Transseptal Puncture Guided by Three-Dimensional Electroanatomical Mapping: Early Experience Using a Simplified Approach in Adults with Congenital Heart Disease

AIMS

The widespread use of three-dimensional (3D) mapping systems and echocardiography in the field of cardiac electrophysiology has made it possible to perform transseptal punctures (TSP) with low or no fluoroscopy. However, such attempts in adults with congenital heart disease (ACHD) who have previously undergone surgical or interventional treatment are limited. Therefore, we sought to explore the feasibility and safety of an approach to perform zero- or low-fluoroscopy TSP in ACHD patients undergoing left atrial cardiac ablation procedures.

METHODS AND RESULTS

This study included 45 ACHD patients who underwent TSP for ablation of left-sided tachycardias (left atrium or pulmonary venous atrium). Computed tomography (CT) of the heart was performed in all patients prior to ablation. 3D mapping of the right-sided heart chambers before TSP was used to superimpose the registered anatomy, which was subsequently used for the mapping-guided TSP technique. TSP was performed with zero-fluoroscopy in 27 patients, and the remaining 18 patients had a mean fluoroscopy exposure of 315.88 ± 598.43 μGy.m² and a mean fluoroscopy duration of 1.9 ± 5.4 min. No patient in this cohort experienced TSP-related complications.

CONCLUSION

Our study describes a fluoroscopy-free or low-dose fluoroscopy approach for TSP in ACHD patients undergoing catheter ablation of left-sided tachyarrhythmias who had been previously treated surgically or interventionally due to congenital heart defects. By superimposing 3D electroanatomic mapping with cardiac CT anatomy, this protocol proved to be highly effective, feasible and safe.

Arrhythmias and Clinical Outcomes in a Swiss Multicenter Cohort of Patients With Dextro-Transposition of the Great Arteries and Atrial Switch

Background Data on the incidence of arrhythmias, associated cardiac interventions, and outcome in patients with dextro-transposition of the great arteries and atrial switch are scarce. Methods and Results In this multicenter analysis, we included adult patients with dextro-transposition of the great arteries and atrial switch regularly followed up at 3 Swiss tertiary care hospitals. The primary outcome was a composite of left ventricular assist device, heart transplantation, and death. The secondary outcome was occurrence of ventricular tachycardia, ventricular fibrillation, or sudden cardiac death. We identified 207 patients (34% women; median age at last follow-up, 35 years) with dextro-transposition of the great arteries and atrial switch. Arrhythmias occurred in 97 patients (47%) at a median age of 22 years. A pacemaker or an implantable cardioverter-defibrillator was implanted in 39 (19%) and 13 (6%) patients, respectively, and 33 (16%) patients underwent a total of 51 ablation procedures to target 60 intra-atrial re-entry tachycardias, 4 atrioventricular nodal re-entry tachycardias, and 1 atrial fibrillation. The primary outcome occurred in 21 patients (10%), and the secondary outcome occurred in 18 patients (9%); both were more common in patients with concomitant ventricular septum defect than in those without (hazard ratio [HR], 3.06 [95% CI, 1.29-7.27], P=0.011; and HR, 3.62 [95% CI, 1.43-9.18], P=0.007, respectively). Conclusions In patients with dextro-transposition of the great arteries and atrial switch reaching adulthood, arrhythmias occur in almost half of patients, and associated rhythm interventions are frequent. One-tenth of those patients do not survive until the age of 35 years free from left ventricular assist device or heart transplantation, and the outcome is worse in patients with concomitant ventricular septum defect.

The effect of first step right atrial mapping (FRAM) on ablation duration and fluoroscopy exposure during cavotricuspid isthmus ablation of atrial flutter

Aim

To investigate the clinical significance of right atrial mapping prior to cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL).

Methods

Clinical and ablation parameters were retrospectively assessed and compared in patients undergoing CTI ablation with or without a first-step right atrial mapping (FRAM) by using the CARTO 3D mapping system.

Results

CTI block by radiofrequency ablation (RFA) was achieved in all 143 patients. In the FRAM group there was a shorter ablation duration and fluoroscopy exposure compared with the non-FRAM group. CHA₂DS₂-VASc score was associated with higher ablation durations, more ablation applications and increased fluoroscopy exposure. Body mass index (BMI) was associated with longer ablation duration and more ablation applications. Furthermore, patients with reduced left ventricular ejection fraction (LVEF) had longer ablation durations and more fluoroscopy exposure. One patient in the non-FRAM group developed cardiac effusion after ablation. None of the patients had recurrence after 6 months of follow-up.

Conclusions

Patients with high BMI, high CHA₂DS₂-VASc score and reduced LVEF may benefit from the FRAM approach by reducing ablation duration, number of ablation applications and fluoroscopy exposure.

[Enhanced endoplasmic reticulum RyR1 receptor phosphorylation leads to diaphragmatic dysfunction in septic rats]

OBJECTIVE

To explore the role of endoplasmic reticulum ryanodine receptor 1 (RyR1) expression and phosphorylation in sepsis- induced diaphragm dysfunction.

METHODS

Thirty SPF male SD rats were randomized equally into 5 groups, including a sham-operated group, 3 sepsis model groups observed at 6, 12, or 24 h following cecal ligation and perforation (CLP; CLP-6h, CLP-12h, and CLP-24h groups, respectively), and a CLP-24h group with a single intraperitoneal injection of KN- 93 immediately after the operation (CLP-24h+KN-93 group). At the indicated time points, diaphragm samples were collected for measurement of compound muscle action potential (CMAP), fatigue index of the isolated diaphragm and fitted frequencycontraction curves. The protein expression levels of CaMK Ⅱ, RyR1 and P-RyR1 in the diaphragm were detected using Western blotting.

RESULTS

In the rat models of sepsis, the amplitude of diaphragm CMAP decreased and its duration increased with time following CLP, and the changes were the most obvious at 24 h and significantly attenuated by KN-93 treatment (P < 0.05). The diaphragm fatigue index increased progressively following CLP (P < 0.05) irrespective of KN- 93 treatment (P>0.05). The frequency-contraction curve of the diaphragm muscle decreased progressively following CLP, and was significantly lower in CLP-24 h group than in CLP-24 h+KN-93 group (P < 0.05). Compared with that in the sham-operated group, RyR1 expression level in the diaphragm was significantly lowered at 24 h (P < 0.05) but not at 6 or 12 following CLP, irrespective of KN-93 treatment; The expression level of P-RyR1 increased gradually with time after CLP, and was significantly lowered by KN-93 treatment at 24 h following CLP (P < 0.05). The expression level of CaMKⅡ increased significantly at 24 h following CLP, and was obviously lowered by KN-93 treatment (P < 0.05).

CONCLUSION

Sepsis causes diaphragmatic dysfunction by enhancing CaMK Ⅱ expression and RyR1 receptor phosphorylation in the endoplasmic reticulum of the diaphragm.

[The related factors of postoperative recurrence in trigeminalneuralgia patients undergoing fully neuroendoscopic microvascular decompression]

Objective: To evaluate the related factors of postoperative recurrence intrigeminal neuralgia (TN) patients treated with fully neuroendoscopic microvascular decompression (MVD). Methods: The clinical baseline data and preoperative MRI imaging data of 112 patients with TN treated by neuroendoscopic MVD from December 2008 to December 2020 in the Department of Neurosurgery, Beijing Shijitan Hospital Affiliated to Capital Medical University were retrospectively analyzed, including: area ratio of cerebellopontine area (CPA)(healthy side/affected side), trigeminal nerve(TGN)length ratio(healthy side/affected side), TGN angle ratio(healthy side/affected side), and criminal vessel type. Multivariate Cox proportional hazards model was used to analyze the factors affecting postoperative recurrence. Results: Among the 112 patients in this group, there were 49 males and 63 females. The age ranged from 20 to 82 (59±9) years, and the course of disease was 0.05 to 30.00 (5.60±5.15) years. Pain was located on the left side in 43 cases (38.39%) and on the right side in 69 cases (61.61%), respectively. All patients were followed up for more than 1 year, with an average follow-up time of 21.5 months, and 11 cases recurred. Multivariate Cox regression analysis revealed that disease duration≥3 years(HR=9.34, 95%CI:1.12-39.07), CPA area ratio(healthy side/affected side)>1 (HR=27.47, 95%CI:1.69-44.20), criminal vessel type with vein(HR=35.39, 95%CI:1.26-18.60) and criminal vessel type with arteriovenous (HR=46.07, 95%CI: 2.74-27.75) were the main factors influencing recurrence of MVD surgery (all P<0.05). Conclusion: The disease duration≥3 years, CPA area ratio(healthy side/affected side)>1, and criminal vessel type with vein/arteriovenous are the relevant factors that affect the recurrence rate after the fully neuroendoscopic MVD treatment for trigeminal neuralgia.

Periprocedural complications of cardiac implantable electronic device implantation in very elderly patients with cognitive impairment: A prospective study

Very elderly people (over 80 years) with cardiac implantable electronic devices (CIEDs) indications often have a higher prevalence of aging comorbidity, among which cognitive impairment is not uncommon. This study aimed to investigate periprocedural complications of CIED implantation among very elderly patients with and without cognitive impairment. One hundred eighty patients ≥80 years of age indicated for CIED implantation were included in our study. During hospitalization, the cognitive evaluation was performed according to the Diagnostic and Statistical Manual of Mental Disorders (fifth edition). According to the cognitive test results, patients were divided into 2 groups (90 patients with normal cognitive function and 90 patients with cognitive impairment). Meanwhile, their physical parameters and laboratory measurements were completed. The procedural data and periprocedural complications were collected from both groups. The association between cognitive impairment and periprocedural complications was analyzed using univariate and multiple logistic regression analyses. During a one-month follow-up, the most frequent periprocedural complications in very elderly patients were pocket hematoma and thrombosis events. Cognitively impaired patients had a higher incidence of complications than normal cognitive patients. Multivariate regression analysis showed that cognitive impairment was positively correlated with periprocedural complications in very elderly patients. Cognitive impairment is associated with increased periprocedural complications of CIED implantation in very elderly patients.

Distinctive characteristics of his bundle potentials in patients with atrioventricular nodal reentrant tachycardia

BACKGROUND

His bundle (HB) potentials vary in amplitude and duration in patients with and without slow pathways. The aim of this study was to determine the characteristics of HB potentials and to elucidate whether they can provide clues for identification of slow pathway (SP).

METHODS

The present research prospectively studied the electrophysiological findings of 162 patients with symptomatic atrioventricular nodal reentrant tachycardia (AVNRT) due to slow-fast or fast-slow type and atrioventricular reentrant tachycardia (AVRT). Maximal HB potential (HBmax, HB with the highest amplitude) among HB cloud was recorded in both groups. For AVNRT patients, the following were measured: (1) AH interval at the "jump" during programmed atrial stimulation (A2H2, taken as a reflection of SP conduction time); (2) Distance from HBmax to the successful SP ablation site (HBmax-ABL) and from HBmax to the ostium of coronary sinus (HBmax-CSO).

RESULTS

HBmax was 0.29 ± 0.10 mV in AVNRT patients, whereas it was 0.17 ± 0.05 mV in AVRT group (p < 0.0001). Likewise, the HBmax duration was 22 ± 5 ms in AVNRT group and 16 ± 3 ms in AVRT group (p < 0.0001). The area under the ROC curve of HBmax amplitude in AVNRT patients was 0.86 and the optimal HBmax cut-off to predict AVNRT was ≥ 0.22 mV with a sensitivity of 0.78 and specificity of 0.84. HBmax-CSO was positively correlated with HBmax-ABL, and HBmax-ABL was positively correlated with A2H2.

CONCLUSIONS

HBmax amplitudes were higher and durations longer in patients with AVNRT, as compared to those with AVRT. Moreover, the distance between HBmax and successful ablation site was positively correlated with the SP conduction time and with the distance from HBmax to the CS ostium.

[Efficacy analysis of fully endoscopic microvascular decompression in primary trigeminal neuralgia via keyhole approach]

Objective: To explore the efficacy and technical features of fully endoscopic microvascular decompression(MVD) in primary trigeminal neuralgia(PTN) via keyhole approach. Methods: The clinical data of 97 patients with PTN underwent fully endoscopic MVD via keyhole approach in the Department of Neurosurgery, Beijing Shijitan Hospital, Capital Medical University from December 2014 to February 2019 was collected. During fully endoscopic MVD in PTN via keyhole approach, performer use natural clearance without grinding except developed rock bone crest or excessive retraction of the brain tissue, visually and panoramically observe and evaluate the CPA area, accurately identify the responsible vessels, to avoid the omission of responsible vessels or insufficient decompression. And the use of preplaced technology, bridging technology and submersible technology, ensure the efficacy of surgery and reduce the surgical side injuries.Barrow Neurological Institute (BNI) pain score was used to evaluate the efficacy and identify the recurrence. The surgical efficacy was analyzed. Results: The offending vessels were identified under endoscope in 96 cases. Among them, arterial compression was found in 77 cases, venous compression in 6 cases, and both arterial and venous compression in 13 cases. About the pain outcomes, 87 cases had immediate and complete relief of pain, 5 cases had almost relief of pain, 4 cases had partial relief of pain, and still needed medication control, but the dose was lower than that before operation, and 1 case had no obvious relief of pain. About complications, there were 4 cases of temporary facial numbness, 1 case of temporary hearing loss, both of them recovered after symptomatic treatment. There was no cerebral infarction or hemorrhage, intracranial or incision infection. All cases were followed up for 3.0-38.0 months with a median period of(22.4±2.2) months. During the follow-up periods, postoperative recurrence occurred in 3 cases. Conclusion: Fully endoscopic MVD for PTN through keyhole approach, provides panoramic view to avoid omission of offending vessels and reduce complications, seemed to be a safe and effective surgical method.

Delayed management of atrial lead dislodgment after pacemaker implantation: a case report

Background

Pacemaker lead dislodgement may cause malfunction in the pacing system, which may lead to severe adverse events. For patients with sick sinus syndrome but normal atrioventricular conduction, atrial lead dislocation may cause excessive unnecessary ventricular pacing, resulting in nonphysiological pacing leading to heart failure. The longer the unwanted ventricular pacing continues, the greater the chances that irreversible heart failure may occur. Ironically, we admitted a patient who had been refusing dislodged lead relocation for 7 years. The symptoms of heart failure were significantly resolved after new atrial lead implantation. We reviewed her clinical data before and after the procedure and believed the case was worthy of reflection.

Case presentation

An 83-year-old Han Chinese woman presented with heart failure symptoms for 7 years due to the late macro-dislodgement of an atrial pacing lead. Her echocardiogram showed average left ventricular ejection fraction (LVEF) but reduced left ventricular end-diastolic volume (LVEDV) during right ventricular pacing, indicating heart failure with preserved ejection fraction (HFpEF). After 7 years of refusal, she finally agreed to implantation of a new atrial lead. She has been doing well since the operation.

Conclusions

For patients with sick sinus syndrome with dual-chamber pacemaker indication, atrial lead dislodgement should be appropriately managed if the atrioventricular function is normal. As the consequences are subtle and appear gradually, they might be overlooked by patients and even doctors. Implanting a new atrial lead is the right thing to do rather than just passively waiting or treating with symptom relief medications.

MiR-448 downregulates CTTN to inhibit cell proliferation and promote apoptosis in glioma

OBJECTIVE

miRNAs have been confirmed to be related to cell proliferation and apoptosis. In this study, we detected the potential effect of miR-448 on glioma cell proliferation and apoptosis.

MATERIALS AND METHODS

miR-448 and CTTN expression levels were detected in glioma cell lines with quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cells were transfected with miR-448 mimics and inhibitor by using lipofectamine 2000 respectively. The proliferative ability of transfected cells was detected via methyl thiazolyl tetrazolium (MTT) and cell counting kit-8 (CCK8) assays. Cell apoptosis and cell-cycle were tested using flow cytometry. The regulatory correlation between miR-448 and CTTN was explored by bioinformatics analysis and luciferase reporter assay.

RESULTS

Lower expression of miR-448 and higher level of CTTN were detected in glioma cells. MiR-448 could regulate cell proliferation, cell apoptosis, and cell cycle. CTTN was negatively regulated by miR-448.

CONCLUSIONS

miR-448 downregulates CTTN to inhibit cell proliferation and promote apoptosis in glioma, which indicates a potential therapeutic target of glioma.

[Application of complete endoscopic technique in microvascular decompression related tovertebrobasilar artery compression]

Objective: To study the operative method, special technique and curative effect of complete neuroendoscopic microvascular decompression(MVD) related to vertebrobasilar artery compression. Methods: Thirteen patients with functional cranial nerve disease caused by vertebrobasilar artery as direct or indirect responsible vessel accepted complete endoscopic MVD, including 11 patients with hemifacial spasm and 2 patients with trigeminal neuralgia. The procedure and curative effect of endoscopic surgery were analyzed retrospectively. Results: All procedures of complete neuroendoscopic MVD were successfully completed.Intraoperative observation by endoscope showed that 6 cases were oppressed directly by vertebral artery, 2 cases were oppressed directly by basilar artery, 5 cases were combined oppressed by displaced basilar artery and other vessels (1 case was superior cerebellar artery and 4 cases were anterior inferior cerebellar artery). During the operation, Teflon sheets was placed directly into the compression point in 2 cases, the "Pre-placed" technique was used to place Teflon sheets in 7 cases, and the "Set up bridge" technique was used to place Teflon sheets in 4 cases. Follow-up for 8-38 months,the symptoms disappeared completely in 12 cases and improved in 1 case. No deaths and severe complications occurred, such as postoperative bleeding, cerebellar infarction and intracranial infection. Conclusion: MVD related to vertebrobasilar artery compression can be performed by complete neuroendoscopic technique, which can achieve sufficient decompression effect and curative effect.Flexible use of the special technology of placing Teflon sheets by single-hand under endoscope, such as the "Pre-placed" and "Set up bridge" technique, is an important technical guarantee for the successful completion of endoscopic MVD.

[Efficacy analysis of soft neuroendoscopic techniques in the treatment of chronic subdural hematoma]

Objective: To investigate the efficacy of soft neuroendoscopic techniques in the treatment of chronic subdural hematoma (CSDH). Methods: A retrospective analysis of 201 cases of CSDH diagnosed and treated at Beijing Shijitan Hospital (CMU) from January 2006 to December 2017 was conducted. From January 2006 to December 2010, 126 cases of CSDH were treated with skull drilling and drainage (non-endoscopic group). From January 2011 to December 2017, 75 cases of CSDH were treated with soft neuroendoscopy (endoscopic group). The operation time of the non-endoscopic and endoscopic groups, the hematoma clearance rate on the first day after surgery, the time of the drainage tube, the length of hospital stay, the incidence of complications, mortality and recurrence rate were compared. Results: There were no deaths in both groups. The average operation time of the non-endoscopic group was 43 min, compared with the average operation time of the endoscopy group of 50 min, there was no significant difference (P>0.05). The average hematoma clearance rate on the first day after surgery in the endoscopy group (98.2%) was significantly higher than that in non-endoscopic group (87.3%) (P<0.01). The average time of drainage tube in the endoscopy group (23 h) was significantly shorter than that in the non-endoscopic group (50 h) (P<0.01). On the first postoperative day, the proportion of patients with mRS≤3 in the endoscopic group was significantly higher than that in the non-endoscopic group (P<0.01). At the time of discharge, the proportion of patients with mRS≤3 in the endoscopy group was also significantly higher than that in the non-endoscopic group, P<0.05. There was no significant difference in the average hospital stay between endoscopy group (7 d) and non-endoscopic group (8 d) (P>0.05). The postoperative complication rate in the endoscopy group was significantly lower than that in the non-endoscopic group (P<0.01). During 0.5-8 years of follow-up, the recurrence rate of CSDH in the endoscopic group (5.33%) was significantly lower than that in the non-endoscopic group (15.07%) (P<0.01). Conclusion: The application of visualization features of soft neuroendoscopy in the treatment of CSDH can significantly improve hematoma clearance, shorten the time of drainage tube, reduce postoperative complications and recurrence rate, and improve surgical outcomes.

Berberine Improves Cognitive Deficiency and Muscular Dysfunction via Activation of the AMPK/SIRT1/PGC-1a Pathway in Skeletal Muscle from Naturally Aging Rats

OBJECTIVE

The manifestations of aging include cognitive deficits and muscular dysfunction, which are closely linked to impairment of mitochondrial biogenesis. Berberine, an isoquinoline alkaloid, presents multiple anti-diabetic pharmacological effects. Evidence has indicated that insulin resistance and cognitive impairment share the same pathogenesis, and berberine could reverse glucose metabolism abnormalities and muscle mitochondrial dysfunction induced by a high-fat diet. This study was used to investigate whether berberine could be used as an anti-aging drug to prevent cognitive deficits and muscular dysfunction in natural aging.

METHODS

Biochemical indicators and an intraperitoneal glucose tolerance test were tested in 5-month-old rats (5 mo group), 24-month-old rats (24 mo group) and 24-month-old rats that had undergone 6 months of berberine treatment (BBR group). A Morris water maze test was conducted to assess the cognitive ability of the rats. Insulin resistance in whole-body was evaluated by intraperitoneal glucose tolerance test (IPGTT). The morphology of the skeletal muscle tissue was observed by hematoxylin-eosin (HE) staining. The levels of total cholesterol, triglyceride, ATP and reactive oxygen species (ROS) were assessed with corresponding reagent kits. The protein expressions of GLUT4, AMPK, SIRT1 and PGC-1α in skeletal muscle were examined by Western blot.

RESULTS

The results showed that administration of berberine for 6 months significantly improved cognitive deficits and insulin resistance in naturally aging rats (p<0.01). Furthermore, berberine treatment helped normalize the disordered alignment and the decreased number of muscle fibers (p<0.01) in the skeletal muscle of 24 mo rats. Berberine decreased the levels of ROS in both the serum and the skeletal muscle of 24 mo rats (p<0.01). Berberine increased the protein expression of p-AMPK, SIRT1 and PGC-1α and increased the production of ATP in the skeletal muscle of aging rats (p<0.01).

CONCLUSIONS

Berberine markedly ameliorates aging-related reductions in cognitive ability and muscular function, and the activation of the AMPK/SIRT1/PGC-1α pathway in skeletal muscle may be the underlying protective mechanism of berberine on muscular function.

Iron overload induced by ferric ammonium citrate triggers reactive oxygen species-mediated apoptosis via both extrinsic and intrinsic pathways in human hepatic cells

BACKGROUND

Hepatic iron overload is common in patients with myelodysplastic syndromes undergoing hematopoietic cell transplantation (HCT) and may predispose to peri- and post-HCT toxicity. To better understand the mechanisms of iron overload-induced liver injury, we examined the effects of iron overload induced by ferric ammonium citrate (FAC) on oxidative stress and apoptosis signaling pathway in human hepatic cell line HH4.

METHODS AND RESULTS

Hepatic HH4 cells were exposed to FAC to force iron uptake, and cellular responses were determined. Incubation with 5 mM FAC resulted in increased intracellular iron content in a time-dependent manner. High concentration of FAC impaired cell viability and increased level of reactive oxygen species (ROS), and addition of antioxidant reagent such as glutathione or N-acetylcysteine dramatically reduced FAC-induced intracellular ROS generation. FAC overload significantly increased the phosphorylation of inhibitor of κB-α, p38 mitogen-activated protein kinase (MAPK), and nuclear factor κ light chain enhancer of activated B cells (NF-κB) p65 and promoted the nuclear translocation of NF-κB p65. Knockdown of Fas and Bid expression by small interfering RNA in iron-treated HH4 cells resulted in restoration of cell viability.

CONCLUSIONS

We reported that FAC treatment is capable of inducing both extrinsic death receptor and intrinsic mitochondrial signaling pathway-mediated HH4 cells apoptosis through ROS-activated p38 MAPK and NF-κB pathways.

Schistosoma japonicum: susceptibility of neonate mice born to infected and noninfected mothers following subsequent challenge

This study was to investigate the differences between neonate mice born to Schistosoma japonicum-infected mothers and those born to noninfected mothers in subsequent challenge. The intensity of infection (evidenced by worm burden and liver egg burden) and liver immunopathology (number and size of liver granulomas) were significantly reduced in neonates from infected mothers (I.M.) compared with neonates from noninfected mothers (N.M.). Anti-soluble worm antigen of S. japonicum (SWA) IgG could be detected in sera of neonates from I.M. (N.N./I.M.) at 1 week after delivery, remained a plateau for 2 weeks and gradually decreased until 8 weeks of age. Parasite-specific IgM was not detected in sera from N.N./I.M. at any time after delivery. At 6 weeks after infection, the level of anti-SWA IgG in infected neonates from I.M. (I.N./I.M.) was significantly higher than that of infected neonates from N.M. (I.N./N.M.). In addition, production of IFN-γ, IL-12 and TGF-β by cultured splenocytes from I.N./I.M. was significantly increased, while the level of IL-4 was significantly decreased when compared to those from I.N./N.M.. These data demonstrate that congenital exposure to schistosomiasis japonica may render neonatal mice born to I.M. less susceptible to subsequent challenge and result in down-regulation of both infection intensity and immunopathology.

Polymorphisms of KAP6, KAP7, and KAP8 genes in four Chinese sheep breeds

High glycine-tyrosine proteins (HGTPs), also known as keratin-associated proteins (KAPs), play a key role in the major structures and mechanical properties of wool fiber. Sheep HGTPs consist of three multigene families: KAP6, KAP7, and KAP8 genes. Polymorphisms of these three genes have been proposed to have important effects on wool fiber traits. The aim of the present study was to identify polymorphisms of the KAP6, KAP7, and KAP8 genes in four sheep breeds, including Chinese Merino superfine wool sheep, Hu sheep, a Merino x Hu crossed breed, and Romney sheep. Polymerase chain reaction (PCR) product direct sequencing, PCR-single-strand conformation polymorphism, and cloned sequencing methods were used to find genetic variation and identify polymorphisms in these genes. The Mutation Surveyor v3.97 software was used to analyze the sequences. These methods revealed six different sequences of the KAP6 gene, two different sequences of the KAP7 gene, and five different sequences of the KAP8 gene. Accordingly, three (with frequencies>1%) single nucleotide polymorphisms (SNPs) of the KAP6 gene, one SNP of the KAP7 gene, and five SNPs of the KAP8 gene were detected. Interestingly, some of these sequences were present in only certain sheep breeds, thereby suggesting that these special allele sequences could be used as candidate genes of wool characteristics in further studies.

Cav-1 deletion impaired hematopoietic stem cell function

A tightly controlled balance between hematopoietic stem and progenitor cell compartments is required to maintain normal blood cell homeostasis throughout life, and this balance is regulated by intrinsic and extrinsic cellular factors. Cav-1 is a 22-kDa protein that is located in plasma membrane invaginations and is implicated in regulating neural stem cell and embryonic stem cell proliferation. However, the role of Cav-1 in hematopoietic stem cell (HSC) function is largely unknown. In this study, we used Cav-1^−/− mice to investigate the role of Cav-1 in HSCs function during aging. The results showed that Cav-1^−/− mice displayed a decreased percentage of B cells and an increased percentage of M cells in the bone marrow and peripheral blood, and these changes were due to an increased number of HSCs. FACS analysis showed that the numbers of Lin⁻Sca1⁺c-kit⁺ cells (LSKs), long-term HSCs (LT-HSCs), short-term HSCs and multipotent progenitors were increased in Cav-1^−/− mice compared with Cav-1^+/+ mice, and this increase became more pronounced with aging. An in vitro clonogenic assay showed that LT-HSCs from Cav-1^−/− mice had reduced ability to self-renew. Consistently, an in vivo competitive transplantation assay showed that Cav-1^−/− mice failed to reconstitute hematopoiesis. Moreover, a Cav-1 deletion disrupted the quiescence of LSKs and promoted cell cycle progression through G2/M phase. In addition, we found that Cav-1 deletion impaired the ability of HSCs to differentiate into mature blood cells. Taken together, these data suggest that Cav-1-deficient cells impaired HSCs quiescence and induced environmental alterations, which limited HSCs self-renewal and function.

Radiosensitization of breast cancer cells by TRAIL-endostatin-targeting gene therapy

One of the key issues in cancer radiotherapy research is to sensitize tumor cells to the cell killing effects of ionizing radiation while leaving normal tissues intact. One potential approach to achieve this is gene-radiotherapy, i.e. a combination of radiation therapy and gene therapy. It is to choose certain exogenous radiation-inducible regulatory genes, for example, early growth response-1 (Egr-1), and transcript its downstream tumor-therapeutic genes under ionizing radiation so as to kill the tumor cells synergistically by the expressed gene products together after transfection and irradiation exposure. In this study, we engineered a plasmid encoding both TRAIL and endostatin under the control of the radiation-inducible Egr-1 promoter, and evaluated its anti-tumor efficacy in combination with radiotherapy. Our plasmid showed significant efficacy in up-regulating the levels of TRAIL and endostatin proteins after transfected into breast cancer cells and exposed to X-ray irradiation. The detected cellular effects in vitro manifested that TRAIL-endostatin-based gene therapy could enhance radiosensitizing effects in breast cancer cells in terms of tumor cell growth inhibition, promoting apoptosis and the induction of cell cycle arrest. In summary, our results suggest that TRAIL-endostain-targeting approach might be a promising method to sensitize solid tumors to radiation therapy.