[Analysis of clinical characteristics and risk factors of postoperative complications in infants with early-onset necrotizing enterocolitis after enterostomy]

Objective: To investigate the clinical characteristics of children with early-onset necrotizing enterocolitis (NEC) undergoing enterostomy and analyze the risk factors for postoperative complications. Methods: Retrospective analysis was conducted on the clinical data (perinatal conditions, clinical characteristics, clinical outcomes, etc.) of NEC patients who underwent enterostomy at Beijing Children's Hospital from May 2016 to May 2023. The patients were divided into two groups based on the age of onset: an early-onset enterostomy group (<14 days) and a late-onset enterostomy group (≥14 days). Furthermore, the children with NEC were categorized into complication group and non-complication group based on whether there were complications after enterostomy. The differences in clinical data between these groups were analyzed, and the clinical characteristics of children with early-onset NEC and enterostomy were summarized. Multivariate logistic regression model was employed to analyze the risk factors for postoperative complications in NEC children with enterostomy. Results: A total of 68 cases were enrolled, including 43 cases in the early-onset enterostomy group [26 males and 17 females, aged (6.5±3.0) days] and 25 cases in the late-onset enterostomy group [15 males and 10 females, aged (21.0±3.0) days]. There were 28 cases (17 males and 11 females), age [M (Q1, Q3)] 9 (5, 14) days in the complication group and 33 cases (22 males and 11 females), aged of 14 (6, 21) days in the non-complication group. Compared to the late-onset enterostomy group, the early-onset enterostomy group had significantly higher rates of intraventricular hemorrhage [30.2% (13/43) vs 8.0% (2/25)], hemodynamically significant patent ductus arteriosus [37.2% (16/43) vs 12.0% (3/25)], mechanical ventilation≥72 hours after birth [39.5% (17/43) vs 16.0% (4/25)], stage Ⅲ NEC [(69.8% (30/43) vs 40.0% (10/25)], extensive NEC [27.9% (12/43) vs 8.0% (2/25)], and short-term postoperative complications [56.8% (21/37) vs 29.2% (7/24)] (all P<0.05).Multivariate logistic regression model analysis revealed that residual length of proximal small intestine was a protective factor for postoperative complications after enterostomy in NEC infants (OR=0.764, 95%CI: 0.648-0.901, P=0.001), but stage Ⅲ NEC was a risk factor (OR=1.042, 95%CI: 1.004-5.585, P=0.017). Conclusions: The incidence of postoperative complications is high, and the prognosis is poor in children with early-onset NEC enterostomy. The residual length of proximal enterostomy is a protective factor for postoperative complications of NEC enterostomy, but stage Ⅲ NEC is a risk factor.

[Status of fungal sepsis among preterm infants in 25 neonatal intensive care units of tertiary hospitals in China]

Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34⁺⁰ weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.

Characteristics and long-term ablation outcomes of supraventricular arrhythmias in hypertrophic cardiomyopathy: a 10-year, single-center experience

Background

A variety of supraventricular arrhythmias (SVAs) may occur in patients with hypertrophic cardiomyopathy (HCM). The characteristics and long-term ablation outcomes of different types of SVAs in HCM have not been comprehensively investigated.

Methods

We retrospectively enrolled 101 consecutive symptomatic HCM patients with suspected arrhythmia from May 2010 to October 2020. The clinical features and ablation outcomes of patients with SVAs were further analyzed.

Results

Seventy-eight patients had SVAs, consisting of 50 (64.1%) atrial fibrillation (AF), 16 (20.5%) atrial flutter (AFL), 15 (19.2%) atrioventricular reentrant tachycardia (AVRT), 11 (14.1%) atrial arrhythmia (AT), and 3 (3.8%) atrioventricular nodal reentrant tachycardia (AVNRT). Thirty-four patients underwent catheter ablation including 14 for AF, 9 for AVRT, 6 for AFL, 3 for AVNRT, 1 for both AF and AFL, and 1 for both AF and AVRT. They were followed up for a median (interquartile range) of 58.5 (82.9) months. There were no recurrences for patients with non-AF SVAs. For patients with AF, the 1- and 7-year AF-free survival were 87.5% and 49.5%, respectively. A ROC analysis revealed that a greater left ventricular end-diastolic dimension (LVEDD) was associated with higher recurrence of AF with an optimum cutoff value of 47mm (c-statistic = 0.91, p=0.011, sensitivity = 1.00, specificity = 0.82). In Kaplan-Meier analysis, patients with LVEDD ≥47mm had worse AF-free survival (log-rank p=0.014).

Conclusions

AF is the most common SVA in HCM, with AFL, AVRT, AT, and AVNRT ranking the second to the last according to the prevalence. The long-term catheter ablation outcome for non-AF SVAs in HCM is satisfying. A greater LVEDD predicts AF recurrence after catheter ablation in patients with HCM.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Natural Science Foundation of China Figure 1Figure 2

MicroRNA-217 alleviates development of non-small cell lung cancer by inhibiting AKT3 via PI3K pathway

OBJECTIVE

To explore the role of microRNA-217 in non-small cell lung cancer (NSCLC) and its underlying mechanism.

PATIENTS AND METHODS

MicroRNA-217 expression in 48 NSCLC tissues and paracancerous tissues were detected by qRT-PCR (quantitative Real-time polymerase chain reaction). The relationship between microRNA-217 expression and prognosis of NSCLC patients was analyzed. Target gene of microRNA-217 was predicted by bioinformatics method and further verified by luciferase reporter gene assay. Cell proliferation, cell cycle and apoptosis were detected after altering microRNA-217 expression in NSCLC cells. The effect of microRNA-217 on regulating PI3K pathway was detected by Western blot.

RESULTS

MicroRNA-217 was downregulated in NSCLC tissues than that of paracancerous tissues. Shorter overall survival (OS) was observed in NSCLC patients with lower expression of microRNA-217 than those with higher expression. Overexpressed microRNA-217 remarkably inhibited proliferation and cell cycle, whereas induced apoptosis of NSCLC cells. AKT3 was screened out to be the target gene of microRNA-217. Western blot results demonstrated that microRNA-217 upregulated AKT3 and PI3K pathway-related genes.

CONCLUSIONS

Downregulated microRNA-217 promotes the occurrence and progression of NSCLC through upregulating AKT3 via PI3K pathway.

LncRNA-UCA1 promotes PD development by upregulating SNCA

OBJECTIVE

The study aims to investigate whether Long non-coding RNA (LncRNA)-UCA1 can regulate the progression of Parkinson's disease (PD) by mediating a-synuclein (SNCA) expression.

MATERIALS AND METHODS

PD mouse model was first constructed by intraperitoneal injection of MPTP. SH-SY5Y cells were treated with MPP+ for inducing in vitro PD model. Expression levels of lncRNA-UCA1 and SNCA in brain tissues extracted from PD mice and MPP+-induced SH-SY5Y cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression of SNCA was accessed by Western blot. After transfection of pcDNA-NC+DMSO, pcDNA-UCA1+DMSO, pcDNA-NC+α-amantin or pcDNA-UCA1+α-amanitin in SH-SY5Y cells, SNCA expression was detected. Cell viability and SNCA expression were determined after UCA1 overexpression or knockdown in SH-SY5Y cells. Neuronal apoptosis in MPP+-induced SH-SY5Y cells was detected by flow cytometry after the UCA1 knockdown.

RESULTS

UCA1 and SNCA were highly expressed in brain tissues extracted from PD mice and MPP+-induced SH-SY5Y cells. UCA1 overexpression remarkably upregulated mRNA and protein expressions of SNCA in SH-SY5Y cells. Higher viability was seen after the UCA1 knockdown in MPP+-induced SH-SY5Y cells. UCA1 knockdown remarkably inhibited caspase-3 activity and decreased MPP+-induced neuronal apoptosis in SH-SY5Y cells.

CONCLUSIONS

LncRNA-UCA1 promotes the occurrence and progression of PD by upregulating SNCA expression.

Transforming Growth Factor-β Partially Reversed the Immunosuppressive Effect of Mesenchymal Stem Cells in Mice

BACKGROUND

Mesenchymal stem cells (MSCs) possess powerful immunosuppression capacity. Transforming growth factor-β (TGF-β) is a well-known anti-inflammatory cytokine and plays an important role in various inflammatory processes. We hypothesized that TGF-β could synergize with MSCs in suppressing immune responses, and therefore established a mouse skin graft model to evaluate the effect of MSCs and MSCs combined with TGF-β on transplantation immunity in vivo.

METHODS

Balb/c and C57BL/6 mice were used to establish the skin graft model. The recipients were divided into 3 groups and received intravenous bone marrow mesenchymal stem cells (BMSCs), BMSCs pretreated with TGF-β, and 0.9% saline solution, respectively. Skin graft survival time, pathological detection, the ratio of CD4+CD25+Foxp3+Treg cell of spleens, and the level of IFN-γ, IL-2, IL-10, and TGF-β expression were tested.

RESULTS

The survival time of skin grafts were prolonged in both BMSC (12.5 ± 1.35 days) and BMSC-TGF-β (10.6 ± 1.90 days) recipients compared to the blank control recipients (8.0 ± 1.05 days). The ratio of CD4+CD25+Foxp3+Treg cell of spleens from BMSC and BMSC-TGF-β recipients was higher than that of the blank control, and the upregulated proliferation in the BMSC group occurred earlier and was prolonged compared to the BMSC-TGF-β group. The expression of IFN-γ and IL-2 was inhibited in both the BMSC and BMSC-TGF-β groups compared to the blank, while the expression of IL-10 and TGF-β was boosted. In contrast to the BMSC group, the BMSC-TGF-β group exhibited a weaker effect on the expression of cytokines.

CONCLUSION

TGF-β partially reversed the immunosuppressive effect of MSCs in vivo. This immunoregulatory feature may have potential applications for treating transplant rejection.

[Preparation of bioactive denatured acellular dermal matrix from burn mice riched in mice bone marrow mesenchymal stem cells]

Objective: To investigate the preparation of bioactive denatured acellular dermal matrix (DADM) from burn mice riched in mice bone marrow mesenchymal stem cells. Methods: Twelve BALB/c mice were collected and 20% total body surface area scalds (hereinafter referred to as burns) with deep partial thickness were inflicted on the back skin of each mouse. After removing epidermis, the burned skin were collected and divided into Triton X-100 group and elhylene diamine tetraacetic acid (EDTA) group according to the random number table, with 15 samples in each group. Samples in Triton X-100 group and EDTA group were respectively placed in mixture of 2.5 g/L Triton X-100 and 2.5 g/L trypsin solution and mixture of 0.2 g/L EDTA and 2.5 g/L trypsin solution for sustained vibration and elution for 24 hours to make mice DADM. The general appearance of DADM was observed. The structure and arrangement of collagen fibers of DADM were observed by scanning electron microscope and tissue structure of DADM were observed by fluorescence microscope. Bone marrow mesenchymal stem cells (BMSCs) from mice were transplanted in mice DADM in the two groups with concentration of 2×105 cells per well to prepare bioactive mice DADM. After cultured for 3 days, tissue structure of bioactive mice DADM was observed by hematoxylin and eosin staining, distribution and number of BMSCs of bioactive mice DADM were observed by immunofluorescence staining. Proliferation of BMSCs of bioactive mice DADM after cultured for 2 h, 1 d, 3 d, and 5 d was detected by cell count kit-8. Data were processed with analysis of variance for repeated measurement and t test. Results: (1) Mice DADM in the two groups were white in appearance with certain tenacity and elasticity. Mice DADM in the two groups maintained good three-dimensional porous network structure. Collagen fibers of mice DADM in EDTA group were with good continuity, and collagen fibers of mice DADM in Triton X-100 group were fractured in varying degrees. Mice DADM in the two groups were decellularized completely, and the collagen fibers were loose and arranged disorderly. The continuity of tissue structure of mice DADM in EDTA group was better than that of mice DADM in Triton X-100 group. (2) After cultured for 3 days, the BMSCs in bioactive mice DADM in the two groups were evenly distributed. The number of bioactive BMSCs in mice DADM in EDTA group was 37±7, which was significantly more than that of mice DADM in Triton X-100 group (25±8, t=0.128, P<0.05). The proliferation of bioactive BMSCs in mice DADM in Triton X-100 group and EDTA group was similar at 2 hours and on day 1 after cultured (t=1.292, 0.656, P>0.05). On 3, 5 days after cultured, the proliferation of bioactive BMSCs in mice DADM in EDTA group was significantly higher than that of mice DADM in Triton X-100 group (t=2.309, 14.128, P<0.05 or P<0.01). Conclusions: Mice DADM prepared by decellularization of EDTA has better three-dimensional porous network structure and good continuity of collagen fiber. The BMSCs in bioactive DADM from burn mice prepared by transplanting BMSCs are evenly distributed with large quantity and strong proliferative capacity, which has the potential to be good autologous dermal substitute.

Probing the influence of carboxyalkyl groups on the molecular flexibility and the charge density of apigenin derivatives

Apigenin is an important flavonoids due to its antidiabetic bioactivity. It was reported experimentally that the 7-substituent derivative of apigenin has higher biological activity than 4'- and 5-substituted derivatives while introducing sole carboxyalkyl group -(CH₂)₇COOH into the parent structure. Molecular docking studies indicated that the other two derivatives have lower binding affinities than the 7-substituent derivative (-7.52 kcal mol^-1), which is considered to be a better inhibitor than the parent molecule. Almost all of the carbon atoms and oxygen atoms are coplaner for all three molecules in solution phase, however, all carboxyalkyl groups bend inside into the parent molecules in the active site, and the jagged geometries of the carbon chains are destroyed correspondingly. In addition, most of the electron densities of the chemical bonds for all molecules are decreased, especially the 7-substituent derivative. In contrast, most of the Laplacian values for three molecules are increased in the active site, which suggests that the charge densities at the bond critical point (bcp) are much more depleted than the solution phase. Dipole moments of derivatives are all increased in the active site, suggesting strong intermolecular interactions. After interacting with the S. cerevisiae α-glucosidase, only the 7-substituent derivative has the lowest energy gap ΔE _HOMO-LUMO, which indicates the lowest stability and the highest inhibition activity. Graphical abstract Probing the influence of carboxyalkyl groups on the molecular flexibility and the charge density of apigenin derivatives.

Comparison of the molecular interactions of 7'-carboxyalkyl apigenin derivatives with S. cerevisiae α-glucosidase

As one of the most investigated flavonoids, apigenin, is considered to be a strong α-glucosidase inhibitor. However, the clinical utility of apigenin is limited due to its low solubility. It was reported that the solubility and biological activity can be improved by introducing sole carboxyalkyl group into apigenin, especially the 7'-substitution. With the increase of length of the alkyl chain in carboxyalkyl group, B ring of the apigenin derivative is embedded much more deeply into the binding cavity while the carboxyalkyl stretches to the neighboring cavity. All of the terminal carboxyl groups form hydrogen bonding interactions easily with the surrounding polar amino acids, such as His239, Ser244, Arg312 and Asp349. Thus, the electron density values of the carbonyl in the carboxyl group become higher than the solution status due to the strong molecular interactions. In fact, electron densities of most of the chemical bonds are decreased after molecular docking procedure. On compared with the solution phase, however, dipole moments of most of these molecules are increased, and their vectors are reoriented distinctly in the active sites. It is noticed that all of the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) are distributed throughout the whole parent apigenin ring in solution phase, whereas the disappeared situation happened on the B rings of some molecules (II-IV) in the active site, leading to higher energy gaps.

Transcriptome analysis of peach (Prunus persica L. Batsch) during the late stage of fruit ripening

Fruit ripening is a complex developmental process, the details of which remain largely unknown in fleshy fruits. In this paper, the fruit flesh of two peach varieties, "Zhongyou9" (a nectarine; Prunus persica L. Batsch) and its mutant "Hongyu", was analyzed by RNA-seq technology during two stages of ripening at 20-day intervals. One hundred and eighty significant upregulated and two hundred and thirty-five downregulated genes were identified in the experiment. Many of these genes were related to plant hormones, chlorophyll breakdown, accumulation of aroma and flavor volatiles, and stress. To the best of our knowledge, this is the first transcriptome analysis of peach ripening, and our data will be useful for further studies of the molecular basis of fruit ripening.

Relationship between deficiencies in vitamin A and E and occurrence of infectious diseases among children

OBJECTIVE

To investigate the relationship between vitamin A deficiency (VAD), vitamin E deficiency (VED) and infectious diseases.

PATIENTS AND METHODS

We chose 684 cases of healthy children age 5 months-12 years from our hospital, measured their VA, VE from vein under the light proof condition with high-pressure liquid chromatography. Thereafter, the children who get the acute respiratory tract infection (ARI) or diarrhea two weeks later were registered.

RESULTS

After the two weeks trial (N=684 cases), the VA level of children with ARI was lower than that of children without ARI (0.23±0.02 mg/ml/0.33±0.01 mg/ml), p<0.05. Moreover, the VE level of children with ARI was significantly lower than that of children without ARI (p<0.05). Most interestingly, the proportion of children with diarrhea accompanied with decreased VA level in serum was higher than that of children without diarrhea, indicating that VA level <0.2 mg/L more easily affected acute respiratory tract infection.

CONCLUSIONS

We were able to demonstrate that Children who presented vitamin A deficiency were easier to get the acute respiratory tract infection (ARI) and diarrhea. Children who presented vitamin E deficiency were easier to get the acute respiratory tract infection (ARI). Vitamin A and vitamin E deficiencies are one of the important factors related to occurrences of acute infectious diseases in children.

Identification of Pseudomonas syringae pv. actinidiae strains causing bacterial canker of kiwifruit in the Anhui Province of China, and determination of their streptomycin sensitivities

Bacterial canker, caused by Pseudomonas syringae pv. actinidiae, is one of the most severe diseases of kiwifruit. It has become an international pandemic and threatens the sustainable development of kiwifruit production in all main kiwi-growing regions worldwide. Streptomycin has been the major bactericide for the control of kiwifruit canker, especially in Anhui Province, one of the main kiwifruit production regions in China. However, until now, no studies on the baseline sensitivity to streptomycin of field isolates of P. syringae pv. actinidiae from China have been available. During 2012-2013, a total of 102 single-colony P. syringae pv. actinidiae strains were isolated: 36, 12, 13, 26, and 15 strains from Yuexi, Jinzhai, Huoshan, Qianshan, and Taihu counties, respectively. All strains were confirmed by production of a 280-bp fragment using the specific primers PsaF1/R2 upon polymerase chain reaction amplification, followed by an assay for confirmation of pathogenicity to fulfill Koch's postulates. In this study, the streptomycin sensitivity of the 102 isolated strains was determined. The half-maximal effective concentration values for inhibition of growth by streptomycin were 0.03-0.42 μg/mL (average 0.12 ± 0.06 μg/mL). The baseline sensitivity curve was unimodal, representing range-of-variation factors of 14.0. No resistant subpopulation was identified among the strains used in the study. Thus, these sensitivity data could be used as a baseline for monitoring the shift in sensitivity of P. syringae pv. actinidiae populations to streptomycin in Anhui Province. Continuous resistance monitoring should be carried out, as streptomycin is an at-risk bactericide agent.

In vivo accumulation of Broad bean wilt virus 2 VP37 protein and its ability to bind single-stranded nucleic acid

The VP37 protein encoded by the RNA2 of Broad bean wilt virus 2 (BBWV2) was overexpressed in Escherichia coli. The protein was purified and a polyclonal antibody specific for the protein was produced. Time course studies by Western blot assays in BBWV2-infected Chenopodium quinoa leaves showed that the VP37 protein was present in cells of the inoculated leaves by 12 h post inoculation and in cells of systemically-infected leaves by 2 days post inoculation. The protein was able to accumulate to a high level in infected leaves at the late infection stage. Gel retardation and UV cross-linking assays demonstrated that the VP37 protein bound preferentially single-stranded (ss) RNA and DNA in a non-sequence-specific manner. The VP37 protein-RNA complex was stable in solutions containing less than 400 mM NaCl, but became fully dissociated in the solutions containing 800 mM NaCl. Sequence analysis of the VP37 protein and its ability to bind ssRNA and ssDNA suggest that the protein may play a role similar to the movement proteins reported for other plant viruses.

Time-dependent plasticity of synaptic transmission produced by long-term potentiation of C-fiber evoked field potentials in rat spinal dorsal horn

Our previous work has shown that repetitive stimulation of Adelta-fibers depresses long-term potentiation (LTP) of C-fiber evoked field potentials in spinal dorsal horn. Here, we tested the effects of the Adelta stimulation on the spinal LTP at different time points following LTP induction. Fifteen minutes after LTP induction Adelta stimulation depressed LTP by 44.1+/-4.2% (mean+/-SEM, n=7) for 69.3+/-18.5 min and 1 h after LTP the same Adelta stimulation depressed spinal LTP by only 16.9+/-3.1% for 21.9+/-2.0 min (n=7). Three hours after LTP, however, the Adelta stimulation produced a further potentiation (31.9+/-6.3%, n=7) lasting for all the recording periods (1-3 h). These data indicate that the effects of repetitive stimulation of Adelta-fibers on established spinal LTP of C-fiber evoked field potentials is time-dependent.

Molecular characterization of a novel defective DNA isolated from tobacco tissues infected with tobacco leaf curl virus

Defective DNA of tobacco leaf curl virus (TLCV) was identified in TLCV-infected tobacco plants. The defective DNA was cloned and sequenced. The sequence showed it was about half the size of the TLCV DNA-A, and was derived from TLCV DNA-A by a large deletion. The defective DNA contained the intergenic region and part of the AC1 (Rep) gene of TLCV, and also novel open reading frames (ORFs). The immunotrapping tests showed the defective DNA was associated with geminate particles, suggesting it could be encapsidated in virus particles. It was transmitted, along with full-length DNA-A, to tobacco plants by grafting and whitefly (Bemisia tabaci).