[Erdheim-Chester disease initially discovered at extraskeletal locations: a clinicopathological analysis of four cases].

Objective: To investigate the clinicopathological features of Erdheim-Chester disease (ECD) initially diagnosed at extraskeletal locations. Methods: Clinical and pathological data of four cases of ECD diagnosed initially in extraskeletal locations were collected at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, from January 2013 to June 2023. BRAF V600E gene was detected by reverse transcription polymerase chain reaction (RT-PCR). Pertinent literatures were reviewed. Results: Four ECD patients included two males and two females ranging in ages from 2 years 11 months to 69 years. The lesions located in the lung (two cases), central nervous system (one case), and the testicle (one case) were collected in the study. One patient had occasional fever at night, one had nausea and vomiting, and two were asymptomatic. Radiologically, the two pulmonary ECD showed diffuse ground-glass nodules in both lungs, and the lesions in central nervous system and testicle both showed solid masses. Microscopically, there were infiltration of foamy histiocyte-like cells and multinucleated giant cells in a fibrotic background, accompanied by varying amounts of lymphocytes and plasma cells. The infiltration of tumor cells in pulmonary ECD was mainly seen in the subpleural area, interlobular septa, and perivascular and peribronchiolar areas. The fibrosis was more pronounced in the pleura and interlobular septa, and less pronounced in the alveolar septa. Immunohistochemical staining showed that all tumor cells expressed CD68, CD163 and Fô€ƒ¼a; one case showed S-100 expression; three cases were positive for BRAF V600E; all were negative for CD1α and Langerin. RT-PCR in all four cases showed BRAF V600E gene mutation. Conclusions: Extraskeletal ECD is often rare and occult, and could be easily misdiagnosed, requiring biopsy confirmation. The radiologic findings of pulmonary ECD is significantly different from other types of ECD, and the histopathological features of pronounced infiltration in the subpleura area, interlobular septa, perivascular and peribronchiolar areas can be helpful in the differential diagnosis from other pulmonary diseases. Detection of BRAF V600E gene mutation by RT-PCR and its expression by immunohistochemical staining are also helpful in the diagnosis.

Effects of systemic therapies on pruritus in adults with atopic dermatitis: a systematic review and meta-analysis.

Pruritus is a hallmark of atopic dermatitis (AD), which affects disease severity and patient quality of life. In AD uncontrolled with first-line topical therapies or in moderate to severe AD, systemic therapies are used; however, there is a paucity of head-to-head trials comparing the effectiveness of these therapies. The aim of this study was to compare the effectiveness of systemic therapies in relieving pruritus in moderate to severe AD in adults, using a meta-analysis. The PubMed, EMBASE, Medline and CINAHL databases were searched from inception up to 31 May 2020 for randomized, placebo-controlled trials investigating the effectiveness of systemic therapies on pruritus with moderate to severe AD in patients aged ≥ 16 years. In total, 26 studies (n = 5190 participants) were identified. Compared with placebo, there was a large and statistically significant (P < 0.001 for all) reduction in pruritus [standard mean difference (SMD); 95% CI] with dupilumab every 2 weeks (-0.88; -1.13 to -0.63), dupilumab every 2 weeks plus topical corticosteroids (-0.77; -0.91 to -0.62), dupilumab once weekly (-0.99; -1.29 to -0.68), dupilumab once weekly plus topical corticosteroids (-0.70; -0.81 to -0.59). There was also a large and statistically significant reduction with ciclosporin (-1.30; -2.34 to -0.26; P = 0.01) and a large, although not statistically significant reduction with azathioprine (-0.85; -2.07 to 0.35). There was a small reduction with both mepolizumab (-0.27; -0.89 to 0.35) and interferon-γ (-0.31; -0.75 to 0.12). Of the investigational drugs, nemolizumab 2.0 mg/kg was the most effective (-8.13; -9.31 to -6.94). The majority of systemic therapies were superior to placebo in reducing pruritus. In particular, the dupilumab studies consistently showed large improvements in pruritus, while nemolizumab showed the strongest antipruritic effects. However, future head-to-head trials are required for conclusive evidence.

[Comparison of QuantiFERON-TB Gold Plus and QuantiFERON-TB Gold In Tube in the diagnosis of pulmonary tuberculosis].

Objective: To compare the screening value of QuantiFERON-TB Gold Plus (QFT-Plus) and QuantiFERON®-TB Gold in tube (QFT-GIT) in the auxiliary diagnosis of pulmonary tuberculosis (TB). Methods: A screening test was performed. Patients who were hospitalized in Guangzhou Chest Hospital and underwent QFT-GIT testing from October to December 2020 were prospectively included as research subjects, QFT-Plus testing was added. And the basic information, clinical manifestations, laboratory test results, imaging examinations and other data of these patients were collected. A total of 207 patients were included and divided into tuberculosis group and non-tuberculosis group according to these data. There were 124 cases in the tuberculosis group (94 confirmed patients and 30 clinically diagnosed patients), including 90 males and 34 females, aged 18-93 years, with a median age of 57 (38, 67) years. The non-tuberculosis group included 83 patients (16 patients with non-tuberculous Mycobacteria and 67 patients with other lung diseases), including 49 males and 34 females, with a median age of 60 (51, 68) years. The confirmed patients were subdivided into three grades of low, medium and high Mycobacteriam tuberculosis (MTB) bacterial load, and three grades of mild, moderate and severe pulmonary tuberculosis. The results of QFT-Plus and QFT-GIT were compared, and the levels of IFN-γ in different antigen tubes were compared. Differences between different groups were compared using Mann-Whitney U test and Kruskal-Wallis H test. Results: The QFT-Plus showed a high degree of agreement with the QFT-GIT (κ=0.786, 95%CI: 0.740-0.832), while the main discordant result was QFT-GIT negative/QFT-Plus positive, accounting for 15/17. The sensitivity of QFT-GIT was 80.7%(95%CI: 0.706-0.880), the specificity was 76.3%(95%CI: 0.649-0.850), the positive predictive value was 79.8%(95%CI: 0.697-0.873), and the negative predictive value was 77.3%(95%CI: 0.659-0.859), repectively. QFT-Plus showed a sensitivity of 84.3%(95%CI: 0.743-0.910), a specificity of 78.8% (95%CI: 0.679-0.868), and a positive predictive value of 80.5%(95%CI: 0.703-0.879), the negative predictive value being 82.9%(95%CI: 0.721-0.902), slightly improved to that of the QFT-GIT. Also, this study found that there were significant differences in IFN-γ values between different MTB load or disease severity (P<0.05). Conclusions: There is a good consistency between the QFT-Plus test and the QFT-GIT test, both of which show good application value in the auxiliary diagnosis of pulmonary tuberculosis. Moreover, because of the addition of tuberculosis-specific CD8 cell antigen, the QFT-Plus test has higher sensitivity, lower uncertainty and more application value. This study also found that the bacterial load and disease severity of patients with pulmonary tuberculosis may have a certain correlation with the measured value of IFN-γ.

[Current situation of screening, prevention and treatment of bleeding esophageal varices in cirrhotic portal hypertension in Tibet region: a multicenter study].

Objective: To investigate and analyze the current situation, screening, clinical characteristics, prevention and treatment of bleeding esophageal varices in cirrhotic patients with portal hypertension in Tibet region. Methods: Clinical data of cirrhotic patients with portal hypertension through March 2017 to February 2020 from Tibet region were collected and analyzed retrospectively. Results: 511 cases with liver cirrhosis were included in the study, of which 185 cases (36.20%) had compensated cirrhosis and 326 cases (63.80%) had decompensated cirrhosis. Further analysis of the etiological data of liver cirrhosis showed that 306 cases (59.88%) were of chronic hepatitis B, 113 cases (22.11%) of alcoholic liver disease, and 68 cases (13.31%) of chronic hepatitis B combined with alcoholic liver disease. Among patients with compensated liver cirrhosis, 48 cases (25.95%) underwent endoscopic examination of which 33 diagnosed as high-risk variceal bleeding. However, none of these 33 cases had received non-selective ß-blocker therapy, and only four patients had received endoscopic variceal banding therapy. Among patients with decompensated liver cirrhosis, 83 cases (25.46%) had a history of upper gastrointestinal bleeding, 297 cases (91.10%) had ascites, 23 cases (7.05%) had hepatic encephalopathy, and 3 cases (0.92%) had hepatorenal syndrome. Among the patients with a history of upper gastrointestinal bleeding, 42 cases (50.60%) had received secondary preventive treatment for bleeding esophageal varices, including 39 cases of endoscopic treatment, 1 case of endoscopic combined drug treatment, 3 cases of interventional treatment, and 2 cases of surgical treatment. Conclusion: Chronic hepatitis B and alcoholic liver diseases are the main causes of liver cirrhosis in Tibet region. Moreover, this region lacks screening, prevention and treatment for bleeding esophageal varices in cirrhotic patients with portal hypertension. Therefore, it is necessary to increase the screening of high-risk groups to prevent and improve the first-time bleeding, and promote multidisciplinary team to prevent and treat re-bleeding.

[An advanced imaging method for measuring and assessing meibomian glands based on deep learning].

Objective: To evaluate the application value of a deep-learning-based imaging method for rapid measurement and evaluation of meibomian glands. Methods: Diagnostic evaluation study. From January 2017 to December 2018, 2 304 meibomian gland images of 576 dry eye patients who were treated at the Eye Center of Wuhan University People's Hospital with an average age of (40.03±11.46) years were collected to build a meibomian gland image database. These images were labeled by 2 clinicians, and a deep learning algorithm was used to build a model and detect the accuracy of the model in identifying and labeling the meibomian glands and calculating the rate of meibomian gland loss. Mean average precision (mAP) and validation loss were used to assess the accuracy of the model in identifying feature areas. Sixty-four meibomian gland images apart from the database were randomly selected and evaluated by 7 clinicians independently. The results were analyzed with paired t-test. Results: This model marked the meibomian conjunctiva (mAP>0.976, validation loss<0.35) and the meibomian gland (mAP>0.922, validation loss<1.0), respectively, thereby achieving high accuracy to calculate the area and ratio of meibomian gland loss. The proportion of meibomian glands marked by the model was 53.24%±11.09%, and the artificial marking was 52.13%±13.38%. There was no statistically significant difference (t=1.935, P>0.05). In addition, the model took only 0.499 second to evaluate each image, while the average time for clinicians was more than 10 seconds. Conclusion: The deep-learning-based imaging model can improve the accuracy of the examination and save time and be used for clinical auxiliary diagnosis and screening of diseases related to meibomian gland dysfunction.(Chin J Ophthalmol, 2020, 56: 774-779).

Detection rate of colonic polyp among patients who had undergone colonoscopy at gastroenterology unit of Serdang Hospital, Malaysia.

OBJECTIVE: The aim of this study was to evaluate the demography, and to determine the detection rate of polyps, and detection rate of adenoma at a Malaysian tertiary hospital. METHODS: This is a retrospective study of all the patients who had undergone colonoscopy at Gastroenterology endoscopy unit, Serdang Hospital from 1st January 2010 to 31st December 2016. Patients who had a history of colorectal cancer, polyp or inflammatory bowel disease were excluded. Data collected which included patients' demography, indication for colonoscopy, colonoscopy finding, and histopathology results. Data was analysed with SPSS version 16. RESULTS: Among the 559 patients who had fulfilled the inclusion criteria (68 males, 44 females), 112 patients were found to have at least one polyp giving the polyp detection rate (PDR) of 20% and 168 polypectomies were performed. The PDR among male patients was higher than that of females (22.5% vs 17.1%, p<0.05). The detection rate of polyp was nearly equal in Malays, Chinese, Indians, and Others. The polyps were more common in those of age 40 years old and above (p<0.05), with the mean age of 63.0±1.5 years. The commonest morphology of polyp in our patients was sessile (58%) and majority was medium size (5-9mm). Otherwise, the polyps were commonly found in the distal colon those that in proximal colon (55.3% vs 38.7%, p<0.05). The adenoma detection rate (ADR) was 19.1% (107/559). CONCLUSION: The detection rate of colonic polyp from colonoscopy is 20% in our centre.

[The ratio of tuberculosis-specific antigen to phytohemagglutinin in T-SPOT assay in the diagnosis of active tuberculosis].

Objective: The aim of this study was to determine the performance of the ratio of tuberculosis-specific antigen (TBAg) to phytohemagglutinin (PHA) (TBAg/PHA ratio) in T-SPOT assay in the diagnosis of active tuberculosis (ATB). Methods: Between January 2014 and January 2017, 378 Mycobacterium tuberculosis (MTB) culture positive patients (268 cases of pulmonary tuberculosis, 110 extra-pulmonary tuberculosis) and 824 healthy individuals were recruited from Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. T-SPOT assay was performed and TBAg/PHA ratio was calculated in all the participants. To validate the study, another group of 223 MTB culture positive TB patients with positive T-SPOT results were recruited from Guangzhou Chest Hospital between January 2017 and December 2017. This was a retrospective case-control study and differences between groups were analyzed using the Mann-Whitney U-test. Results: Of the 378 culture positive ATB patients, 344 patients had positive T-SPOT results. Of the 824 healthy individuals, 204 individuals had positive T-SPOT results. Using healthy individuals as the control group, the sensitivity and specificity of T-SPOT assay in the diagnosis of ATB were 91.0% (344/378) and 75.2% (620/824). Directly using T-SPOT results had a limited accuracy in distinguishing ATB from latent tuberculosis infection (LTBI). The area under the receiver operating characteristic (ROC) curve was between 0.7 and 0.8. However, a further calculation of the TBAg/PHA ratio showed a better performance than TBAg in distinguishing these two conditions, and the area under the ROC curve was 0.881 (95% CI: 0.853-0.909). If using the threshold value of 0.234, the sensitivity and specificity of the TBAg/PHA ratio in distinguishing ATB from LTBI were 69.5% (239/344) and 94.12% (192/204). The validation data showed that the performance of the TBAg/PHA ratio in distinguishing ATB from LTBI was also satisfactory, and the area under the ROC curve was 0.901 (95% CI: 0.872-0.931). Furthermore, the TBAg/PHA ratio had an important role in the diagnosis of extra-pulmonary tuberculosis. If using the threshold value of 0.234, the sensitivity and specificity of the TBAg/PHA ratio in the diagnosis of extra-pulmonary tuberculosis were 79.2% (76/96) and 94.1% (192/204). The area under the ROC curve was 0.932 (95% CI: 0.897-0.967). Conclusions: The TBAg/PHA ratio in T-SPOT assay was better than directly using T-SPOT results in distinguishing ATB from LTBI. This ratio also showed a potential use in the diagnosis of extra-pulmonary tuberculosis.

[Effects of zinc ions on biological functions of human umbilical vein endothelial cells].

Objective: To evaluate the effect of zinc ions on human umbilical vein endothelial cells biological functions. Methods: The primary human umbilical vein endothelial cells were cultured with the ECM medium, and cells were divided into 8 groups: the control group(routine culture,n=3), 20 µmol/L zinc group(20 µmol/L zinc chloride solution was added into the cell medium, n=3), 40 µmol/L zinc group(40 µmol/L zinc chloride solution was added into the cell medium, n=3),80 µmol/L zinc group(80 µmol/L zinc chloride solution was added into the cell medium, n=3), 100 µmol/L zinc group(100 µmol/L zinc chloride solution was added into the cell medium, n=3), 200 µmol/L zinc group(200 µmol/L zinc chloride solution was added into the cell medium, n=3),300 µmol/L zinc group(300 µmol/L zinc chloride solution was added into the cell medium, n=3), 500 µmol/L zinc group(500 µmol/L zinc chloride solution was added into the cell medium, n=3). The cell proliferation curve was derived from real time cell analysis (RTCA). The viability value was obtained via CCK-8 reagent, and the migration distance was tested by scratch-wound assay while the adhesion function was detected by RTCA. Results: (1)After 18 hours, RTCA showed that the proliferation cell indexes were 4.5±0.6, 3.7±0.4, 3.6±0.3, 2.5±0.4, and 2.5±0.4 in the 20, 40, 80, 100, and 200 µmol/L zinc groups, as compared with 3.5±0.3 in the control group (all P<0.05). Proliferation cell indexes were 0 in both of the 300 µmol/L and 500 µmol/L zinc groups. (2)After 96 hours, the viability were 1.21±0.05, 1.10±0.03, 0.99±0.05, 0.62±0.02, 0.45±0.04, 0.11±0.01, and 0.12±0.06, respectively in the 20, 40, 80, 100, 200, 300, and 500 µmol/L zinc groups, as compared with 0.75±0.05 in the control group (all P<0.05). (3)After 12 hours, the migration distances were (0.56±0.11),(0.96±0.07),(0.49±0.02), and (0.29±0.01)mm in the 20, 40, 80, and 100 µmol/L zinc groups, as compared with (0.24±0.04)mm in the control group (all P<0.05). (4)After 18 hours, the adhesion cell index were 0.40±0.05, 0.31±0.01, 0.38±0.05, and 0.40±0.03 in the 20, 40, 80, and 100 µmol/L zinc groups, as compared with 0.24±0.04 in the control group (all P>0.05). Conclusions: Zinc ions at lower concentration (≤80 µmol/L) can promote proliferation, viability and migration of human umbilical vein endothelial cells, but the adhesion function was not significantly affected by zinc ions. Zinc ions at higher concentration (≥200 µmol/L) can inhibit the cellular function of the human umbilical vein endothelial cells.

Epidemiology and Factors Affecting Functional Outcome of Distal Radial Fracture in an Urban Tertiary Medical Centre in Malaysia.

INTRODUCTION: Distal radial fracture is a commonly encountered fracture. This study aims to study the epidemiology of distal radial fracture and factors affecting the patients' functional outcome one to two years after the injury. MATERIALS AND METHODS: This is a retrospective cohort study. The records of patients, fulfilling the radiographical diagnosis of distal radial fracture, and aged 18 and above, who presented to our Emergency Department from 1st January 2018 to 31st December 2018 were retrieved. According to AO classification, we grouped our patients into A (extra-articular), B (partial articular) and C (complete articular). Patients with congenital abnormalities were excluded. Epidemiological data and relevant medical history were obtained and tabulated. A Malaysian language translation of Disability of the Arm, Shoulder and Hand (DASH) questionnaire was used to assess the functional outcome. RESULTS: Out of 168 patients' data retrieved, only 110 patients' data were found complete for purposes of this study. The mean DASH score was 13.7 ± 7.87 approximately one to two years post-injury regardless of treatment method. Increasing age was associated with higher DASH score with r=0.407(p<0.001). Several variables had significantly better functional outcome: male gender (p=0.01), Type A fracture configuration (p=0.007) and non-operational treatment (p=0.03). There was no significant difference between treatment modalities in Type A fracture (p=0.094), but Type B (p=0.043) and Type C (p=0.007) had better outcome without surgery. There was no significant difference between different ethnic groups, open or closed fracture and mechanism of injury. CONCLUSION: Better functional outcome after sustaining distal radial fracture was associated with young age, male gender, type A fracture and treated non-operatively. Interestingly, more complex fracture pattern had better functionality were observed without surgery.

MiR-218 suppresses metastasis and invasion of endometrial cancer via negatively regulating ADD2.

OBJECTIVE: Endometrial cancer (EC) is one of the three most common gynecological cancers. Due to the lack of effective treatment for EC patients in an advanced stage, the mortality rate of EC is increasing rapidly. Hence, it is essential to seek for novel molecular therapeutic targets and biomarkers for EC. The aim of this study was to explore the role of miR-218 in the occurrence and development of EC and to investigate the possible underlying mechanism. PATIENTS AND METHODS: The expression level of miR-218 in EC tissues and cell lines was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Wound healing assay and Matrigel assay were performed to determine the migration and invasion abilities of EC cells. Meanwhile, the potential targets of miR-218 were predicted by bioinformatics analysis and confirmed by Luciferase reporter gene assay. In addition, the protein expression level of Adducin 2 (ADD2) was assessed by Western blotting analysis. RESULTS: QRT-PCR results revealed that miR-218 was significantly downregulated in EC tissues and cell lines. Wound healing assay and Matrigel assay demonstrated that miR-218 suppressed the migration and invasion abilities of EC cells. Online prediction databases predicted that ADD2 was a direct target of miR-218, which was verified by Luciferase reporter gene assay. Rescue experiments further validated that miR-218 could serve as a carcinoma suppressor by negatively regulating ADD2 expression in EC. CONCLUSIONS: In the present study, we elucidated that miR-218 served as a tumor suppressor in EC by negatively regulating ADD2. This might bring a novel insight into new molecular therapeutic targets and biomarkers for EC.

Expressions of VEGF and miR-21 in tumor tissues of cervical cancer patients with HPV infection and their relationships with prognosis.

OBJECTIVE: To investigate the expressions of vascular endothelial growth factor (VEGF) and micro-ribonucleic acid-21 (miR-21) in cervical cancer patients with human papillomavirus (HPV) infection and determine the potential relationships with prognosis. PATIENTS AND METHODS: Expressions of VEGF in cervical cancer tissues and cancer-adjacent tissues were detected by immunohistochemistry, and the expressions of miR-21 and VEGF in both tissues were quantitatively analyzed using reverse transcription polymerase chain reaction (RT-PCR). Patients with cervical cancer were followed up after operation, and the survival rates of patients with different expression levels of miR-21 and VEGF were compared. RESULTS: VEGF was expressed in both cervical cancer tissues and cancer-adjacent tissues. The positive expression rate of VEGF in cervical cancer tissues (75.69%) was significantly higher than that in cancer-adjacent tissues (10.45%). RT-PCR results showed that the expression levels of miR-21 and VEGF in cervical cancer tissues were significantly higher than those in cancer-adjacent tissues (p<0.05). Correlation analyses revealed that miR-21 expression was significantly positively correlated with VEGF expression in cervical cancer tissues (r2=0.4174, p<0.0001). Prognostic analyses showed that the 5-year survival rate of patients was relatively high when miR-21 and VEGF were lowly expressed. CONCLUSIONS: VEGF and miR-21 are highly expressed in tumor tissues of cervical cancer patients with HPV infection. VEGF expression is significantly positively correlated with miR-21 expression, and the high levels of VEGF and miR-21 predict unfavorable prognosis of cervical cancer. Data provide a theoretical support for clinical treatment of cervical cancer patients with HPV infection.

A physiologically relevant 3D collagen-based scaffold-neuroblastoma cell system exhibits chemosensitivity similar to orthotopic xenograft models.

3D scaffold-based in vitro cell culturing is a recent technological advancement in cancer research bridging the gap between conventional 2D culture and in vivo tumours. The main challenge in treating neuroblastoma, a paediatric cancer of the sympathetic nervous system, is to combat tumour metastasis and resistance to multiple chemotherapeutic drugs. The aim of this study was to establish a physiologically relevant 3D neuroblastoma tissue-engineered system and explore its therapeutic relevance. Two neuroblastoma cell lines, chemotherapeutic sensitive Kelly and chemotherapeutic resistant KellyCis83 were cultured in a 3D in vitro model on two collagen-based scaffolds containing either glycosaminoglycan (Coll-GAG) or nanohydroxyapatite (Coll-nHA) and compared to 2D cell culture and an orthotopic murine model. Both neuroblastoma cell lines actively infiltrated the scaffolds and proliferated displaying >100-fold increased resistance to cisplatin treatment when compared to 2D cultures, exhibiting chemosensitivity similar to orthotopic xenograft in vivo models. This model demonstrated its applicability to validate miRNA-based gene delivery. The efficacy of liposomes bearing miRNA mimics uptake and gene knockdown was similar in both 2D and 3D in vitro culturing models highlighting the proof-of-principle for the applicability of 3D collagen-based scaffolds cell system for validation of miRNA function. Collectively, this data shows the successful development and characterisation of a physiologically relevant, scaffold-based 3D tissue-engineered neuroblastoma cell model, strongly supporting its value in the evaluation of chemotherapeutics, targeted therapies and investigation of neuroblastoma pathogenesis. While neuroblastoma is the specific disease being focused upon, the platform may have multi-functionality beyond this tumour type. STATEMENT OF SIGNIFICANCE: Traditional 2D cell cultures do not completely capture the 3D architecture of cells and extracellular matrix contributing to a gap in our understanding of mammalian biology at the tissue level and may explain some of the discrepancies between in vitro and in vivo results. Here, we demonstrated the successful development and characterisation of a physiologically relevant, scaffold-based 3D tissue-engineered neuroblastoma cell model, strongly supporting its value in the evaluation of chemotherapeutics, targeted therapies and investigation of neuroblastoma pathogenesis. The ability to test drugs in this reproducible and controllable tissue-engineered model system will help reduce the attrition rate of the drug development process and lead to more effective and tailored therapies. Importantly, such 3D cell models help to reduce and replace animals for pre-clinical research addressing the principles of the 3Rs.

Metallic powder-bed based 3D printing of cellular scaffolds for orthopaedic implants: A state-of-the-art review on manufacturing, topological design, mechanical properties and biocompatibility.

Metallic cellular scaffold is one of the best choices for orthopaedic implants as a replacement of human body parts, which could improve life quality and increase longevity for the people needed. Unlike conventional methods of making cellular scaffolds, three-dimensional (3D) printing or additive manufacturing opens up new possibilities to fabricate those customisable intricate designs with highly interconnected pores. In the past decade, metallic powder-bed based 3D printing methods emerged and the techniques are becoming increasingly mature recently, where selective laser melting (SLM) and selective electron beam melting (SEBM) are the two representatives. Due to the advantages of good dimensional accuracy, high build resolution, clean build environment, saving materials, high customisability, etc., SLM and SEBM show huge potential in direct customisable manufacturing of metallic cellular scaffolds for orthopaedic implants. Ti-6Al-4V to date is still considered to be the optimal materials for producing orthopaedic implants due to its best combination of biocompatibility, corrosion resistance and mechanical properties. This paper presents a state-of-the-art overview mainly on manufacturing, topological design, mechanical properties and biocompatibility of cellular Ti-6Al-4V scaffolds via SLM and SEBM methods. Current manufacturing limitations, topological shortcomings, uncertainty of biocompatible test were sufficiently discussed herein. Future perspectives and recommendations were given at the end.

Potential drugs against cervical cancer: zinc-ejecting inhibitors of the human papillomavirus type 16 E6 oncoprotein.

BACKGROUND: The principal agent in the etiology of cervical cancer, i.e., human papillomavirus (HPV) type 16, encodes three oncoproteins, E5, E6, and E7. Structural and mutational studies have identified two potential zinc-finger domains as critical for E6 protein function. We investigated several assays to identify and characterize compounds that interfere with the binding of zinc to E6. METHODS: Thirty-six compounds were selected on the basis of their structure, which would facilitate their participation in sulfhydryl residue-specific redox reactions, and were tested for their ability to release zinc from E6 protein. The zinc-ejecting compounds were then tested for their ability to inhibit E6 binding to E6-associated protein (E6AP) and E6-binding protein (E6BP), two coactivators of E6-mediated cellular transformation. The binding of E6 to E6BP and E6AP was measured by use of surface plasmon resonance (a technique that monitors molecular interactions by measuring changes in refractive index) and by use of in vitro translation assays. The compounds were also tested for their effects on the viability of HPV-containing cell lines. RESULTS: Nine of the 36 tested compounds ejected zinc from E6. Two of the nine compounds inhibited the interaction of E6 with E6AP and E6BP, and one of these two, 4, 4'-dithiodimorpholine, selectively inhibited cell viability and induced higher levels of p53 protein (associated with the induction of apoptosis [programmed cell death]) in tumorigenic HPV-containing cells. CONCLUSION: We have described assay systems to identify compounds, such as 4,4'-dithiodimorpholine, that can potentially interfere with the biology and pathology of HPV. These assay systems may be useful in the development of drugs against cervical cancer, genital warts, and asymptomatic infections by genital HPVs.

Titration properties and thermodynamics of the transition state for folding: comparison of two-state and multi-state folding pathways.

CI2 folds and unfolds as a single cooperative unit by simple two-state kinetics, which enables the properties of the transition state to be measured from both the forward and backward rate constants. We have examined how the free energy of the transition state for the folding of chymotrypsin inhibitor 2 (CI2) changes with pH and temperature. In addition to the standard thermodynamic quantities, we have measured the overall acid-titration properties of the transition state and its heat capacity relative to both the denatured and native states. We were able to determine the latter by a method analogous to a well-established procedure for measuring the change in heat capacity for equilibrium unfolding: the enthalpy of activation of unfolding at different values of acid pH were plotted against the average temperature of each determination. Our results show that the transition state of CI2 has lost most of the electrostatic and van der Waals' interactions that are found in the native state, but it remains compact and this prevents water molecules from entering some parts of the hydrophobic core. The properties of the transition state of CI2 are then compared with the major folding transition state of the larger protein barnase, which folds by a multi-state mechanism, with the accumulation of a partly structured intermediate (Dphys or I). CI2 folds from a largely unstructured denatured state under physiological conditions via a transition state which is compact but relatively uniformly unstructured, with tertiary and secondary structure being formed in parallel. We term this an expanded pathway. Conversely, barnase folds from a largely structured denatured state in which elements of structure are well formed through a transition state that has islands of folded elements of structure. We term this a compact pathway. These two pathways may correspond to the two extreme ends of a continuous spectrum of protein folding mechanisms. Although the properties of the two transition states are very different, the activation barrier for folding (Dphys-->++) is very similar for both proteins.

Perturbed pKA-values in the denatured states of proteins.

We show in this study that the ionisation equilibria of denatured proteins in pure water are inconsistent with the "fully-unfolded" conformation being an extended coil where the residues are isolated from one another by the intervening solvent. The effects of acid and salt on the stability of the barley chymotrypsin inhibitor 2 (CI2) were investigated and the pKA-values of all carboxylate residues in the native protein were determined by NMR. A comparison of the experimentally determined pH-dependence of the protein stability and that calculated using observed pKA-values in the native state, reveals that the pKA-values in the denatured state are, on average, 0.3 pH units lower than those of model compounds. An increase in ionic strength eliminates these pKA shifts in the denatured state. This shows that there are electrostatic interactions in the denatured state of CI2. Since previous studies on barnase and the Ovomucoid Third Domain also report anomalous titration behaviours of the denatured states, it appears that perturbed pKA-values in the denatured state is a general phenomenon, indicating that the unfolded conformation in pure water is a fairly compact species. In addition, we used a mutational approach to determine the pKA-values of a carboxylate group in both the native and denatured states. The pKA-value in the native state obtained by this method is in precise agreement with that obtained by NMR.

The rate of isomerisation of peptidyl-proline bonds as a probe for interactions in the physiological denatured state of chymotrypsin inhibitor 2.

There are four peptidyl-proline bonds in the 64-residue protein chymotrypsin inhibitor 2 (CI2), all of which are in the trans conformation in the native structure. The isomerisation of one or more of these peptidyl-proline bonds to the cis conformation in the denatured state gives rise to heterogeneity, leading to both fast and slow-folding species. The refolding of the fast-folding species, which has all trans peptidyl-proline bonds, is much faster than that of the slow-folding species, which have one or more cis peptidyl-proline bonds. In CI2, the slow-folding species can be classified into two groups by their rates of refolding, temperature-dependence, pH-dependence and [GdmCl]-dependence of the rate constants and the effect of peptidyl-prolyl isomerase on the rate constants. The replacement of Pro6 by Ala removes one of the slow refolding phases, suggesting that the cis peptidyl-Pro6 conformation is solely responsible for one of the slow-folding species. Pro6 is located in a region of the protein where non-random interactions have been found in a series of N-terminal fragments of CI2 (residues 1 to 13, 1 to 25, 1 to 28 and 1 to 40). In addition, NMR studies on a mutant fragment, (1-40)T3A, have confirmed that this non-native interaction is associated with the bulky side-chain of Trp5. The atypical rate of cis to trans isomerisation of the peptidyl-Pro bond is indicative of the presence of a similar hydrophobic cluster in the physiological denatured state of intact CI2.

The changing nature of the protein folding transition state: implications for the shape of the free-energy profile for folding.

According to landscape theory proteins do not fold by localised pathways, but find their native conformation by a progressive organisation of an ensemble of partly folded structures down a folding funnel. Here, we use kinetics and protein engineering to investigate the shape of the free-energy profile for two-state folding, which is the macroscopic view of the funnel process for small and rapidly folding proteins. Our experiments are based mainly on structural changes of the transition state of chymotrypsin inhibitor 2 (CI2) upon destabilisation with temperature and GdnHCl. The transition state ensemble of CI2 is a localised feature in the free-energy profile that is sharply higher than the other parts of the activation barrier. The relatively fixed position of the CI2 transition state on the reaction coordinate makes it easy to characterise but contributes also to overshadow the rest of the free-energy profile, the shape of which is inaccessible for analysis. Results from mutants of CI2 and comparison with other two-state proteins, however, point at the possibility that the barrier for folding is generally broad and that localised transition states result from minor ripples in the free-energy profile. Accordingly, variabilities in the folding kinetics may not indicate different folding mechanisms, but could be accounted for by various degrees of ruggedness on top of very broad activation barriers for folding. The concept is attractive since it summarises a wide range of folding data which have previously seemed unrelated. It is also supported by theory. Consistent with experiment, broad barriers predict that new transition state ensembles are exposed upon extreme destabilisation or radical mutations.