Non-heart-beating donor is an important source for lung transplantation, and has been successfully used in clinical practice for many years with satisfactory outcomes. But donor shortage, imperfect lung preservation techniques and ethical controversies still limit the development of non-heart-beating donor. In recent years, with continuous scientific progress, great progress has been made in each aspect of non-heart-beating donor. Here we review the clinical categories, ischemia time, death determination, ethical progress, and lung preservation techniques of non-heart-beating donor.
ObjectiveTo explore the light sensitivity and kinetic of the new optogenetics tools Channelrhodopsin-XXM2.0 (XXM2.0) and Channelrhodopsin-PsCatCh2.0 (PsCatCh2.0), and analyze whether they could be used to restore the visual function by optogenetics.MethodsMolecular biology techniques were used to link the gene fragments of XXM2.0 and PsCatCh2.0 to the vector pCIG(c)-msFoxn3 containing ampicillin resistant screening gene and reporter gene to form new plasmid pCIG(c)-msFoxn3-XXM2.0 and pCIG(c)-msFoxn3-PsCatCh2.0. The constructed plasmids were transfected into HEK 293T cells, and light responses were recorded in the whole cell mode with the HEKA patch clamp system. The photocurrent was recorded under three light intensity included 2.7×1016, 4.7×1015, and 6.4×1014 photons/(cm2·s). And then, XXM2.0 and PsCatCh2.0 were stimulated with 2.7×1016 photons/(cm2·s) and fully recovered. The opening and closing time constants were analyzed with Clampfit 10.6 software. At the same light intensity, photocurrents of XXM2.0 and PsCatCh2.0 were recorded by the light pulse stimulating of 2-32 Hz. The current attenuation was analyzed at long intervals of 4000 ms and short intervals of 200 ms after repeated stimulation. Comparisons between groups were performed by independent samples t test.ResultsRestriction endonuclease sites of EcoRⅠ and EcoRⅤ were successfully introduced at XXM2.0 and PsCatCh2.0 sequences. When the digestion was completed, they were ligated by T4 DNA ligase to construct new plasmids pCIG(c)-msFoxn3-XXM2.0 and pCIG (c)-msFoxn3-PsCatCh2.0, and then transfected on HEK 293T cells. The light intensity dependence was showed in XXM2.0 and PsCatCh2.0. The greater light intensity was accompanied by the greater photocurrent. Under the light intensity 6.4×1014 photons/(cm2·s) below the retinal safety threshold, large photocurrent was still generated in XXM2.0 and PsCatCh2.0 with 92.8±142.0 and 13.9±5.6 pA (t=1.24, 1.24; P=0.28, 0.29). The opening time constants of XXM2.0 and PsCatCh2.0 were 23.9±6.7 and 2.4±0.8 ms, and the closing time constants were 5803.0±568.2 and 219.9±25.6 ms. Compared with PsCatCh2.0, the opening and closing time constant of XXM2.0 were both larger than PsCatCh2.0. The differences were statistically significant (t=7.10, 31.60; P=0.00, 0.00). In terms of response frequency, XXM2.0 and PsCatCh2.0 could follow to 32 Hz high-frequency pulsed light stimulation, and all could respond to repeated light stimulation at a long (4000 ms) and a short time (200 ms) interval with the small current decay rate.ConclusionXXM2.0 and PsCatCh2.0 could be activated under light intensity with safety for the retina, and could respond to high frequency (at least 32 Hz) pulsed light stimuli with low current attenuation, which could meet the characteristics of opsins required to restore the visual function by optogenetics.
Retinal degeneration is a blind eye disease caused by changes in the function of retinal pigment epithelial cells and photoreceptor cells. Stem cell transplantation, gene therapy, retinal prosthesis implantation and other new biological technologies have made great progress in the restoration of visual function, but they still face many difficulties. Optogenetic is a new interdisciplinary technology that combines optics, physiology and genetics. It can express photosensitive proteins on retinal neurons in retinal degeneration. The light stimulation causing depolarization or hyperpolarization reaction of cells that expressed photosensitive proteins to gain light sensitivity. Compared with the immune rejection of stem cell therapy, the greater individualization of gene therapy and the greater traumatic nature of retinal prosthesis implantation, optogenetic technology has significant advantages, and it is also urgent to solve the problems of low spatial and temporal resolution and light sensitivity. With the gradual development of optogenetics technology, it is bound to form a deeper level of cross and fusion with other fields, so as to contribute to the recovery of visual function of patients with retinal degeneration.
目的:〖HT5”SS〗探讨原发性喉部恶性淋巴瘤的临床诊断治疗方案,提出早期诊断此类疾病的合理有效方法。〖HTH〗方法:〖HTSS〗对临床29例病理确诊原发于喉部的恶性淋巴瘤患者临床资料进行回顾性分析,并且与同时期原发于鼻腔鼻窦的恶性淋巴瘤患者临床资料对比分析。〖HTH〗结果:〖HTSS〗29例原发性喉部恶性淋巴瘤病例均进行了手术干预,在术中或术后病理明确诊断后进行了后继的放射及化学综合治疗,病员的平均住院日较原发于鼻腔鼻窦的恶性淋巴瘤患者为长。〖HTH〗结论:〖HTSS〗本病的合理有效的诊断治疗,需早期明确诊断和判定病变累及范围,在尽可能早期获取病理诊断基础上,提高对喉部影像学的认识,对于此类疾病及时制订合理有效的治疗方案,获得更好的预后有着重要意义。
At present, interventional therapy for structural heart disease is in a period of vigorous development. Among them, transcatheter aortic valve replacement, as a representative of the interventional treatment of heart valve disease, has made rapid progress, which is a bright spot in the field of cardiovascular disease. The future development of transcatheter tricuspid valve repair/replacement is also promising. With the availability of important clinical evidence, the indications of transcatheter aortic valve replacement have been extended to the full risk range of severe aortic stenosis. More and more data showed that transcatheter mitral and tricuspid valve interventions could effectively alleviate patients’ symptoms and improve their prognosis. Transcatheter valve interventions have developed rapidly and have made tremendous progress in China. This article will review and interpret the important progress in the field of transcatheter valve interventions.
Mitral valve regurgitation is one of the most common heart valve diseases, of which secondary mitral valve regurgitation (sMR) has large proportion and poor prognosis. For patients who still have symptoms after the guideline-directed management and therapy, the effects of surgery are controversial, and transcatheter therapy provides a new option. Transcatheter edge-to-edge repair has become one of the recommended therapies by the guidelines, meanwhile transcatheter mitral valve annuloplasty and transcatheter mitral valve replacement are developing. However, the etiological mechanism of sMR is complex and diverse. There is an interaction between cardiac function and structure and sMR in dynamic change. It brings challenges to the selection of indicators and evaluation timing. The complex anatomical structure also makes it more difficult to design instruments and select surgical methods. This paper reviews the challenges and progress of transcatheter therapy for sMR.
ObjectiveTo explore the light response, retinal inflammation and apoptosis of the retinal ganglion cells (RGCs) 1 year after the new type of channelrhodopsin PsCatCh2.0 was transfected into the retina of rd1 mice. MethodsTwenty-four male rd1 mice were randomly divided into rd1 experimental group and rd1 control group, 12 mice in each group. 1.5 μl of recombinant adeno-associated virus (rAAV)2/2-cytomegalovirus (CMV)-PsCatCh2.0-enhanced green fluorescent protein (EGFP) was injected into the vitreous cavity 1 mm below the corneoscleral limbus of mice in the rd1 experimental group, and the same dose of recombinant virus was injected 2 weeks later at temporal side 1 mm below the corneoscleral limbus. One year after virus injection, the light response of RGCs expressing PsCatCh2.0 was recorded by patch clamp technique; the expression of PsCatCh2.0 in the retina was evaluated by immunofluorescence staining; the transfection efficiency of recombinant virus was evaluated by the transfection efficiency of virus and the number of RGCs. Hematoxylin-eosin staining was performed to measure the inner retinal thickness. Western blotting was used to detect the protein expression of nuclear factor (NF)-κB p65 in retina; real-time quantitative polymerase chain reaction was used to detect the relative expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and Bax mRNA. Terminal deoxynucleotidyl transferase kit was used to observe the apoptosis of retinal cells in each group of mice. ResultsOne year after the intravitreal injection of recombinant virus, PsCatCh2.0-expressing RGCs can still generate 30 pA photocurrent. The virus PsCatCh2.0-EGFP was mainly transfected into RGCs, and partly transfected into amacrine cells, almost no transfection was seen in bipolar and horizontal cells. There were no significant differences in the number of RGCs and thickness of the inner retina between the rd1 experimental group and the rd1 control group (F=14.35, 0.05; P＞0.05), while the rd1 experimental group NF-κB p65 protein expression, TNF-α and IL-6 mRNA quantification were significantly lower than those of rd1 control group (F=4.61, 5.91, 5.78; P＜0.05). The number of red fluorescent apoptotic cells in the retina of mice in the rd1 experimental group was less than that in the rd1 control group, and the Bax mRNA expression was lower than that in the rd1 control group, and the difference was statistically significant (F=7.52, P＜0.01). ConclusionOne year after intravitreal injection of recombinant virus, the PsCatCh2.0 expressing RGCs can still generate photocurrent. Long term transfection and expression of PsCatCh2.0 has no obvious cytotoxic effect on RGCs, nor it increases the inflammatory effect of the retina of rd1 mice with retinal degeneration.
Mitral regurgitation is the most prevalent valvular heart disease, with a poor prognosis that brings a heavy burden to population health and socio-economics. Transcatheter repair is a relatively mature technique for mitral regurgitation, but is strict in anatomical screening and the reduction of regurgitation is limited. With the advance in techniques and technology, transcatheter replacement has become an attractive treatment modality for mitral regurgitation in succession to transcatheter repair. At present, several replacement devices have initiated clinical trials to establish feasibility. Early data has shown that transcatheter replacement for mitral regurgitation is safe and effective, which needs to be confirmed with larger population and longer follow-up. Besides, some technical challenges remain to be addressed, in order to increase accessibility of this innovative technology.
As the indications for transcatheter aortic valve replacement (TAVR) expand, multi-valve lesions are becoming more common in clinical practice. Moderate to severe atrioventricular regurgitation, particularly when persistent after TAVR, significantly increases the risk of adverse events. Therefore, many studies have evaluated factors that contribute to the improvement of atrioventricular regurgitation. However, this field remains controversial due to the heterogeneity of retrospective studies and the lack of randomized controlled trials. Despite advances in atrioventricular valve intervention techniques, evidence for atrioventricular regurgitation intervention after TAVR is still scarce. The management decision for atrioventricular regurgitation in patients who underwent TAVR is complex and must take into account the severity of valve disease, anatomical characteristics, quality of life, and procedural complexity. We conducted a review of atrioventricular regurgitation in patients who have received TAVR in hope that it will help decision-making in clinical practice.
Objective To explore the effectiveness of artificial hemi-knee prosthesis reconstruction for bone defects after resection of pediatric osteosarcoma. Methods A retrospective analysis was conducted on the clinical data of 18 children with osteosarcoma who met the selection criteria and were treated between January 2016 and December 2019. There were 11 males and 7 females, aged 6-10 years (mean, 8.9 years). Osteosarcoma located in the distal femur in 11 cases and the proximal tibia in 7 cases. Among them, 12 cases were conventional osteosarcoma and 6 cases were small cell osteosarcoma, with a disease duration of 1-9 months (mean, 3.1 months). All patients received 2 cycles of preoperative chemotherapy with doxorubicin, cisplatin, and ifosfamide. After en bloc tumor segment resection, bone defects were reconstructed using custom-made artificial hemi-knee prostheses. Rehabilitation training was initiated at 8 weeks postoperatively under the protection of a knee immobilizer brace, combined with 4 cycles of adjuvant chemotherapy. During follow-up, lower limb growth length and limb shortening (compared with the healthy side) were measured, and limb function was evaluated using the Musculoskeletal Tumor Society-93 (MSTS-93) scoring system. Results All surgeries were successfully completed, with an operation time of 2.0-3.1 hours (mean, 2.4 hours) and intraoperative blood loss of 180-320 mL (mean, 230.0 mL). Incisional edge necrosis occurred in 1 case at 10 days postoperatively, while the incisions of the remaining 17 patients healed by first intention. One case developed periprosthetic infection caused by Staphylococcus aureus at 1 week postoperatively, which was cured after symptomatic treatment. All 18 patients were followed up 60-96 months (mean, 74.2 months). No local tumor recurrence was observed during follow-up. Imaging examinations showed prosthesis loosening in 2 cases, while the prosthesis of other patients were well-positioned. At last follow-up, the knee joint range of motion was 80°-120° (mean, 106.7°). The MSTS-93 score was 16-29 (mean, 24.7), with 12 cases rated as excellent, 5 good, and 1 fair. The patients’ height increased by 12.8-20.0 cm (mean, 15.5 cm), the lower limb growth length was 6.0-13.0 cm (mean, 9.7 cm), and limb shortening was 1.8-4.6 cm (mean, 3.1 cm). There was no significant difference in MSTS-93 scores, lower limb growth length, or limb shortening between the distal femur group and the proximal tibia group (P>0.05). Conclusion Artificial hemi-knee prosthesis reconstruction can preserve the adjacent normal epiphysis of the knee joint, maximize limb growth potential, and reduce adult limb length discrepancy, making it a suitable reconstruction option for children with knee osteosarcoma.