Metabolomics efficiently discriminates monozygotic twins in peripheral blood.

Monozygotic (MZ) twins cannot be distinguished using conventional forensic STR typing because they present identical STR genotypings. However, MZ twins do not always live in the same environment and often have different dietary and other lifestyle habits. Metabolic profiles are deyermined by individual characteristics and are also influenced by the environment in which they live. Therefore, they are potential markers capable of identifying MZ twins. Moreover, the production of proteins varies from organism to organism and is influenced by both the physiological state of the body and the external environment. Hence, we used metabolomics and proteomics to identify metabolites and proteins in peripheral blood to discriminate MZ twins. We identified 1749 known metabolites and 622 proteins in proteomic analysis. The metabolic profiles of four pairs of MZ twins revealed minor differences in intra-MZ twins and major differences in inter-MZ twins. Each pair of MZ twins exhibited distinct characteristics, and four metabolites-methyl picolinate, acesulfame, paraxanthine, and phenylbenzimidazole sulfonic acid-were observed in all four MZ twin pairs. These four differential exogenous metabolites conincidently show that the different external environments and life styles can be well distinguished by metabolites, considering that twins do not all have the same eating habits and living environments. Moreover, MZ twins showed different protein profiles in serum but not in whole blood. Thus, our results indicate that differential metabolites provide potential biomarkers for the personal identification of MZ twins in forensic medicine.

Epitranscriptomic orchestrations: Unveiling the regulatory paradigm of m6A, A-to-I editing, and m5C in breast cancer via long noncoding RNAs and microRNAs.

Breast cancer (BC) poses a persistent global health challenge, particularly in countries with elevated human development indices linked to factors such as increased life expectancy, education, and wealth. Despite therapeutic progress, challenges persist, and the role of epitranscriptomic RNA modifications in BC remains inadequately understood. The epitranscriptome, comprising diverse posttranscriptional modifications on RNA molecules, holds the potential to intricately modulate RNA function and regulation, implicating dysregulation in various diseases, including BC. Noncoding RNAs (ncRNAs), acting as posttranscriptional regulators, influence physiological and pathological processes, including cancer. RNA modifications in long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) add an extra layer to gene expression control. This review delves into recent insights into epitranscriptomic RNA modifications, such as N-6-methyladenosine (m6A), adenine-to-inosine (A-to-I) editing, and 5-methylcytosine (m5C), specifically in the context of lncRNA and miRNAs in BC, highlighting their potential implications in BC development and progression. Understanding this intricate regulatory landscape is vital for deciphering the molecular mechanisms underlying BC and identifying potential therapeutic targets.

A retrospective study of the management and outcomes of pregnancies with inherited antithrombin deficiency.

INTRODUCTION: Antithrombin (AT) deficiency is a rare but highly thrombogenic inherited thrombophilia. Its association with adverse pregnancy outcomes (APO) is undefined. There is limited guidance on managing AT deficiency in pregnancy. Some significant issues remain controversial, including risk assessment for prophylactic anticoagulation, anticoagulant therapy, and monitoring. Our goal was to examine if the antepartum management of patients with AT deficiency affected their pregnancy outcomes. MATERIALS AND METHODS: This retrospective, single-center observational study included pregnant women with inherited AT deficiency in Peking Union Medical College Hospital between 2013 and 2024. RESULTS: Seventeen pregnancies in 6 women with AT deficiency were identified. A total of 7 pregnancies received adjusted-dose low-molecular-weight heparin (LMWH) and were monitored by anti-Xa level, AT activity, and D-dimer. There were 5 live births (all received LMWH), 7 second-trimester abortions (1 received LMWH), and 5 early pregnancy losses (1 received LMWH). There were 5 abruptio placentae events (3 received LMWH) and 7 thrombotic events (2 received LMWH). CONCLUSIONS: AT deficiency is at least an important partial factor contributing to APO. It is suggested to make a full assessment of AT patients both for venous thrombus embolism and APO risk. We observed a high prevalence of heparin resistance and a positive correlation between adequate anticoagulation and pregnancy outcome based on tight monitoring with anti-Xa level and timely adjustment of the LMWH dosage.

Impact of female stress urinary incontinence and related treatments on the sexual function of male partners: a systematic review and meta-analysis.

BACKGROUND: No conclusions have been reached on whether female stress urinary incontinence (SUI) and related treatments affect male partners' sexual function. AIM: To assess the effects of female SUI and related treatments on male partners' sexual function. METHODS: A comprehensive search of the PubMed, Embase, Web of Science, Cochrane, and Scopus databases was performed up to September 6, 2022. Studies were included that investigated the effect of female SUI and related treatments on male partners' sexual function. OUTCOME: Male partners' sexual function. RESULTS: Of the 2294 citations identified, 18 studies with 1350 participants were included. Two studies assessed the effect of female SUI without treatment on male partners' sexual function, finding that partners had more erectile dysfunction, more sexual dissatisfaction, and less sexual frequency than partners of women without urinary incontinence. Seven studies directly assessed the effect of female SUI treatments on male partners' sexual function by surveying the male partners. Among these, 4 assessed transobturator suburethral tape (TOT) surgery; 1 assessed TOT and tension-free vaginal tape obturator surgery; and the remaining 2 assessed pulsed magnetic stimulation and laser treatment. Among the 4 TOT studies, 3 used the International Index of Erectile Function (IIEF). TOT surgery significantly improved the total IIEF score (mean difference [MD] = 9.74, P < .00001), along with erectile function (MD = 1.49, P < .00001), orgasmic function (MD = 0.35, P = .001), sexual desire (MD = 2.08, P < .00001), intercourse satisfaction (MD = 2.36, P < .00001), and overall satisfaction (MD = 3.46, P < .00001). However, the improvements in IIEF items may be of unclear clinical significance, as 4 points in the erectile function domain of the IIEF are typically defined as the minimal clinically important difference. In addition, 9 studies indirectly assessed the effect of female SUI surgery on male partners' sexual function by surveying patients with the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire. The results demonstrated no significant differences in erectile function (MD = 0.08, P = .40) or premature ejaculation (MD = 0.07, P = .54). CLINICAL IMPLICATIONS: The effects of female SUI and related treatments on male partners' sexual function were summarized for the first time, providing a reference for future clinical practice and scientific research. STRENGTHS AND LIMITATIONS: A limited number of studies that used various scales met the standardized eligibility criteria. CONCLUSION: Female SUI may affect male partners' sexual function, and female patients' anti-incontinence surgery does not appear to have a clinically significant improvement on the sexual function of their partners.

Ovariectomy with simulated vaginal delivery to establish a rat model for pelvic organ prolapse.

The widespread prevalence of Pelvic Organ Prolapse (POP) and the paucity of ongoing treatments prompted us to develop a unique rat model combining ovariectomy and simulated vaginal delivery. We hypothesized that the tissue changes caused by low hormone levels and mechanical stretch could complement each other. Thus, the combined model can potentially mimic the collagen metabolism of vaginal wall tissue as well as mechanical stretch properties to complement disease progression in POP. Ovariectomy with sequential simulated vaginal delivery was performed on rats in the modeling group. Sham surgeries were performed as control. At 2, 4, and 12 weeks after modeling, the vaginal tissues of rats were evaluated by Masson's trichrome staining, Picro-Sirius red staining, immunohistochemistry, western blotting, and uniaxial tensile tests. Compared to the control group, the vaginal tissues of the model rats showed an atrophic epithelial layer and loose collagen fibers. The smooth muscle fibers were ruptured, smaller in diameter, and disorganized. The ratio of collagen type I/III significantly increased, but the contents of both Collagen I and III decreased. The expression of metalloproteinases 2 and 9 in the tissues increased, and the expression of tissue inhibitors of metalloproteinases 1 and 2 decreased. The tangent modulus of the tissues was significantly increased in the model rats. We verified a novel method to establish a pelvic organ prolapse model in rats. This approach combined the advantages of low hormone levels and mechanical stretch effects.

Magnetic bead-based separation of sperm cells from semen-vaginal fluid mixed stains using an anti-ACRBP antibody.

Forensic DNA analysis of semen-vaginal fluid mixed stains is essential and necessary in sexual assault cases. Here, we used a magnetic bead conjugated acrosin binding protein (ACRBP) antibody to separate and enrich sperm cells from mixed stains. Previously, western blotting indicated that ACRBP was specifically expressed in sperm cells, but not in female blood and epithelial cells, while immunofluorescence data showed ACRBP was localized to the acrosome in sperm cells. In our study, sperm were separated from mixed samples at three sperm cell/female buccal epithelial cell ratios (103:103; 103:104; and 103:105) using a magnetic bead conjugated ACRBP antibody. Subsequently, 23 autosomal short tandem repeat (STR) loci were amplified using the Huaxia™ Platinum PCR Amplification System and genotyped using capillary electrophoresis. The genotyping success rate for STR loci was 90% when the sperm to female buccal epithelial cell ratio was > 1:100 in mixed samples. Our results suggest that the magnetic bead conjugated ACRBP antibody is effective for isolating sperm cells in sexual assault cases.

Discrimination of monozygotic twins using mtDNA heteroplasmy through probe capture enrichment and massively parallel sequencing.

Differentiating between monozygotic (MZ) twins remains difficult because they have the same genetic makeup. Applying the traditional STR genotyping approach cannot differentiate one from the other. Heteroplasmy refers to the presence of two or more different mtDNA copies within a single cell and this phenomenon is common in humans. The levels of heteroplasmy cannot change dramatically during transmission in the female germ line but increase or decrease during germ-line transmission and in somatic tissues during life. As massively parallel sequencing (MPS) technology has advanced, it has shown the extraordinary quantity of mtDNA heteroplasmy in humans. In this study, a probe hybridization technique was used to obtain mtDNA and then MPS was performed with an average sequencing depth of above 4000. The results showed us that all ten pairs of MZ twins were clearly differentiated with the minor heteroplasmy threshold at 1.0%, 0.5%, and 0.1%, respectively. Finally, we used a probe that targeted mtDNA to boost sequencing depth without interfering with nuclear DNA and this technique can be used in forensic genetics to differentiate the MZ twins.

Ischemic postconditioning protects against acute kidney injury after limb ischemia reperfusion by regulating HMGB1 release and autophagy.

Ischemic postconditioning (I-PostC) has a protective effect against acute kidney injury (AKI) induced by limb ischemia-reperfusion (LIR); however, the exact mechanism remains to be elucidated. Our study aims to investigate the potential involvement of high-mobility group box 1 protein (HMGB1) and autophagy in renoprotection generated by I-PostC. A rat model of LIR-induced AKI was established and rats were randomly assigned to five groups: (i) sham-operated control, (ii) I/R, (iii) I/R + I-PostC, (iv) I/R + I-PostC + rapamycin (autophagy activator), and (v) I/R + I-PostC + 3-methyladenine (autophagy inhibitor). Morphological changes in the kidneys were assessed by histology, and ultrastructural changes in renal tubular epithelial cells and glomerular podocytes were observed by transmission electron microscopy. The levels of kidney function parameters, serum inflammatory factors, and autophagy markers were detected. The results showed that the levels of HMGB1, Beclin1, LC3-II/LC3-I, and inflammatory cytokines (TNF-α and IL-6) were significantly higher in the I/R group compared to the sham control in serum and in renal tissues. I-PostC significantly reduced the levels of HMGB1, Beclin1, LC3-II/LC3-I, and inflammatory cytokines in renal tissues and improved renal function. Renal histopathology and ultrastructural observations indicated that I-PostC alleviated renal tissue injury. In addition, rapamycin (autophagy activator) treatment increased the levels of inflammatory cytokine expression levels and decreased renal function, reversed the protective effect of I-PostC against LIR-induced AKI. In conclusion, I-PostC could play a protective role against AKI by regulating the release of HMGB1 and inhibiting autophagy activation.

Delay between admission and surgery as a potential risk factor for postoperative morbidity and mortality in elderly patients with hip fractures: A retrospective study.

BACKGROUND: This study aimed to assess the impact of delay between admission and surgery on the postoperative outcomes such as mortality and related complications in elderly patients with acute hip fractures. METHODS: 840 patients aged ≥65 years from January 2009 to September 2015 were included in this retrospective study. According to the interval from admission to surgery, the patients were divided into four groups: group A (surgery within 24 h), group B (surgery within 24 h-48 h), group C (surgery within 48 h-72 h), and group D (surgery later than 72 h). Postoperative complications during hospitalization and mortality at different follow-up time points were compared. RESULTS: A total of 763 cases were successfully followed up, with an average follow-up time of 30.4 ± 13.1 months. The mean age of the patients was 79.4 ± 6.8 years. The difference in gross postoperative complications among groups was statistically significant in terms of pressure sore (P = 0.02), respiratory complications (P = 0.001), and urological complications (P < 0.001). The multivariate logistic regression analysis identified 3 factors independently associated with the postoperative morbidity, including age (odds ratio [OR] = 1.040), postoperative drainage volume (OR = 1.002) and time from admission to surgery (OR = 1.108). The difference in postoperative mortality among groups was statistically significant at 1 year (P = 0.046) after operation. The multivariate logistic regression analysis identified that age, postoperative drainage volume and time from admission to surgery were independently associated with mortality at 1 year postsurgery. CONCLUSION: The incidence of postoperative morbidity and mortality in elderly patients with hip fracture is usually the result of multiple factors, surgeons should pay attention to the patient's age, postoperative wound status and surgical delay time, which may significantly affect the outcome of the treatment.

Effect of implementing quality control management in the treatment of severely injured patients: a retrospective cohort study in a level I trauma center in China.

BACKGROUND: This study aimed to review the impact of quality control management on the treatment of severely injured patients. METHODS: A retrospective analysis was conducted on patients with severe injury (injury severity score [ISS] ≥ 16) between January 1, 2018 and February 1, 2020. The selected patients were stratified as follows. The patients who were admitted prior to the implementation of quality control management-from January 1 to December 31, 2018-were assigned to the PRE group; the POST group included patients who were admitted after the implementation-from February 1, 2019 to February 1, 2020. Quality control management was implemented from January 1, 2019 to January 31, 2019. Parameters were compared to account for differences in terms of demographics, surgical procedures, results of process quality, and 72-h mortality. RESULTS: This study included 599 patients (PRE group: 212 males and 86 females; POST group: 228 males and 73 females; P = 0.20). The extent of document completion was 97.3 and 100% in the PRE and POST groups, respectively (P < 0.001). There was no delay in the arrival of the trauma surgeons or the multidisciplinary team after implementation. However, following implementation of quality control management, there was a significant reduction in the duration of basic diagnostics, time until receipt of laboratory data, time until first computed tomography scan, time until intubation, and time until an emergency operation (P < 0.05). The deaths were caused by severe head injury (PRE: 5.4%, POST: 4%), hemorrhagic shock (PRE: 2.4%, POST: 0.7%), multiple-organ failure (PRE: 1.0%, POST: 0.3%), or other causes (PRE: 0.7%, POST: 0.0%). The 72-h mortality decreased after the implementation of quality control management (PRE vs. POST groups: 9.4 vs. 5.0%, P = 0.04). CONCLUSIONS: The implementation of quality control management resulted in decreased time to critical interventions, improved patient care efficiency, and reduced early mortality. We recommend that this approach be replicated at other trauma centers in China.

A cross-sectional study of mental health status and self-psychological adjustment in nurses who supported Wuhan for fighting against the COVID-19.

AIMS AND OBJECTIVES: To evaluate the mental health status, stressors and self-adjustment of nurses in isolation wards at different periods in Wuhan, China. BACKGROUND: Mental health issues easily occurred among the frontline medical workers of a major epidemic. However, the stressors and psychological adjustments experienced by nurses have not been well described. This is crucial to improving clinical quality and nursing safety and ensuring nurses' physical and psychological health. METHODS: We performed a cross-sectional prospective study using the Self Reporting Questionnaire-20, stressor and self-adjustment questionnaire administered to frontline nurses in Wuhan at two time points: after they had worked in isolation wards for 7-10 days (T1 ) and 2 months (T2 ). This paper complies with the STROBE reporting guideline for cross-sectional studies. RESULTS: T1 has 92 respondents, and T2 has 86. The positive rates of mental health problems were 26.09% and 9.30%, respectively, showing significantly different in the two periods. The main factors influenced mental health were self-perceived stress and only child status. The most common stressors were as follows: a large infected population, high infectivity; concerned about family's health status; high mortality if not treated in time (T1 ); and long duration of the epidemic, separate from family for a long time (T2 ). In terms of self-adjustment, 97.83%(T1 )/88.04%(T2 ) of nurses thought it was necessary, but 9(T1 ) /5(T2 ) chose to avoid addressing it, and 8(T1 ) /5(T2 ) utilised a professional psychological counselling hotline. CONCLUSIONS: Mental health problems among frontline nurses fighting COVID-19 need special attention, so administrators should offer timely counselling and strengthen effective psychosocial support to improve their mental resilience. RELEVANCE TO CLINICAL PRACTICE: This study surveyed the mental problems and self-adjustment status among nurses working Wuhan during the outbreak of COVID-19, to provide administrators with a scientific basis to effectively intervene.

In silico toxicity evaluation of dioxins using structure-activity relationship (SAR) and two-dimensional quantitative structure-activity relationship (2D-QSAR).

Prediction of pEC50 values of dioxins binding with the aryl hydrocarbon receptor (AhR) is of great significance for exploring how dioxins induce toxicity in human body and evaluating their environmental behaviors and risks. To reveal the factors that influence the toxicity of dioxins, provide more accurate mathematical models for predicting the pEC50 values of dioxins, and supplement the toxicity database of persistent organic pollutants, qualitative structure-activity relationship (SAR) and two-dimensional quantitative structure-activity relationship (2D-QSAR) were used in this study. The research objects in this study were 60 organic compounds with pEC50 values and 162 compounds without pEC50 values, which included polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polybrominated dibenzo-p-dioxins (PBDDs). The qualitative structure-activity relationship (SAR) was performed first and concluded that halogen substitutions at any of the 2, 3, 7, and 8 sites increased the pEC50 value of the compound. Moreover, two-dimensional quantitative structure-activity relationship (2D-QSAR) models were established by employing multiple linear regression (MLR) method and artificial neural network (ANN) algorithm to investigate the factors affecting the pEC50 values of dioxins molecules. MLR was used to establish the well-understood linear model and ANN was used to establish a more accurate non-linear model. Both models have good fitting, robustness, and predictive ability. Importantly, the ability of dioxins binding to AhR is mainly determined by molecular descriptors including E1m, SM09_AEA (dm), RDF065u, F05 [Cl-Cl], and Neoplastic-80. In addition, the pEC50 values of the 162 dioxins without toxicity data were predicted by MLR and ANN models, respectively.

Analyzing the distribution of rabies clinics and achievements of standardized rabies clinics implementation in mainland China.

BACKGROUND: For rabies prevention and treatment, the Chinese government has been establishing standardized rabies clinics since 2016. This study aimed to investigate the distribution of rabies clinics and the achievements of newly-implemented standardized rabies clinics in mainland China, for the purpose of providing further rabies control strategies. METHODS: The number of rabies clinics, including per million inhabitants in each region, was determined. We sampled 1200 clinics from 8 provinces by multi-stage stratified sampling, and a questionnaire survey was carried out to record each clinic's achievements. Data collected from 1185 questionnaires were analyzed. RESULTS: We found that rabies clinics were mostly located in the southwest, central, and eastern regions of China; these accounted for 67.1% of all clinics. The eastern and south regions showed the lowest number of rabies clinics per million inhabitants (0.15 and 0.12, respectively). The total standard-reaching rate of rabies clinics in mainland China was only 11.0%, with significant differences in the rate among regions (X2 = 33.004, p <  0.001). Specifically, the qualified rates of supporting facilities and functional areas were 13.9% (X2 = 34.003, p <  0.001) and 56.1% (X2 = 9.943, p = 0.019), respectively. Vaccines with 2 different substrates and professional flushing equipment were provided by 40.5% (X2 = 27.935, p = 0.001) and 37.7% (X2 = 54.922, p = 0.001) of clinics, respectively. CONCLUSION: Regional differences do exist in the distribution of rabies clinics in mainland China, with relative low number per million population in south and eastern China. There are few standardized rabies clinics in mainland China. Efforts are needed to establish supporting facilities, especially for wound treatment and vaccination. Future research should focus on the improvement of rabies clinics standardization.

Feasibility and Safety of a Cemented PEEK-on-PE Knee Replacement in a Goat Model: A Preliminary Study.

Polyether-ether-ketone (PEEK) is a potential alternative to metal alloys for use in the orthopedic implants; however, an in vivo study in an appropriate animal model is essential and has not yet been initiated. The aim of the present study was to gather some preliminary evidence regarding the performance and safety of a cemented PEEK-based knee replacement device in a goat model. Fifteen adult goats were randomly divided into two groups; the control group (n = 5), which received a sham operation, and the experimental group (n = 10), which received a total knee arthroplasty with a PEEK-based knee replacement device. The animals were sacrificed at 12 (control n = 5; experimental n = 5) or 24 weeks (experimental n = 5). Blood parameter measurements and radiographs of the knee joints were obtained. The synovium and main organs were removed and histologically assessed. The knee joints with the prosthesis were analyzed via micro-computed tomography and laser confocal microscopy. There was no occurrence of implant fracture or prosthesis sinking during the 24 weeks of radiological observations, except for one case of prosthesis dislocation at 4 weeks. There was a 6% decrease in femoral bone density (BD) at 12 weeks, but no further decrease by 24 weeks. No changes in BD were observed in the tibial ends. The bulk implant was biocompatible in terms of histological analysis of the local synovium and organs. There were no optical scratches on the surface of the retrieved components; the femoral component surface was rougher, while the tibial insert was smoother after 24 weeks. The novel PEEK-based knee replacement device in a goat model was feasible and safe; however, prior to use in humans, further studies concerning PEEK high load-bearing implant designs should be carried out to expand on our results.

Differences between native and prosthetic knees in terms of cross-sectional morphology of the femoral trochlea: a study based on three-dimensional models and virtual total knee arthroplasty.

BACKGROUND: The cross-sectional morphology of the prosthetic knee is crucial to understanding patellar motion and quadriceps strength after total knee arthroplasty. However, few comparative evaluations of the cross-sectional morphology of the femoral trochlea have been performed in the native knee and currently available femoral implants, and the relationship between the trochlear anatomy of prosthetic components and post-operative patellofemoral complications remains unclear. We aimed to investigate the differences in cross-sectional morphology of the femoral trochlea between native knees and prosthetic femoral components. METHODS: Virtual total knee arthroplasty was performed, whereby four different femoral components (medial-pivot, Triathlon, NRG and NexGen) were virtually superimposed onto three-dimensional models of 42 healthy femurs. The following morphological parameters were measured in three cross-sections (0, 45 and 90°) of the femoral trochlea: sulcus height, lateral tilt angle, medial tilt angle and sulcus angle. Only statistically significant differences are described further (p < 0.05). RESULTS: In the 0° cross-section, sulcus height was smaller in the native knee than in the Triathlon, NRG and NexGen components; all prosthetic components had smaller lateral tilt angles and larger medial tilt angles. In the 45° cross-section, sulcus height was larger in the native knee than in the medial-pivot, Triathlon and NexGen components; both lateral and medial tilt angles were smaller in the prosthetic components. In the 90° cross-section, sulcus height was smaller in the native knee than in the medial-pivot component; all prosthetic components had a larger lateral tilt angle and smaller medial tilt angle. In all cross-sections, the sulcus angle was smaller in the native knee. CONCLUSIONS: The discrepancy between native and prosthetic trochlear geometries suggests altered knee mechanics after total knee arthroplasty, but further cadaveric, computational or fluoroscopic investigations are necessary to clarify the implications of this observation. Our findings can be used to optimize biomechanical guidelines for total knee arthroplasty (patellar resurfacing or non-resurfacing) in Chinese individuals so as to decrease the risk of patellar lateral dislocation, to maintain stability and to optimize extensor kinematics.

Do size, shape, and alignment parameters of the femoral condyle affect the trochlear groove tracking? A morphometric study based on 3D- computed tomography models in Chinese people.

BACKGROUND: Our study aimed to investigate whether geometrical features (size, shape, or alignment parameters) of the femoral condyle affect the morphology of the trochlear groove. METHODS: Computed tomography models of 195 femurs (97 and 98 knees from male and female subjects, respectively) were reconstructed into three-dimensional models and categorised into four types of trochlear groove morphology based on the position of the turning point in relation to the mechanical axis (types 45°, 60°, 75°, and 90°). Only subjects with healthy knees were included, whereas individuals with previous knee trauma or knee pain, soft tissue injury, osteoarthritis, or other chronic diseases of the musculoskeletal system were excluded. The size parameters were: radius of the best-fit cylinder, anteroposterior dimension of the lateral condyles (AP), and distal mediolateral dimension (ML). The shape parameters were: aspect ratio (AP/ML), arc angle, and proximal- and distal- end angles. The alignment parameters were: knee valgus physiologic angle (KVPA), mechanical medial distal femoral angle (mMDFA), and hip-knee-ankle angle (HKA). All variables were measured in the femoral condyle models, and the means for each groove type were compared using one-way analysis of variance. RESULTS: No significant difference among groove types was observed regarding size parameters. There were significant differences when comparing type 45° with types 60°, 75°, and 90° regarding aspect ratio and distal-end angle (p < 0.05), but not regarding proximal-end angle. There were significant differences when comparing type 90° with types 45°, 60°, and 75° regarding KVPA, mMDFA, and HKA (p < 0.05). CONCLUSION: Among size, shape, and alignment parameters, the latter two exhibited partial influence on the morphology of the trochlear groove. Shape parameters affected the trochlear groove for trochlear type 45°, for which the femoral condyle was relatively flat, whereas alignment parameters affected the trochlear groove for trochlear type 90°, showing that knees in type 90° tend to be valgus. The morphometric analysis based on trochlear groove classification may be helpful for the future design of individualized prostheses.

Morphological classification of the femoral trochlear groove based on a quantitative measurement of computed tomographic models.

PURPOSE: This study aimed to investigate the natural morphology of the femoral trochlear groove based on quantitative measurement. METHODS: Computed tomographic femur models of 50 male and 50 female healthy Chinese adults (30-60 years) were analysed using three-dimensional software. Coaxial cutting planes (15° increments) rotating about the trochlear groove axis from the proximal to distal point were created, followed by the deepest point of the trochlear groove marked at each cross section. The shape, position, and orientation of the trochlear groove were analysed. RESULTS: The trochlear groove was located laterally relative to the mechanical axis and consisted of the laterally oriented proximal part and medially oriented distal part. Based on the turning points located on different cross sections, the trochlear groove was classified into four types: types 45°, 60°, 75°, and 90°. The mediolateral position relative to the mechanical axis was types 45°, 60°, 75°, and 90°, from the lateral to medial side, while the distal parts of them extended along the same path. The orientation of the trochlear groove was relatively consistent and smooth, which oriented at approximately 1° medially between two adjacent segments, except at approximately 10° medially at the turning point. CONCLUSION: The trochlear groove tracking varies greatly amongst a population that is mainly categorized into four types. This study may be helpful for better understanding of the natural trochlear groove anatomy, prosthetic design modification, and provide the reference value for studying patellofemoral diseases such as patellar maltracking and trochlear dysplasia. LEVEL OF EVIDENCE: Prospective study, Level II.

Landscape position influences microbial composition and function via redistribution of soil water across a watershed.

Subalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil microbial communities in a subalpine forest watershed in central Montana (Stringer Creek Watershed within the Tenderfoot Creek Experimental Forest) and to investigate their relationships with environmental conditions and soil carbonaceous gases. As assessed by tagged Illumina sequencing of the 16S rRNA gene, community composition and structure differed significantly among three landscape positions: high upland zones (HUZ), low upland zones (LUZ), and riparian zones (RZ). Soil depth effects on phylogenetic diversity and ß-diversity varied across landscape positions, being more evident in RZ than in HUZ. Mantel tests revealed significant correlations between microbial community assembly patterns and the soil environmental factors tested (water content, temperature, oxygen, and pH) and soil carbonaceous gases (carbon dioxide concentration and efflux and methane concentration). With one exception, methanogens were detected only in RZ soils. In contrast, methanotrophs were detected in all three landscape positions. Type I methanotrophs dominated RZ soils, while type II methanotrophs dominated LUZ and HUZ soils. The relative abundances of methanotroph populations correlated positively with soil water content (R = 0.72, P < 0.001) and negatively with soil oxygen (R = -0.53, P = 0.008). Our results suggest the coherence of soil microbial communities within and differences in communities between landscape positions in a subalpine forested watershed that reflect historical and contemporary environmental conditions.