ROS scavenging enzyme-encoding genes play important roles in the desert moss Syntrichia caninervis response to extreme cold and desiccation stresses

Abiotic stress is one of the major environmental constraints limiting plant growth. Syntrichia caninervis is one of the unique plant models that can cope with harsh environments. Reactive oxygen species (ROS) are a vital signaling molecule for protecting plants from oxidative stress, but research on ROS in S. caninervis is limited. Here, we identified 112 ROS genes in S. caninervis, including 40 GSTs, 51 PODs, 9 SODs, 6 CATs, 3 GPXs and 3 APXs families. GO and KEGG analyses showed that ROS genes are involved in responses to various stimuli and phenylpropanoid biosynthesis. ROS genes contain many stress-responsive and hormonal cis-elements in their promoter regions. More ROS genes were induced by cold stress than desiccation stress, and both conditions changed the transcript abundances of several ROS genes. CAT and POD, H2O2, MDA, and GSH were also induced under biotic stress, specifically CAT activity. The results indicated that the ScCAT genes and their activities could be strongly associated with the regulation of ROS production. This is the first systematic identification of ROS genes in S. caninervis and our findings contribute to further research into the roles of ScROS adjustment under abiotic stress while also providing excellent genetic resources for plant breeding.

Climate change reshaping plant-fungal interaction

Plant diseases pose a severe threat to modern agriculture, necessitating effective and lasting control solutions. Environmental factors significantly shape plant ecology. Human-induced greenhouse gas emissions have led to global temperature rise, impacting various aspects, including carbon dioxide (CO2) concentration, temperature, ozone (O3), and ultraviolet-B, all of which influence plant diseases. Altered pathogen ranges can accelerate disease transmission. This review explores environmental effects on plant diseases, with climate change affecting fungal biogeography, disease incidence, and severity, as well as agricultural production. Moreover, we have discussed how climate change influences pathogen development, host-fungal interactions, the emergence of new races of fungi, and the dissemination of emerging fungal diseases across the globe. The discussion about environment-mediated impact on pattern-triggered immunity (PTI), effector-triggered immunity (ETI), and RNA interference (RNAi) is also part of this review. In conclusion, the review underscores the critical importance of understanding how climate change is reshaping plant-fungal interactions. It highlights the need for continuous research efforts to elucidate the mechanisms driving these changes and their ecological consequences. As the global climate continues to evolve, it is imperative to develop innovative strategies for mitigating the adverse effects of fungal pathogens on plant health and food security.

Genome-Wide Characterization and Expression Analysis of Transcription Factor Families in Desert Moss Syntrichia caninervis under Abiotic Stresses

Transcription factor (TF) families play important roles in plant stress responses. S. caninervis is a new model moss for plant desiccation tolerance studies. Here, we report a high-confidence identification and characterization of 591 TFs representing 52 families that covered all chromosomes in S. caninervis. GO term and KEGG pathway analysis showed that TFs were involved in the regulation of transcription, DNA-templated, gene expression, binding activities, plant hormone signal transduction, and circadian rhythm. A number of TF promoter regions have a mixture of various hormones-related cis-regulatory elements. AP2/ERF, bHLH, MYB, and C2H2-zinc finger TFs were the overrepresented TF families in S. caninervis, and the detailed classification of each family is performed based on structural features. Transcriptome analysis revealed the transcript abundances of some ScAP2/ERF, bHLH, MYB, and C2H2 genes were accumulated in the treated S. caninervis under cold, dehydration, and rehydration stresses. The RT-qPCR results strongly agreed with RNA-seq analysis, indicating these TFs might play a key role in S. caninervis response to abiotic stress. Our comparative TF characterization and classification provide the foundations for functional investigations of the dominant TF genes involved in S. caninervis stress response, as well as excellent stress tolerance gene resources for plant stress resistance breeding.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Genome-wide identification and expression analysis of Polyamine Uptake Transporter gene family in sweet orange (Citrus sinensis)

Polyamine uptake transporter (PUT) plays important roles in polyamine homeostasis, but knowledge regarding PUT family genes in sweet orange (Citrus sinensis) remains elusive. Herein, our study aimed to perform a genome-wide identification of the PUT gene family in C. sinensis. A total of eight putative PUT genes (CsPUT1-CsPUT8) were identified in the sweet orange genome and distributed on three chromosomes. The CsPUT genes were divided into two major groups according to the phylogenetic tree analysis, with high similarities in protein domains and gene structure organization. The CsPUT genes were differentially expressed in different tissues, with the highest transcript levels being in the flowers and roots. Interestingly, the CsPUT genes were significantly induced by polyamines, putrescine, spermidine and spermine, indicating that CsPUT were possibly associated with intracellular polyamine transport and uptake. In addition, CsPUT showed differential expression in callus treated with ABA, cold, salt or osmotic shock. CsPUT4 was selected as a candidate for functional analysis of PUT. Overexpression of CsPUT4 elevated endogenous polyamine content and led to enhanced cold tolerance in transgenic callus cultures. Overall, these data provide valuable information for better understanding the potential biological functions of PUT genes in future.

Genomic analysis of WD40 protein family in the mango reveals a TTG1 protein enhances root growth and abiotic tolerance in Arabidopsis

WD40 domain-containing proteins constitute one of the most abundant protein families in all higher plants and play vital roles in the regulation of plant growth and developmental processes. To date, WD40 protein members have been identified in several plant species, but no report is available on the WD40 protein family in mango (Mangifera indica L.). In this study, a total of 315 WD40 protein members were identified in mango and further divided into 11 subgroups according to the phylogenetic tree. Here, we reported mango TRANSPARENT TESTA GLABRA 1 (MiTTG1) protein as a novel factor that functions in the regulation of Arabidopsis root growth and development. Bimolecular fluorescence complementation (BiFC) assay in tobacco leaves revealed that MiTTG1 protein physically interacts with MiMYB0, MiTT8 and MibHLH1, implying the formation of a new ternary regulatory complex (MYB-bHLH-WD40) in mango. Furthermore, the MiTTG1 transgenic lines were more adapted to abiotic stresses (mannitol, salt and drought stress) in terms of promoted root hairs and root lengths. Together, our findings indicated that MiTTG1 functions as a novel factor to modulate protein-protein interactions and enhance the plants abilities to adjust different abiotic stress responses.

Identification, characterization and expression profiling of circular RNAs in the early cotton fiber developmental stages

Circular RNA is one of the endogenous non-coding RNAs with a covalently closed loop structure and largely involved in regulating gene expression. However, the abundance of circular RNAs and their regulatory functions during the early stages of fiber development are still not known. In this work, we conducted high-throughput sequencing of the Ligonlintless-1 and its wild-type at 0 DPA, 8 DPA and stem. A total of 2811 circular RNAs were identified and unevenly distributed across cotton chromosomes. We found 34, 142 and 27 circular RNAs were differentially expressed between Ligonlintless-1 and wild-type at 0 DPA, 8 DPA and stem, respectively. Both circular RNA-microRNA-mRNA network and MeJA treatment results in Ligonlintless-1 and wild-type might provide a strong indication of four circular RNAs and ghr_miR169b being important biological molecular associating with fiber development. The results provide new insight into the putative molecular function of circular RNAs in the regulation of fiber development.

Genome-Wide Identification and Comparative Analysis of MYB Transcription Factor Family in Musa acuminata and Musa balbisiana

MYB transcription factors (TFs) make up one of the most important TF families in plants. These proteins play crucial roles in processes related to development, metabolism, and stimulus-response; however, very few studies have been reported for the characterization of MYB TFs from banana. The current study identified 305 and 251 MYB genes from Musa acuminata and Musa balbisiana, respectively. Comprehensive details of MYBs are reported in terms of gene structure, protein domain, chromosomal localization, phylogeny, and expression patterns. Based on the exon-intron arrangement, these genes were classified into 12 gene models. Phylogenetic analysis of MYBs involving both species of banana, Oryza sativa, and Arabidopsis thaliana distributed these genes into 27 subfamilies. This highlighted not only the conservation, but also the gain/loss of MYBs in banana. Such genes are important candidates for future functional investigations. The MYB genes in both species exhibited a random distribution on chromosomes with variable densities. Estimation of gene duplication events revealed that segmental duplications represented the major factor behind MYB gene family expansion in banana. Expression profiles of MYB genes were also explored for their potential involvement in acetylene response or development. Collectively, the current comprehensive analysis of MYB genes in both species of banana will facilitate future functional studies.

Investigation of the EIL/EIN3 Transcription Factor Gene Family Members and Their Expression Levels in the Early Stage of Cotton Fiber Development

The ethylene-insensitive3-like/ethylene-insensitive3 (EIL/EIN3) protein family can serve as a crucial factor for plant growth and development under diverse environmental conditions. EIL/EIN3 protein is a form of a localized nuclear protein with DNA-binding activity that potentially contributes to the intricate network of primary and secondary metabolic pathways of plants. In light of recent research advances, next-generation sequencing (NGS) and novel bioinformatics tools have provided significant breakthroughs in the study of the EIL/EIN3 protein family in cotton. In turn, this paved the way to identifying and characterizing the EIL/EIN3 protein family. Hence, the high-throughput, rapid, and cost-effective meta sequence analyses have led to a remarkable understanding of protein families in addition to the discovery of novel genes, enzymes, metabolites, and other biomolecules of the higher plants. Therefore, this work highlights the recent advance in the genomic-sequencing analysis of higher plants, which has provided a plethora of function profiles of the EIL/EIN3 protein family. The regulatory role and crosstalk of different metabolic pathways, which are apparently affected by these transcription factor proteins in one way or another, are also discussed. The ethylene hormone plays an important role in the regulation of reactive oxygen species in plants under various environmental stress circumstances. EIL/EIN3 proteins are the key ethylene-signaling regulators and play important roles in promoting cotton fiber developmental stages. However, the function of EIL/EIN3 during initiation and early elongation stages of cotton fiber development has not yet been fully understood. The results provided valuable information on cotton EIL/EIN3 proteins, as well as a new vision into the evolutionary relationships of this gene family in cotton species.

Genome-wide analysis of cotton C2H2-zinc finger transcription factor family and their expression analysis during fiber development

BACKGROUND

C2H2-zinc finger protein family is commonly found in the plant, and it is known as the key actors in the regulation of transcription and vital component of chromatin structure. A large number of the C2H2-zinc finger gene members have not been well characterized based on their functions and structure in cotton. However, in other plants, only a few C2H2-zinc finger genes have been studied.

RESULTS

In this work, we performed a comprehensive analysis and identified 386, 196 and 195 C2H2-zinc finger genes in Gossypium hirsutum (upland cotton), Gossypium arboreum and Gossypium raimondii, respectively. Phylogenetic tree analysis of the C2H2-zinc finger proteins encoding the C2H2-zinc finger genes were classified into seven (7) subgroups. Moreover, the C2H2-zinc finger gene members were distributed in all cotton chromosomes though with asymmetrical distribution patterns. All the orthologous genes were detected between tetraploid and the diploid cotton, with 154 orthologous genes pair detected between upland cotton and Gossypium arboreum while 165 orthologous genes were found between upland cotton and Gossypium raimondii. Synonymous (Ks) and non-synonymous (Ka) nucleotide substitution rates (Ka/Ks) analysis indicated that the cotton C2H2-zinc finger genes were highly influenced mainly by negative selection, which maintained their protein levels after the duplication events. RNA-seq data and RT-qPCR validation of the RNA seq result revealed differential expression pattern of some the C2H2-zinc finger genes at different stages of cotton fiber development, an indication that the C2H2-zinc finger genes play an important role in initiating and regulating fiber development in cotton.

CONCLUSIONS

This study provides a strong foundation for future practical genome research on C2H2-zinc finger genes in upland cotton. The expression levels of C2H2-zinc finger genes family is a pointer of their involvement in various biochemical and physiological functions which are directly related to cotton fiber development during initiation and elongation stages. This work not only provides a basis for determining the nominal role of the C2H2-zinc finger genes in fiber development but also provide valuable information for characterization of potential candidate genes involved in regulation of cotton fiber development.

Long non-coding RNAs and their potential functions in Ligon-lintless-1 mutant cotton during fiber development

Background

Long non-coding RNAs (LncRNAs) are part of genes, which are not translated into proteins and play a vital role in plant growth and development. Nevertheless, the presence of LncRNAs and how they functions in Ligon-lintless-1 mutant during the early cessation of cotton fiber development are still not well understood. In order to investigate the function of LncRNAs in cotton fiber development, it is necessary and important to identify LncRNAs and their potential roles in fiber cell development.

Results

In this work, we identified 18,333 LncRNAs, with the proportion of long intergenic noncoding RNAs (LincRNAs) (91.5%) and anti-sense LncRNAs (8.5%), all transcribed from Ligon-lintless-1 (Li1) and wild-type (WT). Expression differences were detected between Ligon-lintless-1 and wild-type at 0 and 8 DPA (day post anthesis). Pathway analysis and Gene Ontology based on differentially expressed LncRNAs on target genes, indicated fatty acid biosynthesis and fatty acid elongation being integral to lack of fiber in mutant cotton. The result of RNA-seq and RT-qPCR clearly singles out two potential LncRNAs, LNC_001237 and LNC_017085, to be highly down-regulated in the mutant cotton. The two LncRNAs were found to be destabilized or repressed by ghr-miR2950. Both RNA-seq analysis and RT-qPCR results in Ligon-lintless-1 mutant and wild-type may provide strong evidence of LNC_001237, LNC_017085 and ghr-miR2950 being integral molecular elements participating in various pathways of cotton fiber development.

Conclusion

The results of this study provide fundamental evidence for the better understanding of LncRNAs regulatory role in the molecular pathways governing cotton fiber development. Further research on designing and transforming LncRNAs will help not only in the understanding of their functions but will also in the improvement of fiber quality.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5978-5) contains supplementary material, which is available to authorized users.

Genome-wide characterization, identification, and expression analysis of the WD40 protein family in cotton

WD40 repeat proteins are largely distributed across the plant kingdom and play an important role in diverse biological activities. In this work, we performed genome-wide identification, characterization, and expression level analysis of WD40 genes in cotton. A total of 579, 318, and 313 WD40 genes were found in Gossypium hirsutum, G. arboreum, and G. raimondii, respectively. Based on phylogenetic tree analyses, WD40 genes were divided into 11 groups with high similarities in exon/intron features and protein domains within the group. Expression analysis of WD40 genes showed differential expression at different stages of cotton fiber development (0 and 8 DPA) and cotton stem. A number of miRNAs were identified to target WD40 genes that are significantly involved in cotton fiber development during the initiation and elongation stages. These include miR156, miR160, miR162, miR164, miR166, miR167, miR169, miR171, miR172, miR393, miR396, miR398, miR2950, and miR7505. The findings provide a stronger indication of WD40 gene function and their involvement in the regulation of cotton fiber development during the initiation and elongation stages.

Characterization of the late embryogenesis abundant (LEA) proteins family and their role in drought stress tolerance in upland cotton

Background

Late embryogenesis abundant (LEA) proteins are large groups of hydrophilic proteins with major role in drought and other abiotic stresses tolerance in plants. In-depth study and characterization of LEA protein families have been carried out in other plants, but not in upland cotton. The main aim of this research work was to characterize the late embryogenesis abundant (LEA) protein families and to carry out gene expression analysis to determine their potential role in drought stress tolerance in upland cotton. Increased cotton production in the face of declining precipitation and availability of fresh water for agriculture use is the focus for breeders, cotton being the backbone of textile industries and a cash crop for many countries globally.

Results

In this work, a total of 242, 136 and 142 LEA genes were identified in G. hirsutum, G. arboreum and G. raimondii respectively. The identified genes were classified into eight groups based on their conserved domain and phylogenetic tree analysis. LEA 2 were the most abundant, this could be attributed to their hydrophobic character. Upland cotton LEA genes have fewer introns and are distributed in all chromosomes. Majority of the duplicated LEA genes were segmental. Syntenic analysis showed that greater percentages of LEA genes are conserved. Segmental gene duplication played a key role in the expansion of LEA genes. Sixty three miRNAs were found to target 89 genes, such as miR164, ghr-miR394 among others. Gene ontology analysis revealed that LEA genes are involved in desiccation and defense responses. Almost all the LEA genes in their promoters contained ABRE, MBS, W-Box and TAC-elements, functionally known to be involved in drought stress and other stress responses. Majority of the LEA genes were involved in secretory pathways. Expression profile analysis indicated that most of the LEA genes were highly expressed in drought tolerant cultivars Gossypium tomentosum as opposed to drought susceptible, G. hirsutum. The tolerant genotypes have a greater ability to modulate genes under drought stress than the more susceptible upland cotton cultivars.

Conclusion

The finding provides comprehensive information on LEA genes in upland cotton, G. hirsutum and possible function in plants under drought stress.

Electronic supplementary material

The online version of this article (10.1186/s12863-017-0596-1) contains supplementary material, which is available to authorized users.

Characterization of the late embryogenesis abundant (LEA) proteins family and their role in drought stress tolerance in upland cotton

BACKGROUND

Late embryogenesis abundant (LEA) proteins are large groups of hydrophilic proteins with major role in drought and other abiotic stresses tolerance in plants. In-depth study and characterization of LEA protein families have been carried out in other plants, but not in upland cotton. The main aim of this research work was to characterize the late embryogenesis abundant (LEA) protein families and to carry out gene expression analysis to determine their potential role in drought stress tolerance in upland cotton. Increased cotton production in the face of declining precipitation and availability of fresh water for agriculture use is the focus for breeders, cotton being the backbone of textile industries and a cash crop for many countries globally.

RESULTS

In this work, a total of 242, 136 and 142 LEA genes were identified in G. hirsutum, G. arboreum and G. raimondii respectively. The identified genes were classified into eight groups based on their conserved domain and phylogenetic tree analysis. LEA 2 were the most abundant, this could be attributed to their hydrophobic character. Upland cotton LEA genes have fewer introns and are distributed in all chromosomes. Majority of the duplicated LEA genes were segmental. Syntenic analysis showed that greater percentages of LEA genes are conserved. Segmental gene duplication played a key role in the expansion of LEA genes. Sixty three miRNAs were found to target 89 genes, such as miR164, ghr-miR394 among others. Gene ontology analysis revealed that LEA genes are involved in desiccation and defense responses. Almost all the LEA genes in their promoters contained ABRE, MBS, W-Box and TAC-elements, functionally known to be involved in drought stress and other stress responses. Majority of the LEA genes were involved in secretory pathways. Expression profile analysis indicated that most of the LEA genes were highly expressed in drought tolerant cultivars Gossypium tomentosum as opposed to drought susceptible, G. hirsutum. The tolerant genotypes have a greater ability to modulate genes under drought stress than the more susceptible upland cotton cultivars.

CONCLUSION

The finding provides comprehensive information on LEA genes in upland cotton, G. hirsutum and possible function in plants under drought stress.

Genome-wide characterization and expression analysis of MYB transcription factors in Gossypium hirsutum

Background

MYB family proteins are one of the most abundant transcription factors in the cotton plant and play diverse roles in cotton growth and evolution. Previously, few studies have been conducted in upland cotton, Gossypium hirsutum. The recent release of the G. hirsutum genome sequence provides a great opportunity to identify and characterize the entire upland cotton MYB protein family.

Results

In this study, we undertook a comprehensive genome-wide characterization and expression analysis of the MYB transcription factor family during cotton fiber development. A total of 524 non-redundant cotton MYB genes, among 1986 MYB and MYB-related putative proteins, were identified and classified into four subfamilies including 1R-MYB, 2R-MYB, 3R-MYB, and 4R-MYB. Based on phylogenetic tree analysis, MYB transcription factors were divided into 16 subgroups. The results showed that the majority (69.1 %) of GhMYBs genes belong to the 2R-MYB subfamily in upland cotton.

Conclusion

Our comparative genomics analysis has provided novel insights into the roles of MYB transcription factors in cotton fiber development. These results provide the basis for a greater understanding of MYB regulatory networks and to develop new approaches to improve cotton fiber development.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-016-0436-8) contains supplementary material, which is available to authorized users.

[Long term results of implantable loop recorder in patients with syncope: results of a French survey]

BACKGROUND AND OBJECTIVE

A first publication of our group demonstrated that implantation of a loop recorder in 30 patients experiencing an unexplained syncope (Medtronic Reveal DX or XT) definitively determined that an arrhythmia was the cause of symptoms in 10 patients (32%). However, we lack the results of a survey evaluating the results of long term follow-up after a loop recorder implantation and the results in case of wider indications of implantation of loop recorders.

METHODS AND RESULTS

A device (Medtronic Reveal DX or XT) was implanted in 97 patients between january 2009 and june 2014. During a mean follow-up of 21±19 months, loop recording determined that an arrhythmia was the cause of symptoms in 34 patients (35%). For the management of these arrhythmias, treatments received by patients were a pacemaker implantation in 18 patients (53%), an implantable cardioverter-defibrillator in four patients (12%) and a supraventricular tachycardia ablation (cryo or radiofrequency ablation) in three patients (9%). For nine patients (26%), the arrhythmic events were asymptomatic and didn't justify a specific treatment. The final positive rate of loop monitoring implantation was of 25/97 (26%). The study demonstrated that the positivity of the follow-up was demonstrated after two years of follow-up in 26% of the cases.

CONCLUSION

Long-term follow-up of 97 patients implanted by a loop monitor leaded to an interventional rythmology procedure in 26% of the cases. In 26% of patients, loop-monitoring follow-up was positive after a duration of more than two years.

[Recovered sudden cardiac death associated with an early repolarization syndrome: case analysis and pratical aspects]

In this article, we report the case of a 61-year-old man who presented a cardiac arrest which has been resuscitated successfully. An early repolarization syndrome has been diagnosed by the ECG recorded the first 3 days after admission. This abnormality disappeared after that. The patient received an implantable cardioverter-defibrillator. Practical messages to the clinician concerning early repolarization are provided in this article.

[Long-term follow-up after implantable loop recorder in patients with syncope: results of a French general hospital survey]

BACKGROUND AND OBJECTIVE

Despite recent advances in diagnostic procedures, syncope remains unexplained in 15 to 35% of patients. If implantable loop recorder is a validated diagnostic tool for unexplained syncope, results of this strategy are largely issued from randomized studies. We lack the results of surveys. The aim of this study was to report a single center experience with implantable loop recorders, in patients with unexplained syncope.

METHODS AND RESULTS

A device (Medtronic Reveal DX or XT) was implanted in 31 patients between January 2009 and January 2012. During a mean follow-up of 10.5±8.5 months, loop recording definitively determined that an arrhythmia was the cause of symptoms in 10 patients (32%). Fourteen patients (45%) experienced syncope or pre-syncope. In eight of the 14 patients with syncope, during follow-up, no arrhythmic diagnosis could be made (one patient has been diagnosed as presenting epilepsy and seven as having hypotensive vasovagal syncope). In six patients, the ILR showed an arrhythmic aetiology. Four other patients presented an abnormal ILR result without symptoms. Diagnosis included sinusal arrest in four patients, bradycardia in one patient, advanced atrioventricular block in two patients, ventricular arrythmias in two patients, and supraventricular tachycardia of 180/min in one patient. Therapy was instituted in all patients, in whom an arrhythmic cause was found except one who refused the therapy (six pacemaker, two implantable cardioverter-defibrillator implantations, and one cryoablation of atrioventricular nodal reentrant tachycardia confirmed by an invasive exploration).

CONCLUSION

In this survey, implantable loop recorder implantation led to the diagnosis of an arrhythmic cause in 32% of patients and excluded an arrhythmic cause in 26% of patient with a mean follow-up of 10.5 months.

[Severe sick sinus syndrome associated with a Werner's syndrome]

A 39-year-old woman was explored for recurrent syncopes. She was already known for a Werner's syndrome with symptoms of aging disorders. The explorations revealed an episode of sinusal arrest. A pacemaker was implanted. This case emphasises the relation between Werner syndrome and the development of cardiovascular abnormalities. This pathology should be recalled in young patients with symptoms of aging disorders and cardiovascular abnormalities. Valvular abnormalities, myocardial infarction and stroke are the major complications of Werner's syndrome. This case indicates that a sick sinus syndrome is a rare but possible complication of Werner's syndrome.

Serum-free generation and quantification of functionally active Leukemia-derived DC is possible from malignant blasts in acute myeloid leukemia and myelodysplastic syndromes

Functional dendritic cells (DC) are professional antigen presenting cells (APC) and can be generated in vitro from leukemic cells from acute myeloid leukemia AML patients, giving rise to APC of leukemic origin presenting leukemic antigens (DC(leu)). We have already shown that DC can be successfully generated from AML and myeloplastic syndromes (MDS) cells in serum-free 'standard' medium (X-vivo + GM-CSF + IL-4 +TNFalpha + FL) in 10-14 days. In this study, we present that DC counts generated from mononuclear cells (MNC) varied between 20% (from 55 MDS samples), 34% (from 100 AML samples) and 25% (from 38 healthy MNC samples) medium. Between 53% and 58% of DC are mature CD83+ DC. DC harvests were highest in monocytoid FAB types (AML-M4/M5, MDS-CMML) and independent from cytogenetic risk groups, demonstrating that DC-based strategies can be applied for patients with all cytogenetic risk groups. Proof of the clonal derivation of DC generated was obtained in five AML and four MDS cases with a combined FISH/immunophenotype analysis (FISH-IPA): The clonal numerical chromosome aberrations of the diseases were regularly codetectable with DC markers; however, not with all clonal cells being convertible to leukemia-derived DC(leu) (on average, 53% of blasts in AML or MDS). To the contrary, not all DC generated carried the clonal aberration (on average, 51% of DC). In 41 AML and 13 MDS cases with a suitable antigen expression, we could confirm FISH-IPA data by Flow cytometry: although DC(leu) are regularly detectable, on average only 57% of blasts in AML and 64% of blasts in MDS were converted to DC(leu). After coculture with DC in mixed lymphocyte reactions (MLR), autologous T cells from AML and MDS patients proliferate and upregulate costimulatory receptors. The specific lysis of leukemic cells by autologous T cells could be demonstrated in three cases with AML in a Fluorolysis assay. In six cases with only few DC(leu) or few vital T cells available after the DC/MLR procedure, no lysis of allogeneic or autologous leukemic cells was seen, pointing to the crucial role of both partners in the lysis process. We conclude: (1) the generation of DC is regularly possible in AML and also in MDS under serum-free conditions. (2) Clonal/leukemia-derived DC(leu) can be regularly generated from MDS and AML-MNC; however, not with all blasts being converted to DC(leu) and not all DC generated carrying leukemic markers. We recommend to select DC(leu) for vaccinations or ex vivo T-cell activations to avoid contaminations with non-converted blasts and non-leukemia-derived DC and to improve the harvest of specific, anti-leukemic T cells. DC and DC-primed T cells could provide a practical strategy for the immunotherapy of AML and MDS.

The value of percutaneous fine needle aspiration cytology under ultrasound guidance in the diagnosis of pancreatic masses

Between September 1996 and May 1999 twenty six pa-tients with a pancreatic mass were studied. In 24 patients (92.3%) the masses could be detected by ultrasound but were not detectable in the other two cases. In the 24 pa-tients percutaneous FN AC under u/s guidance produced only one complication.

The accuracy of this test in diagnosing pancreatic ma-lignant tumours was 90.4%. Laparotomy was not neces-sary in three cases with advanced pancreatic carcinoma (11.5%) and the material aspirated was not suitable for di-agnosis in three cases. No benign lesions were found and so it was not possible to estimate the reliability of FN AC in their diagnosis.

Role of target antigen in bispecific-antibody-mediated killing of human glioblastoma cells: a pre-clinical study

Bispecific antibodies (bsAbs) directed to tumor-associated antigens and to receptors mediating T-cell activation, such as the TCR/CD3 complex and the co-stimulatory CD28 molecule, are capable of activating T cells at the surface of tumor cells, resulting in tumor-cell killing. Here we report the pre-clinical characterization of bispecific-antibody fragments (bsFab2) directed to 2 different glioblastoma-associated antigens: the EGF receptor (EGFR) and a chondroitin-sulfate proteoglycan (CSPG). Using cultured glioblastoma cells expressing both target antigens, we found that the ability of anti-tumor x anti-CD28 bsFab2 to mediate "targeted T-cell co-stimulation" is superior for constructs targeting the CSPG molecule, correlating with an approximately 6-fold higher expression level of this antigen on the cell surface. In contrast, bsFab2 triggering CD3 are more effective if they contain EGFR-target specificity. This indicates that the activity of anti-tumor x anti-CD3 constructs critically depends on properties of the antigen other than its expression level on the cell surface, e.g., its mobility in the membrane. These findings prompted us to use EGFR-targeting bsFab2 in an ongoing clinical trial with glioma patients.

Inhibitory effect of heparin on neutrophil phagocytosis and burst production using a new whole-blood cytofluorometric method for determination

The influence of heparin on Polymorphonuclear (PMN s) leukocytes was investigated using a new whole-blood cytofluorometric method (patent granted for the test with the number P 4334935.8-41) with Candida albicans and Staphylococcus aureus as test microorganisms. After comparing the effect of equal volumes of two widely used heparins we examined the influence of 5 different heparin-concentrations. Using both yeasts and bacteria, we found a significant, dose-depending decrease of the percentage of phagocyting PMN's and of phagocytized microorganisms as well as of the resulting percentage of PMN s producing respiratory burst along the kinetics. Furthermore we could demonstrate that heparin independently of phagocytosis produces a dose-dependent decrease of burst production of PMN's. Our results indicate that the use of heparins as anticoagulant for immunological investigations as well as clinically with patients under immunosuppressive therapy should be critically reconsidered. This applies even more because due to the evaluated dose-dependent decrease of phagocyte function no boundary for the inhibiting effect can be declared.

Immunoassay of O6-methyldeoxyguanosine in DNA: the use of polyethylene glycol to separate bound and free nucleoside

Radioimmunoassay (RIA) method has been established to O6-methyldeoxyguanosine (O6-medGua), using precipitation with polyethylene glycol (PEG) to separate bound and free alkyldeoxyguanosine and antisera of higher affinity (1 x 10(9) M-1) and titre (1:10000) than previously reported. The lower limit of detection (2 S.D. from zero standard) is 40 pg (0.14 pmol) of O6-medGua. Hydrolysates of non-alkylated DNA extracts show interference in the precipitation of antigen-antibody complex, thus making necessary the construction of a standard curve with the same amount of DNA hydrolysates as in the sample to be analysed. Precision of the method was assessed using DNA hydrolysates from livers of rats injected with 15 mg/kg dimethylnitrosamine (DMN). Within assay variation of a single DNA extract was 85.9 +/- 5.9 ng/mg DNA (n = 5, CV = 6.9%). Day-to-day variation of the assay for four DNA extracts measured over 3 days were (ng/mg DNA S.D.), 99.8 +/- 6.9, CV = 6.9%; 88.2 +/- 6.5, CV = 7.4%; 81.3 +/- 3.9, CV = 4.8%; 77.0 +/- 6.4 CV = 8.3%. Coefficient of variation was 10.8% with DNA hydrolysate spiked with a known concentration of O6-medGua and assayed (n = 5). Cross-reactivity of one of our best antisera coded R68/4, and raised against O6-medGua-BSA conjugate were: O6-methylguanosine (O6-meGua), 9.6%; O6-methylguanine (O6-meGua), 0.4%; O6-ethylguanine (O6-EtGua), 0.12%; 7-methylguanosine (7-meGuo), 0.03%; 2'-deoxyadenosine (2'-dAdo), 0.007%; 2'-deoxyguanosine-5'-monophosphoric acid (2'-dGuaMP), 2'-deoxyguanosine (2'-dGua), 7-meGua and 7-meGuo did not significantly inhibit the binding of O6-me[1-2'-3H]dGuo at concentrations of up to 10 micrograms/tube. The application of such methods underline the potential of RIAs for quantification of DNA components structurally modified by non-radioactive carcinogens.

Immunocytochemical and autoradiographic demonstration of prolactin binding to human breast cancer cells in tissue culture

Specific binding of human prolactin to human breast cancer cells in culture was demonstrated for the first time by immunocytochemistry ad autoradiography. Using the former technique, it was found that prolactin binding to the cell surface was heterogeneous: some cells showing intense to moderate peroxidase reaction product and some cells showing absence of reaction product. After the cells were incubated with 125I-labeled prolactin and then embedded in plastic, autoradiography of sections revealed both surface-localized and intracellular silver grains, the latter suggesting internalization of prolactin. These two cytological techniques are useful for visualizing prolactin binding to human breast cancer cells and are applicable to studies on prolactin binding in human breast cancer.