Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

High species diversity in Diaporthe associated with citrus diseases in China

Species in Diaporthe have broad host ranges and cosmopolitan geographic distributions, occurring as endophytes, saprobes and plant pathogens. Previous studies have indicated that many Diaporthe species are associated with Citrus. To further determine the diversity of Diaporthe species associated with citrus diseases in China, we conducted extensive surveys in major citrus-producing areas from 2017-2020. Diseased tissues were collected from leaves, fruits, twigs, branches and trunks showing a range of symptoms including melanose, dieback, gummosis, wood decay and canker. Based on phylogenetic comparisons of DNA sequences of the internal transcribed spacer regions (ITS), calmodulin (cal), histone H3 (his3), translation elongation factor 1-alpha (tef1) and beta-tubulin (tub2), 393 isolates from 10 provinces were identified as belonging to 36 species of Diaporthe, including 32 known species, namely D. apiculata, D. biconispora, D. biguttulata, D. caryae, D. citri, D. citriasiana, D. compacta, D. discoidispora, D. endophytica, D. eres, D. fusicola, D. fulvicolor, D. guangxiensis, D. hongkongensis, D. hubeiensis, D. limonicola, D. litchii, D. novem, D. passifloricola, D. penetriteum, D. pescicola, D. pometiae, D. sackstonii, D. sennicola, D. sojae, D. spinosa, D. subclavata, D. tectonae, D. tibetensis, D. unshiuensis, D. velutina and D. xishuangbanica, and four new species, namely D. gammata, D. jishouensis, D. ruiliensis and D. sexualispora. Among the 32 known species, 14 are reported for the first time on Citrus, and two are newly reported from China. Among the 36 species, D. citri was the dominant species as exemplified by its high frequency of isolation and virulence. Pathogenicity tests indicated that most Diaporthe species obtained in this study were weakly aggressive or non-pathogenic to the tested citrus varieties. Only D. citri produced the longest lesion lengths on citrus shoots and induced melanose on citrus leaves. These results further demonstrated that a rich diversity of Diaporthe species occupy Citrus, but only a few species are harmful and D. citri is the main pathogen for Citrus in China. The present study provides a basis from which targeted monitoring, prevention and control measures can be developed. Citation: Xiao XE, Liu YD, Zheng F, et al. 2023. High species diversity in Diaporthe associated with citrus diseases in China. Persoonia 51: 229-256. doi: 10.3767/persoonia.2023.51.06.

Resilience Factors Preventing Schizophrenia in Ultra-high Risk Patients: Lessons from Genetics

Over the past decades, researchers and psychiatrists in the field of psychosis have moved from a conception of a chronic presentation to a more dynamic paradigm. Accordingly, schizophrenia is now conceptualized as a progressive illness that typically emerges during late adolescence and follows different stages: early vulnerability, ultra-high risk state, first episode of psychosis, and chronic disease. Only one-quarter of the ultra-high risk patients will convert to a full-blown psychotic episode within 3 years while the others, called non-converters, will remain at-risk, develop other psychiatric disorders, or fully recover. The reasons for this differential outcome are not yet understood but this concept opens the way to scientific research to determine the protective factors involved in resilience for non-converters. Based on the Gene X Environment interaction model, schizophrenia results from genetic vulnerability and environmental aggressions which can have an impact on the epigenome and gene expression. Recent studies have shown that genetic variants play a role in the resilience of psychosis. Polygenic risk scores, computed as the addition of genetic polymorphisms, can modulate the effects of genetic at-risk deletions (i.e. del22q11) that predispose to psychosis and may also influence the cognitive symptoms of ultra-high risk patients. Resilience, defined as the ability to withstand adversity, is not only related to external skills or psychotherapeutic care but could also be explained by internal molecular factors. Identifying the genetic factors of resilience might help to stratify the risk and to develop precision medicine in psychiatry.

Species of Botryosphaeriaceae associated with citrus branch diseases in China

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of Botryosphaeriaceae are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of Botryosphaeriaceae species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (tef1), the β-tubulin gene (tub2) and the DNA-directed RNA polymerase II second largest subunit (rpb2), 111 isolates from nine provinces were identified as 18 species of Botryosphaeriaceae, including Botryosphaeria dothidea, B. fabicerciana, Diplodia seriata, Dothiorella alpina, Do. plurivora, Lasiodiplodia citricola, L. iraniensis, L. microconidia, L. pseudotheobromae, L. theobromae, Neodeightonia subglobosa, Neofusicoccum parvum, and six previously undescribed species, namely Do. citrimurcotticola, L. guilinensis, L. huangyanensis, L. linhaiensis, L. ponkanicola and Sphaeropsis linhaiensis spp. nov. Botryosphaeria dothidea (28.8 %) was the most abundant species, followed by L. pseudotheobromae (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of Botryosphaeriaceae obtained from diseased citrus tissues in this study were pathogenic to the tested Citrus reticulata shoots in vitro, while not all species are pathogenic to the tested Cocktail grapefruit (C. paradisi × C. reticulata) shoots in vivo. In addition, Lasiodiplodia was the most aggressive genus both in vitro and in vivo. This is the first study to identify Botryosphaeriaceae species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures. Citation: Xiao XE, Wang W, Crous PW, et al. 2021. Species of Botryosphaeriaceae associated with citrus branch diseases in China. Persoonia 47: 106-135. https://doi.org/10.3767/persoonia.2021.47.03.

Species of Botryosphaeriaceae associated with citrus branch diseases in China

Citrus is an important and widely cultivated fruit crop in South China. Although the species of fungal diseases of leaves and fruits have been extensively studied, the causal organisms of branch diseases remain poorly known in China. Species of Botryosphaeriaceae are known as important fungal pathogens causing branch diseases on citrus in the USA and Europe. To determine the diversity of Botryosphaeriaceae species associated with citrus branch diseases in China, surveys were conducted in the major citrus-producing areas from 2017 to 2020. Diseased tissues were collected from twigs, branches and trunks with a range of symptoms including cankers, cracking, dieback and gummosis. Based on morphological characteristics and phylogenetic comparison of the DNA sequences of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha gene (tef1), the β-tubulin gene (tub2) and the DNA-directed RNA polymerase II second largest subunit (rpb2), 111 isolates from nine provinces were identified as 18 species of Botryosphaeriaceae, including Botryosphaeria dothidea, B. fabicerciana, Diplodia seriata, Dothiorella alpina, Do. plurivora, Lasiodiplodia citricola, L. iraniensis, L. microconidia, L. pseudotheobromae, L. theobromae, Neodeightonia subglobosa, Neofusicoccum parvum, and six previously undescribed species, namely Do. citrimurcotticola, L. guilinensis, L. huangyanensis, L. linhaiensis, L. ponkanicola and Sphaeropsis linhaiensis spp. nov. Botryosphaeria dothidea (28.8 %) was the most abundant species, followed by L. pseudotheobromae (23.4 %), which was the most widely distributed species on citrus, occurring in six of the nine provinces sampled. Pathogenicity tests indicated that all 18 species of Botryosphaeriaceae obtained from diseased citrus tissues in this study were pathogenic to the tested Citrus reticulata shoots in vitro, while not all species are pathogenic to the tested Cocktail grapefruit (C. paradisi × C. reticulata) shoots in vivo. In addition, Lasiodiplodia was the most aggressive genus both in vitro and in vivo. This is the first study to identify Botryosphaeriaceae species related to citrus branch diseases in China and the results provide a theoretical basis for the implementation of prevention and control measures. Citation: Xiao XE, Wang W, Crous PW, et al. 2021. Species of Botryosphaeriaceae associated with citrus branch diseases in China. Persoonia 47: 106-135. https://doi.org/10.3767/persoonia.2021.47.03.

MOF-Mediated Interfacial Polymerization to Fabricate Polyamide Membranes with a Homogeneous Nanoscale Striped Turing Structure for CO2/CH4 Separation

Control of the surface morphology of polyamide membranes fabricated by interfacial polymerization is of great importance in dictating the separation performance. Herein, polyamide membranes with a specific nanoscale striped Turing structure are generated through facile addition of Zr-based metal-organic framework UiO-66-NH₂ in the aqueous triethylenetetramine phase. Interestingly, accompanied by the degradation of UiO-66-NH₂ in aqueous solution, an intermediate complex is in situ formed through the strong interaction between the Zr metal center and the amine group from triethylenetetramine, which can lower amine diffusion and induce a local interfacial reaction, contributing to the generation of a homogeneous nanoscale striped Turing structure. The resulting membranes are used for CO₂/CH₄ gas separation. Compared with the parent polyamide membrane displaying a CO₂/CH₄ selectivity of 43.1 and a CO₂ permeance of 31.5 GPU, the membrane with 0.02 wt % of UiO-66-NH₂ introduced into the aqueous phase shows a higher CO₂/CH₄ selectivity of 58.3, along with a CO₂ permeance of 27.1 GPU. Additionally, when 0.1 wt % of UiO-66-NH₂ is incorporated into the aqueous phase, the membrane exhibits a combination of a higher CO₂/CH₄ selectivity and an enhanced CO₂ permeance in contrast with the parent polyamide membrane.

Prophylaxis of implant-related infections by local release of vancomycin from a hydrogel in rabbits

Local prophylaxis with antibiotic-loaded bone cement is a successful method to prevent post-operative infections in patients receiving orthopaedic implants. No comparable method is available for uncemented implants. Therefore, a hydrogel consisting of hyaluronic and polylactic acids was evaluated in a rabbit model for delivery of antimicrobial agents to prevent post-operative infections. In a pilot study, the suitability of the in vivo model was assessed by testing the hydrogel as carrier material for antimicrobial agents.In the main study, the antimicrobial-agent-loaded hydrogel was evaluated for infection prophylaxis. Rabbits received a titanium rod intramedullary in the tibia after contamination with Staphylococcus aureus. The rods were coated with unloaded hydrogel (Gel), hydrogel loaded with 2 % (Van2) or 5 % vancomycin (Van5), bioactive glass (BAG) or N-acetyl-L-cysteine (NAC). To analyse the infection severity after 28 d, histopathological, bacteriological, micro-computed tomographic and haematological analyses were performed. In the pilot study, the Van5 group had less infection (0/6 infected) as compared to the Gel group (5/5, p = 0.000) and the in vivo model was deemed suitable. In the main study, in the Van2 and Van5 groups, the number of infected animals was lower [1/6 (p = 0.006) and 2/6 (p = 0.044) infected, respectively]. In contrast, BAG and NAC groups showed no infection reduction (5/6 both groups, p = 0.997). The hydrogel can be used as a local carrier of vancomycin for prophylaxis of implant-related infections.The present study showed promising results for local delivery of antibacterial agents by hydrogel to prevent implant-related infections.

[Mid-to-long term outcomes and influence factors of postoperative concurrent chronic ankle instability and posterior ankle impingement]

OBJECTIVE

To investigate the mid-to-long-term efficacy of patients with chronic ankle instability combined with posterior impingement syndrome after 3-9 years of follow-up, and to analyze the influencing factors.

METHODS

From February 2010 to December 2015, 46 patients underwent concurrent lateral ankle ligament repair with posterior ankle arthroscopic surgery at the Institute of Sports Medicine, Peking University Third Hospital. The patient was first placed in a prone position and underwent arthroscopic debridement for the posterior impingement. After finishing the posterior arthroscopy, the surgeon and assistants first translated the patient to the affected side, then turned to the healthy side, and changed the position to the supine position. During the turning over, another assistant held the arthroscope and the instrument to ensure that it was sterile and could be used without replacement. The anterior ankle arthroscopy was operated if necessary and the lateral ankle ligament repair was anatomic repaired with anchors. The 42 patients were followed up, including 26 males and 16 females. The average age was (28.9±10.0) years. The patient's clinical symptoms, joint stability, mobility and motor function were compared by questionnaire and physical examination. The preoperative and postoperative visual analogue scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Tegner scores were compared, and the clinical scores and the patient age, gender, height and weight were compared. The correlations between body mass index (BMI), preoperative duration, surgery duration, and cartilage injury were analyzed.

RESULTS

The mean follow-up time was (71.8±22.8) months. The postoperative VAS scores (1.0 vs. 5.0, P<0.001), AOFAS scores (92 vs. 80, P<0.001), and Tegner scores (6.5 vs. 2, P<0.001) were significantly superior to the preoperative levels. The excellent and good rate was 97.6%. The postoperative VAS score (t=2.719, P=0.10), AOFAS score (t=-2.853, P=0.10), Tegner score (t=-3.443, P=0.001) and time to return exercise (t=2.814, P=0.008) were negatively correlated with the patient age, and the postoperative VAS score was negatively correlated with cartilage injury (Z=-2.195, P=0.028).

CONCLUSION

The mid-to-long-term clinical outcomes of the chronic ankle ligament instability combined with the posterior impingement were good. The age of the patients was negatively correlated with the clinical outcome. The combined cartilage injury could aggravate the postoperative pain.

[Retrospective analysis of modified Karlsson surgery for chronic calcaneofibular ligament injury]

Objective: To retrospectively evaluate the therapeutic effect and influencing factors of the modified Karlsson operation (anchor method) in treating chronic rupture of the calcaneofibular ligament (CFL). Methods: From August 2010 to May 2014, the data of 24 patients with calcaneofibular ligament rupture treated in Institute of Sports Medicine, Third Hospital of Peking University were retrospectively analyzed. All cases were repaired with modified Karlsson operation (anchor method). There were 14 males and 10 females, with an average age of (30±9) years, and the average body mass index (BMI) was (25±5) kg/m(2). Visual analogue pain score (VAS), American Foot and Ankle Surgery Association score (AOFAS), Tegner knee motion score, ankle stability and mobility were followed up and analyzed. The paired t test was used to compare the normal distribution data before and after the operation. Results: The average follow-up time was (41±13) months. Compared with pre-operation, VAS score decreased significantly at the last follow-up [0(0,7) vs 5(0,8), Z=4.13,P=0.000], AOFAS score increased significantly (94±10 vs 70±14, t=8.94, P<0.05), Tegner score increased significantly (4.7±1.5 vs 2.8±1.3, t=6.87, P<0.05), all improved significantly. AOFAS score was excellent in 19 cases, good in 4 cases and moderate in 1 case, the excellent and good rate was 95.8%. Among them, 20 cases (83.3%) were satisfied with the recovery effect after the operation. Postoperative sprain occurred in 5 cases (20.8%) and ankle mobility was limited in 3 cases (12.5%). Conclusions: The modified Karlsson operation (anchor method) can restore the stability of the ankle joint by treating the chronic rupture of CFL. It is an effective therapy for lateral ankle instability.

[Reconstruction of neglected Achilles tendon rupture: flexor hallucis longus transfer versus gastrocnemius turn-down flaps]

Objective: To compare the outcome of either flexor hallucis longus transfer or turn-down of proximal Achilles tendon tissue repair in treating chronic Achilles tendon rupture. Methods: The clinical data of 21 patients who underwent repair of Myerson type Ⅲ chronic Achilles tendon rupture at Peking University Sports Medicine Research Institute from May 2012 to March 2015 were retrospectively analyzed. Among them, 11 cases were treated with flexor hallucis longus (FHL) transfer, and 10 cases were treated with gastrocnemius turn-down flaps repair. The American Orthopedic Foot & Ankle Society (AOFOS) hindfoot score and Tegner motor function score before and after surgery were recorded and compared between the two groups. Data comparison between groups was performed with t test. Results: The patients in the both group were followed up for an average of (21±7) months. The postoperative AOFOS hindfoot score in the long flexor and gastrocnemius groups were both significantly higher than those before surgery, and the differences were statistically significant (97.7±2.6 vs 72.0±8.1 and 96.0±5.5 vs 78.5±6.4, t=10.70, 6.42, both P<0.05).The postoperative Tegner scores of the two groups were also significantly higher than those before surgery (4.2±1.4 vs 0.7±0.4 and 4.1±0.8 vs 0.6±0.5,t=7.29, 9.35, both P<0.05). There were no significant differences in postoperative AOFOS hindfoot scores and Tegner motor function scores between the two groups (both P>0.05). Conclusion: The flexor hallucis longus transfer and turn-down of proximal Achilles tendon tissue repair can both get satisfactory results in treating chronic Achilles tendon rupture.

Magnesium and Nitrogen Co-Doped Mesoporous Carbon with Enhanced Microporosity for CO₂ Adsorption

Mesoporous carbons (MC) have attracted a tremendous amount of interest due to their efficient molecular transport properties. However, the limited number of active sites and low microporosity generally impede their use for practical applications. Herein, we have fabricated Mg and N co-doped mesoporous carbon (Mg-NMC) with high microporosity via one-pot synthetic route followed by further steam activation. In comparison with the parent N-doped mesoporous carbon, Mg-NMC shows partially ordered mesostructure and improved CO₂ adsorption capacity attributed to the introduction of basic site after Mg doping. Upon further steam activation, the microporosity is enhanced to 37.3%, while the CO₂ adsorption capacity is also increased by 70.4% at 273 K and 1.0 bar.

Novel MgO/hollow carbon sphere composites for CO2 adsorption

MgO/hollow carbon sphere composites with enhanced CO₂ uptake capacity and recyclability have been synthesized through a one-pot self-assembly approach.

NiCo nanoalloy encapsulated in graphene layers for improving hydrogen storage properties of LiAlH4

NiCo nanoalloy (4-6 nm) encapsulated in grapheme layers (NiCo@G) has been prepared by thermolysis of a 3D bimetallic complex CoCo[Ni(EDTA)]2·4H2O and successfully employed as a catalyst to improve the dehydrogenation performances of LiAlH4 by solid ball-milling. NiCo@G presents a superior catalytic effect on the dehydrogenation of LiAlH4. For LiAlH4 doped with 1 wt% NiCo@G (LiAlH4-1 wt% NiCo@G), the onset dehydrogenation temperature of LiAlH4 is as low as 43 °C, which is 109 °C lower than that of pristine LiAlH4. 7.3 wt% of hydrogen can be released from LiAlH4-1 wt% NiCo@G at 150 °C within 60 min. The activation energies of LiAlH4 dehydrogenation are extremely reduced by 1 wt% NiCo@G doping.

Evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects

The high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. The genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid Acyrthosiphon pisum: sucrase 1 (SUC1), a sucrase in glycoside hydrolase family 13 (GH13), and aquaporin 1 (AQP1), a member of the Drosophila integral protein (DRIP) family of aquaporins. Here, we describe molecular analysis of GH13 and AQP genes in phloem-feeding representatives of the four phloem-feeding groups: aphids (Myzus persicae), coccids (Planococcus citri), psyllids (Diaphorina citri, Bactericera cockerelli) and whiteflies (Bemisia tabaci MEAM1 and MED). A single candidate GH13-SUC gene and DRIP-AQP gene were identified in the genome/transcriptome of most insects tested by the criteria of sequence motif and gene expression in the gut. Exceptionally, the psyllid Ba. cockerelli transcriptome included a gut-expressed Pyrocoelia rufa integral protein (PRIP)-AQP, but has no DRIP-AQP transcripts, suggesting that PRIP-AQP is recruited for osmoregulatory function in this insect. This study indicates that phylogenetically related SUC and AQP genes may generally mediate osmoregulatory functions in these diverse phloem-feeding insects, and provides candidate genes for empirical validation and development as targets for osmotic disruption of pest species.

Expression of a GDP-L-galactose phosphorylase-like gene in a Chinese wild Vitis species induces responses to Erysiphe necator and defense signaling molecules

Using rapid amplification of cDNA ends, a full-length cDNA sequence of a GDP-L-galactose phosphorylase-like gene was isolated from leaves infected by Erysiphe necator in the Chinese wild (Vitis pseudoreticulata) clone, 'Baihe-35-1', an E. necator-resistant genotype. The full-length cDNA, designated as VpVTC, comprised 1943 bp and putatively encodes a 453-amino acid polypeptide containing an HIT motif. The deduced amino acid sequence showed high similarity with that of VTC genes from other plants. The expression of VpVTC, determined by reverse transcriptase-polymerase chain reaction, was induced by E. necator and defense signaling molecules, including salicylic acid, methyl jasmonate, and ethephon, in 'Baihe-35-1', the V. quinquangularis genotype 'Shang-24', and the E. necator-susceptible V. pseudoreticulata genotype, 'Hunan-1'. Transcript levels of VpVTC correlated well with the degree of disease resistance in the 3 genotypes. Maximum induction of VpVTC by E. necator (>7-fold at 96 h post-inoculation) occurred in 'Baihe-35-1', which also showed the fastest response to signaling molecules. Upregulating the expression of VpVTC in 'Baihe-35-1' resulted in a gradual increase in the ascorbic acid concentration of leaves inoculated with E. necator. Furthermore, VpVTC was expressed in leaves, stems, inflorescence, tendrils, and fruit at all developmental stages, with the highest level occurring in fruit 35 days after flowering.

The chemokine (C-X-C motif) receptor 4 inhibitor AMD3100 accelerates blood flow restoration in diabetic mice

AIMS/HYPOTHESIS

Bone marrow cell mobilisation potently induces vascular growth in ischaemic tissue, possibly by mobilising endothelial cell progenitors. Thus, mobilising agents might not be therapeutic when endothelial cell progenitors are dysfunctional, as in diabetes mellitus. Local injection of autologous endothelial cell progenitors also stimulates vascular growth in ischaemic tissue, but endothelial cell progenitors from people with multiple cardiovascular risk factors and from obese diabetic mice are marginally therapeutic or inhibitory. We sought to identify possible strategies to improve vascularisation in patients with diabetes mellitus by determining if (1) mobilisation accelerates neovascularisation in diabetic animals, and (2) mobilised cells from a non-diabetic source accelerate vascularisation in diabetic animals.

METHODS

We tested whether systemic administration of the chemokine (C-X-C motif) receptor 4 inhibitor AMD3100 or local injection of human CD34(+) circulating cells mobilised by AMD3100 could speed or enhance blood flow restoration in ischaemic limbs of diabetic mice. The small-molecule-mobilising drug AMD3100 was selected because mobilisation and apheresis can be done on the same day.

RESULTS

Systemic administration of AMD3100 and local injection of cells mobilised by AMD3100 greatly accelerated the restoration of blood flow to ischaemic limbs of diabetic mice. CD34(+) cells mobilised by AMD3100 appeared to be more potent growth stimulators than their unmobilised counterparts.

CONCLUSIONS/INTERPRETATION

Unlike other mobilising agents requiring multi-day mobilisation, AMD3100 enables mobilised donors to undergo mobilisation and apheresis on the same day. The combination of excellent therapeutic benefits as well as ease of use indicates that AMD3100 could be a powerful tool to ameliorate tissue ischaemia in the diabetic environment.

Alterations in grip strength during male sexual arousal

Although it is known that alterations in grip strength occur under a number of conditions, little is known about relationships between grip strength and sexual arousal. This relationship was investigated in 30 healthy heterosexual males, who viewed both erotic and nonerotic videos. A questionnaire was used to assess the extent of sexual arousal. The grip strengths of both hands were measured with a five-position (P1-P5) dynamometer, before and after watching the videos. After watching the erotic video, there was a statistically significant reduction in grip strength for the P2 position, with nonsignificant overall reductions in grip strength for all other positions tested. No such effect was observed in control tests. The results indicate that during sexual arousal, the neural system is likely to reduce the output to muscles not directly related to sexual function, presumably to enhance the physiological responses of sexual arousal.

CD34- blood-derived human endothelial cell progenitors

A subset of adult peripheral blood leukocytes functions as endothelial cell progenitors called angioblasts. They can incorporate into the vasculature in animal models of neovascularization and accelerate the restoration of blood flow to mouse ischemic limbs. Earlier reports suggested that CD34-expressing (CD34+) but not CD34+ cell-depleted (CD34-) leukocytes can differentiate into endothelial cells (EC) in vitro and in vivo. Recent findings suggest that CD14+ cells, which are typically CD34-, also have angioblast-like properties in vitro. To determine the identity of angioblasts, the potential of CD34+, CD34-, CD34- CD14+, and CD34- CD14- cells to produce EC was compared. We show that a subset of monocyte (CD34- CD14+)-enriched cells can take on an EC-like phenotype in culture, but that the EC-like cells also express dendritic cell antigens. These findings suggest that monocytes differentiate into macrophages, dendritic cells, or EC depending on environmental cues. The data also demonstrate that angioblasts are more abundant in the blood than previously thought. Finally, we demonstrate that CD34- and CD34- CD14+ cells incorporate into the endothelium of blood vessels in mouse ischemic limbs. However, incorporation of these cells requires co-injection with CD34+ cells, indicating that leukocyte-leukocyte interactions may play a critical role in governing angioblast behavior in vivo.

Blood-derived angioblasts accelerate blood-flow restoration in diabetic mice

Endothelial cell progenitors, angioblasts, have been detected in the peripheral blood of adult humans, mice, and rabbits. These cells have been shown to incorporate into the endothelium of newly forming blood vessels in pathological and nonpathological conditions. Here we investigated the possibility that the CD34-expressing leukocytes (CD34(+) cells) that appear to be enriched for angioblasts could be used to accelerate the rate of blood-flow restoration in nondiabetic and diabetic mice undergoing neovascularization due to hindlimb ischemia. CD34(+) cells did not accelerate the restoration of flow in nondiabetic mice, but dramatically increased it in diabetic mice. Furthermore, CD34(+) cells derived from type 1 diabetics produced fewer differentiated endothelial cells in culture than did their type 2 diabetic- or nondiabetic-derived counterparts. In vitro experiments suggest that hyperglycemia per se does not alter the ability of angioblasts to differentiate or of angioblast-derived endothelial cells to proliferate. In contrast, hyperinsulinemia may enhance angioblast differentiation but impair angioblast-derived endothelial cell survival or proliferation. Our findings suggest that CD34(+) cells may be a useful tool for therapeutic angiogenesis in diabetics.

Lecithin vesicular carriers for transdermal delivery of cyclosporin A

Two kinds of vesicles with and without the presence of sodium cholate (flexible vesicles and conventional vesicles) were prepared, using cyclosporin A as model drug. When applied onto the excised abdominal skin of mice non-occlusively, the enhancing effects of vesicles on the penetration of cyclosporin A were assessed by an in vitro permeation technique. The effect of sodium cholate micelles was also studied. In vivo study was carried out by topical application of vesicles onto the mice skin and drug serum concentration was detected. Results showed that after 8 h of administration, flexible vesicles transported 1.16 microg of cyclosporin A through per cm(2) mice skin and amounted to 1.88 microg 24 h later. The residual amount in the skin was 1.78+/-0.51 microg/cm(2). However, flexible vesicles failed to transport measurable amount of drug through pre-hydrated skin while deposited 2.39+/-0.26 microg/cm(2) into the skin. Conventional vesicles failed to transfer cyclosporin A into the receiver while accumulated 0. 72+/-0.19 microg/cm(2) of drug in the skin. Furthermore, 1 and 40% sodium cholate micelles precluded the transport of cyclosporin A. In vivo studies indicated that with the application of flexible vesicles, serum drug concentration of 53.43+/-9.24 ng/ml was detected 2 h later. After the stratum corneum of mouse skin has been destroyed by shaving, flexible vesicles transferred large amount of drug into blood, up to 187.32+/-53.21 ng/ml after 1 h of application. Conventional vesicles failed to deliver measurable amount of drug into the blood under normal skin condition. In conclusion, flexible vesicle is better than conventional vesicle as the carrier for transdermal delivery of cyclosporin A. Penetration and fusion have been suggested to be two major functional mechanisms. Hydration is detrimental to the enhancement effect. Stratum corneum constitutes main barrier to the transport of lipophilic cyclosporin A.