Clinical study of polyetheretherketone resin-bonded bridge for restoring anterior missing teeth in patients with periodontitis / 口腔疾病防治

Objective@#To study the clinical effect of a polyetheretherketone (PEEK) bonding bridge on the loss of 3 internal incisors in patients with periodontitis.@*Methods@#This study was reviewed and approved by the ethics committee, and informed consent was obtained from the patients. Thirty-eight patients with periodontitis and 3 missing central or lateral teeth were selected to undergo restoration with a PEEK bonding bridge and then returned to the hospital 3, 6, 12, and 24 months after the restoration was completed. The survival rate of the restorations was assessed by the modified USPHS/Ryge criteria. The plaque index, gingival index, periodontal probing depth and attachment loss of the abutments were recorded, and the changes in periodontal tissues after restoration were observed and compared.@*Results@#Over 24 months of clinical follow-up observation of 38 patients, only 1 patient underwent secondary bonding after partial debonding (evaluated as grade B), while bonding was successful in the other 37 cases (evaluated as grade A). The plaque index, gingival index and periodontal probing depth were significantly lower after restoration than before (P<0.05). There was no significant change in attachment loss between before and after restoration (P>0.05).@*Conclusion@#For periodontitis patients missing 3 internal incisors, short-term PEEK bonding bridge repair has good clinical efficacy.

A neglected normal anatomical structure in mammal: a study in bats and tree shrews / Una estructura anatómica normal desatendida en mamíferos: un estudio en murciélagos y musarañas arborícolas

SUMMARY: The myodural bridge is a dense connective tissue connecting muscles and ligaments to the spinal dura mater in the atlanto-occipital interspace. Some researchers believe that the myodural bridge may play a vital physiological role. It is possible, for instance, that the prevention of spinal dura mater infoldings might be involved in regulated cerebrospinal fluid circulation. For instance, it is possible to prevent spinal dura mater infoldings, regulating cerebrospinal circulation. Bats are nocturnal and the only mammals that can perform a genuine and sustained flight, whereas tree shrews are arboreal mammals that often climb to a high altitude of about 10,000 feet. Both animals have lifestyles that are different from other previously studied mammals. The study of these two animals will shed further light on the existence of the myodural bridge in mammals. Gross anatomical dissection was used to observe the connections between the deep muscles of the neck and the dura mater at the level of the atlanto-occipital interspace. The existing structures were analyzed using conventional and special histological staining techniques. The suboccipital regions in bats and tree shrews contained the rectus capitis dorsal major (RCDma), rectus capitis dorsal minor (RCDmi), oblique capitis anterior (OCA), and oblique capitis posterior (OCP). Dense connective tissue connects the RCDmi to the posterior atlanto-occipital membrane (PAOM) and the latter to the spinal dura mater. The myodural bridge in these mammals shares a similar structure to the myodural bridge in humans. Histological analyses confirmed that the connective fibers of the myodural bridge were primarily type I collagen fibers. In this study, it is supplemented by the existence of the myodural bridge in mammals. This further demonstrates that myodural bridge widely exists in the normal anatomy of mammals. This provides morphological support for a comparative anatomical study of the physiological function of the myodural bridge.

El puente miodural es un tejido conjuntivo denso que conecta los músculos y los ligamentos a la duramadre espinal en el espacio atlanto-occipital. Algunos investigadores creen que el puente miodural puede desempeñar un papel fisiológico vital. Es posible, por ejemplo, que la prevención de los pliegues de la duramadre espinal pueda estar involucrada en la circulación regulada del líquido cefalorraquídeo. En esta instancia, es posible prevenir los pliegues de la duramadre espinal, regulando la circulación cerebro espinal. Los murciélagos son animales nocturnos y los únicos mamíferos que pueden realizar un vuelo real y sostenido, mientras que las musarañas arborícolas son mamíferos arbóreos que a menudo ascienden a una gran altura de unos 10 000 pies. Ambos animales tienen estilos de vida diferentes a los de otros mamíferos previamente estudiados. El estudio de estos dos animales ofrecerá más información sobre la existencia del puente miodural en los mamíferos. Se realizó una disección anatómica macroscópica para observar las conexiones entre los músculos profundos del cuello y la duramadre a nivel del espacio atlanto-occipital. Las estructuras existentes se analizaron mediante técnicas de tinción histológica convencionales y especiales. Las regiones suboccipitales en murciélagos y musarañas arbóreas presentaban el músculo recto dorsal mayor de la cabeza (RCDma), el recto dorsal menor de la cabeza (RCDmi), el oblicuo anterior de la cabeza (OCA) y el oblicuo posterior de la cabeza (OCP). El tejido conjuntivo denso conecta el RCDmi con la membrana atlanto- occipital posterior (PAOM) y esta última con la duramadre espinal. El puente miodural en estos mamíferos comparte una estructura similar al puente miodural en humanos. Los análisis histológicos confirmaron que las fibras conectivas del puente miodural son principalmente fibras de colágeno tipo I. Esto demuestra además que el puente miodural existe ampliamente en la anatomía normal de los mamíferos. Esta investigación proporciona apoyo morfológico para un estudio anatómico comparativo de la función fisiológica del puente miodural.

A Bibliometric Analysis of Resin-Bonded Bridge: Performance Analysis and Science Mapping

@#The objective of this study was to identify and characterise various resin-bonded bridge (RBB) articles published in dental journals using bibliometric analysis. The search was performed using the Scopus database to generate publications related to RBB. Data analysis and visualisation were done using Microsoft Excel, Biblioshiny software or VOSviewer. The trend of publication shows an annual growth rate of 7.19 percent within the years 1973–2022. Sixteen articles were cited more than 100 times, with seven highly cited articles focusing on the survival and/or complications of RBB. Matthias,Kern is the most prolific author in RBB research with Journal of Prosthetic Dentistry being the most influential journal. “survival”, “dental bonding” and “zirconia” were identified as core research areas for RBB for the past 10 years. Future research on the incorporation of new technology in prosthesis fabrication to assess the survival and longevity of RBB is expected to increase, with an emphasis on bonding to new materials. This paper presents an overview of scientific production, prominent researchers and countries, emerging keywords and core research areas in RBB research.

Extracorporeal membrane oxygenation bridging heart transplantation in the treatment of two children with end-stage heart failure / 中国小儿急救医学

Objective:To investigate the application of extracorporeal membrane oxygenation(ECMO)bridging heart transplantation in critically ill children.Methods:The clinical data of two cases of critical infants with venous-arterial ECMO(VA-ECMO)bridging heart transplantation and literature review were retrospectively analyzed.Results:Two cases received orthotopic heart allograft with VA-ECMO support, and were discharged uneventfully without significant postoperative complications.On the 13th day of ECMO assistance, the first child was treated with orthotopic heart transplantation in a hospital qualified for heart transplantation, and the ECMO was evacuated during the operation.After 21 days of the heart transplantation, the patient was discharged from the hospital.The patient was followed up to be healthy after heart transplantation, and had the same development as children of the same age, and had been taking anti-rejection drugs for a long time.On the 10th day of VA-ECMO treatment, the second case received awake ECMO after cardiac function improved.On the 12th day of VA-ECMO treatment, the patient was successfully evacuated from VA-ECMO and waited for heart transplantation.Cardiac orthotopic transplantation was performed after the 17 days after VA-ECMO evacuation.The patient was transferred to the general ward after 6 days of hospitalization in the intensive care unit, and was discharged 23 days after transplantation with conventional anti-rejection therapy.Discharge follow-up in good health, normal school life.Conclusion:When VA-ECMO cannot be withdrawn from the heart of the critically ill children and the end-stage heart, VA-ECMO bridging heart transplantation should be selected at the right time for the children who meet the indications for heart transplantation to create survival opportunity for the previously hopeless children, save the life of the end-stage children, and improve the quality of life.

Progress and prospect of heart transplantation in children / 器官移植

Pediatric heart transplantation is the standard treatment for children complicated with refractory heart failure which is difficult to be treated by conventional surgery or drugs. At present, an increasing quantity of pediatric heart transplantation is being performed worldwide, whereas relevant experience is still lacking in China. In recent 10 years, significant progress has been achieved in pediatric heart transplantation. On one hand, the number of pediatric heart transplantation has been increased year by year. On the other hand, ABO-incompatible heart transplantation, application of ventricular assist device in children, and recipient-donor weight mismatch transplantation have been widely employed to resolve the shortage of donor heart in pediatric heart transplantation. However, relevant experience of pediatric heart transplantation is lacking in China, especially in understanding the indications of pediatric heart transplantation and the application of specific strategies for pediatric heart transplantation, etc. In this article, the development history, advances in therapeutic strategy and clinical prognosis of pediatric heart transplantation were reviewed.

Existence and morphology features of the myodural bridge in JapaLura Splendida / 解剖学报

Objective The dense fibrous connective tissue that connects sub-occipital muscles which consist of the rectus capitis posterior minor muscle (RCPmi), rectus capitis posterior major muscle (RCPma), obliquus capitis inferior muscle (OCI) and nuchal ligament (NL) to the spinal dura mater (SDM), is described as the myodural bridge (MDB) in humans. The MDB is perceived as an essential anatomical structure and has been a subject of interest for clinicians. Studies have revealed that MDB may be related to the dynamic circulation of the cerebrospinal fluid (CSF) and a chronic cervicogenic headache. To date, the MDB is identified as a universal, existing structure in mammals and it exists in other vertebrates as well, such as Gallus domesticus and Rock pigeons in Avifauna, Siamese crocodile and Trachemys scripta elegans in Reptile. The current study is to further analyze different structures features of the MDB in sundry classes and provide the anatomical basis for functional studies. The JapaLura Splendida is the most common species in Lacertiformes, Reptilia. So we chose it as the experimental object to supply the morphological study of the MDB in Reptilia. Methods The study was based on gross anatomical dissection, thick sheet section, histological staining to observe the structural characteristics of the post-occipital area of twenty JapaLura Splendidas and the existence of the MDB. Results The deep post-occipital muscles were composed of the rectus capitis dorsal muscle (RCD) and the obliquus capital posterior (OCP) muscle. The RCD was merged by the rectus capitis dorsal major muscle (RCDma), the rectus capitis dorsal minor muscle (RCDmi) and the obliquus capitis anterior muscle (OCA). In the atlanto-occipital space, the dense fibrous bundles were found to originate from the ventral aspect of the RCD and run ventral, closely inserting into the SDM. In the atlanto-axial space, the dense fibrous bundles were found to originate from the ventral aspect of the OCP and run ventral, closely contacted with the SDM. These dense fibrous bundles were the collagen type I fibers with strong double refraction. Conclusion The result of this study indicates that the MDB is located between the post-occipital muscles and the SDM in JapaLura Splendida. The MDB of Japalura splendida may be related to the activities of the head and neck, and exert a physiological function similar to the MDB in humans.

Colonic stenting in acute malignant large bowel obstruction: audit of efficacy and safety in a Singapore tertiary referral centre

INTRODUCTION@#Acute malignant large bowel obstruction (MBO) occurs in 8%-15% of colorectal cancer patients. Self-expandable metal stents (SEMS) have progressed from a palliative modality to use as bridge to surgery (BTS). We aimed to assess the safety and efficacy of SEMS for MBO in our institution.@*METHODS@#The data of patients undergoing SEMS insertion for MBO were reviewed. Technical success was defined as successful SEMS deployment across tumour without complications. Clinical success was defined as colonic decompression without requiring further surgical intervention. Rates of complications, median time to surgery, types of surgery and rates of recurrence were studied.@*RESULTS@#Seventy-nine patients underwent emergent SEMS placement from September 2013 to February 2020. Their mean age was 68.8 ± 13.8 years and 43 (54%) patients were male. Mean tumour length was 4.2 cm ± 2.2 cm; 89.9% of malignant strictures were located distal to the splenic flexure. Technical and clinical success was 94.9% and 98.7%, respectively. Perforation occurred in 5.1% of patients, with none having stent migration or bleeding. Fifty (63.3%) patients underwent SEMS insertion as BTS. Median time to surgery was 20 (range 6-57) days. Most (82%) patients underwent minimally invasive surgery. Primary anastomosis rate was 98%. Thirty-nine patients had follow-up beyond 1-year posttreatment (median 34 months). Local recurrence and distant metastasis were observed in 4 (10.3%) and 5 (12.8%) patients, respectively.@*CONCLUSION@#Insertion of SEMS for acute MBO has high success rates and a good safety profile. Most patients in this audit underwent minimally invasive surgery and primary anastomosis after successful BTS.

Effectiveness analysis of "tail compression fixation+suture bridge" technology under shoulder arthroscopy for treating primary tear in medial enthesis of rotator cuff / 中国修复重建外科杂志

OBJECTIVE@#To investigate the feasibility and effectiveness of "tail compression fixation+suture bridge" technology under shoulder arthroscopy for treating primary tear in medial enthesis of rotator cuff.@*METHODS@#The clinical data of 11 patients with primary tear in medial enthesis of rotator cuff who met the selection criteria between October 2020 and October 2022 were retrospectively analyzed, including 3 males and 8 females, aged 39-79 years, with an average of 61.0 years. Rotator cuff injury was caused by traumatic fall in 8 cases, and the time from injury to admission was 1-4 months, with an average of 2.0 months; the remaining 3 cases had no obvious inducement. The active range of motion of the affected shoulder was limited, with an active forward flexion range of motion of (64.1±10.9)°, abduction of (78.1±6.4)°, internal rotation of (48.2±6.6)°, and external rotation of (41.8±10.5)°; 5 cases had shoulder stiffness. The preoperative visual analogue scale (VAS) score was 7.8±0.8 and the American Society of Shoulder and Elbow Surgeons (ASES) score was 23.9±6.4. The patients were treated with "tail compression fixation+suture bridge" technology under shoulder arthroscopy, and the pain and functional recovery were evaluated by VAS score, ASES score, and active range of motion of shoulder joint at last follow-up; MRI was performed after operation, and the integrity of rotator cuff was evaluated by Sugaya classification system.@*RESULTS@#All the 11 patients were followed up 2-22 months, with an average of 13.5 months. All incisions healed by first intention, and there was no complication such as infection, rotator cuff re-tear, and anchor falling off. At last follow-up, the VAS score was 0.8±0.7 and the ASES score was 93.5±4.2, which significantly improved when compared with those before operation ( P<0.05). All 11 patients had no significant swelling in the shoulders, and the active range of motion was (165.1±8.8)° in flexion, (75.3±8.4)° in abduction, (56.6±5.5)° in internal rotation, and (51.8±4.0)° in external rotation, which significantly improved when compared with those before operation ( P<0.05). Shoulder MRI showed adequate tendon thickness and good continuity in 9 cases, including 4 cases with partial high signal area; and 2 cases with inadequate tendon thickness but high continuity and partial high signal area. According to Sugaya classification system, there were 4 cases of type 1 (36.4%), 5 cases of type 2 (45.5%), and 2 cases of type 3 (18.1%).@*CONCLUSION@#For the patients with primary tear in medial enthesis of rotator cuff, the "tail compression fixation+suture bridge" technology under shoulder arthroscopy is simple and effective.

Clinical application of Flow-through bridge anterolateral thigh flap in repair of complex calf soft tissue defects / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of Flow-through bridge anterolateral thigh flap transplantation in the treatment of complex calf soft tissue defects.@*METHODS@#The clinical data of the patients with complicated calf soft tissue defects, who were treated with Flow-through bridge anterolateral thigh flap (study group, 23 cases) or bridge anterolateral thigh flap (control group, 23 cases) between January 2008 and January 2022, were retrospectively analyzed. All complex calf soft tissue defects in the two groups were caused by trauma or osteomyelitis, and there was only one major blood vessel in the calf or no blood vessel anastomosed with the grafted skin flap. There was no significant difference between the two groups in general data such as gender, age, etiology, size of leg soft tissue defect, and time from injury to operation ( P>0.05). The lower extremity functional scale (LEFS) was used to evaluate the sufferred lower extremity function of the both groups after operation, and the peripheral blood circulation score of the healthy side was evaluated according to the Chinese Medical Association Hand Surgery Society's functional evaluation standard for replantation of amputated limbs. Weber's quantitative method was used to detect static 2-point discrimination (S2PD) to evaluate peripheral sensation of the healthy side, and the popliteal artery flow velocity, toenail capillary filling time, foot temperature, toe blood oxygen saturation of the healthy side, and the incidence of complications were compared between the two groups.@*RESULTS@#No vascular or nerve injury occurred during operation. All flaps survived, and 1 case of partial flap necrosis occurred in both groups, which healed after free skin grafting. All patients were followed up 6 months to 8 years, with a median time of 26 months. The function of the sufferred limb of the two groups recovered satisfactorily, the blood supply of the flap was good, the texture was soft, and the appearance was fair. The incision in the donor site healed well with a linear scar, and the color of the skin graft area was similar. Only a rectangular scar could be seen in the skin donor area where have a satisfactory appearance. The blood supply of the distal limb of the healthy limb was good, and there was no obvious abnormality in color and skin temperature, and the blood supply of the limb was normal during activity. The popliteal artery flow velocity in the study group was significantly faster than that in the control group at 1 month after the pedicle was cut, and the foot temperature, toe blood oxygen saturation, S2PD, toenail capillary filling time, and peripheral blood circulation score were significantly better than those in the control group ( P<0.05). There were 8 cases of cold feet and 2 cases of numbness on the healthy side in the control group, while only 3 cases of cold feet occurred in the study group. The incidence of complications in the study group (13.04%) was significantly lower than that in the control group (43.47%) ( χ 2=3.860, P=0.049). There was no significant difference in LEFS score between the two groups at 6 months after operation ( P>0.05).@*CONCLUSION@#Flow-through bridge anterolateral thigh flap can reduce postoperative complications of healthy feet and reduce the impact of surgery on blood supply and sensation of healthy feet. It is an effective method for repairing complex calf soft tissue defects.

X-ray evaluation of pulp calcification in adult permanent teeth after pulpotomy / 北京大学学报(医学版)

OBJECTIVE@#To compare the clinical effects of pulpotomy with two kinds of calcium silicate materials, and to evaluate the formation of dentin bridge and pulp calcification after pulpotomy of adult permanent teeth.@*METHODS@#Patients who visited the General Department of Peking University School and Hospital of Stomatology from November 2017 to September 2019 and planned for pulpotomy on permanent premolars and molars with carious exposed pulp were selected. They were randomly divided into two groups. Bioceramic putty material iRoot BP (iRoot group, n=22) and mineral trioxide aggregate MTA (MTA group, n=21) were used as pulp capping agents, respectively. The patients were recalled after one year and two years. The clinical efficacy, dentin bridge index (DBI) and pulp calcification index (PCI) were recorded. Blinding method was used for the patients and evaluators.@*RESULTS@#There was no significant difference in gender, mean age, dentition and tooth position between the two groups (P>0.05). Seven cases were lost during the first year (4 cases in iRoot group and 3 cases in MTA group). In the iRoot group, 1 case had transient sensitivity at the time of 1-year follow-up. The cure rate of the two groups was 100% at the time of 2-year follow-up. The proportion of dentin bridge formation was 38.9% one year after operation, 55.6% two years after operation. The proportion of partial or even complete disappearance of root canal image was 5.6% before operation, 38.9% and 55.6% one and two years after operation, respectively. The difference was statistically significant by rank sum test (P < 0.05). There was no significant difference in dentin bridge formation and pulp calcification between the two groups (P < 0.05). DBI and PCI after operation was as the same as those before operation (44.4% cases of DBI and 25% cases of PCI) or gradually increased (55.6% cases of DBI and 75% cases of PCI). Spearman's nonparametric correlation analysis showed that age was positively correlated with preoperative pulp calcification index (PCI0, P < 0.05), but not with the dentin bridge index (DBI1, DBI2), pulp calcification index (PCI1, PCI2) and the degree of change (DBI2 vs. DBI1, PCI1 vs. PCI0, PCI2 vs. PCI0) 1-year and 2-year after operation (P>0.05).@*CONCLUSION@#According to this study, good clinical effects were obtained within 2-year after pulpotomy of adult permanent teeth with MTA and iRoot. In some cases, the root canal system had a tendency of calcification aggravation, and there was no statistical difference in the development of this trend between the two groups.

Early effectiveness of arthroscopic repair of supraspinatus tendon tears with douple-pulley suture-bridge / 中国修复重建外科杂志

OBJECTIVE@#To investigate the early effectiveness of arthroscopic repair of supraspinatus tendon tears with douple-pulley suture-bridge.@*METHODS@#The clinical data of 38 patients with supraspinatus tendon tears who met the selection criteria between September 2020 and July 2022 were retrospectively analyzed, and all of them were treated with arthroscopic double-pulley suture-bridge technique. There were 15 males and 23 females, aged from 43 to 77 years, with an average of 61.5 years. There were 15 cases of left shoulder and 23 cases of right shoulder. Seven cases had a history of trauma, and the other 31 cases had no obvious inducement. The main clinical symptoms of the patient were pain in lifting the shoulder joint and hug resistance test (+). The time from onset of symptoms to admission ranged from 6 to 19 months, with an average of 10.3 months. Flexion, abduction, and external rotation of the shoulder were recorded before operation and at 3 and 12 months after operation. Pain and function of the shoulder were evaluated by visual analogue scale (VAS) score, University of California Los Angeles (UCLA) shoulder score, and American Society of Shoulder and Elbow Surgeons (ASES) score before operation and at 12 months after operation. Tendon healing, tendon continuity, and tension were evaluated by MRI at 3-6 months after operation, and patient's satisfaction was evaluated at last follow-up.@*RESULTS@#All the incisions healed by first intention, and there was no complication such as incision infection or nerve injury. All patients were followed up 12-34 months, with an average of 23.3 months. VAS score, UCLA shoulder score, and ASES score at 12 months after operation were significantly better than those before operation ( P<0.05). The external rotation range of shoulder joint significantly improved at 3 and 12 months after operation ( P<0.05), and it further improved at 12 months after operation when compared with 3 months after operation ( P<0.05). There was no significant difference in the range of flexion and abduction at 3 months after operation when compared with those before operation ( P>0.05), but the range of flexion and abduction at 12 months after operation significantly improved when compared with those before operation and at 3 months after operation ( P<0.05). MRI reexamination was performed in 28 patients at 3-6 months after operation. Among them, 25 patients had intact supraspinatus tendon structure, good tension, and tendon healing, and 3 patients had type 1 retear. The remaining 10 patients refused to undergo MRI reexamination because of the satisfactory effectiveness. At last follow-up, 29 patients (76.3%) were very satisfied with the results, 6 (15.7%) were satisfied, and 3 (7.8%) were not satisfied.@*CONCLUSION@#Arthroscopic double-pulley suture-bridge technique can achieve the effect of suture bridge operation, reduce the cost of operation and the risk of type 2 retear, and the early effectiveness is satisfactory, but the shoulder joint movement is limited within 3 months after operation.

Histological study of platelet-rich fibrin combined with MTA for direct pulp capping of rabbit teeth / 口腔疾病防治

Objective @# To investigate the outcomes of a novel direct pulp capping agent containing platelet-rich fibrin (PRF) and mineral trioxide aggregate (MTA). @*Methods @# A total of 32 New Zealand rabbits were randomly divided into 4 groups, namely, the PRF+MTA group (P+M group), PRF group (P group), MTA group (M group) and blank control group (BC group), with 8 rabbits per group. Dental pulp exposure and direct pulp capping were performed, and complete crown square sealing was performed on 2 mandibular central incisor teeth of each rabbit. Four rabbits from each group were euthanized after each observation period (7 and 28 days). The experimental teeth were subjected to HE staining. Inflammatory cell infiltration, calcified bridge formation and pulp tissue disorganization were observed and graded. @*Results@#Inflammatory cell infiltration: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05); group P+M and group M did not significantly differ (P>0.05). Calcified bridge formation: on the 7th and 28th days, group P+M was lighter than group P, group M and group BC (P<0.05); on the 28th day, group M was higher than group BC (P<0.05). Under microscope, the calcified bridge contained cellular components and was surrounded by odontoblast-like cells, sharing a structure resembled osteodentin; dentin tubule-like structure could not be observed in calcified bridge, and the calcified bridge resembled certain points of osteodentin. Pulp tissue disorganization: on the 7th day, group P+M and group M were lighter than group BC (P<0.05); on the 28th day, group P+M was lighter than group P and group BC (P<0.05). group P+M and group M did not significantly differ (P>0.05). @*Conclusion @# The combination of PRF and MTA for direct pulp capping provided light inflammatory cell infiltration, stable pulp status and a strong ability of pulp tissue to form calcified bridge, and the calcified bridge resembled certain points of osteodentin.

Three ways for protein aggregation and the control strategies / 生物工程学报

Protein aggregation is a critical issue in the production of biopharmaceuticals. During protein production, transport and storage, various factors can lead to protein aggregation. With the in-depth study, different ways of protein aggregation and various influencing factors were identified. This includes physical and chemical factors, translation modifications and protein structure. Since protein aggregation exerts major impact on the activity and homogeneity of proteins, it is of great importance to study the ways of protein aggregation and how to control it to obtain high-quality proteins. The review focuses on three ways of protein aggregation, namely 3D domain swapping, salt bridge formation, and oxidative stress, as well as methods to control protein aggregation during protein production, transport and storage. This may facilitate reducing the loss caused by the formation of protein aggregation and improving the purity and homogeneity of protein in research and commercial production.

Qualitative and quantitative characteristics of the passive compartment underneath the myocardial bridge comprising the blood vessel adventitia and the perivascular connective tissue / Características cualitativas y cuantitativas del compartimento pasivo debajo del puente miocárdico que comprende la adventicia del vaso sanguíneo y el tejido conectivo perivascular

SUMMARY: Myocardial bridges are inborn anomalies frequently found in authopsies. Although tipically clinically silent, they are occasionally associated with severe clinical manifestations, e.g. myocardial ischemia or even sudden death. The pathophysiology and risk factors for these manifestations have not yet been completely elucidated. The connective tissue underneath the bridge has been considered as one of the factors the symptoms depend on. Thus, the aim of this research was to determine the histological characteristics of the connective tissue lying underneath the myocardial bridge and to contribute to a better understanding of the protective effects this passive compartment might have in prevention of severe clinical manifestations of myocardial bridging. The study was carried out on twenty hearts with myocardial bridges. Length of the bridge was determined using a precise electronic caliper. Sections of the myocardial bridges with the underlying connective tissue were obtained and prepared for qualitative and quantitative analysis. The connective tissue underneath the bridges was composed of adipose tissue and loose connective tissue in different ratios. The tissue underneath thin bridges was predominantly composed of adipose tissue, while loose connective tissue was the dominant component under thick bridges. The myocardial bridges had an average thickness of 0,98 ± 0.44 mm and an average length of 15,25±5,65 mm. We found a strong positive correlation between the myocardial bridge thickness and length (r = 0,860, p = 0,0001). The thickness of the passive connective tissue compartment under the myocardial bridges was 0,58±0,22 mm, and there was no correlation between this parameter and the myocardial bridge thickness (r = -0,011; p = 0,963). In the clinical evaluation of patients with these anomalies it is necessary to take into account independently the myocardial bridge thickness and length on one side and the thickness of the connective tissue lying underneath it on the other.

Los puentes miocárdicos son anomalías congénitas que se encuentran con frecuencia en las autopsias. Aunque típicamente éstos son clínicamente silenciosos, ocasionalmente se asocian con manifestaciones clínicas graves, como isquemia miocárdica o incluso muerte súbita. La fisiopatología y los factores de riesgo de estas manifestaciones aún no se han dilucidado por completo. El tejido conectivo debajo del puente se ha considerado como uno de los factores de los que dependen los síntomas. Por lo tanto, el objetivo de esta investigación fue determinar las características histológicas del tejido conectivo que se encuentra debajo del puente miocárdico y contribuir a una mejor comprensión de los efectos protectores que este compartimento pasivo podría tener en la prevención de manifestaciones clínicas graves de puente miocárdico. El estudio se llevó a cabo en veinte corazones con puentes miocárdicos. La longitud del puente se determinó utilizando un calibrador electrónico preciso. Se obtuvieron secciones de los puentes miocárdicos con el tejido conjuntivo subyacente y se prepararon para análisis cualitativo y cuantitativo. El tejido conectivo debajo de los puentes estaba compuesto de tejido adiposo y tejido conectivo laxo en diferentes proporciones. El tejido debajo de los puentes delgados estaba predominantemente compuesto de tejido adiposo, mientras que el tejido conectivo laxo era el componente dominante debajo de los puentes gruesos. Los puentes de miocardio tenían un espesor promedio de 0,98 ± 0,44 mm y una longitud promedio de 15,25 ± 5,65 mm. Encontramos una fuerte correlación positiva entre el grosor y la longitud del puente miocárdico (r = 0,860, p = 0,0001). El grosor del compartimiento de tejido conectivo pasivo debajo de los puentes miocárdicos era de 0,58±0,22 mm, y no hubo correlación entre este parámetro y el grosor del puente miocárdico (r = -0,011; p = 0,963). En la evaluación clínica de pacientes con estas anomalías es necesario tener en consideración de forma independiente el grosor y la longitud del puente de miocardio por un lado y el grosor del tejido conectivo que se encuentra debajo del mismo por el otro.

Ectodermal Dysplasia in Primary Dentition – A Rare Case Report

Development of the primary and permanent dentition is a complex process wherein there is series of interactions between the ectoderm and ectomesenchyme. A cascade of signaling pathways occur in a spatio-temporal manner resulting in the development and eruption of the human dentition. Any developmental aberrations in shape, size, number, and position can lead to deviations from normal development of teeth. In this book, dental anomalies including gemination, fusion, concrescence, dilaceration, dens invaginatus, DE, taurodontism, enamel pearls, fluorosis, peg?shaped laterals, dentinal dysplasia, regional odontodysplasia and hypodontia etc. are discussed. Diagnosing dental abnormality needs a thorough evaluation of the patient and careful clinical and radiographical examination is required. Furthermore, more complex cases need multidisciplinary planning and treatment.

Structural and functional phenotypic features and molecular analysis of Indian patients with Bietti crystalline dystrophy

Purpose: Bietti crystalline dystrophy (BCD) is a rare retinal dystrophy, uncommon in Indians. This study describes the various phenotypic features seen in the Indian population. Methods: In this retrospective, descriptive case series, records of patients with either clinical or molecular diagnosis of BCD from 2009 to 2020 were perused. Phenotypic and genotype information was collected and analyzed. Results: This study included 58 patients of BCD (31 males) aged 21–79 years (mean: 47 ± 14 years). The age at onset ranged from 7 to 41 years (mean: 28.8 ± 5.1 years). Vision ranged from 20/20 to counting fingers. There were 18 (31%) patients with stage 1 with crystals and mild retinochoroidal atrophy, 22 (38%) with stage 2 with atrophy extending beyond arcades, and 18 (31%) with absent crystals and extensive atrophy of stage 3. Choroidal neovascular membrane was seen in four patients. The optical coherence tomography showed retinochoroidal thinning (84.6%), outer retinal tubulations (71.8%), and paradoxical foveal thickening with interlaminar bridges (7.7%). Electrophysiology and visual fields showed reduced responses in advanced retinochoroidal changes. Molecular confirmation was available in five patients; five mutations were seen in the CYP4V2. Conclusion: A wide variation is seen in the phenotypic picture of BCD. A molecular diagnosis is helpful in differentiating from other retinal dystrophies. The OCT shows the peculiar feature of the interlaminar bridge in early cases with photoreceptor loss. Further investigations into this OCT feature may provide insights into the pathogenesis of BCD. A genotype–phenotype correlation could not be done.

Congenital atlanto-occipital fusion and its effect on the myodural bridge: a case report utilizing the P45 plastination technique / Fusión atlanto-occipital congénita y su efecto sobre el puente miodural: reporte de un caso utilizando la técnica de plastinación P45

SUMMARY: The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations.

RESUMEN: La articulación atlanto-occipital está compuesta por las caras articulares superiores de las masas laterales del atlas (C1) y los cóndilos occipitales. La fusión atlanto-occipital congénita (FAO) implica la unión ósea de la base del occipucio (C0) y el atlas (C1). La FAO u occipitalización/asimilación del atlas representa una malformación de la unión craneovertebral (MUCV) que puede presentar otras malformaciones craneales o espinales. La FAO puede ser asintomática o los pacientes pueden experimentar síntomas de compresión neural así como movimiento limitado del cuello. El complejo del puente miodural (PMD) es una estructura fibrosa densa que conecta el músculo suboccipital y su fascia relacionada con la duramadre espinal cervical, pasando a través de los espacios intermedios atlanto-occipital posterior y atlanto-axial. No se sabe si la occipitilización del atlas puede inducir cambios estructurales en el complejo PMD y en la musculatura suboccipital. Se observó en la región suboccipital de un espécimen cadavérico, cabeza y cuello de un varón chino de 87 años con una malformación congénita de FAO con los cambios resultantes en el complejo PMD. Se examinaron múltiples cortes obtenidos de la muestra de cabeza y cuello después de ser tratados con el método de plastinación P45, con especial atención a la región suboccipital y la MUCV. Las malformaciones congénitas por fusión atlanto-occipital se definen como la fusión parcial o completa de la base del occipucio (C0) con el atlas (C1). En el presente caso de MUCV se observó la fusión unilateral del cóndilo occipital izquierdo con la masa lateral izquierda de C1, así como fusión posterior central del margen posterior del foramen magnum con el arco posterior de C1. También se observó una variación unilateral del curso de la arteria vertebral por el estrechamiento del espacio interatlanto-occipital posterior. Se observó además agenesia completa de los músculos Rectus capitis posterior minor (RCPmi) y oblicuos capitis superior (OCS) en los cortes plastinados. Curiosamente, se observó que el MDB, que normalmente se origina en parte del músculo RCPmi, se origina en una bifurcación superior dentro de un aspecto del ligamento nucal. Por lo tanto, los cambios observados en el complejo PMD parecen ser una compensación de las malformaciones suboccipitales.

Saphenous vascular periosteal flap in prevention of bone bridge formation after epiphyseal plate injury: An experimental study / 中华显微外科杂志

Objective:To establish a model of epiphyseal plate injury in juvenile rabbits and explore the effect of periosteum flap with saphenous artery on preventing the formation of bone bridge after epiphyseal plate injury.Methods:From July 2017 to January 2018, 30 young New Zealand immature rabbit were randomly grouped into 3 groups (group A, B and C, with 10 rabbits per group). The blood vessels of knee joint were dissected and a periosteum flap with saphenous artery were designed. A model of distal femoral epiphyseal plate injury was established in immature rabbits with a 3.0 mm Kirschner wire on one side of the distal femoral epiphyseal plate as experimental side, and the other side of the distal femoral epiphyseal plate was assigned as control side. The injured epiphysis were prepared and described as follow: in experimental side of group A, a piece of periosteum with the same size as that in group C was resected and discarded. In experimental side of group B, a periosteal flap without vascular pedicle was filled in the injured area. And in experimental side of group C, a periosteum flap with saphenous artery was filled in the injured area. The length and varus angle of femur specimens of length and varus angle of femur specimens wihthin groups were measured at 24 weeks after surgery to evaluate the effect on bone growth in epiphyseal plate injury. The effect of the periosteum flap with saphenous artery on preventing a formation of bone bridge was assessed by section view of decalcified specimens, HE staining and toluidine blue staining. The measured data were expressed as Mean and standard deviation (Mean±SD), and data were compared within and between the groups using one-way analysis of variance (ANOVA). P<0.05 was considered as statistically significant. Results:The femur of experimental side of group A and B showed obvious short with valgus deformity compared with that of control side, and the difference of length and varus angle of femur specimens wihthin groups was statistically significant ( P<0.05). There were no significant differences in the length and valgus angle of the femur between experimental side and its control side in group C ( P>0.05). In experimental side of group A, there were bone bridges in the epiphyseal lesion area, with a clear boundary to the surrounding epiphyseal plate. In experimental side of group B, the periosteum flap in the injured area was absorbed, accompanied by the formation of a few pale white bone tissue, and with a clear boundary to the surrounding epiphyseal plate. In experimental side of group C, the lesion area was filled with milky white cartilage tissue with the same colour as the epiphyseal plate, and with an unclear boundary with the epiphyseal plate. HE stain and toluidine blue staining showed that the injured area of group A was filled with a large number of bone tissue, but no obvious cartilage tissue was observed. In group B, the area of lesion was filled mainly with fibrous tissue, with a small amount of bone tissue. In group C, a large number of hyaline cartilage tissues were formed along the tunnel of the injury area, and closely connected with the normal epiphyseal plate. Conclusion:Filling a periosteum flap with saphenous artery after epiphyseal plate injury can prevent the formation of bone bridge and prevent the affected limb form shortening and angulation.

Regular characteristics of the effects of double-bridge and single-bridge exercises on the surface EMG activity of related core muscles in stroke patients with hemiplegia / 中国综合临床

Objective:To observe and analyze the effect of double and single bridge exercise on the electromyographic activities of related core muscle groups in stroke patients, and to explore its rules and characteristics.Methods:A prospective cohort study was conducted on 40 stroke patients hospitalized in the Department of rehabilitation medicine, Hefei second people's Hospital, Anhui Province from March 2020 to May 2021.The surface electromyography (sEMG) instrument was used to collect the surface electromyographic signals of erector spinalis, rectus abdominis, gluteus maximus and biceps femoris during double and single bridge exercise, and the root mean square (RMS) and integrated electromyography (iEMG) of the time domain indexes were analyzed. The measurement data conforming to normal distribution was expressed in xˉ± s.The non normal distribution data was expressed in M (Q1, Q3). Wilcoxon rank sum test was used to compare the difference between the two groups. Results:There was significant difference between RMS (30.0 (21.3, 45.5) μV vs. 24.0 (14.0, 35.8) μV) and IEMG (15.5. (10.0, 23.0) μV?s vs. 9.0 (5.0, 13.0) μV?s s) values of gluteus maximus on the healthy side and the affected side during double bridge exercise ( Z values were 2.07, 4.19; P values were 0.039, <0.001, respectively). There was significant difference in RMS (31.0 (15.3, 70.0) μV ratio of the healthy and affected biceps femoris 17.0 (11.0, 28.8) μV) and IEMG (14.5 (8.0, 26.5) μV?s vs. 7.0 (5.0, 10.8) μV?s) values of biceps femoris on the healthy side during double bridge exercise ( Z values were 3.44, 3.64; P values were 0.001 and <0.001, respectively ). There was significant difference between RMS(38.5(32.3, 46.0) μV vs. 35.0(22.3, 43.0) μV) and IEMG (16.5(12.0, 22.8) μV?s vs. 12.0(7.0, 21.0) μV?s) values of the gluteus maximus on the healthy side during single bridge exercise ( Z values were 2.24, 2.45; P values were 0.025, 0.014, respectively). There was significant difference between RMS (38.0 (15.3, 70.0) μV vs. 19.0 (12.0, 35.5) μV) and IEMG (16.0 (10.0, 27.0) μV?s vs. 6.5 (5.0, 12.5) μV?s s) values of biceps femoris on the healthy side during single bridge exercise ( Z values were 2.98,4.34; P values were 0.003 and <0.001, respectively). There was significant difference between RMS (24.0 (14.0, 35.8) μV vs. 35.0 (22.3, 43.0) μV) and IEMG (9.0 (5.0, 13.0) μV?s vs. 12.0 (7.0, 21.0) μV?s) values of double and single gluteus maximus on the affected side ( Z values were 2.24, 1.99; P values were 0.025,0.047, respectively). Conclusion:Double bridge and single bridge exercise could improve the related core muscle groups of stroke patients with hemiplegia, and single bridge was better than double bridge for the activation of gluteus maximus