Types 2c Research Articles

Causes of revision hip arthroplasty after hemiarthroplasty for femoral neck fracture

Background. Hemiarthroplasty as a surgical choice for elderly patients with femoral neck fractures is still a matter of scientific controversy. The aim of the study is to analyse unsatisfactory outcomes of hemiarthroplasty and compare them with the similar outcomes of total hip arthroplasty in elderly patients with femoral neck fractures. Methods. We conducted a retrospective randomized study, which enrolled 36 patients who underwent revision endoprosthetics after various types of arthroplasty for a femoral neck fracture. The patients were divided into 3 groups. Group 1 included 10 patients who underwent arthroplasty with the use of hemiendoprostheses; Group 2 — 15 patients with cemented acetabular components; Group 3 — 11 patients who had cementless acetabular components. Results. The average age of patients in Group 1 at the time of revision arthroplasty was 79 years and was statistically significantly different from the age of patients in Groups 2 and 3 (74.4 and 74.9 years, respectively). The average time for revision interventions after hemiarthroplasty was 40.2 months and significantly differed from the time for the revisions after total cemented (82.7) as well as total cementless (86.6) arthroplasties. The average time for the onset of pain among patients in Group 2 was 68.2 months, and among patients in Group 3 — 71.2 months. The most common bone defects were types 2C and 3A (total of 41.6% in all groups). There were errors in choice of the size of the acetabular bipolar or monopolar component in all 100% of hemiarthroplasty cases. The use of a larger hemiendoprosthesis cup compared to the femoral head led to early erosion of cartilage tissue. Smaller hemiendoprosthesis cups were complicated by early protrusions of the acetabulum floor. The main errors in total arthroplasty were malposition of the acetabular component (33.3-54.5%) and inadequate cement mantle (20%). It should be noted that infections among patients from Groups 2 and 3 developed up to 24.7 months after primary arthroplasty. Conclusions. Errors associated with incorrect choice of the acetabular endoprosthesis component size during primary hemiarthroplasty lead to early complications: erosion and protrusion of the acetabulum. Severe pain syndrome due to incorrect selection of the acetabular hemiendoprosthesis component size develops on average after 13.9 months, and the time period for revision endoprosthetics is 40.2 months after the primary operation. With erosions of the acetabulum, there are no bone defects; with protrusions — bone defects of type 2C and 3A more often occur. In comparison with the outcomes of total hip arthroplasty, the use of hemiendoprostheses shows a low survival rate of 40.2 months.

The first step of two-stage hip revision: what affects the result?

Background. The most common method of treatment of chronic periprosthetic joint infection (PJI) is considered to be a two-stage revision arthroplasty. The efficacy of this technique is largely determined by the results of infection management after the first (debridement) stage, which may depend on many factors. At the same time, the widespread tendency to reduce the duration of patients’ hospital stay brings to the forefront the problem of long wait for the results of preoperative microbiological examination. Aims of the study: 1) to retrospectively evaluate the efficacy of the debridement stage of chronic periprosthetic hip joint infection in 2021 depending on the availability of preoperative microbiological examination results; 2) to determine the factors influencing the treatment outcome. Methods. Patients (n = 86) with chronic PJI of the hip were allocated into two groups depending on the presence or absence of results of the microbiological examination of preoperative biomaterials (aspirate and/or tissue biopsy) at the time of performing the first stage of the two-stage revision arthroplasty. Results. The availability of final results of the microbiological examination (MBE) of joint aspirate at the time of surgery had no significant effect on the efficacy of infection management (p = 0.536; OR = 1.53, 95% CI 0.43-5.45). There was a significant reduction of the risk when the results of preoperative and intraoperative MBE coincided (p = 0.024; OR = 0.121, 95% CI 0.015-0.990). An increased risk of adverse outcome of the debridement stage of treatment was observed in the case of types 2C (p = 0.042; OR = 6.66; 95% CI 1.26-35.2) and 3B (p = 0.078; OR = 8.1, 95% CI 1.015-64.8) acetabular defects, type 3A femoral defects (p = 0.021; OR = 6.57, 95% CI 1.49-29.01), and connective tissue diseases (p = 0.062; OR = 5.25, 95% CI 1.05-26.2). The presence of microbial associations (p=0.02; OR = 6.75, 95% CI 1.36-33.44) and the presence of Gram-negative bacteria in them (p = 0.058; OR = 4.2, 95% CI 1.02-17.20) significantly worsened the treatment prognosis. As the number of patient’s risk factors increased, the probability of an unfavorable outcome increased significantly (p0.001). Conclusion. Polymicrobial infection, presence of Gram-negative bacteria in microbial associations, connective tissue diseases, types 2C and 3B acetabular defects, type 3A femoral bone defects, and total number of risk factors in one patient had a significant negative impact on the outcome of debridement surgery. Apparently, the results of the microbiological examination of preoperatively sampled biomaterials are much more important as a diagnostic criterion for suspected periprosthetic infection than as a criterion for the drug choice for etiotropic antibacterial therapy. However, this assumption should be studied on a larger sample of patients.

Use of dual mobility cup cemented into a tantalum acetabular shell for hip revision with large bone loss can decrease dislocation risk without increasing the risk of mechanical failure

BackgroundPorous tantalum components and augments have demonstrated short to midterm fixation stability in acetabular total hip arthroplasty (THA) revision but do not offer a novel option to decrease the postoperative dislocation rate. Recently, dual mobility (DM) cups have gained interest to decrease the prevalence of recurrent hip instability after revision hip arthroplasty, but this issue was not confirmed combined with use of tantalum reconstruction devices. Therefore, we did a retrospective study aiming to: (1) evaluate at a 5-year minimum follow-up period the dislocation rate (and other intra- and postoperative complications), (2) assess radiographic results specifically looking at osseointegration and restoration of the hip center, (3) and also clinical results in a cohort of patients who underwent complex acetabular reconstruction with trabecular metal revision components associated with a cemented DM socket. HypothesisUsing a DM socket cemented in porous tantalum components can reach the low risk of hip dislocation reported with DM components in revision setting without increasing the risk of a mechanical failure. MethodsA cross-sectional study identified 174 THA revision including an acetabular revision. Were excluded 118 revisions with acetabular defects Type 1, 2a or 2B according to Paprosky's classification, as well as 18 hips revised without a dual mobility and 3 patients (3 hips) lost to follow-up. Were thus included in this study 35 hips (35 patients) implanted with uncemented total hip arthroplasty revision using both trabecular metal acetabular cup-cage reconstruction and a cemented DM cup. Seven hips were classified Paprosky types 2C, 15 type 3A and 13 types 3B. Patients were followed with clinical and radiological evaluation regarding dislocation rate, infection, reoperation or re-revision, osseointegration and restoration of the hip center, and functional results according to the Harris hip score and psoas impingement presence. ResultsAt a mean follow-up of 8.1±1.8 years (5.1–12.6), one dislocation was recorded, and one acute deep infection. No patient required a cup re-revision for septic or aseptic loosening. The survivorship at 8years regarding revision for any cause as an endpoint was 96.5% (CI95%: 92–99). Osseointegration of TM implants was analyzed and found no acetabular migration at the last follow-up in the cohort. The mean hip center position was optimized from 48±7mm (37–58) to 34±5mm (29–39) vertically and from 26±5mm (–18–36) to 24±8mm (7–31) horizontally without reaching significance (p=0.1). On the last follow-up X-rays, the mean acetabular inclination was 47̊±9̊ (32̊–61̊). According to the criteria of Hirakawa, 97.1% (34/35) of the hip centers were restored. One cup (2.9%) was more than 5mm proximally from the hip center, and none more than 10mm. Clinical results assessed a Harris Hip Score improved from 36±17 (23–62) preoperatively to 82±15 (69–93) at last follow-up (p<0.0001). Two patients (2/35, 5.7%) complained of psoas impingement. ConclusionThis study suggests effectiveness of DM cups in association with a tantalum-made acetabular shell for reconstruction of large bone defect in THRs for both solving postoperative instability and aseptic loosening without increasing the re-revision rate for any reason in a midterm follow-up. Level of evidenceIV; observational study.

Morphological analysis and classification of posterior malleolar fractures based on CT scans

ObjectivesThe aim of the study was to propose a classification system of posterior malleolar fractures by fracture lines with the use of CT scans, including 3D CT reconstruction, which can better understand morphological characteristics, analyze the mechanism and guide the surgeon to choose the optimal approach and fixation. MethodsPatients with OTA/AO type 44 fractures involving the posterior malleolus and preoperative CT scans were included. We retrospectively analyzed 128 consecutive patients with posterior malleolar fractures from January 2013 to December 2019 at our institution. CT data were loaded into Mimics software (V20.0, Materialize), in which 3D CT reconstruction, morphological analysis and data measurements were made. ResultsBased on the number of fracture lines in 128 consecutive patients, posterior malleolar fractures were classified into three types: type 1 with a single fracture line, type 2 with double fracture lines and type 3 with multiple fracture lines. According to the distribution of the fracture line, type 1 was divided into types 1A, 1B and 1C, and type 2 was divided into types 2A, 2B and 2C. The fracture line from the fibular notch to the posterior rim of the distal tibia was defined as type 1A, and the fracture line to the medial malleolus was defined as type 1B. Type 1C was a small fragment in the posterior rim of the distal tibia. Type 2A was regarded as type 1A with type 1C. It was considered type 2B because another fracture line started from the fracture line of type 1A and extended to the medial malleolus. In type 2C, we could see that the double fracture lines were all from the fibular notch to the posterior rim of the distal tibia and did not cross. Type 3 fractures were comminuted fractures with multiple fracture lines. ConclusionThe morphology of posterior malleolar fractures, involvement of the fibular notch, or the medial malleolus can be obviously assessed by our classification system. We found the relation of the injury mechanism between type 1 and type 2 by comparing the area of the fragment. We have indicated that each type of fracture corresponds to its associated injury mechanism and which surgical approach and fixation can be chosen.

Posterior-only correction surgery for idiopathic scoliosis Lenke type 5c: differences of strategies and outcomes between adult patients and adolescent patients

PurposeTo compare radiographic parameters, and functional and surgical outcomes between lumbar adolescent idiopathic scoliosis (AIS) and lumbar adult idiopathic scoliosis (AdIS).MethodsA retrospective study was performed to identify Lenke 5c type AIS and AdIS patients from our scoliosis database who had undergone posterior surgical treatment for scoliosis. Preoperative and postoperative radiographic and clinical outcomes were compared between the two groups.ResultsA total of 22 patients were included in AdIS group, and 44 matched patients in AIS group. AdIS group had significantly larger L3 and L4 tilt and translation than AIS group (P < 0.05). AdIS group had larger T10-L2 angle and smaller T5–T12 angle (P < 0.05). AdIS group had higher VAS scores (P < 0.05) and pain domain of SRS-22 scores (P < 0.05) as compared to AIS group. Correlation analysis demonstrated positive relationship between VAS scores and T10-L2 angle (r = 0.492, P < 0.05). AdIS group was fused longer than AIS group (P < 0.05). Cobb angle of TL/L curve was larger and correction ratio was smaller at AdIS group (P < 0.05). AdIS group still had significantly larger L3 and L4 tilt and translation than AIS group (P < 0.05). CT measurements demonstrated larger postoperative vertebral body rotation at apical vertebrae and LIV at AdIS group (P < 0.05). Vertebral correction ratio was smaller at AdIS group (P < 0.05).ConclusionLenke 5c AdIS patients had greater preoperative and postoperative L3 and L4 tilt and translation, as well as less correction of major curve and vertebral body derotation than AIS patients. However, the incidence of adding-on was similar between the two groups.

Fusobacterium nucleatum CbpF Mediates Inhibition of T Cell Function Through CEACAM1 Activation.

F. nucleatum is an anaerobic bacterium that is associated with several tumor entities and promotes tumorigenesis. Recent evidence suggests that F. nucleatum binds the inhibitory receptor carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) via the trimeric autotransporter adhesin CbpF. However, whether this binding is functional or whether other fusobacterial trimeric autotransporter adhesins are involved in CEACAM1 activation is unknown. In this study, using F. nucleatum mutants lacking the type 5c trimeric autotransporter adhesins fvcA (CbpF), fvcB, fvcC, and fvcD, we show that F. nucleatum CbpF binds and activates CEACAM1 and also binds carcinoembryonic antigen (CEA), a tumor-associated protein. We further find that CEACAM antibodies directed against the CEACAM N-terminal domain block the CbpF-CEACAM1 interaction. In functional assays, we demonstrate CbpF-dependent inhibition of CD4+ T cell response. Thus, we characterize an immune evasion mechanism in which F. nucleatum uses its surface protein CbpF to inhibit T cell function by activating CEACAM1.

Transoral Laser Surgery for Early Glottic Carcinoma: A Single Surgeon Experience of 101 Consecutive Cases

Purpose: Investigate the clinical and oncological results of early-stage glottic laryngeal carcinoma patients performed by a single surgeon. Methods: This study was carried out at a tertiary academic center. A total of 101 patients were included (92 males [91.1%], 9 females [8.9%]). Mean age was 62.98 ± 10.2 years (range 33–87). Recurrence, disease-free survival, overall survival, laryngeal preservation rates were analyzed. Results: Tumor stage was Tis (carcinoma in situ) in 11 patients (10.9%), T1a in 66 patients (65.3%), T1b in 12 patients (11.9%), and T2 in 12 patients (11.9%). Postoperative pathology was squamous cell carcinoma in 69 patients (68.3%), carcinoma in situ in 26 patients (25.7%), and high-grade dysplasia in 6 patients (5.9%). Five patients (5.0%) underwent type 1, 7 (6.9%) type 2, 45 (44.6%) type 3, 24 (23.8%) type 4, 6 (5.9%) type 5a, 8 (7.9%) type 5c, 4 (4.0%) type 5d, and 2 (2.0%) type 6 cordectomy. Median follow-up time was 30 months (range 14–66). There were 5 recurrences (5.0%). Three-year disease-free survival was 94.4%. Three-year disease-free survival for stage I and II patients was 94.9 and 91.7%, respectively. Overall survival was 93.8%. Only 1 patient died related to cardiovascular disease. Disease-specific survival was 100%. Conclusions: In conclusion, this is a large case series with good oncological outcomes presented with the perspective of a single surgeon. The data of the study is in accordance with the previous reports.

The first isolation and genetic characterization of canine parvovirus types 2a and 2c from dogs with suspected enteritis in the Republic of Korea

The first isolation and genetic characterization of canine parvovirus types 2a and 2c from dogs with suspected enteritis in the Republic of Korea

Detection of canine parvovirus types 2b and 2c in canine faecal samples contaminating urban thoroughfares in Brazil.

Canine parvovirus type 2 (CPV-2) is a highly contagious virus that causes acute gastroenteritis in dogs all over the world. Because of its stability in the environment, CPV-2 can remain infective for a long time, especially if protected in organic matter. To demonstrate CPV-2's potential as an environmental hazard for nonimmunized susceptible hosts, we investigated 50 faecal samples collected from public areas in a municipality of Paraná state, Brazil. Seven samples tested positive for CPV by a PCR assay targeting the partial VP2 gene, with three strains being confirmed as CPV-2b variant and one as CPV-2c variant by sequence analysis. These findings were supported by phylogenetic analysis, and the species identity of faecal samples source was confirmed by canine mitochondrial DNA amplification and sequencing. Our results demonstrate the presence of CPV in canine faeces contaminating urban thoroughfares and reinforce the importance of environmental control to reduce the potential exposure risks to susceptible hosts.

Genetic and Molecular Typing of Canine Parvovirus Strains Circulating in Symptomatic Dogs in Egypt

Canine parvovirus (CPV) is considered one of the serious and problematic diseases in young puppies. It causes hemorrhagic enteritis and myocarditis in affected dogs. The aim of the present study was to detect CPV-2 in feces of clinically diseased puppies by polymerase chain reaction (PCR) followed by VP2 gene partial sequencing and molecular characterization of circulating strains in Egypt as well as studying some factors associated with the disease incidence. Forty fecal samples were collected from clinically suspected dogs with CPV-2. The clinical diagnosis was confirmed in 35 suspected clinical cases (87.5%) by PCR using common and specific primers sets for detection of (CPV-2, CPV-2a, CPV-2b, CPV-2c) validating that presumptive clinical diagnosis is practically dependable. Nucleotide sequencing of parvovirus (CPV-2) isolates showed that all the three antigenic types (2a, 2b, and 2c) are currently circulating in Egypt.

A single centre study of 41 cases on the use of porous tantalum metal implants in acetabular revision surgery

BackgroundThis study aims at investigating cup survival of porous tantalum revision cups and identifies risk factors for failure.MethodsWe retrospectively reviewed 41 patients treated between 2010 and 2012. Main indications were aseptic loosening in 83% and two-stage exchange after periprosthetic joint infection in 17% of cases. Mean follow-up period was 72 months. Femoral megaprostheses were used in 13% of cases. Most defects were classified as Paprosky 3b (29%). Function was assessed using the Harris Hip score.ResultsAseptic cup survivorship was 80% at 104 months (95% Confidence Interval 67.4–92.4). Overall implant survival was 73%. Major bone loss defects (Paprosky types 2c to 3b) were associated with a significantly higher rate of failure than minor defects (P = 0.002). There were eight cases of aseptic loosening (19.5%) and two of infection (4.9%). Previous surgeries, indication for acetabular revision, patient-related risk factors and use of megaprostheses did not significantly influence implant survival. The Harris Hip Score improved from a median of 40 (Interquartile range 31–45) to 82 (interquartile range 65–88) postoperative (P < 0.0001).ConclusionsIn summary, the use of porous tantalum metal implants in acetabular revision surgery achieves good to excellent short- term and mid-term functional results and an acceptable complication rate relative to the extent of defect and previous surgery. However, one should be aware of potential limitations of the implants in addressing large defects and discontinuity.

151. Evaluation of Pneumococcal Vaccine Effectiveness Against Invasive Pneumococcal Disease Among US Medicare Beneficiaries ≥65 Years Old

BackgroundPneumococcal conjugate vaccine (PCV13) was recommended in series with PPSV23 for all US adults ≥65 years in late 2014. We evaluated effectiveness of PCV13 against invasive pneumococcal disease (IPD) among Medicare beneficiaries ≥65 years old to assess this new policy.MethodsWe linked records for IPD cases (pneumococcus isolated from sterile sites) in persons ≥65 years old identified through Active Bacterial Core surveillance with those of Medicare beneficiaries. Isolates were serotyped and classified as PCV13 (with or without cross-reacting type 6C), and nonvaccine types. We selected Medicare beneficiaries with no record of IPD or pneumonia as controls, and matched to cases on age, residence census tract, and length of Medicare enrollment; we included all eligible controls. Vaccination and medical histories were obtained through Medicare. We estimated vaccine effectiveness (VE) as 1 minus the IPD odds ratio for vaccinated (PCV13) vs. unvaccinated (no PCV13 or PPSV23) persons using conditional logistic regression, adjusted for sex and underlying conditions.ResultsFrom 2,246 IPD cases identified in 2015–2016, 1,017 (45%) were matched to Medicare beneficiaries. After excluding cases in persons residing in long-term care facilities or with <1 year of Medicare enrollment, we included 699 eligible cases and 10,152 controls in our analysis. PCV13-types (+6C) accounted for 164 (23%) cases, and serotype 3 was the most common PCV13-type. Case patients were more likely than controls to have one or more chronic (88% vs. 58%) or immunocompromising (54% vs. 32%) conditions present. Fourteen percent, 22%, and 8% of case patients, and 18%, 21%, and 8% of controls received PCV13 only, PPSV23 only, or both vaccines, respectively. PCV13-only VE against PCV13-types was 36% (95% CI −18, 65%). When we included type 6C with PCV13-types, VE was 67% (95% CI 11, 88%). PCV13 showed similar effectiveness against PCV13 type (+6C) IPD among adults >75 years of age (VE 61%, 95% CI 14, 82). VE was 26% (95% CI −58, 65%) against serotype 3 and 67% (95% CI 11, 88%) against other PCV13-types (+6C). PCV13 was not effective against nonvaccine types.ConclusionPCV13 was effective in preventing IPD caused by PCV13 types when excluding type 3; no effectiveness was demonstrated against serotype 3.Disclosures W. Schaffner, Merck: Member, Data Safety Monitoring Board, Consulting fee. Pfizer: Member, Data Safety Monitoring Board, Consulting fee. Dynavax: Consultant, Consulting fee. Seqirus: Consultant, Consulting fee. SutroVax: Consultant, Consulting fee. Shionogi: Consultant, Consulting fee.

Criteria for Ending the Distal Fusion at the L3 Vertebra vs. L4 in Surgical Treatment of Adolescent Idiopathic Scoliosis Patients with Lenke Type 3C, 5C, and 6C Curves: Results After Ten Years of Follow-up.

IntroductionThe selection of the most distal caudal vertebra in spinal fusion surgeries in adolescent idiopathic scoliosis patients with structural lumbar curvatures is still a matter of debate. The aim of this study was to determine the preoperative radiological criteria on the traction X-rays under general anesthesia (TrUGA) for selection between the L3 and L4 vertebrae and to assess the efficacy of these criteria via the long-term results of patients with Lenke Type 3C, 5C, and 6C curves.MethodsRadiological data of 93 patients (84 females, 9 males) who met the inclusion criteria were retrospectively evaluated. The relationship between the L3 vertebra and the central sacral vertebral line, the portion of the L3 vertebra in the stable zone of Harrington, the parallelism of the L3 with the sacrum, and the tilt and rotation of the L3 on TrUGA radiographs were evaluated for the selection of the lowest instrumented vertebrae (LIV). Clinical results were analyzed using the Scoliosis Research Society-22 (SRS-22) questionnaire.ResultsThe mean follow-up period of the study group was 149.3 months. According to the Lenke classification, 29 patients had Type 3C, 33 had Type 5C, and 31 had Type 6C curves. The preoperative analysis was based on standing anteroposterior (AP), supine traction, and bending X-rays, and the L3 vertebra was selected as the LIV in 37 patients (40%). These X-rays suggested L4 as the LIV in 56 patients (60%); however, based on our study criteria, the L3 vertebra was selected. No significant loss of correction was observed nor additional surgery due to decompensation was required in the follow-up period.Conclusion The use of TrUGA radiographs with the identified criteria is an efficient alternative method in the selection of the LIV in patients with Lenke Type 3C, 5C, and 6C curves.

Canine parvovirus types 2a and 2c detection from dogs with suspected parvoviral enteritis in Peru.

Canine parvovirus type 2 (CPV-2) has been reported worldwide as the main agent related to acute hemorrhagic enteritis of high morbidity and variable mortality in puppies. The detection and characterization of this virus is essential to understand the etiology of the disease and to develop control measures. To characterize the virus circulating in Peruvian dogs and to provide new insights into the local diversity of CPV-2, rectal swabs from 39 puppies with clinical symptoms and with no history of previous vaccinations were analyzed. Total DNA was extracted by fast boiling method, and PCR and sequencing were performed using specific primers that amplify a 1316bp fragment corresponding to the VP2 gene of CPV-2. CPV-2 was detected in 62% of the analyzed samples. The sequencing of PCR product was possible in 9 samples, which were identified as type 2a (4 samples) and type 2c (5 samples). A phylogenetic analysis of both variants circulating in Peruvian dogs showed similarities to Equatorian and Uruguayan strains. This work constitutes the first report about genetic characterization of CPV-2 in Peru.

Meniscal Root Tears

Background: Meniscal root tears present in many forms and can have profound consequences on the health of knee articular cartilage. While the biomechanics, natural history, and treatment of root tears have been increasingly investigated, the spectrum of meniscal root tear patterns observed during arthroscopic examination has yet to be defined and categorized. Purpose: To establish a classification system for meniscal root tears by reporting the morphology of meniscal root tears from a consecutive series of arthroscopic surgeries. It was hypothesized that meniscal root tears could be grouped into types by distinct tear patterns and that recognition of tear pattern would affect treatment choice. Study Design: Case series; Level of evidence, 4. Methods: All patients who underwent arthroscopic surgery from April 2010 to May 2014 by a single orthopaedic surgeon were included. After arthroscopic examination, data regarding the integrity of the meniscal roots were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos. Results: A total of 71 meniscal root tears in 67 patients were grouped into tear types with similar tear morphologies. Meniscal root tear patterns were categorized into partial stable root tears (type 1; n = 5); complete radial tears within 9 mm of the bony root attachment (type 2; n = 48), further subclassified into types 2A, 2B, and 2C, located 0 to <3 mm, 3 to <6 mm, and 6 to 9 mm from the root attachment, respectively; bucket-handle tears with a complete root detachment (type 3; n = 4); complex oblique tears with complete root detachments extending into the root attachment (type 4; n = 7); and bony avulsion fractures of the root attachments (type 5; n = 7). Conclusion: This study demonstrated that it was possible to establish a concise classification system to group patients with meniscal root tears by tear morphology. Treatments received varied across tear types.

Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists – in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

Analysis of karyotype diversity of 40 Chinese chrysanthemum cultivars

AbstractTo investigate the genetic differences in Chinese large‐flowered chrysanthemum (Chrysanthemum×morifolium Ramat.) cultivars, we selected 40 typical and stable cultivars on which to carry out cytological studies using karyotype analysis. The results showed that 67.5% of these cultivars were hexaploid‐based aneuploid and that the proportion of hexaploid decreased with passing time. Moreover, 35% of the cultivars had 1–4 satellite chromosome(s). The probability of satellite chromosomes rose with increasing chromosome number. Most of the karyotypes were 2A and 2B. The probability of types 2A and 2C also increased with increasing ploidy of the cultivars. The mean of long‐/short‐arm ratio and the variation of long‐/short‐arm ratio were positively correlated (r2 = 0.72). There was no obvious difference in the asymmetry coefficient of karyotypes, but the discrepancy in the variance of karyotype asymmetry index and relative length of chromosomes was quite distinct. In terms of karyotype parameters, the petal types of chrysanthemums were classified to five groups as flat, tubular, spoon, abnormal, and anemone. We did not observe any obvious orderliness among flower head types. Considering the relationship between karyotype parameters and phenotypic characters, variation of long‐/short‐arm ratio and asymmetry coefficient of karyotypes had the greatest relevance toward most phenotypic characters. The above results indicate that karyotype parameters possess great values for cultivar identification, classification, and genetic analysis in chrysanthemums.

Interaction mechanisms between poly(amido‐amine) and nano‐silicon dioxide

AbstractTo gain insight into the attachment of Si+ (SC) and SiO− (SOA) ions (regarded as guests) to the lowest generation, NH2‐terminated poly(amidoamine) (PAMAM) dendrimers (regarded as host) in the gas phase, density functional theory is used to investigate the structures and energetics of the complexes with B3LYP/6‐31+G (d) and HF/6‐31G basis sets. The initial parameters are obtained through the initial optimizations at the HF level using the most basic STO‐3G basis set. Various initial configurations of the ions bound to PAMAM are tested, and four stable conformers are found, i.e., types A to D. Types 1A and 2C are the most stable due to the chemical bond formations of SiN° and SiO, respectively. For type B, SC coordination to amide O sites occurs via electrostatic induction. For type D, SOA coordination to amide hydrogen and amine hydrogen sites occurs via hydrogen bond interaction. Spatial hindrance, electrostatic induction force, and hydrogen‐bond interaction play important roles in the complexation process. © 2013 Wiley Periodicals, Inc.This article was published online on 5 July 2012. An error was subsequently identified. This notice is included in the online and print version to indicate that both have been corrected on 3 August 2012.

Comparison of the aorta impingement risks between thoracolumbar/lumbar curves with different convexities in adolescent idiopathic scoliosis: a computed tomography study

To compare the positions of the aorta relative to vertebral bodies and the potential risk of the aorta impingement for pedicle screw (PS) placement between right-sided and left-sided thoracolumbar/lumbar curves of adolescent idiopathic scoliosis (AIS). Thirty-nine AIS patients with a main thoracolumbar or lumbar curve were recruited. The Lenke's classification was type 5C in all patients. According to the convexity of the thoracolumbar or lumbar curves, the patients were divided into either group R or Group L. The patients in Group R had a main right-sided thoracolumbar/lumbar curve, and the patients in Group L had a main left-sided thoracolumbar/lumbar curve. Axial CT images from T12 to L4 at the midvertebral body level were obtained to evaluate Aorta-vertebra angle (α), Vertebral rotation angle (β), Lefty safety distance (LSD), and Right safety distance (RSD). The risks of the aorta impingement from T12 to L4 were calculated and then compared between the two groups. The α increased from T12 through L4 in Group R, increased from T12 through L1, and then decreased from L1 through L4 in Group L. The β decreased from T12 through L4 in both groups. The LSD constantly increased from T12 through L4 in Group R, increased from T12 through L3, and then decreased from L3 through L4 in Group L. The RSD increased from T12 through L3 and then decreased from L3 through L4 in both groups. With the increment of the lengths of the simulated screws, the aorta impingement risks were constantly elevated at all levels in both groups. The aorta was at a high risk of impingement from left PS regardless of the diameters of the simulated screws in Group R (80-100% at T12 and 53.3-100% at L1). In Group L, the aorta was completely safe when using 35mm (0 at all levels) PS and at high risks of the aorta impingement on the right side from 45mm PSs (31.8-72.7%). In all, the risks of the aorta impingement were mainly from left PS in Group R and from right PS in Group L, and the risk of the aorta impingement from PS placement was generally higher in right thoracolumbar or lumbar curves when compared with that of the left. The present study illustrated different changed positions of the aorta relative to vertebrae between thoracolumbar/lumbar curves with different convexities. In right-sided curve, the risks of the aorta impingement were mainly from left PS while in left-sided curves, from right PS. The aorta was more proximal to entry points in right-sided lumbar curve when compared with left-sided curve; thus placing PS carries more risks in right-sided thoracolumbar/lumbar curve. Surgeons should be more cautious when placing PSs on the concave sides of T12 and L1 vertebrae of right-sided thoracolumbar/lumbar curves.

Molecular characterisation of canine parvovirus strains circulating in China

Canine parvovirus (CPV) was first isolated at 1978 in the USA. Analysis of CPV isolates by monoclonal antibodies and restriction enzymes have shown that after the first emergence of CPV (CPV-2) it evolved to give rise to new antigenic types, which were designated CPV types 2a, 2b and 2c. These new types have replaced the original CPV type 2, although the proportions of each of the new antigenic types vary in different countries. In China, CPV infections were first observed in 1982, however, there has been no information concerning the antigenic types of CPV prevailing in China now. In this study, we designed a PCR assay to type canine parvovirus strains in fecal samples collected from symptomatic dogs from 2006 to 2009. Our data showed that the CPV prevalent strain is mostly 2b, the proportion of CPV-2a is very low, no CPV-2c and CPV-2 were observed.