BACKGROUND:Near infrared responsive hydrogels,have a variety of excellent properties such as high spatial and temporal precision,remote tunability,and safety and non-invasiveness,providing a new direction of exploration for the development of tissue engineering. OBJECTIVE:To summarize the application progress of near infrared responsive hydrogels in the field of tissue engineering in recent years. METHODS:The literature search was performed on PubMed and CNKI databases.The keywords were"near infrared responsive hydrogels,tissue engineering,bone defect,bone repair,bone regeneration,wound healing,wound dressing,angiogenesis"in Chinese and English.The search time limit was from May 2006 to October 2022 and extended for some classical literature.The abstracts and contents of the retrieved literature were analyzed,and the relevant literature was obtained according to inclusion and exclusion criteria.Finally,97 articles were included for review. RESULTS AND CONCLUSION:(1)Near infrared responsive materials are involved in tissue repair by controlling infection and reducing inflammation,promoting angiogenesis,osteoblast differentiation and new bone formation.(2)Near infrared responsive hydrogel can be prepared by constructing a thermosensitive hydrogel with a photothermal effect or by using a photochemical reaction.(3)Near infrared responsive hydrogels as wound dressings perform various functions such as rapid hemostasis,tissue adhesion through polymerization of polymer monomers,antibacterial and anti-inflammatory effects,and promotion of angiopoiesis and epithelial regeneration through the local photothermal effect of photothermal nanomaterials during soft tissue healing and regeneration.(4)Near infrared responsive hydrogels function during bone reconstruction and repair by promoting osteogenic differentiation of mesenchymal stem cells,stimulating the expression of heat shock proteins,and increasing angiogenesis.(5)Near infrared responsive hydrogels present a combination of multiple therapeutic strategies with significant synergistic therapeutic functions and are also being progressively developed for application in other tissue reconstruction and disease treatment scenarios.

Objective:To analyze the clinical features of children with cryptogenic organizing pneumonia (COP) confirmed by pathology.Methods:The clinical manifestations, imaging, pathology, treatment and outcome data of 4 children with COP confirmed by thoracoscopic lung biopsy were retrospectively analyzed, who were hospitalized at Respiratory Department of Shenzhen Children′s Hospital from January 2004 to December 2022.Results:All of the 4 patients were male, the age ranged from 1 year 3 months to 14 years. The time from onset to diagnosis was 3 months to 3 years. The follow-up duration was 6 months to 6 years. All the 4 cases had cough, 2 cases had tachypnea and wheezing, 1 case had expectoration, 1 case had chest pain, 1 case had decreased activity tolerance and weight loss. Rales in 2 cases and hypoxemia in 1 case. Pulmonary high resolution CT showed diffuse distribution, involvement of both lungs in 3 cases, and single lung combined migration in 1 case.Three cases showed ground-glass opacity, consolidation, patchy or fibrous strips, and 1 case presented air bronchogram and "reversed halo sign". All the 4 cases were performed thoracoscopic lung biopsy, and the pathological findings showed cellulose exudate or small nodules filled with granulation tissue or fibroblasts in the alveolar cavity and small airways, and 1 case was Masson corpuscle positive. Three patients achieved remission after glucocorticoid therapy. Spontaneous remission without treatment was seen in 1 patient.Two cases were followed up for 17 months and 6 years, respectively, who had excellent outcome.Conclusions:The manifestations of COP in children include cough, expectoration and chest pain. Infants and young children may have tachypnea and wheezing. The most common chest CT findings are diffuse distribution of ground-glass opacity, patchy and consolidation in both lungs. Diagnosis should depend on pathological examination. The effect of glucocorticoid therapy is good.

Post-COVID-19 condition in children refers to the presence of physical symptoms or syndromes lasting more than 12 weeks after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which can be manifested as a combination of various signs and symptoms.Girls, school-aged, adolescents, and children with severe illness in the acute phase of COVID-19, with underlying allergic diseases and poor baseline physical and mental health are high-risk factors for post-COVID-19 condition in children.Pathogenesis may be related to viral persistence, autoimmunity, chronic inflammatory responses, chronic inflammation of vascular endothelial cells, and microthrombosis.A comprehensive treatment scheme including symptoms relieving treatment, rehabilitation, and psychological support.This article reviews the epidemiology, clinical manifestations, pathogenesis, diagnosis, treatment, and management of the post-COVID-19 condition in children to improve clinicians′ comprehension of the disease.

The clinical data of a case diagnosed with MIRAGE syndrome in the Respiratory Department of Shenzhen Children′s Hospital in June 2020 were analyzed retrospectively.The 11-month-old boy was admitted to the hospital because of " intermittent fever for 1.5 months and blood oxygen decline for half a day" . Whole exome detection was carried out by using second-generation sequencing technology.The results showed spontaneous, heterozygous, missense variation in SAMD9 gene (NM_017654) and the mutation site was c. 2471G>A.Review of the literature found that all of the children (47 cases) were born prematurely and their parents were not intermarriage.Besides, they had overall growth retardation, and some suffered from myelodysplasia, recurrent infection, adrenal insufficiency, genital phenotypes and enteropathy.Among SAMD9 gene variation, mutations c. 1376G>A and c. 2471G>A are most frequent.Attention should be paid to the MIRAGE syndrome in children with premature birth and full development lag after birth.

Objective:To investigate the feasibility of nebulizing injectable Tobramycin for the treatment of Pseudomonas aeruginosa (Pa) in pediatric cystic fibrosis (CF) patients. Methods:The clinical data of 3 CF children with Pa infection who were treated by nebulizing injectable Tobramycin in Shenzhen Children′s Hospital from September 2017 to March 2021 were retrospectively analyzed.The efficacy and safety were explored.The nebulized injectable Tobramycin (160 mg/dose) was given twice daily after airway clearance.After one-month treatment course, oral Ciprofloxacin would be given [30 mg/(kg·d)] to patients for another 1 month if Pa was still positive in repeat sputum cultures.Results:There were 2 males and 1 female in 3 cases recruited.The youngest patient was 1-year-old when receiving Tobramycin treatment.After airway clearance and inhalation of injectable Tobramycin, all had improvements in respiratory symptoms and chest CT scan.Two cases took additional oral Ciprofloxacin as Pa was still positive after the 1-month treatment course of Tobramycin.Pa turned to negative in all 3 cases after treatment for 3 months to 1.5 years.Besides, after treatment all the 3 patients had normal liver and renal functions, and normal hearing in multiple follow ups.One patient had a normal brainstem auditory evoked potential in the reexamination.Conclusions:Nebulizing injectable Tobramycin would be a reasonable alternative to inhaled Tobramycin solution for treating pediatric CF patients with Pa in view of the present condition in mainland China.However, it is still worth further study and discussion.

Objective:To analyze the characteristics of sleep disordered breathing (SDB) in children with allergic rhinitis (AR), and improve the diagnosis and treatment at AR combined with obstructive sleep apnea (OSA).Methods:The clinical data of 120 patients with AR and OSA (AR and OSA group) admitted to the respiratory department at Shenzhen Children′s Hospital from May 2019 to December 2020 were retrospectively analyzed.A total of 120 children diagnosed with OSA and excluded AR during the same period were selected as control group.The SDB day and night symptoms, sleep structure characteristics and sleep breathing events were compared between two groups.Results:The average course of disease in children with AR and OSA was significantly longer than that in control group ( P=0.030). The main manifestations of children in AR and OSA group were mouth breathing (100.0%), snoring (99.2%), nasal obstruction (88.5%), and restless sleep (68.0%). There was no significant difference in sleep structure between two groups ( P>0.05), but the sleep efficiency of AR and OSA group was significantly lower than that of control group ( P=0.028). The respiratory events apnea hypopnea index, obstructive apnea index, obstructive apnea hypopnea index, hypopnea index and oxygen desaturation index of each sleep period in AR and OSA group were significantly higher than those in control group ( P<0.05). Among the children in AR and OSA group, moderate and severe OSA were the main manifestations, and the difference between two groups was statistically significant ( P<0.001). Conclusion:The combination of AR delayed the course of OSA in children.The main characteristics of sleep disordered breathing in children with AR are mouth opening, restless sleep, snoring and nasal obstruction.The sleep efficiency is decreased.Obstructive hypopnea and apnea are the most common respiratory events, and oxygen deficiency often occurs in rapid eye movement phase.Children with AR are more likely to have moderate or severe obstructive sleep apnea.

Clinical data of a case of occult pulmonary actinomycosis with foreign body admitted to Shenzhen Children′s Hospital were retrospectively analyzed, and the relevant literatures were retrieved and reviewed.A female patient aged 6 years and 9 months planned to receive hematopoietic stem cell transplantation due to thalassemia.During the plain chest CT examination before the transplantation, flakes of shadows were examined in the right lower lung.The child had no clinical symptoms or pulmonary signs.The granulation tissue hyperplasia of the right lower lobe was detected by tracheoscopy, which was harvested for examination under tracheoscopy, and actinomycete infection was confirmed.Several bone fragments were found wrapped inside the granulation.After 6 months of treatment with Amoxicillin and Clavulanate potassium, the tracheoscopic manifestations and chest CT were improved.Pulmonary actinomycosis is a rare pulmonary infectious disease, which is much rarer in children than adults, manifesting as an insidious onset and atypical clinical manifestations.However, foreign bodies in children′s airway are common, which is favorable to infection.In clinical detection of actinomycete infection, the cause of infection should be concerned to prevent misdiagnosis and mistreatment.

Objective:To investigate the clinical characteristics and serotyping characteristics of respiratory syncytial virus(RSV)infection in children prevalent during summer of 2020 in Shenzhen City, and provide basis for the diagnosis, monitoring and prevention of RSV infection in this area.Methods:The clinical data of 509 cases of RSV infection were analyzed in the Respiratory Department at Shenzhen Children′s Hospital from July 1, 2020 to August 31, 2020.The children diagnosed with pneumonia were divided into mild RSV pneumonia group and severe RSV pneumonia group according to the severity.The age, sex, clinical manifestations, basic diseases, mixed infection, clinical diagnosis of the patients were analyzed.Results:In 509 children with RSV infection, the male to female ratio was 1.84∶1, and the mean thermal range was (3.98±3.25) d. The detection rate of RSV was 51.4% (126/245) in children aged < 6 months, 45.6% (247/542) in children aged from 6 months to 2 years, 41.8% (123/294) in children aged from 2 to 5 years, and 8.5% (13/153) in children aged > 5 years.Common clinical manifestations were cough (96.2%), fever (72.5%), runny nose (61.9%), and nasal congestion (54.6%). Of the 509 cases, 123 (24.2%) had underlying diseases and 49 (9.6%) had mixed infections.A total of 371 cases had RSV pneumonia, including 280 mild cases (55.0%) and 91 severe cases (17.8%). Compared with the mild RSV pneumonia group, the severe RSV pneumonia group was significantly higher in male, age < 1 years, proportion of wheezing, underlying disease, mixed infection, and hospitalization time and fever time (all P<0.05). Multivariate analysis showed that age less than 1 year, mixed infection and underlying diseases were the high risk factors of severe RSV pneumonia( OR=10.1, 14.3 and 3.4, respectively, all P<0.05). Of the 198 serotyping cases, 18 were type A and 180 were type B. Conclusion:During the summer of 2020, the epidemic of RSV infection in children in Shenzhen is dominated by type B. In addition to children aged from 6 months to 2 years, children aged 2-5 years are also susceptible groups.Age<1 year, underlying diseases and mixed infection are independent risk factors of severe RSV pneumonia in children.

Objective:To investigate the etiological characteristics and changes of plastic bronchitis(PB)in children from 2010 to 2019 at Shenzhen Children′s Hospital, and provide reference basis for improving the understanding of PB etiology.Methods:The clinical data of children diagnosed with infectious-associated PB at Shenzhen Children′s Hospital from Jan 2010 to Dec 2019 were retrospectively analyzed, and the etiological characteristics and changes were summarized.Results:There were 94 cases of mycoplasma pneumoniae, 38 cases of influenza virus, 41 cases of adenovirus, 16 cases of mixed infection, 11 cases of bacteria, and 57 cases of unclear etiology in 266 infectious-associated PB children.The distribution of PB in each age group: 15 cases were infants, 63 cases were toddlers, 112 cases were preschoolers, and 76 cases were school-age children.Adenovirus was the main pathogen of PB in infants and toddlers(60.0%, 28.6%), and mycoplasma pneumoniae(34.8%, 60.5%) as well as influenza virus(13.4%, 22.4%) were the main pathogen in preschool and school-age children, with statistically significant difference( P<0.001). From 2010 to 2019, the annual positive rates of pathogens were 62.5%, 60.0%, 66.7%, 74.1%, 64.0%, 50.0%, 93.3%, 57.1%, 75.0%, and 84.7%, respectively.PB was caused by mycoplasma pneumoniae infection every year.From 2016 to 2019, PB caused by mycoplasma pneumoniae infection increased year by year, while PB caused by adenovirus infection increased every other year. Conclusion:Mycoplasma pneumoniae was the most common pathogen of PB, followed by adenoviruses and influenza viruses, while bacteria, fungi and other viruses were relatively rare.In the infant group, adenovirus infection was predominant, while in preschool and school-age children group, mycoplasma pneumoniae and influenza virus infection were predominant.

Objective:To investigate the etiology, clinical characteristics and outcome of severe pneumonia-associated hemophagocytic lymphohistiocytosis, and to analyze the risk factors for mortality.Methods:Clinical data of patients with severe pneumonia-associated hemophagocytic lymphohistiocytosis admitted to Shenzhen Children′s Hospital from February 2009 to February 2019 were retrospectively analyzed.The data included clinical characteristics, etiology, clinical manifestations, laboratory data, treatment and outcomes of the patients.The clinical characteristics and laboratory data of the survival group and the death group were compared by independent sample t-test. Results:(1) Clinical characteristics: the patients were aged from 3 months to 8 years and 7 months, including 15 males and 15 females.Severe pneumonia-associated hemophagocytic lymphohistiocytosis accounted for 2.74% (30/1 096 cases) of severe pneumonia in the same period.(2) Etiology: Mycoplasma pneumoniae infection was found in 8 cases (8/30 cases, 26.67%), virus infection in 7 cases (7/30 cases, 23.33%, including 5 cases with adenovirus infection, 1 case with EB virus infection, and 1 case with cytomegalovirus infection), Mycoplasma pneumoniae complicated with adenovirus infection in 4 cases (4/30 cases, 13.33%), bacterial infection in 3 cases (3/30 cases, 10%), and fungal infection in 2 cases, Mycobacterium tuberculosis infection in 1 case.The pathogens were not identified in 5 patients.(3) Clinical manifestations: fever and hepatomegaly were present in all patients.Besides, 86.67% (26/30)patients had fever duration more than 10 days, 83.33% (25/30 cases) patients had cough, 76.66% (23/30 cases) patients had splenomegaly, and 33.33% (10/30 cases) patients had nervous system symptoms.Laboratory data showed varying degrees of reduction of binary and ternary systems in 80.00%(24/30 cases) of the patients.Liver function impairment was found in half of the patients, and serum ferritin and lactate dehydrogenase levels were elevated in all patients.(4) The mortality rate was 30.00% (9/30 cases). The differences in age, hypertriglyceridemia and high serum ferritin levels between the survival and death groups were significant (all P<0.05). Conclusions:Severe pneumonia-associated hemophagocytic lymphohistiocytosis is a disease with a high mortality rate.Patients with Mycoplasma pneumoniae and adenovirus pneumonia are more likely to suffer from secondary hemophagocytic lymphohistiocytosis.Younger age, hypertriglyceridemia and high serum ferritin levels are indicative of poor prognosis.