Prognostic value of multiphase CT angiography: estimated infarct core volume in the patients with acute ischaemic stroke after mechanical thrombectomy.

BACKGROUND AND PURPOSE: Recent studies reported the feasibility of quantifying a reliable infarct core (IC) volume using multiphase computed tomography (mCTA) based on deep learning, however its prognostic value was not fully clarified. Therefore, we aimed to evaluate the prognostic value of mCTA-estimated IC volume in patients with acute ischemic stroke (AIS) after mechanical thrombectomy (MT). MATERIALS AND METHODS: We retrospectively reviewed patients who underwent mCTA and MT for large vessel occlusion in middle cerebral artery and (or) internal carotid artery within 6 hours after symptom onset between January 2018 and November 2019. Patients were dichotomized into good (modified Rankin Scale [mRS] score, 0-2) and poor (mRS, 3-6) outcome groups. mCTA-estimated IC volume were generated based on a multi-scale three-dimensional convolutional neural network. Univariate, multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were used to identify the independent variables, and evaluate their performances in predicting the clinical outcome. RESULTS: Of 44 included patients, 27 (61.4%) patients achieved good outcome. National Institutes of Health Stroke Scale scores at admission [NIHSSpre] (odds ratio [OR], 1.191; 95%confidence interval [CI], 1.028-1.379; P=0.020) and mCTA-estimated IC volume (OR, 1.076; 95%CI, 1.016-1.140; P=0.013) were found to be independently associated with functional outcome in patients with AIS after MT. After integrating NIHSSpre and mCTA-estimated IC volume, optimal performance (area under the ROC curve, 0.874; 95%CI, 0.739-0.954) could be obtained in predicting the clinical outcome. CONCLUSIONS: mCTA-estimated IC volume might be promising for predicting the prognosis, and assisting in making individualized treatment decision in patients with AIS.

Endovascular treatment for acute ischaemic stroke caused by isolated internal carotid artery occlusion: treatment strategies, outcomes, and prognostic factors.

AIM: To describe the experience of endovascular treatment (EVT) of acute ischaemic stroke caused by isolated internal carotid artery (ICA) occlusion, with emphasis on treatment strategies, outcomes, and prognostic factors. MATERIALS AND METHODS: A retrospective examination was performed of 66 consecutive patients with acute moderate-to-severe stroke who underwent EVT for isolated ICA occlusion from July 2016 to June 2021. The modified thrombolysis in cerebral ischaemia (mTICI) score was used to evaluate reperfusion outcomes. A multivariate analysis was performed to identify risk factors associated with poor 90-day outcome (modified Rankin Scale [mRS] 3-6). RESULTS: The National Institutes of Health Stroke Scale (NIHSS) median score of the 66 patients at admission was 15. Twelve patients (18.2%) showed thrombus migration to the M1 segment or proximal M2 during EVT and underwent additional intracranial thrombectomy. Successful reperfusion (mTICI 2b-3) was achieved in 60 patients (90.9%) and complete reperfusion (mTICI 3) in 42 (63.6%). A poor functional outcome was seen in 27 patients (40.9%). The rate of 90-day mortality was 9.1% (6/66). Higher NIHSS scores and a lower Alberta Stroke Program Early CT Score (ASPECTS) were independently associated with poor outcomes. Complete reperfusion was the only treatment factor with a significant predictive value (adjusted odds ratio [OR] 0.03; 95% CI = 0.01 to 0.25; p=0.001). CONCLUSION: Endovascular therapy is safe and effective in patients with acute ischaemic stroke due to isolated ICA occlusion. Prevention of thrombus migration and complete reperfusion should be the aim of EVT.

Association between Infarct Location and Hemorrhagic Transformation of Acute Ischemic Stroke following Successful Recanalization after Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: The association between infarct location and hemorrhagic transformation of acute ischemic stroke after mechanical thrombectomy is not understood. We aimed to evaluate the association between CTP-based ischemic core variables at admission and hemorrhagic transformation after a successful thrombectomy. MATERIALS AND METHODS: We retrospectively analyzed patients who underwent endovascular thrombectomy for acute anterior circulation large-vessel occlusion between October 2019 and June 2021. We enrolled 146 patients with visible ischemic core on pretreatment CTP who had successful reperfusion. The ischemic core infarct territories were classified into the cortical and subcortical areas and then qualitatively and quantitatively analyzed by CTP. Logistic regression and receiver operating characteristic curve analyses were performed to determine the association between ischemic core variables and hemorrhagic transformation. RESULTS: Of the 146 patients analyzed, 72 (49.3%) had hemorrhagic transformation and 23 (15.8%) had symptomatic intracerebral hemorrhage. Multivariate analysis showed that subcortical infarcts were independently associated with hemorrhagic transformation (OR, 8.06; 95% CI, 2.31-28.10; P = .001) and subcortical infarct volume was independently linked to symptomatic intracerebral hemorrhage (OR, 1.05; 95% CI, 1.01-1.09; P = .039). The receiver operating characteristic curve indicated that subcortical infarcts can predict hemorrhagic transformation accurately (area under the curve = 0.755; 95% CI, 0.68-0.82; P < .001) and subcortical infarct volume can predict symptomatic intracerebral hemorrhage (area under the curve = 0.694; 95% CI, 0.61-0.77; P = .002). CONCLUSIONS: Subcortical infarcts seen on CTP at admission are associated with hemorrhagic transformation in patients after successful thrombectomy, and subcortical infarct volume may influence the risk of symptomatic intracerebral hemorrhage.

Simvastatin is beneficial to lung cancer progression by inducing METTL3-induced m6A modification on EZH2 mRNA.

OBJECTIVE: To elucidate the molecular mechanism of Simvastatin on inhibiting malignant progression of lung cancer. PATIENTS AND METHODS: Relative levels of METTL3 and EZH2 in lung cancer tissues and adjacent normal ones were detected by quantitative real-time polymerase chain reaction (qRT-PCR). In addition, their levels in lung cancer patients with different pathological stages were determined as well. A549 cells were induced with different doses of Simvastatin for 24 h. Subsequently, relative levels of METTL3 and EZH2 in cells were detected. Proliferative and metastatic abilities in A549 cells were examined by cell counting kit-8 (CCK-8), 5-Ethynyl-2'- deoxyuridine (EdU) and transwell assay, respectively. RIP assay was conducted to detect the presence of m6A modification on EZH2 mRNA and the interaction between IGF2BP2 and EZH2. Relative levels of EZH2 and epithelial-mesenchymal transition (EMT)-associated genes (E-cadherin and N-cadherin), and metastatic abilities were detected in Simvastatin-induced A549 cells transfected with pcDNA-METTL3. RESULTS: METTL3 and EZH2 levels were upregulated in lung cancer tissues, which were higher in advanced stage lung cancer patients. Their levels, as well as cell proliferative and metastatic abilities, were dose-dependently inhibited in Simvastatin-induced A549 cells. METTL3 positively regulated EZH2 level, and m6A modification on its mRNA. Moreover, the interaction between IGF2BP2 and EZH2 could be inhibited by knockdown of METTL3. Simvastatin could abolish the role of METTL3 in regulating relative levels of EZH2 and EMT-associated genes, as well as metastatic abilities in A549 cells. CONCLUSIONS: Simvastatin induces METTL3 down-regulation in lung cancer tissues, which further influences EMT via m6A modification on EZH2 mRNA and thus inhibits the malignant progression of lung cancer.

[Fornix reconstruction with conjunctival inclusion cyst marsupialization in severe symblepharon].

Objective: To report the efficacy of fornix reconstruction with conjunctival inclusion cyst marsupialization in severe symblepharon. Methods: Retrospective cases series study. Four patients (4 eyes) with Conjunctival Inclusion Cyst Marsupialization and severe Symblepharon during June 2016 to June 2018 at the PLA General Hospital were included. All of them were treated with Conjunctival Inclusion Cyst Marsupialization. The morphology, depth of the conjunctival sac and the degree of symblepharon before and after treatment were compared to observe the surgical results. Results: After operation, the conjunctival sacs were deepened, and the average depth was 4.75 mm. After follow-up, 2 cases of conjunctival sac were basically normal, and 2 cases of conjunctival sac became shallow, but still better than before surgery. Conclusions: For the patients with large Conjunctival Inclusion Cyst and severe symblepharon, the Conjunctival Inclusion Cyst Marsupialization have many positive effects of deepening conjunctival sac, relieving symblepharon, increasing the degree of eye movement, improving appearance and relieving dry eyes. At the same time, this operation can avoid recurrence due to incomplete cystectomy. (Chin J Ophthalmol, 2018, 54: 897-901).

A two-step method for identification of the Chinese glutinous rice Suyunuo, based on ISSR-SCAR and allele-specific markers.

Suyunuo is a valuable glutinous rice variety cultivated mainly in the Lake Taihu area of China. Historically, Suyunuo was presented to emperors as a tribute, and, still today, enjoys a great reputation in China. This study aimed to develop a unique, specific molecular marker for the identification of Suyunuo rice. Polymerase chain reaction (PCR) amplification of inter-simple sequence repeat (ISSR) molecular markers was performed on Suyunuo and 11 other glutinous rice varieties that are mainly cultivated in the Yangtze River Delta region. A Suyunuo-specific band was detected in the PCR products generated from primer ISSR-807. A sequence characterized amplified region (SCAR) primer pair targeting a Suyunuo-specific band was subsequently designed. The SCAR primers amplified a target band in all individuals of Suyunuo and in four glutinous indica varieties, whereas no bands were found in the seven glutinous japonica varieties. Subsequently, sequences amplified by the SCAR primer pair were analyzed to facilitate the design of Suyunuo allele-specific primers. The allele-specific primer pair produced target bands in all individuals of Suyunuo rice but no bands in individuals of any of the other 11 rice varieties. This study provides a theoretical guideline for rice germplasm identification and innovation of other valuable rice landraces.

Two-step identification of taro (Colocasia esculenta cv. Xinmaoyu) using specific psbE-petL and simple sequence repeat-sequence characterized amplified regions (SSR-SCAR) markers.

Colocasia esculenta cv. Xinmaoyu is an eddoe-type taro cultivar local to Taicang, Jiangsu Province, China; it is characterized by its pure flavor, glutinous texture, and high nutritional value. Due to its excellent qualities, the Trademark Office of the State Administration for Industry and Commerce of the People's Republic of China awarded Xinmaoyu, a geographical indication certification in 2014. Therefore, there is an urgent need to develop an efficient molecular marker for the specific identification of this cultivar, which would greatly facilitate the conservation and utilization of this unique germplasm resource. In the present study, amplifying the psbE-petL fragment from two dasheen-type and seven eddoe-type taro cultivars revealed three conserved insertions/deletions among sequences from the two taro types. Based on these sequence differences, a pair of site-specific primers was designed targeting the psbE-petL sequence from the dasheen-type taro, which specifically amplified a DNA band in all individuals from cultivars of this type, but not in those from the seven eddoe-type cultivars. To discriminate Xinmaoyu from the other eddoe-type taro cultivars, a pair of simple sequence repeat-sequence characterized amplified region (SSR-SCAR) primers was further developed to specifically amplify a DNA band from all Xinmaoyu individuals, but not from individuals of other eddoe-type taro cultivars. In conclusion, through a two-step-screening procedure using psbE-petL and SSR-SCAR markers, we developed a pair of primers that could specifically discriminate Xinmaoyu from nine taro cultivars commonly cultivated in Jiangsu Province and Fujian Province.

Analysis of genetic diversity of Brassica rapa var. chinensis using ISSR markers and development of SCAR marker specific for Fragrant Bok Choy, a product of geographic indication.

Non-heading Chinese cabbage [Brassica rapa var. chinensis (Linnaeus) Kitamura] is a popular vegetable and is also used as a medicinal plant in traditional Chinese medicine. Fragrant Bok Choy is a unique accession of non-heading Chinese cabbage and a product of geographic indication certified by the Ministry of Agriculture of China, which is noted for its rich aromatic flavor. However, transitional and overlapping morphological traits can make it difficult to distinguish this accession from other non-heading Chinese cabbages. This study aimed to develop a molecular method for efficient identification of Fragrant Bok Choy. Genetic diversity analysis, based on inter-simple sequence repeat molecular markers, was conducted for 11 non-heading Chinese cabbage accessions grown in the Yangtze River Delta region. Genetic similarity coefficients between the 11 accessions ranged from 0.5455 to 0.8961, and the genetic distance ranged from 0.0755 to 0.4475. Cluster analysis divided the 11 accessions into two major groups. The primer ISSR-840 amplified a fragment specific for Fragrant Bok Choy. A pair of specific sequence-characterized amplified region (SCAR) primers based on this fragment amplified a target band in Fragrant Bok Choy individuals, but no band was detected in individuals of other accessions. In conclusion, this study has developed an efficient strategy for authentication of Fragrant Bok Choy. The SCAR marker described here will facilitate the conservation and utilization of this unique non-heading Chinese cabbage germplasm resource.

Applying DNA barcodes for identification of economically important species in Brassicaceae.

Brassicaceae is a large plant family of special interest; it includes many economically important crops, herbs, and ornamentals, as well as model organisms. The taxonomy of the Brassicaceae has long been controversial because of the poorly delimited generic boundaries and artificially circumscribed tribes. Despite great effort to delimitate species and reconstruct the phylogeny of Brassicaceae, little research has been carried out to investigate the applicability and effectiveness of different DNA regions as barcodes - a recent aid for taxonomic identification - to identify economically important species in Brassicaceae. In this study, we evaluated the feasibility of five intensively recommended regions [rbcL, matK, trnH-psbA, internal transcribed spacer (ITS), ITS2] as candidate DNA barcodes to discriminate economic species of Brassicaceae in China and try to establish a new digital identification method for economic plants of Brassicaceae. All sequences of 58 samples from 27 economic species (Brassicaceae) in China were assessed in the success rates of PCR amplifications, intra- and inter-specific divergence, DNA barcoding gaps, and efficiency of identification. Compared with other markers, ITS showed superiority in species discrimination with an accurate identification of 67.2% at the species level. Consequently, as one of the most popular phylogenetic markers, our study indicated that ITS was a powerful but not perfect barcode for Brassicaceae identification. We further discuss the discrimination power of different loci due to inheritance pattern, polyploidization and hybridization in species-specific evolution. Further screening of other nuclear genes related to species isolation as plant barcode candidates is also proposed.

Transcriptomic analysis of Camellia ptilophylla and identification of genes associated with flavonoid and caffeine biosynthesis.

Camellia ptilophylla, or cocoa tea, is naturally decaffeinated and its predominant catechins and purine alkaloids are trans-catechins and theobromine Regular tea [Camellia sinensis (L.) O. Ktze.] is evolutionarily close to cocoa tea and produces cis-catechins and caffeine. Here, the transcriptome of C. ptilophylla was sequenced using the 101-bp paired-end technique. The quality of the raw data was assessed to yield 70,227,953 cleaned reads totaling 7.09 Gbp, which were assembled de novo into 56,695 unique transcripts and then clustered into 44,749 unigenes. In catechin biosynthesis, leucoanthocyanidin reductase (LAR) catalyzes the transition of leucoanthocyanidin to trans-catechins, while anthocyanidin synthase (ANS) and anthocyanidin reductase (ANR) catalyze cis-catechin production. Our data demonstrate that two LAR genes (CpLAR1 and CpLAR2) by C. ptilophylla may be advantageous due to the combined effects of this quantitative trait, permitting increased leucoanthocyanidin consumption for the synthesis of trans-catechins. In contrast, the only ANS gene observed in C. sinensis (CsANS) shared high identity (99.2%) to one homolog from C. ptilophylla (CpANS1), but lower identity (~80%) to another (CpANS2). We hypothesized that the diverged CpANS2 might have lost its ability to synthesize cis-catechins. C. ptilophylla and C. sinensis each contain two copies of ANR, which share high identity and may share the same function. Transcriptomic sequencing captured two N-methyl nucleosidase genes named NMT1 and NMT2. NMT2 was highly identical to three orthologous genes TCS2, PCS2, and ICS2, which did not undergo methylation in vitro; in contrast, NMT1 was less identical to TCS, PCS and ICS, indicating that NMT1 may undergo neofunctionalization.

Diode-pumped continuous wave and passively Q-switched Tm, Mg: LiTaO3 lasers.

We have demonstrated the continuous wave and passively Q-switched Tm, Mg: LiTaO3 lasers for the first time. In continuous wave (CW) regime, a maximum CW output power of 1.03 W at 1952 nm was obtained, giving a slope efficiency of 9.5% and a beam quality M2 = 2.2. In passive Q-switching regime, a single walled carbon nanotube (SWCNT) was employed as saturable absorber (SA). The Tm,Mg:LiTaO3 laser has yielded a pulse of 560 ns under repetition rate of 34.2 kHz at 1926 nm, corresponding to a single pulse energy of 10.1 µJ. The results indicate a promising potential of nonlinear crystals in the applications for laser host materials.

Isolation and characterization of polymorphic microsatellite loci from aerial yam (Dioscorea bulbifera L.).

Dioscorea bulbifera L. is widely distributed in pantropical regions along the equator. The taxonomic treatment of this species is ambiguous due to its extreme polymorphic morphological characters. In order to provide tools to facilitate the study of genetic diversity, population structure, patterns of gene flow, and the mating system of this species, and to assess intraspecific variability and relationships in D. bulbifera, 14 novel polymorphic microsatellite loci were developed using the dual-suppression PCR technique. The number of alleles per locus ranged from 4 to 17, with an average of 9.93. The mean observed heterozygosities were 0.7327 and 0.7223, and the mean Shannon-Wiener indices were 1.6431 and 1.811 in the Nanjing and Nanchong populations, respectively. All novel microsatellite loci showed high levels of polymorphism, indicating that these markers offer great potential significance and profound influence for future studies of this species.

The prevalence of carbapenemase genes and plasmid-mediated quinolone resistance determinants in carbapenem-resistant Enterobacteriaceae from five teaching hospitals in central China.

We investigated the prevalence of ß-lactamase genes and plasmid-mediated quinolone resistance (PMQR) determinants in 51 carbapenem-resistant Enterobacteriaceae (CRE) from five teaching hospitals in central China. The prevalence of carbapenem resistance in Enterobacteriaceae was 1·0% (51/5012). Of 51 CRE, 31 (60·8%) isolates were positive for one tested carbapenemase gene, while 10 (19·6%) were simultaneously positive for two tested carbapenemase genes. The positive rates of bla KPC-2, bla NDM-1, bla IMP-4, bla IMP-26 and bla IMP-8 were 54·9%, 17·6%, 11·8%, 11·8% and 3·9%, respectively. Of 10 CRE with two carbapenemase genes, three, five, one and one were positive for bla KPC-2 and bla IMP-4, bla KPC-2 and bla IMP-26, bla KPC-2 and bla IMP-8, and bla KPC-2 and bla NDM-1, respectively. Eight of nine bla NDM-1-positive isolates lacked carbapenemases by the modified Hodge test, while 27/28 isolates harbouring bla KPC-2 were positive for carbapenemases determined by this test; 41·2% of the CRE-positive isolates also harboured ESBL genes in various combinations (three and two positive for bla KPC-2 also carried bla DHA-1 and bla CMY-2). The positive rates of qnrS1, qnrA1, qnrB and aac-(6/)-Ib-cr in CRE were 25·5%, 9·8%, 23·5% and 15·7%, respectively. In particular, 7/9 isolates harbouring bla NDM-1 were positive for these quinolone resistance genes, of which five carried qnrS1 and two carried qnrS1 and qnrB4. All but two of 29 Klebsiella pneumoniae isolates were grouped into 20 clonal clusters by PFGE, with the predominant cluster accounting for four bla KPC-2-positive isolates distributed in the same hospital. We conclude that there is a high prevalence of bla NDM-1 and PMQR determinants in CRE isolates in central China. Multiple resistance determinants in various combinations co-exist in these strains and we report for the first time the co-existence of bla KPC-2 and bla IMP-26 in a strain of Klebsiella oxytoca.

DNA barcoding of populations of Fallopia multiflora, an indigenous herb in China.

Fallopia multiflora, locally known as Heshouwu, is one of the most important and widely used Chinese medicinal herbs. However, there is still considerable confusion concerning its different provenances. DNA barcoding is a recent aid to taxonomic identification and uses a short standardized DNA region to discriminate plant species. We assessed the applicability of 4 candidate DNA barcodes (matK, rbcL, psbA-trnH, and ITS2) to identify populations of F. multiflora. To our knowledge, this is the first attempt involving the plant kingdom to apply DNA barcoding at a level lower than species. Four DNA loci (matK, rbcL, psbA-trnH, and ITS2) of 105 samples, including the wild F. multiflora distributed in 17 provinces of China and 4 cultivated F. multiflora lines, were amplified by PCR and sequenced. The 4 loci were evaluated by PCR amplification for sequence quality, extent of genetic divergence, DNA barcoding gap, and the ability to discriminate between populations by BLAST1 and Nearest Distance. We found that psbA-trnH was the best barcode, with significant inter-population variability and best potential for identifying F. multiflora. The combination of loci gave better performance for distinguishing populations than a single locus. We recommend using matK + rbcL + psbA-trnH + ITS2 or psbA-trnH alone for this species. This research demonstrates the utility of DNA barcoding for geoherbalism identifications.

Development of polymorphic microsatellite markers for Dioscorea zingiberensis and cross-amplification in other Dioscorea species.

Dioscorea zingiberensis C.H. Wright (Dioscoreaceae) is an endemic species in central and southwestern China. In order to study the genetic diversity and population structure of this species, 19 novel polymorphic microsatellite loci were developed using a dual-suppression PCR technique. The number of alleles per locus ranged from 3 to 21, with an average of 9.53. All the markers showed high transferability in cross-species amplification in other species of sect. Stenophora.

B6.g7 mice reconstituted with BDC2·5 non-obese diabetic (BDC2·5NOD) stem cells do not develop autoimmune diabetes.

In BDC2·5 non-obese diabetic (BDC2·5NOD) mice, a spontaneous model of type 1 diabetes, CD4(+) T cells express a transgene-encoded T cell receptor (TCR) with reactivity against a pancreatic antigen, chromogranin. This leads to massive infiltration and destruction of the pancreatic islets and subsequent diabetes. When we reconstituted lethally irradiated, lymphocyte-deficient B6.g7 (I-A(g7+)) Rag(-/-) mice with BDC2·5NOD haematopoietic stem and progenitor cells (HSPC; ckit(+)Lin(-)Sca-1(hi)), the recipients exhibited hyperglycaemia and succumbed to diabetes. Surprisingly, lymphocyte-sufficient B6.g7 mice reconstituted with BDC2·5NOD HSPCs were protected from diabetes. In this study, we investigated the factors responsible for attenuation of diabetes in the B6.g7 recipients. Analysis of chimerism in the B6.g7 recipients showed that, although B cells and myeloid cells were 98% donor-derived, the CD4(+) T cell compartment contained ∼50% host-derived cells. These host-derived CD4(+) T cells were enriched for conventional regulatory T cells (Tregs ) (CD25(+) forkhead box protein 3 (FoxP3)(+)] and also for host- derived CD4(+)CD25(-)FoxP3(-) T cells that express markers of suppressive function, CD73, FR4 and CD39. Although negative selection did not eliminate donor-derived CD4(+) T cells in the B6.g7 recipients, these cells were functionally suppressed. Thus, host-derived CD4(+) T cells that emerge in mice following myeloablation exhibit a regulatory phenoytpe and probably attenuate autoimmune diabetes. These cells may provide new therapeutic strategies to suppress autoimmunity.

Polymorphisms of the myostatin gene (MSTN) and its relationship with growth traits in goat breeds.

Mutations in the myostatin (MSTN) gene can inactivate its expression and result in a non-functional protein, which leads to dramatic muscularity and a "double-muscling" phenomenon in many species. Using gene sequencing and polymerase chain reaction-single-strand conformation polymorphism methods, polymorphisms of the MSTN gene were investigated as a candidate marker for growth in 288 goats. The results showed 2 novel single nucleotide polymorphisms: DQ167575 g.197G>A and 345A>T. Three potential genotypes (AA, AB, and BB) of substitution 197G>A in the 5'-untranslated region were detected in the 2 breeds. The polymorphism (CC and CD) of substitution 345A>T in exon I was segregated. The genetic diversity analysis revealed that Boer goat and Anhui white goat possessed intermediate genetic diversity in the P1 and P3 loci. Significant associations between the genotypes of the P3 locus and body weight, body length, and body height were observed in Boer goat and Anhui white goat (P < 0.05). It could be inferred that the MSTN gene may be a major gene or linked to the major gene affecting the goat growth traits. The polymorphic site could be a molecular marker-assisted selection program for body weight.

Islet-enriched gene expression and glucose-induced insulin secretion in human and mouse islets.

AIMS/HYPOTHESIS: Our understanding of the transcription factors that control the development and function of rodent islet beta cells is advancing rapidly, yet less is known of the role they play in similar processes in human islets. METHODS: To characterise the abundance and regulation of key proteins involved in glucose-regulated insulin secretion in human islets, we examined the expression of MAFA, MAFB, GLUT2 (also known as SLC2A2), ßGK (also known as GCK) and PDX1 in isolated, highly purified human islets with an intact insulin secretory pattern. We also assessed these features in islets from two different mouse strains (C57BL/6J and FVB). RESULTS: Compared with mouse islets, human islets secreted more insulin at baseline glucose (5.6 mmol/l), but less upon stimulation with high glucose (16.7 mmol/l) or high glucose plus 3-isobutyl-1-methyl-xanthine. Human islets had relatively more MAFB than PDX1 mRNA, while mouse islets had relatively more Pdx1 than Mafb mRNA. However, v-maf musculoaponeurotic fibrosarcoma oncogene homologue (MAF) B protein was found in human islet alpha and beta cells. This is unusual as this regulator is only produced in islet alpha cells in adult mice. The expression of insulin, MAFA, ßGK and PDX1 was not glucose-regulated in human islets with an intact insulin secretory pattern. CONCLUSIONS/INTERPRETATION: Our results suggest that human islets have a distinctive distribution and function of key regulators of the glucose-stimulated insulin secretion pathway, emphasising the urgent need to understand the processes that regulate human islet beta cell function.

Association of sirtuin 1 (SIRT1) gene SNPs and transcript expression levels with severe obesity.

Recent studies have reported associations of sirtuin 1 (SIRT1) single nucleotide polymorphisms (SNPs) to both obesity and BMI. This study was designed to investigate association between SIRT1 SNPs, SIRT1 gene expression and obesity. Case-control analyses were performed using 1,533 obese subjects (896 adults, BMI >40 kg/m(2) and 637 children, BMI >97th percentile for age and sex) and 1,237 nonobese controls, all French Caucasians. Two SNPs (in high linkage disequilibrium (LD), r(2) = 0.96) were significantly associated with adult obesity, rs33957861 (P value = 0.003, odds ratio (OR) = 0.75, confidence interval (CI) = 0.61-0.92) and rs11599176 (P value: 0.006, OR = 0.74, CI = 0.61-0.90). Expression of SIRT1 mRNA was measured in BMI-discordant siblings from 154 Swedish families. Transcript expression was significantly correlated to BMI in the lean siblings (r(2) = 0.13, P value = 3.36 × 10(-7)) and lower SIRT1 expression was associated with obesity (P value = 1.56 × 10(-35)). There was also an association between four SNPs (rs11599176, rs12413112, rs33957861, and rs35689145) and BMI (P values: 4 × 10(-4), 6 × 10(-4), 4 × 10(-4), and 2 × 10(-3)) with the rare allele associated with a lower BMI. However, no SNP was associated with SIRT1 transcript expression level. In summary, both SNPs and SIRT1 gene expression are associated with severe obesity.

Role of multidetector-row computed tomography in evaluation of living renal donors.

OBJECTIVES: To assess the value of multidetector-row computed tomography (MDCT) in evaluation of the anatomy of living kidney donors and to reveal the prevalence of renal vascular variations in a Chinese population. PATIENTS AND METHODS: One hundred four potential donors underwent MDCT, and the data sets were postprocessed for reformatted images using maximum intensity projection, a volume-rendering technique, and multiplanar re-formation. Nephrectomy was performed in 97 donors, which enabled correlation of MDCT evaluation with the actual anatomy at surgery as the standard of reference. RESULTS: The MDCT images accurately demonstrated the anatomical structure of the main renal arteries and veins and the upper part of the ureters. The prevalence of accessory arteries was 41.7% (43 of 103), and of early branching was 12.6% (13 of 103). Compared with findings during surgery, the detection rate of accessory arteries on MDCT images was 91.3% (21 of 23), of larger accessory arteries (>1.5 mm in diameter) was 100%, and of early branching was 100%. CONCLUSION: Multidetector-row computed tomography is helpful in accurately evaluating the renal anatomy of potential donors, thus facilitating planning of surgery.