The discovery of hemoglobin variants with low oxygen affinity,diagnostic methods,prognosis of carriers,and developments in analyzing hemoglobin oxygen-carrying and-releasing abilities are reviewed in this article in order to draw the attention of related clinical departments and to provide references for optimizing the process of diagnosis and treatment.Hemoglobin variants with low oxygen affinity originate from gene mutations encoding hemoglobin and autosomal dominant inheritance.The diagnosis should be combined with clinical manifestations and family history and differentiated from methemoglobinemia.A decrease in pulse oxygen saturation(SpO2)is often the first abnormality observed in asymptomatic carriers of hemoglobin variants with low oxygen affinity.Laboratory examinations include arterial blood gas analysis,hemoglobin oxygen affinity testing,protein analysis and gene sequencing.Most carriers do not require specific treatment and have a good prognosis,who should avoid acute hypoxic injuries induced by strenuous exercise,emotional stress,or high temperature.Moreover,health practitioners should pay attention to their responses to anesthetics,agents that induce oxidative stress,drugs that increase hemoglobin oxygen affinity,and prostacyclins.Hemoglobin oxygen-carrying and-releasing analysis is a promising tool to identify carriers of hemoglobin variants with low oxygen affinity because it does not involve unnecessary or invasive examinations and is of significant values for clinical diagnosis and treatment.

Objective To Observe the clinical characteristics and prognosis of patients with the acute macular neuroretinopathy(AMN)associated with novel coronavirus infection(COVID-19).Methods The data of 13 patients diagnosed with COVID-19-associated AMN attending the Department of Ophthalmology of the Affiliated Hospital of Yunnan University from December 2022 to February 2023,as well as 13 case reports in PubMed and Web of Science databases from 2020 to 2023 and a case series study totaling 41 patients were retrospectively selected and analyzed for their ophthalmic imaging and prognostic outcomes in clinic.Results A total of 13 cases with 25 eyes in the clinical case group were included in the study with a mean age of 30.23±6.02 years,of which 10 were females.The literature case group consisted of 41 cases and 72 eyes with a mean age of 30.12±13.24 years,including 31 female patients.(1)Duration between COVID-19 symptoms/diagnosis and ophthalmic symptoms:3(2.0,4.0)days in the clinical case group and 2(0.75,5.0)days in the literature case group.(2)Clinical characteristics:12(92.31％)of the clinical case group had the binocular onset and the literature case group,31(75.61％)had the binocular onset.The symptoms in both groups were mainly dark spots in vision,followed by decreased visual acuity.(3)Ancillary examinations:optical coherence tomography(OCT)showed the ellipsoid zone(EZ)and/or chimeric zone(IZ)breaks with strong reflections in the outer plexiform layer(OPL)and outer nuclear layer(ONL)in 13 patients in the clinical case group,and the near-infrared photography(NIR)showed the low-reflective wedge-shaped foci around the center of the macula,and some patients'optical coherence tomography angiography(OCTA)showed deep capillary lesions,and some patients'OCTA showed low reflectivity.Reduced blood flow in the deep capillary layer(DCP)and choroidal capillary layer(CC)was observed in all patients,7 patients with cotton-wool spots also had the reduced blood flow in the superficial capillary layer(SCP),and 33 patients in the case group in the literature had the visible EZ and/or IZ breaks on OCT.(4)Treatment and prognosis:11 out of 13 patients were treated with oral glucocorticoids,2 were under the observation.After year,the condition of 23 patients had been improved,1 case had visual field defects,1 case had retinal vein occlusion secondary to macular edema,and 1 case had a hyporeflective signal in the outer nuclear layer(ONL)and outer plexiform layer(OPL).Conclusion The age of onset of AMN related to COVID-19 is slightly older,with more cases involving both eyes.The main symptom is visual field scotoma,often accompanied by decreased vision.Near-infrared imaging shows low-reflective wedge-shaped lesions around the fovea,and OCT shows mainly disruption of the EZ and/or IZ.OCTA shows decreased blood flow density in the DCP and CC layers.The visual prognosis of AMN related to COVID-19 is good,but vigilance is needed for the occurrence of complications such as retinal vein occlusion.

Abstract In November 2023, the Jinhua Center for Disease Control and Prevention received a report from a company indicating 3 cases of pulmonary tuberculosis. An on-site epidemiological investigation was immediately conducted. A total of 3 cases were reported, with an attack rate of 9.68%. The first case had cough and expectoration for more than a year, and diagnosed with rifampicin-resistant pulmonary tuberculosis on November 16, 2023, and the other 2 cases were his colleagues who were diagnosed with rifampicin-resistant pulmonary tuberculosis and etiology negative pulmonary tuberculosis on November 20 and 21, respectively. Based on the on-site investigation and laboratory test results, it was a cluster of rifampicin-resistant pulmonary tuberculosis. The likely cause of the spread might be the lack of timely medical attention for the first case, which led to the infection of other colleagues through contact transmission. Eight close contacts screened positive for purified protein derivative (PDD) or recombinantMycobacterium tuberculosisfusion protein skin test (EC-ST), given the injection of mycobaeterium vaccae vaccine, and no new cases of tuberculosis detected in the 3-month follow-up. The outbreak highlighted the necessity for the company to enhance health education concerning the prevention and treatment of pulmonary tuberculosis, implement regular health monitoring and enhance the physical examination for employee in order to increase sensitivity to pulmonary tuberculosis.

Objective:To summarize the clinical features of 8 cases with intramycardial hematoma(IMH) following congenital cardiac surgery in children.Methods:We retrospectly searched 8 patients with intramycardial hematoma after congenital cardiac surgery in Guangzhou Women and Children’s Medical Center from 2008 to 2024.Results:Mean age and mean weight at surgery were(13±15) months and(7.8±3.5)kg respectively. 6 of 8 cases were interventricular septal hematoma. In the other 2 patients, intramycardial hematoma was located in left ventrical free wall. All IMH were postoperatively detected by transthoracic echocardiaography. Two patients were managed with ECMO intraoperatively. Finally, all patients were discharged successfully with good clinical results. Mean time to IMH resolution in six patients was(33.5±4.6) days and mean left ventricular ejection fraction(LVEF) was 0.60±0.09. Another patient was followed up for 3 months and the IMH was not absorbed. One patient was lost to follow-up.Conclusion:IMH is a rare complication after congenital heart disease. The absorption of hematoma is a dynamic process and mean time to IMH resolution is about 1month. In IMH patients with hemodynamic instability, ECMO can be a good treatment to create opportunities for hematoma absorbtion.

Objective To explore the impact of pH value of the reaction system on the properties of bovine hemoglobin modified with aldehydeated polyethylene glycol(PEG-bHb).Methods PEG-bHb conjugates were synthesized under varying pH conditions(6.0,6.5,7.4 and 8.0)of the reaction system while consistent molar ratios,temperature,and reaction time were maintained.The structural and functional attributes of PEG-bHb were characterized.Results The proportion of methemoglobin decreased with an increase in pH.In a weakly acidic reaction environment,the PEG-bHb was found to be relatively highly modified.At pH 6.5,the average number of PEG chains attached to the bHb surface was 6.86±0.38.Selective PEG modification of the N-terminal α-NH2 groups was more pronounced under weakly acidic conditions.Specifically,at pH 6.5,the modification efficiency of the N-terminal α-NH2 groups of bHb by aldehyde-activated PEG reached 95.4％for the α-chains and 99.3％for the β-chains.The PEG modification influenced the heme region microenvi-ronment of bHb,with minimal structural impact observed at pH 6.5.After modification,the oxygen affinity of PEG-bHb was enhanced,the Hill coefficient was reduced,and there were significant increases in colloid osmotic pressure,viscosity,and particle size,all of which differed markedly from the unmodified bHb group(P＜0.001).Conclusion The synthesis of PEG-bHb under weakly acidic conditions can result in a high degree of selective modification of the N-terminal α-NH2 groups and an overall high degree of modification.

Objective:To examine the early and midterm surgical outcome of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCA) using revised surgical strategies.Methods:A retrospective analysis of clinical data, surgical methods, and follow-up results was performed of 104 cases of PA/VSD/MAPCA in Department of Cardiovascular Surgery, Guangzhou Women and Children′s Medical Center from January 2017 to September 2022. There were 55 males and 49 females, aged ( M(IQR)) 33.9(84.0) months (range: 0.5 to 209.6 months) at the first surgical procedures. The anatomical classification included 89 cases of type B and 15 cases of type C. The number of major aortopulmonary collateral arteries was 4.2 (3.0) (range: 1 to 8). The Kaplan-Meier method was used for survival estimation. Results:In the first stage of surgery, 50 patients underwent a complete primary repair, 12 patients underwent partial repair, 32 patients underwent palliative right ventricular-pulmonary artery connection, and only 10 patients chose the Blalock-Taussig shunt. There were 10 cases of early death. In the second stage, 14 patients underwent complete repair and 4 patients underwent partial repair with no early death. The interval between the two surgeries was 19 (10) months (range: 9 to 48 months). Finally, during the 40 (34) months follow-up period, a total of 64 patients were complete repair and the right/left ventricular pressure ratio after complete repair was 0.63±0.16 (range: 0.36 to 1.00). Survival analysis showed that survival rates at 1 and 5 years after first-stage surgery were both 89.4% (95% CI: 83.5% to 95.3%). At 28 (34) months (range: 1 to 67 months) of follow-up after complete repair, the survival analysis showed that the survival rates at 1 and 5 years were both 95.2% (95% CI: 89.9% to 100%). Conclusions:Using combined approaches tailored to individual patients and optimized unifocalization strategy, the complete repair rate at one stage and the cumulative complete repair rate at 5 years improved significantly with a lower right/left ventricular pressure ratio and satisfactory early and intermediate survival.

Objective:To examine the early and midterm surgical outcome of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCA) using revised surgical strategies.Methods:A retrospective analysis of clinical data, surgical methods, and follow-up results was performed of 104 cases of PA/VSD/MAPCA in Department of Cardiovascular Surgery, Guangzhou Women and Children′s Medical Center from January 2017 to September 2022. There were 55 males and 49 females, aged ( M(IQR)) 33.9(84.0) months (range: 0.5 to 209.6 months) at the first surgical procedures. The anatomical classification included 89 cases of type B and 15 cases of type C. The number of major aortopulmonary collateral arteries was 4.2 (3.0) (range: 1 to 8). The Kaplan-Meier method was used for survival estimation. Results:In the first stage of surgery, 50 patients underwent a complete primary repair, 12 patients underwent partial repair, 32 patients underwent palliative right ventricular-pulmonary artery connection, and only 10 patients chose the Blalock-Taussig shunt. There were 10 cases of early death. In the second stage, 14 patients underwent complete repair and 4 patients underwent partial repair with no early death. The interval between the two surgeries was 19 (10) months (range: 9 to 48 months). Finally, during the 40 (34) months follow-up period, a total of 64 patients were complete repair and the right/left ventricular pressure ratio after complete repair was 0.63±0.16 (range: 0.36 to 1.00). Survival analysis showed that survival rates at 1 and 5 years after first-stage surgery were both 89.4% (95% CI: 83.5% to 95.3%). At 28 (34) months (range: 1 to 67 months) of follow-up after complete repair, the survival analysis showed that the survival rates at 1 and 5 years were both 95.2% (95% CI: 89.9% to 100%). Conclusions:Using combined approaches tailored to individual patients and optimized unifocalization strategy, the complete repair rate at one stage and the cumulative complete repair rate at 5 years improved significantly with a lower right/left ventricular pressure ratio and satisfactory early and intermediate survival.

Objective:To summarize the early and middle terms of the revascularization of remnant pulmonary artery in unilateral absent intrapericardial pulmonary artery.Methods:We retrospectively analyzed the medical records of 14 patients(7 males and 7 females) with unilateral absent pulmonary artery, in which 10 were right and 4 were left, the median age at surgery was 5 months. The patients received operation from January 2009 to December 2020. 14 patients, 2 cases associated with tetralogy of Fallot, and 1 case with aortopulmonary window. The diagnosis was made by enhanced CT scan or pulmonary vein wedge angiography. The median diameter of the affected hilar pulmonary artery remnants was(3.20±0.94)mm, and the Z value was -3.92±1.64. All the patients received single-stage revascularization: group A: tube graft interposition in 3 patients, autologous pericardial roll in 5; group B: direct anastomosis in 2, unifocalization in one and main pulmonary artery flap angioplasty in the rest 3.Results:No hospital death occurred. There were no difference finds in the age and weight at operation, the cardiopulmonary bypass time, the mechanical ventilation time, and the length of intensive care unit stay between the two groups. All the patients took aspirin for anticoagulation for 6 months after the operation. The follow-up period was 1 month to 68 months. Because the neo-PA stenosis at the anastomosis was found in one patient in group B, transcatheter balloon angioplasty was performed at 41 months after surgery. Nonetheless, the results were encouraging, symptoms have improved in all patients. The diameter and Z value of the latest ipsilateral pulmonary artery was(6.25±0.99)mm and -2.34±1.18 respectively, significantly improved when compared to the preoperative value. Residual pulmonary artery hypertension was not found. The Z value of the affected side of the pulmonary artery in group B was significantly improved than that in group A.Conclusion:Early and aggressive pulmonary artery revascularization is effective at restoring normal antegrade flow to the affected lung, resulting in improved diameter of the PA, and UAPA patient’s symptoms. The use of autologous pulmonary artery tissue angioplasty may reach a more satisfying result. However, transcatheter intervention may diminish the new pulmonary artery stenosis temporarily, reoperation is still needed in the long-term follow-up.

Objective    To summarize the results of surgical treatment for 79 patients with coarctation of the aorta (CoA) combined with complex anomalies (CA) in recent years. Methods    The data from 79 patients with CoA combined with CA admitted to Guangzhou Women and Children's Medical Center between January 19, 2010 and September 7, 2017 were collected and analyzed. There were 52 males and 27 females. The median age was 71 days, and the median weight was 4.3 kg. There were 26 patients combined with tracheostenosis and 7 patients with preoperative tracheal intubation. Extended end-to-side anastomosis was used to correct the CoA, and the associated cardiac abnormalities were treated simultaneously by an incision through median sternotomy. All operations were performed by the same group of surgeons. Results    The median deep hypothermic circulatory arrest was 18 (13-28) minutes, the median aorta cross-clamp time was 62 (15-199) minutes, the median cardiopulmonary bypass time was 145 (71-674) minutes, the median ventilation time was 72 (9-960) hours, the median length of ICU stay was 144 (12-1 944) hours, and the median length of hospital stay was 24 (2-93) days. Early death occurred in 9 patients and late death occurred in 5 patients. Reoperation occurred in 28 patients and recoarctation developed in 10 patients. After operation, transcoarctation gradient was reduced, and the transcutaneous oxygen saturation, C-reactive protein (CRP), lactate and creatinine were increased. Compared to the survival group, both preoperative and postoperative transcutaneous oxygen saturation were worse and the postoperative levels of plasma brain natriuretic peptide (BNP) and CRP were higher in the death group. Conclusion    Correcting the CoA and the associated CA simultaneously with extended end-to-side anastomosis by an incision through median sternotomy is effective and safe, and the outcomes of immediate and medial-term are satisfactory. Improving oxygenation and limiting elevation of BNP and CRP levels may reduce the death rate.

Objective:To evaluate the early results of pulmonary autograft mitral valve replacement (Ross Ⅱ procedure) in infants with intractable congenital mitral valve lesions.Methods:Between August 2018 and September 2019, 6 infants underwent mitral valve replacement with a pulmonary autograft in Department of Cardiovascular Surgery, Guangzhou Women and Children′s Medical Center. There were 2 males and 4 females.The age at surgery ranged from 50 days to 1 year old.Preoperative diagnoses included severe to critic mitral valve insuffiency in all patients, moderate mitral valve stenosis in 3 patients, and mitral valve prolapse in one. When the pulmonary autograft was harvested, a cuff of bovine or autologous pericardium was sewn onto the proximal (infundibular) end of the autograft ( "top-hat" configuration). The distal (pulmonary) end of the autograft was secured to the mitral annulus.At the level of the left atrial free wall, the pericardial cuff was progressively tailored and sewn onto the atrial wall to remain away from the ostia of the pulmonary veins and to maintain normal morphology of the autograft. The bovine jugular valved conduit was used to reconstruct the right ventricular outflow tract.Results:There was one early death due to sudden cardiac arrest at the night of surgery day. The remaining 5 patients were successfully recovered and discharged. Follow-up of survivors ranged from 3 to 13 months. Echocardiographic follow-up demonstrated the flow velocity across the mitral valve position was 1.5 to 2.3 m/s, with a means gradient of 4 to 6 mmHg (1 mmHg=0.133 kPa). Four patients showed mild mitral insuffiency, normal left atrium and ventricle size and left ventricle ejection fraction.One patient had moderate mitral insuffiency, pulmonary valve endocarditis, and reduced left ventricle ejection fraction. The clinical symptoms of all survivals improved significantly and the weight gain were satisfactory.Conclusion:Pulmonary autograft mitral valve replacement may be a feasible and effective remedial surgical strategy for young infants with intractable congenital mitral valve lesions.