and GC3 % suggests that other selections take part in the formation of codon usage, except for the mutational pressure. It is noted that the similarity degree of codon usage between the CyHV-3 and goldfish, Carassius auratus (L.), is higher than that between the virus and common carp, Cyprinus carpio L., suggesting that the goldfish plays a more important role than the common carp in codon usage pattern of the CyHV-3. The study of codon usage in CyHV-3 can provide some evidence about the molecular evolution of the virus. It can also enrich our understanding about the relationship between the CyHV-3 and its hosts by analysing their codon usage patterns.

Characterization of an acid phosphatase responsible for hydrolysis of pyridoxal 5'-phosphate in tobacco plants

Pyridoxal 5'-phosphate (PLP), the active form of vitamin B(6), is an important cofactor for many enzymatic reactions. PLP is also a very reactive molecule, and the hydrolysis of PLP is crucial for controlling intracellular PLP concentrations. However, little is known about the enzymatic hydrolysis of PLP in plants. In this study, a novel acid phosphatase was purified from tobacco leaves and characterized by using PLP as a substrate. This phosphatase was purified 180-fold with a yield of 28% by ammonium sulfate precipitation and chromatography on DEAE-Sepharose FF, Sephadex G-100 and SP Sephadex C-25. Our data revealed that the purified enzyme was a dimer with a molecular mass of approximately 50 kDa. The purified phosphatase had maximum catalytic activity at pH 5.5, and displayed optimal activity at 50 °C. The enzyme required divalent metal ion for activity, and Mg(2+), among a few tested cations, was the most effective for catalysis under saturating substrate concentrations. The activity of the purified phosphatase was inhibited by molybdate, fluoride and EDTA, but was not inhibited by levamisole and tartrate. The phosphatase hydrolyzed a broad range of substrates at different rates, and the hydrolysis of PLP was competitively inhibited by ATP, pNPP, and by the reaction products, PL and inorganic phosphate. The phosphatase had a Km of 0.24 mM and a Vmax of 2.76 μmol/min/mg with PLP. When pyridoxamine 5'-phosphate or pyridoxine 5'-phosphate was tested as a substrate, the phosphatase activity was reduced by 50%. Our study suggests that the enzyme is a nonspecific acid phosphatase responsible for hydrolysis of all three phosphorylated B(6) vitamers in tobacco plants.

Characterization of Bacterial Susceptibility Isolates in Sixteen Dairy Farms in Taiwan

Bacteria were isolated from dairy cows, dairy farm environments, and dairy workers in 2 geographically different areas of eastern and northern Taiwan. Isolates were evaluated for antimicrobial susceptibility and the phylogenetics of isolated Escherichia coli O157:H7 were characterized. A total of 1,346 bacteria were identified, including 226 E. coli, 30 Pseudomonas spp. (7 Pseudomonas aeruginosa), 259 other gram-negative bacteria, 271 Enterococcus spp., 314 Staphylococcus spp., 195 Streptococcus spp., and 51 other gram-positive bacteria. Among them, 88% (1,184/1,346) of the isolates were resistant to sulfadimethoxine. The percentages of gram-negative bacteria resistant to oxy-tetracycline and streptomycin were 48% (249/515) and 78% (404/515), respectively. Gram-positive bacteria isolated from eastern Taiwan, the least polluted region of Taiwan, were found to have greater antimicrobial resistance than those isolated from northern Taiwan. Two E. coli O157:H7 from 2 different geographical areas were isolated. Both were vt2-positive but vt1-negative and had phylogenetic similarities of 82 and 67%, respectively, compared with previous isolates. Information on antimicrobial susceptibility revealed from this dairy farm survey may serve as a baseline for future studies and may also highlight the need to formulate better regulation strategies for the safe use of antimicrobials on food-producing farms.

[Bepridil inhibition on the delayed rectifier K+ currents in thyroxine induced hypertrophied guinea pig ventricular myocytes]

AIM

To study the effects of bepridil on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current and the inward rectifier potassium current (IK1) in hypertrophied guinea pig ventricular myocytes.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

In hypertrophied guinea pig ventricular myocytes, bepridil 30 mumol.L-1 markedly inhibited IKr and IKs (by 20.9% and 27.2% at 0 mV and mV, respectively). The effect of bepridil on IKs was larger than on IKr. Bepridil 30 mumol.L-1 also significantly inhibited the inward component of IK1 (by 15.1% at +100 mV), but the reverse potential of IK1 was unaffected. Bepridil (1-100 mumol.L-1) was shown to inhibit IKr and IKs in a concentration-dependent manner. Their IC50 were 46.7 mumol.L-1 and 23.8 mumol.L-1, respectively.

CONCLUSION

Bepridil inhibit IKr, IKs and IK1 in hypertrophied guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.

Identification of a mouse brain beta-spectrin cDNA and distribution of its mRNA in adult tissues

A mouse brain beta-spectrin of cDNA was identified within a lambda Gt11 expression library using an antibody which specifically binds with the 235 kDa spectrin beta-subunit. Restriction mapping and DNA sequencing analyses of the brain cDNA revealed that this clone contained 1185 bp of sequence, of which a 999 bp single open reading frame encoding 333 amino acids was determined. The deduced amino acid sequence exhibited homology with beta-spectrins, demonstrating the characteristic 106 amino acid repeating unit. The homology between our mouse brain sequence and human RBC beta-spectrin was approximately 56% beginning at the beta 15 repeat unit and extending to the C-terminus of sequence elucidated for human RBC sequence. An additional 62 amino acids were found at the C-terminus of the 235 kDa brain beta-spectrin subunit not seen in the human RBC sequence. The approximately 1.2 Kb brain spectrin cDNA insert hybridized with a single 9 Kb mRNA transcript in various adult mouse tissues, with the most abundant hybridization demonstrated in RNA isolated from brain tissue. This mRNA was found to be present at high levels in heart tissue and at lower levels in spleen and skeletal muscle tissue. The 9 Kb mRNA was different in content and in size to mRNAs which hybridized with a cDNA encoding the mouse erythroid beta-spectrin subunit, demonstrating that the brain spectrin cDNA is a distinct gene product and represents the first known sequence of a nonerythroid beta-spectrin subunit.

Automatic end-expiratory air sampling device for breath hydrogen test in infants

An automatic electronically operated end-expiratory air sampler has been developed for use in small infants. Upon expiration, which is detected by a hot-wire sensor, a small portion of the end-expiratory air is automatically collected into a syringe mounted on a syringe driver. The sampler obtained 87% of the end-expiratory air sample. Additionally, highly reproducible and consistent results were obtained for the respiratory gases (O2, N2, CO2). The sampler has been applied for studying breath hydrogen excretion to detect lactose malabsorption. It may also be applicable to study other expiratory gases in infants.

[Interaction of component (E) with tumor cellular DNA]

Some antitumor activities of component (E), extracted from the root of Fagopynum Cymosum (TreV) meisn (FCTM), have recently been discovered in vitro and in vivo. The component (E)'s pattern of action with tumor cellular DNA at the molecular pharmacological level was investigated by macromolecular synthesis experiment (MSE) and human DNA interaction HDI system established in our laboratory. The experiments demonstrated that, in vitro, the agent could markedly inhibit incorporation of H3-TdR into the cellular DNA, and the IC50 in P388 and SGC-7901 was 17.86 micrograms/ml and 110.4 micrograms/ml, respectively. The agent, at level of mg/ml, could produce an intercalation reversion pattern with DNA within a short time (2 hours). But when the interval was prolonged for over 4 hours, the pattern of action changed to intercalation irreversible pattern. According to these observations, the authors infer that component (E) interacts with DNA in two ways-directly and indirectly. The indirect action, especially in low concentrations, probably plays the major role. The authors have also compared the interaction of component (E) with those of components (CD1) and (CB3) extracted from FCTM by the same method and found that component (E) is the most active agent against the DNA of cancer cells among the extracts from FCTM.

Pseudo-on-line fast response microvessel dimensions video graphic recorder with electrical signal output

The present article describes a new method of microvessel dimensions measurement in which a writing oscilloscope is used to continuously and graphically record the microvessel video signal from television microscopy at a fast rate of 50 records per second. Dimensions of interest, such as the microvessel red blood cell flux diameter, are then easily marked out manually from the graphic records and a dynamic electrical signal proportional to the dimensions is generated. The signal is then recorded on one channel of a multichannel voltage recorder and is synchronised with other experimental signals which have previously been recorded on-line during the experiment. The result is that the dimension signal appears to have been recorded on-line during the experiment as well. This is desirable for electronic signal correlation and processing. This method is useful when poor experimental conditions, commonly encountered, make automatic recording of microvessel dimension unsatisfactory and manual inspection and processing become necessary.