Females with knee osteoarthritis use a detrimental knee loading strategy when squatting

BackgroundThe purpose of this study was to identify sex differences in lower limb kinematics, kinetics, and muscle activation patterns between individuals with osteoarthritis and healthy controls during a two-legged squat.MethodThirty OA (15 females) and 30 healthy (15 females) participants performed three 2-legged squats. Sagittal and frontal plane hip, knee, and ankle kinematics and kinetics were calculated. Two-way ANOVAs (Sex X OA Status) were used to characterize differences in squatting strategies between sexes and between those with and without knee OA.ResultsA greater decrease in sagittal hip, knee, and ankle range of motion and knee joint power was observed in the OA participants compared to the healthy controls. Females with OA had significantly reduced hip and knee adduction angles compared to the healthy females and males with OA. Females also had decreased hip power, hip flexion, and hip adduction moments and knee adduction moments compared to their male counterparts, with the greatest deficits observed in the females with OA. Females with OA also had the highest magnitude of muscle activation for the quadriceps, hamstrings, and gastrocnemius throughout the squat, while males with OA showed increased activation of the vastus lateralis and medial gastrocnemius compared to the healthy males.ConclusionsOA significantly altered biomechanics and neuromuscular control during the squat, with males employing a hip-dominant strategy, allowing them to achieve a greater lower limb range of motion.     

An individual scoring system for the prediction of postpartum anaemia

Background

Postpartum anaemia (PPA) is a common postpartum complication. The goal of this study was to prospectively construct a predictive score for individual risk of PPA.

Patients et method

We prospectively analyzed factors associated with PPA (< 10 g dL⁻¹ at 48 hours postpartum). Parameters analyzed were demographic data, pregnancy characteristics, delivery and postpartum characteristics. Univariate analysis was performed using Anova or X²; the Cox model was used for multivariate analysis. The scoring system was validated using ROC curve.

Results

Analysis was performed in 475 patients and validation was carried using an additional 95 patients. Multivariate analysis found four factors independently associated with PPA: anaemia during the third trimester of the pregnancy, Southeast Asian ethnic origin, episiotomy and severe postpartum haemorrhage (PPH) identified by the use of sulprostone. According to the score derived from the Cox model, patients were classified as low (22%, score = 0), medium (55%, score = 2 or 3) and high (86%, score > 3) probability of PPA. Using the AUC of the ROC curve for both the first and the validation cohorts (performed on 95 further patients), we recorded AUCs of 72% and 70% respectively.

Conclusions

This study allowed the derivation and validation of a predictive score of PPA. This score might be useful in targeting prophylactic strategies for PPA. Such strategies could include a more active treatment of iron deficiency (increasing oral iron treatment observance or intravenous iron therapy) especially in exposed population, improvement in the prevention and treatment of postpartum haemorrhage and decreasing the use of episiotomy. Future studies must focus on the external validation and generalisation of this scoring system.     

Glucose Content and Efficiency of Glycolysis in Protected Ischemic Kidneys of Different Species

In ischemic canine kidneys protected by Bretschneider's HTK solution the glycolytic lactate production is limited by a low renal substrate content. However, for anaerobic energy supply ischemic organs depend on glycolysis. To evaluate the role of glycolysis in renal protection, the relationship between lactate production and anaerobic energy supply was examined in protected kidneys of dogs, sheep, and swine. Additionally, in canine kidneys an attempt was made to improve anaerobic energy provision by adding glucose to the protective solution. The results were as follows: (1) According to increasing lactate production from swine to dog to sheep, intraischemic ATP decay was delayed least in swine and most in sheep. (2) Glucose addition (10 mM) to the HTK solution roughly doubled the time for ATP to fall to 1 μmollg dry wt (t_Atp) in dogs. (3) The greater the lactate production in all three species, the lower the decrease in SAN (ATP + ADP + AMP) from 5 to 120 min of ischemia. (4) A glucose additive in the protective solution led to a significant (p >. 005) increase of SAN in dogs at 120 min of ischemia. A sufficient substrate supply seems to be an essential component of a reliable renal protection.     

Experimental hypersensitivity pneumonitis: role of MCP-1

Inhalation of Saccharopolyspora rectivirgula causes "farmer's lung" disease, a classic example of hypersensitivity pneumonitis (HP). Monocyte chemoattractant protein-1 (MCP-1) is increased in the bronchoalveolar lavage fluid of mice challenged with S rectivirgula, and S rectivirgula induces MCP-1 secretion by alveolar macrophages. We tested the hypothesis that MCP-1 and its receptor CC chemokine receptor-2 (CCR2) are essential to the development of experimental HP by treating mice with MCP-1 antibody and using CCR2(-/-) mice. Administration of anti-MCP-1 did not change the response to intratracheally administered S rectivirgula. CCR2(-/-) animals responded in a fashion similar to that of wild-type animals to intratracheally administered.S rectivirgula. To determine the influence of the MCP-1-CCR2 interaction in vitro, we transferred S rectivirgula-cultured spleen cells from S rectivirgula-sensitized mice, to na?ve recipients. Later, challenge of the recipients with intratracheal S rectivirgula and examination of both lung histology and bronchoalveolar lavage fluid characteristics were used to determine whether adoptive transfer had occurred. We found that cultured cells from CCR2(-/-) animals were fully capable of adoptive transfer. We conclude that interaction of MCP-1 with CCR2 is not necessary for the development of pulmonary inflammation in response to intratracheally administered S rectivirgula or cells able to adoptively transfer experimental HP.     

Nonalcoholic fatty liver disease shows significant sex dimorphism

Nonalcoholic fatty liver disease (NAFLD), which has been renamed metabolic dysfunction-associated fatty liver disease, is a growing global medical problem. The incidence of NAFLD and its associated end-stage liver disease is increasing each year, and many research advancements have been achieved to date. This review focuses on the current knowledge of the sex differences in NAFLD and does not elaborate on areas without differences. Studies have revealed significant sex differences in the prevalence, influencing factors, pathophysiology, complications and therapies of NAFLD. Men have a higher incidence than women. Compared with women, men exhibit increased visceral fat deposition, are more susceptible to leptin resistance, lack estrogen receptors, and tend to synthesize fatty acids into fat storage. Male patients will experience more severe hepatic fibrosis and a higher incidence of liver cancer. However, once NAFLD occurs, women show a faster progression of liver fibrosis, higher levels of liver cell damage and inflammation and are less likely to undergo liver transplantation than men. In general, men have more risk factors and more severe pathophysiological reactions than women, whereas the development of NAFLD is faster in women, and the treatments for women are more limited than those for men. Thus, whether sex differences should be considered in the individualized prevention and treatment of NAFLD in the future is worth considering.     

Neonatal Injury Results in Sex-Dependent Nociceptive Hypersensitivity and Social Behavioral Deficits During Adolescence,Without Altering Morphine Response

Neonatal injury is associated with persistent changes in sensory function and altered nociceptive thresholds that give rise to aberrant pain sensitivity in later life. Although these changes are well documented in adult rodents, little is known about the consequences of neonatal injury during adolescence. Because adolescence is a critical developmental period during which persistent pain conditions can arise, we examined the effect of neonatal injury on nociception, social behavior, and response to morphine in adolescent Sprague Dawley rats. Male and female rats exposed to plantar incision injury at postnatal day 3 displayed mechanical hypersensitivity that resolved by 24 hours after incision. When these animals reached adolescence (postnatal day 28–40), neonatally-injured male rats showed ipsilaterally restricted mechanical, heat, and cold hypersensitivity, as well as social behavioral deficits. In contrast, these effects were not seen in female rats. Neonatal injury did not alter acute morphine antinociception or the development of analgesic tolerance in either sex. Morphine-induced conditioned place preference, behavioral sensitization, and physical withdrawal were also not affected by neonatal incision. Thus, early-life injury results in sex-dependent pain-related hypersensitivity and social behavior deficits during adolescence, without altering the response to opioids.

Analysis of nociception, sex and peripheral nerve innervation in the TMEV animal model of multiple sclerosis

Although pain was previously not considered an important element of multiple sclerosis (MS), recent evidence indicates that over 50% of MS patients suffer from chronic pain. In the present study, we utilized the Theiler's murine encephalomyelitis virus (TMEV) model of MS to examine whether changes in nociception occur during disease progression and to investigate whether sex influences the development of nociception or disease-associated neurological symptoms. Using the rotarod assay, TMEV infected male mice displayed increased neurological deficits when compared to TMEV infected female mice, which mimics what is observed in human MS. While both male and female TMEV infected mice exhibited thermal hyperalgesia and mechanical allodynia, female mice developed mechanical allodynia at a faster rate and displayed significantly more mechanical allodynia than male mice. Since neuropathic symptoms have been described in MS patients, we quantified sensory nerve fibers in the epidermis of TMEV-infected and non-infected mice to determine if there were alterations in epidermal nerve density. There was a significantly higher density of PGP9.5 and CGRP-immunoreactive axons in the epidermis of TMEV-infected mice versus controls. Collectively these results indicate that the TMEV model is well suited to study the mechanisms of MS-induced nociception and suggest that alterations in peripheral nerve innervation may contribute to MS pain.     

HPLC法测定感冒清热颗粒中欧前胡素含量

目的建立HPLC法测定感冒清热颗粒中欧前胡素含量的方法,同时对6家不同企业生产的产品进行质量比对。方法采用HPLC法欧前胡素含量测定条件：色谱柱：Diamonsil（R）C18（250 mm×4.6 mm,5μm）,流动相：乙腈-水（49.5∶50.5）,检测波长：300 nm,流速：1.0 ml·min-1。,柱温：35℃;葛根素含量测定方法参照《中国药典》。结果欧前胡素线性范围为0.2955～11.82μg·ml-1（r=0.9999）,平均回收率为99.47%,RSD为0.69%（n=6）;不同企业生产的产品质量有差异,葛根素的含量以每袋计为12.20～24.00 mg。结论 HPLC测定欧前胡素的方法简便,准确,重复性好,可有效控制该制剂的质量。     

The neurobiology of the emotional adolescent: From the inside out

Adolescents are commonly portrayed as highly emotional, with their behaviors often hijacked by their emotions. Research on the neural substrates of adolescent affective behavior is beginning to paint a more nuanced picture of how neurodevelopmental changes in brain function influence affective behavior, and how these influences are modulated by external factors in the environment. Recent neurodevelopmental models suggest that the brain is designed to promote emotion regulation, learning, and affiliation across development, and that affective behavior reciprocally interacts with age-specific social demands and different social contexts. In this review, we discuss current findings on neurobiological mechanisms of adolescents’ affective behavior and highlight individual differences in and social-contextual influences on adolescents’ emotionality. Neurobiological mechanisms of affective processes related to anxiety and depression are also discussed as examples. As the field progresses, it will be critical to test new hypotheses generated from the foundational empirical and conceptual work and to focus on identifying more precisely how and when neural networks change in ways that promote or thwart adaptive affective behavior during adolescence.