A multicentric randomized controlled phase III trial of adaptive and 18F-FDG-PET-guided dose-redistribution in locally advanced head and neck squamous cell carcinoma (ARTFORCE).

BACKGROUND AND PURPOSE: This multicenter randomized phase III trial evaluated whether locoregional control of patients with LAHNSCC could be improved by fluorodeoxyglucose-positron emission tomography (FDG-PET)-guided dose-escalation while minimizing the risk of increasing toxicity using a dose-redistribution and scheduled adaptation strategy. MATERIALS AND METHODS: Patients with T3-4-N0-3-M0 LAHNSCC were randomly assigned (1:1) to either receive a dose distribution ranging from 64-84 Gy/35 fractions with adaptation at the 10thfraction (rRT) or conventional 70 Gy/35 fractions (cRT). Both arms received concurrent three-cycle 100 mg/m2cisplatin. Primary endpoints were 2-year locoregional control (LRC) and toxicity. Primary analysis was based on the intention-to-treat principle. RESULTS: Due to slow accrual, the study was prematurely closed (at 84 %) after randomizing 221 eligible patients between 2012 and 2019 to receive rRT (N = 109) or cRT (N = 112). The 2-year LRC estimate difference of 81 % (95 %CI 74-89 %) vs. 74 % (66-83 %) in the rRT and cRT arm, respectively, was not found statistically significant (HR 0.75, 95 %CI 0.43-1.31,P=.31). Toxicity prevalence and incidence rates were similar between trial arms, with exception for a significant increased grade ≥ 3 pharyngolaryngeal stenoses incidence rate in the rRT arm (0 versus 4 %,P=.05). In post-hoc subgroup analyses, rRT improved LRC for patients with N0-1 disease (HR 0.21, 95 %CI 0.05-0.93) and oropharyngeal cancer (0.31, 0.10-0.95), regardless of HPV. CONCLUSION: Adaptive and dose redistributed radiotherapy enabled dose-escalation with similar toxicity rates compared to conventional radiotherapy. While FDG-PET-guided dose-escalation did overall not lead to significant tumor control or survival improvements, post-hoc results showed improved locoregional control for patients with N0-1 disease or oropharyngeal cancer treated with rRT.

Programmed cell death-1-modified pig developed using electroporation-mediated gene editing for in vitro fertilized zygotes.

Programmed cell death-1 (PD-1) is an immunoinhibitory receptor required to suppress inappropriate immune responses such as autoimmunity. Immune checkpoint antibodies that augment the PD-1 pathway lead to immune-related adverse events (irAEs), organ non-specific side effects due to autoimmune activation in humans. In this study, we generated a PD-1 mutant pig using electroporation-mediated introduction of the CRISPR/Cas9 system into porcine zygotes to evaluate the PD-1 gene deficiency phenotype. We optimized the efficient guide RNAs (gRNAs) targeting PD-1 in zygotes and transferred electroporated embryos with the optimized gRNAs and Cas9 into recipient gilts. One recipient gilt became pregnant and gave birth to two piglets. Sequencing analysis revealed that both piglets were biallelic mutants. At 18 mo of age, one pig showed non-purulent arthritis of the left elbow/knee joint and oligozoospermia, presumably related to PD-1 modification. Although this study has a limitation because of the small number of cases, our phenotypic analysis of PD-1 modification in pigs will provide significant insight into human medicine and PD-1-deficient pigs can be beneficial models for studying human irAEs.

Generation of allogenic chimera carrying mutations in PDX1 and TP53 genes via phytohemagglutinin-mediated blastomere aggregation in pigs.

The generation of genetically engineered pig models that develop pancreas-specific tumors has the potential to advance studies and our understanding of pancreatic cancer in humans. TP53 mutation causes organ-nonspecific cancers, and PDX1-knockout results in the loss of pancreas development. The aim of the present study was to generate a PDX1-knockout pig chimera carrying pancreas complemented by TP53 mutant cells via phytohemagglutinin (PHA)-mediated blastomere aggregation using PDX1 and TP53 mutant blastomeres, as a pig model for developing tumors in the pancreas with high frequency. First, the concentration and exposure time to PHA to achieve efficient blastomere aggregation were optimized. The results showed that using 300 µg/mL PHA for 10 min yielded the highest rates of chimeric blastocyst formation. Genotyping analysis of chimeric blastocysts derived from aggregated embryos using PDX1- and TP53-edited blastomere indicated that approximately 28.6% carried mutations in both target regions, while 14.3-21.4% carried mutations in one target. After the transfer of the chimeric blastocysts into one recipient, the recipient became pregnant with three fetuses. Deep sequencing analysis of the PDX1 and TP53 regions using ear and pancreas samples showed that one fetus carried mutations in both target genes, suggesting that the fetus was a chimera derived from embryo-aggregated PDX1 and TP53 mutant blastomeres. Two out of three fetuses carried only the PDX1 mutation, indicating that the fetuses developed from embryos not carrying TP53-edited blastomeres. The results of the present study could facilitate the further improvement and design of high-frequency developing pancreatic tumor models in pigs.

Relationships of BRAF V600E Gene Mutation With Some Immunohistochemical Markers and Recurrence Rate in Patients With Thyroid Carcinoma.

Background: The B-type rafkinase (BRAF) V600E gene mutation plays an important role in the pathogenesis, diagnosis, and prognosis of thyroid carcinoma. This study was conducted to investigate the rate of the BRAF V600E mutation, the relationships between the BRAF V600E gene mutation and some immunohistochemical markers, and recurrence rate in patients with differentiated thyroid cancer. Method: The study was conducted by a descriptive and longitudinal follow-up method on 102 thyroid carcinoma patients at 103 Military Hospital, Hanoi, Vietnam. All patients were identified with the BRAF V600E gene mutation by real-time polymerase chain reaction. Results: The rate of BRAF V600E gene mutation in patients with thyroid cancer was 60.8%. Patients with BRAF V600E gene mutation had a significantly higher rate of positive cyclooxygenase 2 (COX-2) and Ki67 markers than those without the mutation (COX-2: odds ratio [OR] = 2.93; 95% confidence interval [CI] = 1.27-6.74, P = .011; Ki67: OR = 3.41; 95% CI = 1.31-8.88, P = .01). A statistically significant relationship was identified between the rate of BRAF V600E mutation and the rate of positive Hector Battifora mesothelial 1 (HBME-1) (B = -1.040; P = .037) and COX-2 (B = -1.123; P = .023) markers. The recurrence rate in patients with BRAF V600E gene mutation was significantly higher than that in those without the mutation (P = .007). The mean of the recurrence time of patients with BRAF V600E mutation was significantly lower than that in those without the mutation (P = .011). Conclusions: A high prevalence of BRAF V600E gene mutation was found in thyroid carcinoma patients. The rates of positive HBME-1, COX-2, and Ki67 markers were significantly correlated to BRAF V600E gene mutation. Patients with BRAF V600E gene mutation showed a significantly higher relapse rate and earlier relapse time than those without the mutation.

Evaluation of the Retinal Vessel Density and Subfoveal Choroidal Thickness in Central Cerous Chorioretinopathy Using Optical Coherence Tomography.

PURPOSE: The purpose of this study was to quantitatively assess changes in the subfoveal choroidal thickness (SFCT) and superficial retinal vessel density (SRVD) in acute and chronic central serous chorioretinopathy (CSCR) patients, and estimate the correlation of SFCT and SRVD with best-corrected visual acuity (BCVA), respectively, using spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). METHODS: This was a cross-sectional, case-control study. The study included CSCR patients treated at the Ho Chi Minh City Eye Hospital from May 2022 to October 2022. RESULTS: A total of 91 subjects (182 eyes) were included in this study, with 74 eyes in the unilateral acute CSCR group and 17 eyes in the unilateral chronic CSCR group; 91 eyes in the control group were patients' unaffected other eyes. The mean age was 40.78 ± 1.26 years (ranging from 31 to 45 years). The proportions of male and female patients were 78.0% and 22.0%, respectively. The major symptom was reduced vision, and the mean BCVA was 0.36 ± 0.05 logMAR. The mean SFCT of CSCR eyes was 357.2 ± 11.8 µm, which was 290.4 ± 8.5 µm in the control group (p < 0.05). The mean SRVD of chronic CSCR (24.2 ± 4.94%) and acute CSCR (28 ± 2.33%) eyes was lower compared with the control group (21.7 ± 1.87%). SFCT had a correlation with BCVA (r = -0.490, p < 0.05) in chronic CSCR; the center region of SRVD was likewise correlated with BCVA (r = -0.384, p < 0.05) and the parafoveal region of SRVD was also correlated with BCVA (r = -0.271, p < 0.05). CONCLUSION: Both altered SFCT and SRVD were identified in CSCR patients by SD-OCT and 6 x 6 mm OCT angiography scans, and both were found to be correlated with BCVA. SD-OCT along with OCTA could be a good technique for quantitatively evaluating different CSCR courses.

Locoregional treatment of primary tumor in synchronous metastatic head and neck squamous cell carcinomas.

PURPOSE: Patients with synchronous metastatic head and neck squamous cell carcinomas (mHNSCC) are at risk of locoregional progression associated with significant morbidity and mortality. The aim of this study is to assess whether the addition of aggressive locoregional treatment to systemic therapy could be associated with an improved overall survival (OS) compared to systemic therapy alone in upfront mHNSCC patients. MATERIAL AND METHODS: This retrospective study included patients presenting with previously untreated mHNSCC who underwent first-line systemic therapy at a single institution between 1998 and 2018. Locoregional treatment was defined as either exclusive locoregional radiotherapy (RT) or surgery with or without adjuvant RT. RESULTS: One hundred forty-eight patients were included. Eighty patients were treated with systemic therapy alone and 68 patients were treated with a combination of locoregional treatment and systemic therapy. Median overall survival (OS) was 13 months [10.7-15] and median progression free survival (PFS) was 7.7 month [6.5-8.9]. The addition of a locoregional treatment to systemic therapy compared to systemic therapy alone was associated with improved survival (1-year OS, 65.8% vs. 41.1%, p < .001, and 1-year PFS, 42.5% vs. 18.5%, p < .001). Moreover, RT dose equal to 70 Gy was associated with even longer OS compared to a RT dose below 70 Gy and to no locoregional treatment (23.4 vs. 12.7 vs 7.5 months respectively). In a subgroup analysis on 75 patients presenting with a responding or stable metastatic disease after first-line systemic therapy, oropharyngeal primary tumor site and the addition of a locoregional treatment, especially a high radiation dose of 70 Gy, were evidenced as independent prognostic factors for improved OS. CONCLUSION: The addition of a high-dose RT locoregional treatment to systemic therapy is associated with prolonged OS in patients with synchronous mHNSCC and should be discussed for patients who respond to or have a stable disease after first-line systemic therapy.

Splenic Artery Embolization in Conservative Management of Blunt Splenic Injury Graded by 2018 AAST-OIS: Results from a Hospital in Vietnam.

Purpose: This study was conducted to evaluate the results of conservative management of blunt splenic trauma according to the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) in 2018 by embolization. Methods: This observational study included 50 patients (42 men and 8 women) with splenic injury who underwent multidetector computed tomography (MDCT) and embolization. Results: According to the 2018 AAST-OIS, 27 cases had higher grades than they did according to the 1994 AAST-OIS. The grades of two cases of grade II increased to grade IV; those of 15 cases of grade III increased to grade IV; and four cases of grade IV increased to grade V. As a result, all patients underwent successful splenic embolization and were stable at discharge. No patients required re-embolization or conversion to splenectomy. The mean hospital stay was 11.8±7 days (range, 6-44 days), with no difference in length of hospital stay among grades of splenic injury (p >0.05). Conclusion: Compared with the AAST-OIS 1994, the AAST-OIS 2018 classification is useful in making embolization decisions, regardless of the degree of blunt splenic injury with vascular lacerations visible on MDCT.

The Effects of an In Vitro Oocyte Maturation System and Chlorogenic Acid Supplementation during Embryo Culture on the Development of Porcine Cloned Embryos Derived from Native Vietnamese Ban Pigs.

The aim of this study was to improve the production efficiency of Vietnamese native Ban pig embryos using somatic cell nuclear transfer (SCNT). Fibroblast cells from Ban pigs were injected into the enucleated cytoplasts of crossbred gilts, and the reconstructed embryos were subsequently cultured. In the first experiment, cytoplasts were isolated from oocytes matured in either a defined porcine oocyte medium (POM) or in TCM199 medium supplemented with porcine follicular fluid. Both media were supplemented with gonadotropic hormones, either for the first 22 h of in vitro maturation (IVM) or for the entire 44 h of IVM. In the second experiment, the reconstructed SCNT embryos were cultured with or without 50 µM chlorogenic acid (CGA). Furthermore, this study examined parthenogenetic embryos. The IVM medium and duration of hormone treatment did not affect embryo development. CGA supplementation to the culture medium significantly increased blastocyst formation rates in parthenogenetic embryos but not in SCNT embryos. However, CGA supplementation significantly reduced the apoptotic index in blastocysts regardless of embryo source. In conclusion, the IVM method did not affect SCNT embryo production, while CGA supplementation during embryo culture improved the quality of SCNT embryos in indigenous pig breeds.

NAD+ Synthetase is Required for Free-living and Symbiotic Nitrogen Fixation in the Actinobacterium Frankia casuarinae.

Frankia spp. are multicellular actinobacteria that fix atmospheric dinitrogen (N2) not only in the free-living state, but also in root-nodule symbioses with more than 200 plant species, called actinorhizal plants. To identify novel Frankia genes involved in N2 fixation, we previously isolated mutants of Frankia casuarinae that cannot fix N2. One of these genes, mutant N3H4, did not induce nodulation when inoculated into the host plant Casuarina glauca. Cell lineages that regained the ability to fix N2 as free-living cells were isolated from the mutant cell population. These restored strains also regained the ability to stimulate nodulation. A comparative ana-lysis of the genomes of mutant N3H4 and restored strains revealed that the mutant carried a mutation (Thr584Ile) in the glutamine-dependent NAD+ synthetase gene (Francci3_3146), while restored strains carried an additional suppressor mutation (Asp478Asn) in the same gene. Under nitrogen-depleted conditions, the concentration of NAD(H) was markedly lower in the mutant strain than in the wild type, whereas it was higher in restored strains. These results indicate that glutamine-dependent NAD+ synthetase plays critical roles in both free-living and symbiotic N2 fixation in Frankia.

A tale of two lineages: how the strains of the earliest divergent symbiotic Frankia clade spread over the world.

It is currently assumed that around 100 million years ago, the common ancestor to the Fabales, Fagales, Rosales and Cucurbitales in Gondwana, developed a root nodule symbiosis with a nitrogen-fixing bacterium. The symbiotic trait evolved first in Frankia cluster-2; thus, strains belonging to this cluster are the best extant representatives of this original symbiont. Most cluster-2 strains could not be cultured to date, except for Frankia coriariae, and therefore many aspects of the symbiosis are still elusive. Based on phylogenetics of cluster-2 metagenome-assembled genomes (MAGs), it has been shown that the genomes of strains originating in Eurasia are highly conserved. These MAGs are more closely related to Frankia cluster-2 in North America than to the single genome available thus far from the southern hemisphere, i.e., from Papua New Guinea.To unravel more biodiversity within Frankia cluster-2 and predict routes of dispersal from Gondwana, we sequenced and analysed the MAGs of Frankia cluster-2 from Coriaria japonica and Coriaria intermedia growing in Japan, Taiwan and the Philippines. Phylogenetic analyses indicate there is a clear split within Frankia cluster-2, separating a continental from an island lineage. Presumably, these lineages already diverged in Gondwana.Based on fossil data on the host plants, we propose that these two lineages dispersed via at least two routes. While the continental lineage reached Eurasia together with their host plants via the Indian subcontinent, the island lineage spread towards Japan with an unknown host plant.

Lymphangioma of Colon Presenting as an Intramural Tumor.

Lymphangiomas are rare and benign vascular malformations of the lymphatic system. They may arise in any location and at all ages and have variable presentation. These lesions in the intestinal wall are reported very rarely. In the case of colonic lymphangiomas, it is more common in late adulthood and old age, which, in this age group is thought to be associated with local disturbances of lymphatic circulation secondary to inflammation, degeneration, surgical procedure, trauma or radiation. The clinical presentation of colonic lymphangiomas varies from incidental findings on imaging to presenting with acute abdomen. The imaging features are usually multilocular cyst in intramural colon and submucosal mass on endoscopy. However, in the case of symptomatic lesions with atypical image findings, and the fact that the disease is rare, preoperative diagnosis is often difficult. On the other hand, although these cystic tumors do not transform into malignancy, they can be locally invasive or complicated, and often require resection. We report a 53-year-old male who had a cystic lymphangioma of the transverse colon illustrated by imaging modalities and recognized via postoperative histopathological examination.

Abscisic acid signaling activates distinct VND transcription factors to promote xylem differentiation in Arabidopsis.

Plants display remarkable abilities to adjust growth and development to environmental conditions, such as the amount of available water. This developmental plasticity is apparent not only in root and shoot growth rates, but also in tissue patterning and cell morphology.1,2 We have previously shown that in response to limited water availability, Arabidopsis thaliana root displays changes in xylem morphology, mediated by the non-cell-autonomous action of abscisic acid, ABA.2 Here, we show, through analyses of ABA response reporters and tissue-specific suppression of ABA signaling, that xylem cells themselves act as primary signaling centers governing both xylem cell fate and xylem differentiation rate, revealing the cell-autonomous control of multiple aspects of xylem development by ABA. ABA rapidly activates the expression of genes encoding VASCULAR-RELATED NAC DOMAIN (VND) transcription factors. Molecular and genetic analyses revealed that the two ABA-mediated xylem developmental changes are regulated by distinct members of this transcription factor family, with VND2 and VND3 promoting differentiation rate of metaxylem cells, while VND7 promotes the conversion of metaxylem toward protoxylem morphology. This phenomenon shows how different aspects of developmental plasticity can be interlinked, yet genetically separable. Moreover, similarities in phenotypic and molecular responses to ABA in diverse species indicate evolutionary conservation of the ABA-xylem development regulatory network among eudicots. Hence, this study gives molecular insights into how environmental stress modifies plant vascular anatomy and has potential relevance for water use optimization and adaptation to drought conditions.

Healthcare Workers' Knowledge and Attitudes Regarding the World Health Organization's "My 5 Moments for Hand Hygiene": Evidence From a Vietnamese Central General Hospital.

OBJECTIVES: Although the World Health Organization (WHO) initiative "My 5 Moments for Hand Hygiene" has been lauded as effective in preventing hospital-associated infections, little is known about healthcare workers (HCWs)' hand hygiene behavior. In this study, we sought to assess knowledge and attitudes towards the concepts in this initiative, as well as associated factors, among Vietnamese HCWs at a general hospital. METHODS: A structured questionnaire was administered to HCWs at a central Vietnamese general hospital in 2015. Multiple logistic regression analysis was used to identify factors associated with HCWs' knowledge and attitudes towards hand hygiene. RESULTS: Of 120 respondents, 65.8% and 67.5% demonstrated appropriate knowledge and a positive attitude, respectively, regarding all 5 hand hygiene moments. Logistic regression indicated better knowledge of hand hygiene in workers who were over 30 years old, who were direct HCWs (rather than managers), who had frequent access to clinical information, and who received their clinical information from training. Those who worked in infectious and tropical disease wards, who had frequent access to clinical information, and who received information from training were more likely to have a positive attitude towards hand hygiene than their counterparts. CONCLUSIONS: Although many Vietnamese HCWs displayed moderate knowledge and positive attitudes towards the WHO hand hygiene guidelines, a key gap remained. Regular education and training programs are needed to increase knowledge and to improve attitudes and practices towards hand hygiene. Furthermore, a combination of multimodal strategies and locally-adapted interventions is needed for sustainable hand hygiene adherence.

Presence of chlorogenic acid during in vitro maturation protects porcine oocytes from the negative effects of heat stress.

Chlorogenic acid (CGA) is known to protect oocytes from oxidative stress. Here we investigated the effects of CGA on porcine oocyte maturation under heat stress and subsequent embryonic development after parthenogenetic activation. For in vitro maturation (IVM) at 41.0°C (hyperthermic condition), supplementation of the maturation medium with 50 µM CGA significantly improved the percentage of matured oocytes and reduced the rate of apoptosis relative to oocytes matured without CGA (p < .05). CGA treatment of oocytes during IVM under hyperthermia tended to increase (p < .1) percentage of blastocyst formation after parthenogenesis and significantly increased (p < .05) the total cell number per blastocyst relative to oocytes matured without CGA. For IVM at 38.5°C (isothermic condition), CGA significantly improved the rate of blastocyst development compared with oocytes matured without CGA (p < .05), but did not affect oocyte maturation, apoptosis rate or the number of cells per embryo. Omission of all antioxidants from the IVM medium significantly reduced the rate of oocyte maturation, but the rate was restored upon addition of CGA. These results demonstrate that CGA is a potent antioxidant that protects porcine oocytes from the negative effects of heat stress, thus reducing the frequency of apoptosis and improving the quality of embryos.

Frankia-Enriched Metagenomes from the Earliest Diverging Symbiotic Frankia Cluster: They Come in Teams.

Frankia strains induce the formation of nitrogen-fixing nodules on roots of actinorhizal plants. Phylogenetically, Frankia strains can be grouped in four clusters. The earliest divergent cluster, cluster-2, has a particularly wide host range. The analysis of cluster-2 strains has been hampered by the fact that with two exceptions, they could never be cultured. In this study, 12 Frankia-enriched metagenomes of Frankia cluster-2 strains or strain assemblages were sequenced based on seven inoculum sources. Sequences obtained via DNA isolated from whole nodules were compared with those of DNA isolated from fractionated preparations enhanced in the Frankia symbiotic structures. The results show that cluster-2 inocula represent groups of strains, and that strains not represented in symbiotic structures, that is, unable to perform symbiotic nitrogen fixation, may still be able to colonize nodules. Transposase gene abundance was compared in the different Frankia-enriched metagenomes with the result that North American strains contain more transposase genes than Eurasian strains. An analysis of the evolution and distribution of the host plants indicated that bursts of transposition may have coincided with niche competition with other cluster-2 Frankia strains. The first genome of an inoculum from the Southern Hemisphere, obtained from nodules of Coriaria papuana in Papua New Guinea, represents a novel species, postulated as Candidatus Frankia meridionalis. All Frankia-enriched metagenomes obtained in this study contained homologs of the canonical nod genes nodABC; the North American genomes also contained the sulfotransferase gene nodH, while the genome from the Southern Hemisphere only contained nodC and a truncated copy of nodB.

Rubella Vaccination Coverage Among Women of Childbearing Age in Vietnam.

Despite the availability of effective and safe rubella vaccines for women of childbearing age, prevention and control of congenital rubella syndrome in children remains challenging in Vietnam. In order to examine this issue, we conducted a cross-sectional study, examining the current coverage of rubella vaccination before pregnancy among 807 pregnant women and women with children under 12 months of age in urban and rural districts, Dong Da and Ba Vi, in Hanoi, Vietnam. In this population, we observed an alarming non-compliance rate with rubella vaccination before pregnancy in both localities. Among the 82.0% of participants who remained unvaccinated against this contagious viral infection, 95.8% of them were in Ba Vi district, compared to 68.0% in Dong Da district (p < 0.001). Besides the differences in age, number of children, education levels, primary occupations and monthly incomes among the participants between the two districts, other reasons for noncompliance with rubella vaccination includeddisinterest in rubella vaccination, the high cost and long distance to vaccination sites as well as unawareness of vaccination locations. In addition to addressing the unique socio-economicchallenges behind one's accessibility to vaccination services in urban and rural areas, our study supports a continued effort in ensuring proper access to and education about pre-pregnancy vaccines and vaccination among women of childbearing age in order to achieve and sustain sufficient immunization coverage of rubella and other vaccine-preventable diseases in both settings.

Comparative Analysis of the Nodule Transcriptomes of Ceanothus thyrsiflorus (Rhamnaceae, Rosales) and Datisca glomerata (Datiscaceae, Cucurbitales).

Two types of nitrogen-fixing root nodule symbioses are known, rhizobial and actinorhizal symbioses. The latter involve plants of three orders, Fagales, Rosales, and Cucurbitales. To understand the diversity of plant symbiotic adaptation, we compared the nodule transcriptomes of Datisca glomerata (Datiscaceae, Cucurbitales) and Ceanothus thyrsiflorus (Rhamnaceae, Rosales); both species are nodulated by members of the uncultured Frankia clade, cluster II. The analysis focused on various features. In both species, the expression of orthologs of legume Nod factor receptor genes was elevated in nodules compared to roots. Since arginine has been postulated as export form of fixed nitrogen from symbiotic Frankia in nodules of D. glomerata, the question was whether the nitrogen metabolism was similar in nodules of C. thyrsiflorus. Analysis of the expression levels of key genes encoding enzymes involved in arginine metabolism revealed up-regulation of arginine catabolism, but no up-regulation of arginine biosynthesis, in nodules compared to roots of D. glomerata, while arginine degradation was not upregulated in nodules of C. thyrsiflorus. This new information corroborated an arginine-based metabolic exchange between host and microsymbiont for D. glomerata, but not for C. thyrsiflorus. Oxygen protection systems for nitrogenase differ dramatically between both species. Analysis of the antioxidant system suggested that the system in the nodules of D. glomerata leads to greater oxidative stress than the one in the nodules of C. thyrsiflorus, while no differences were found for the defense against nitrosative stress. However, induction of nitrite reductase in nodules of C. thyrsiflorus indicated that here, nitrite produced from nitric oxide had to be detoxified. Additional shared features were identified: genes encoding enzymes involved in thiamine biosynthesis were found to be upregulated in the nodules of both species. Orthologous nodule-specific subtilisin-like proteases that have been linked to the infection process in actinorhizal Fagales, were also upregulated in the nodules of D. glomerata and C. thyrsiflorus. Nodule-specific defensin genes known from actinorhizal Fagales and Cucurbitales, were also found in C. thyrsiflorus. In summary, the results underline the variability of nodule metabolism in different groups of symbiotic plants while pointing at conserved features involved in the infection process.

Effects of chlorogenic acid (CGA) supplementation during in vitro maturation culture on the development and quality of porcine embryos with electroporation treatment after in vitro fertilization.

Electroporation is the technique of choice to introduce an exogenous gene into embryos for transgenic animal production. Although this technique is practical and effective, embryonic damage caused by electroporation treatment remains a major problem. This study was conducted to evaluate the optimal culture system for electroporation-treated porcine embryos by supplementation of chlorogenic acid (CGA), a potent antioxidant, during in vitro oocyte maturation. The oocytes were treated with various concentrations of CGA (0, 10, 50, and 100 µmol/L) through the duration of maturation for 44 hr. The treated oocytes were then fertilized, electroporated at 30 V/mm with five 1 msec unipolar pulses, and subsequently cultured in vitro until development into the blastocyst stage. Without electroporation, the treatment with 50 µmol/L CGA had useful effects on the maturation rate of oocytes, the total cell number, and the apoptotic nucleus indices of blastocysts. When the oocytes were electroporated after in vitro fertilization, the treatment with 50 µmol/L CGA supplementation significantly improved the rate of oocytes that developed into blastocysts and reduced the apoptotic nucleus indices (4.7% and 7.6, respectively) compared with those of the untreated group (1.4% and 13.0, respectively). These results suggested that supplementation with 50 µmol/L CGA during maturation improves porcine embryonic development and quality of electroporation-treated embryos.

Proposal of 'Candidatus Frankia californiensis', the uncultured symbiont in nitrogen-fixing root nodules of a phylogenetically broad group of hosts endemic to western North America.

The genus Frankia comprises a group of nitrogen-fixing actinobacteria that form root-nodule symbioses with perennial dicotyledonous plants in the nitrogen-fixing clade. These bacteria have been characterized phylogenetically and grouped into four clusters (clusters 1-4). Cluster 2 contains mostly uncultured strains that induce nodules on species of the genera Datisca (Datiscaceae), Coriaria (Coriariaceae), Ceanothus (Rhamnaceae) and several genera in the family Rosaceae (Cercocarpus, Chamaebatia, Dryas, Purshia), all of which except members of the genus Coriaria are present within the California Floristic Province (CFP) or neighbouring areas of western North America. Those strains occurring in western North America are genetically very closely related to one another, and genetically distinct from strains characterized from other locales. We hereby propose to create a 'Candidatus Frankia californiensis' species for those cluster 2 strains of the genus Frankia with both high genetic similarity and a geographical distribution in or near the CFP.