[Proximal tibial aspect ratio and matching of tibial component in total knee arthroplasty: a narrative review].

Proximal tibial aspect ratio (PTAR) is closely related to age, disease status and cutting parameters with considerable inter-individual variation independent of gender and race, nevertheless the aspect ratio of tibial components from different manufacturers remains relatively constant from smallest to largest size. As a result, component mismatching is an unavoidable dilemma during tibia preparation in total knee arthroplasty (TKA). Various prosthesis systems all can achieve more than 80% coverage on proximal tibia, whereas their optimal fit rates are generally not more than 50%. It is difficult for symmetrical components to avoid anteroposterior mismatch, internal malrotation tends to occur when maximum coverage is pursued on the resected surface with a medial dominant plateau or lower PTAR. Although it is easier to achieve a balance of rotation and coverage with anatomical components, significant anteromedial overhang tends to appear on the resected surface with a symmetrical or lateral dominant plateau. Further researches should focus on the law of inter-individual variability of proximal tibial morphology, the quantitative definition of "ideal matching" safety zone of key morphological parameters on different areas of proximal tibia and the methodology of realizing"ideal matching"in the majority patients with the least amount of component sizes. In addition, with the rapid development of additive manufacturing and digital orthopedic technology, individual customized implant is expected to become a breakthrough point in the field of TKA component fitting.

[Rotational alignment of the tibial component in total knee arthroplasty:a narrative review].

Component malrotation is one of the major causes of failure in total knee arthroplasty.Based on previous researches,Insall line has excessive external rotation tendency.Although Akagi line is the most recognized anatomical axis at present,it still has a certain tendency of internal rotation.The tibial posterior condylar axis is not suitable for symmetrical component and yet the Curve-on-Curve technique is not suitable for anatomic component.In addition,reference to any fixed anatomical markers cannot ensure the rotation consistency of tibiofemoral component in extension position.Although range of motion technique is beneficial to tibiofemoral rotation synchronization,its clinical effect seems to be unstable.Nevertheless,Patients can obtain good postoperative results with all major techniques.Before the recognized "gold standard" is defined,orthopedic surgeons can determine the rotation alignment of tibial component according to their most accustomed surgical method.With a deeper understanding of knee anatomy,biomechanics and kinematics,digital assistive technology may be expected to become a breakthrough in the tibial rotational alignment.

How much do Indians pay for tuberculosis treatment? A cost analysis.

SETTING: India's National Tuberculosis Elimination Programme (NTEP) covers diagnostic and therapeutic costs of TB treatment. However, persons living with TB (PLWTB) continue to experience financial distress due to direct costs (payment for testing, treatment, travel, hospitalization, and nutritional supplements) and indirect costs (lost wages, loan interest, and cost of domestic helpers). OBJECTIVE: To analyze the magnitude and pattern of TB-related costs from the perspective of Indian PLWTB. DESIGN: We identified relevant articles using key search terms ('tuberculosis,' 'India,' 'cost,' 'expenditures,' 'financing,' 'catastrophic' and 'out of pocket') and calculated variance-weighted mean costs. RESULTS: Indian patients incur substantial direct costs (mean: US$46.8). Mean indirect costs (US$666.6) constitute 93.4% of the net costs. Mean direct costs before diagnosis can be up to four-fold that of costs during treatment. Treatment in the private sector can result in costs up to six-fold higher than in government facilities. As many as one in three PLWTB in India experience catastrophic costs. CONCLUSION: PLWTB in India face high direct and indirect costs. Priority interventions to realize India's goal of eliminating catastrophic costs from TB include decreasing diagnostic delays through active case finding, reducing the need for travel, improving awareness and perception of NTEP services, and ensuring sufficient reimbursement for inpatient TB care.

[Interventional treatment of symptomatic intracranial in-stent restenosis].

Objective: To assess the feasibility and safety of interventional treatment of symptomatic intracranial in-stent restenosis (SISR). Methods: Clinical data of 21 patients with SISR who underwent interventional treatment in the General Hospital of the PLA Rocket Force from January 2012 to May 2018 were retrospectively analyzed. Perioperative complications, angiographic and clinical follow-up results were recorded. Results: The success rate of treatment was 100%, including 21 lesions of SISR (7 at the V4 segment of the vertebral artery, 7 at the basilar artery, 5 at the M1 segment of middle cerebral artery, 2 at the internal carotid artery). The residual stenosis rate was preoperative 84±7, postoperative 30±14 respectively. Balloon angioplasty and stent implantation were performed in 10 patients (48.6%) and 11 patients (52.4%), respectively. After treatment, 1 patient experienced perforating event without neurological sequelae. Of the 11 patients (52.4%) completed angiography follow-up, 3 (3/11, 27.3%) ocurred restenosis and 1 was retreated. During clinical follow-up, 1 patients received intravenous thrombolysis for the symptom of acute cerebral infarction in territory of stenting artery, in-stent restenosis or occlusion was not demonstrated by emergency cerebral angiography. Conclusion: Interventional treatment of SISR is feasible and safe, however, further studies need to warrant the long-term effects.

[Analysis of the therapeutic effect of stent-assisted embolization and surgical clipping for the treatment of middle cerebral artery bifurcation aneurysms].

Objective: To compare the clinical effects of stent-assisted embolization and surgical clipping in the treatment of middle cerebral artery bifurcation wide-necked aneurysms. Methods: From July 2014 to March 2017, the clinical and imaging data of 45 patients with Hunt-Hess 0-Ⅲ grade middle cerebral artery bifurcation wide-necked aneurysms were divided into stent-assisted embolization group (20 patients from PLA Rocktet Army Hospital) and surgical clipping group (25 patients from Peking University International Hospital). The total occlusion rates of aneurysm, operation-related adverse events, clinical outcomes, and results of follow-up imaging from the two groups were compared. Results: The total occlusion rates in the stent-assisted embolization group and surgical clipping group were 90.0% (18/20) and 92.0% (23/25), respectively, and the difference was not statistically significant (P=0.815). The favorable six-month postoperative outcomes defined as the modified Rankin Scale ≤2 were 94.7% (18/19) in the stent-assisted embolization group and 91.3% (21/23) in the surgical clipping group (P=0.667). Fewer patients experienced the operation-related adverse events in the stent-assisted embolization group (15.0%, 3/20), as compared to that of the surgical clipping group (24.0%, 6/25), but the difference were not significant (P=0.453). After 2-24 months (median 7 months) of the operation, the follow-up imaging indicated that in the stent-assisted embolization group, 2 out of the 19 patients had residual or recurrent aneurysms.While in the surgical clipping group, residual or recurrent aneurysms were identified in 2 out of the 23 patients 2-14 months (median 3 months) after the surgery; the frequency was not statistically different between the two groups (P=0.841). Conclusion: Stent assisted embolization is a safe and effective treatment for the low grade middle cerebral artery bifurcation wide-necked aneurysms.

Agouti signalling protein (ASIP) gene: molecular cloning, sequence characterisation and tissue distribution in domestic goose.

Agouti signalling protein (ASIP) is an endogenous antagonist of melanocortin-1 receptor (MC1R) and is involved in the regulation of pigmentation in mammals. The objective of this study was to identify and characterise the ASIP gene in domestic goose. The goose ASIP cDNA consisted of a 44-nucleotide 5'-terminal untranslated region (UTR), a 390-nucleotide open-reading frame (ORF) and a 45-nucleotide 3'-UTR. The length of goose ASIP genomic DNA was 6176 bp, including three coding exons and two introns. Bioinformatic analysis indicated that the ORF encodes a protein of 130 amino-acid residues with a molecular weight of 14.88 kDa and an isoelectric point of 9.73. Multiple sequence alignments and phylogenetic analysis showed that the amino-acid sequence of ASIP was conserved in vertebrates, especially in the avian species. RT-qPCR showed that the goose ASIP mRNA was differentially expressed in the pigment deposition tissues, including eye, foot, feather follicle, skin of the back, as well as in skin of the abdomen. The expression level of the ASIP gene in skin of the abdomen was higher than that in skin of the back. Those findings will contribute to further understanding the functions of the ASIP gene in geese plumage colouring.

Role of the polymorphic residues in HLA-DR molecules in allele-specific binding of peptide ligands.

Analysis of peptide binding to a set of HLA-DR alleles has allowed the proteins to be segregated into functional subsets, depending on the amino acids at positions 57 and 86 of the beta-chain. DR proteins with glycine at 86 beta and aspartic acid at 57 beta bound a simplified peptide with significantly lower IC50 values than alleles that did not have this combination of amino acids. The size of the amino acid at 86 beta seemed to modify the steric requirements for the single most important side chain of the peptide. Within each of the four subgroups, other polymorphic amino acids define allele-specific binding requirements. These were explored by analyzing the ability of eight different DR alleles to bind 13 known T cell determinants. The side chains in the peptides that seemed to be responsible for allele specificity were determined by correlating their common structural features with complementary polymorphic residues in the binding site. The importance of these residues was tested by incorporating them into a polyalanine backbone, and was confirmed by the ability of these residues to transfer allele specificity to these simplified analogues. Even though polymorphic contacts affected peptide affinity, the majority of the free energy of binding in all cases arose from interactions with the peptide backbone and the single hydrophobic amino acid at the third position. These constraints seem to orient all peptides in a similar location, forcing them to adopt a closely related conformation in the binding site. The corresponding side chain in each peptide contacts the same pocket in the binding site, regardless of the allele. This apparent similarity should allow any DR allele to be analyzed by extrapolation from the DR1 crystal structure.

Comparing the human and schistosomal hypoxanthine-guanine phosphoribosyltransferases by circular dichroism.

The hypoxanthine-guanine phosphoribosyltransferases (HGPRTases) of human and the parasitic trematode, Schistosoma mansoni, are of biomedical importance. The conformations of these two enzymes were studied by circular dichroism (CD). The schistosomal HGPRTase is estimated to contain 27% alpha-helix and 30% beta-structure. This result is consistent with what is predicted from a tertiary model (Craig, S.P., Cohen, F.E., Yuan, L., McKerrow, J.H. and Wang, C.C. (1991) in Molecular & Immunological Aspects of Parasitism (Wang, C.C., ed.), pp. 122-138, Am. Assoc. Adv. Sci., Washington DC, USA), which proposes that the enzyme is an alpha/beta barrel protein. The human enzyme is estimated to contain 21% alpha-helix and 53% beta-form. The two enzymes are different in their thermostability. The human enzyme remains active after being heated to 85 degrees C for 15 min, while the schistosomal enzyme only retains its activity at temperature below 65 degrees C. The transition temperature (T1/2) of the schistosomal HGPRTase was determined by CD measurement to be 57.5 degrees C. One of the enzyme substrates, phosphoribose pyrophosphate (PRPP), stabilizes the HGPRTases by preventing the human enzyme from unfolding at 85 degrees C and partially protecting the schistosomal enzyme from unfolding at 65 degrees C. It is suggested that the amino-acid substitutions in the human enzyme improve the spatial structure and stability of its alpha-helices, which may lead to an enhanced thermostability.

Studies on the control region of the p10 gene of the Autographa californica nuclear polyhedrosis virus.

5' deletion mutants of the Autographa californica nuclear polyhedrosis virus very late p10 gene promoter have been prepared and subjected to a transient expression assay in infected Spodoptera frugiperda cells. The control plasmid contained the chloramphenicol acetyltransferase (CAT) reporter gene under the control of the p10 promoter, which was included in a 230 bp sequence upstream from the p10 translation initiation codon. The control plasmid also contained a segment of the hr5 enhancer downstream from the CAT gene. Promoter activity was unaffected by 5' deletion to position -77, which lies about 11 bp upstream from the p10 cap site. However, deletion of 12 more bp completely eliminated p10 promoter activity. Thus, the 5' border of the p10 promoter lies downstream from position -77, and the region between positions -77 and -65 contains an element that is important to promoter activity. This is the region that is conserved near the cap sites of late baculovirus genes. Our studies also show that transient expression of CAT under the control of the p10 promoter and hr5 enhancer is higher when transfection occurs prior to infection by virus.