Predictive factors for infection after osteosynthesis of tibial plateau fractures: a retrospective study of 314 patients.

INTRODUCTION: The reported incidence of infection related with tibial plateau fractures (IRTPF) ranges from 2 to 23%. This complication can result in catastrophic consequences such as deformity, post-traumatic osteoarthritis, chronic pain, loss of function, and substantial economic burdens on healthcare systems due to extended hospital stays and the resources required for treatment. Consequently, it is imperative to emphasize the identification of infection risk factors. METHODS: A retrospective case-control study was designed, encompassing patients who underwent surgery for tibial plateau fractures between 2015 and 2020. Frequencies and measures of central tendency were compared between infected patients (cases) and non-infected patients (controls) using rank-based statistical tests. Subsequently, two logistic regression models were employed to control for potential confounding variables. RESULTS: A total of 314 patients were included, predominantly male (71.15%). Average age of 44.41 years. IRTPF were observed in 7.64% of the patients. In the univariate inferential statistical analysis, high-energy fractures (OR 6.35, p < 0.001), fractures with compartment syndrome (OR 7.10, p < 0.001), two-stage management with temporary external fixation (OR 8.18, p < 0.001), the use of 2 or more approaches in definitive surgery (OR 2.93, p = 0.011), and the use of two or more plates (OR 9.17, p < 0.001) were identified as risk factors for infection. On average, the duration of surgery in infected patients was 201.2 min, compared to 148.4 min in non-infected patients (p < 0.001). When performing two logistic regression models, the following independent risk factors were identified: high-energy fractures (OR 5.04, p = 0.012), the presence of compartment syndrome (OR 4.53, p = 0.007), and the use of two or more plates in definitive surgery (OR 5.04, p = 0.023). CONCLUSIONS: High-energy tibial plateau fractures (Schatzker IV, V, and VI), the presence of concomitant compartment syndrome, and the use of 2 or more plates in definitive surgery are associated with a higher risk of infection related to fracture following open reduction and osteosynthesis treatment. LEVEL OF EVIDENCE: Case-Control Study.

Characteristics and health burden of the undiagnosed population at risk of chronic obstructive pulmonary disease in China.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality in China. However, identifying patients has proved challenging, resulting in widespread under-diagnosis of the condition. We examined the prevalence of COPD diagnosis and COPD risk among adults in urban mainland China, the factors associated with having a COPD diagnosis or COPD risk, and the healthcare resource use and health outcomes of these groups compared with controls. METHODS: Respondents to the 2017 National Health and Wellness Survey in China (n = 19,994) were classified into three groups: 'COPD Diagnosed', 'COPD Risk (undiagnosed)', and Control (unaffected), based on their self-reported diagnosis and Lung Function Questionnaire (LFQ) score. The groups were characterised by sociodemographic, health-related quality of life (HRQoL), productivity impairment, and healthcare resource use. Pairwise comparisons (t tests and chi-squared tests) and multivariable regression analyses were used to investigate factors associated with being at risk of, or diagnosed with, COPD. RESULTS: 3320 (16.6%) respondents had a suspected risk of COPD but did not report receiving a diagnosis. This was projected to 105.3 million people, or 16.9% of adult urban Chinese. Of these respondents with an identified risk, only 554 (16.7%) were aware of COPD by name. Relative to those without COPD, those with a risk of COPD (undiagnosed) had significantly greater healthcare resource use, lower productivity and lower HRQoL not only compared to those without COPD, but also compared to people with a COPD diagnosis. Factors associated with increased odds of being at risk of COPD were older age, smoking, alcohol consumption, overweight BMI, occasional exercise, higher comorbidities, asthma diagnosis, being female, lower education, not being employed, and living in a high pollution province (p < 0.05). CONCLUSIONS: There is a substantial group of individuals, undiagnosed, but living with a risk of COPD, who have impaired HRQoL, lower productivity and elevated healthcare resource use patterns. Case-detection tools such as the LFQ may prove a quick and cost-effective approach for identifying these at-risk individuals for further definitive testing and appropriate treatment in China.

Macrophages protect against loss of adipose tissue during cancer cachexia.

BACKGROUND: Cancer cachexia represents a central obstacle in medical oncology as it is associated with poor therapy response and reduced overall survival. Systemic inflammation is considered to be a key driver of cancer cachexia; however, clinical studies with anti-inflammatory drugs failed to show distinct cachexia-inhibiting effects. To address this contradiction, we investigated the functional importance of innate immune cells for hepatocellular carcinoma (HCC)-associated cachexia. METHODS: A transgenic HCC mouse model was intercrossed with mice harbouring a defect in myeloid cell-mediated inflammation. Body composition of mice was analysed via nuclear magnetic resonance spectroscopy and microcomputed tomography. Quantitative PCR was used to determine adipose tissue browning and polarization of adipose tissue macrophages. The activation state of distinct areas of the hypothalamus was analysed via immunofluorescence. Multispectral immunofluorescence imaging and immunoblot were applied to characterize sympathetic neurons and macrophages in visceral adipose tissue. Quantification of pro-inflammatory cytokines in mouse serum was performed with a multiplex immunoassay. Visceral adipose tissue of HCC patients was quantified via the L3 index of computed tomography scans obtained during routine clinical care. RESULTS: We identified robust cachexia in the HCC mouse model as evidenced by a marked loss of visceral fat and lean mass. Computed tomography-based analyses demonstrated that a subgroup of human HCC patients displays reduced visceral fat mass, complementing the murine data. While the myeloid cell-mediated inflammation defect resulted in reduced expression of pro-inflammatory cytokines in the serum of HCC-bearing mice, this unexpectedly did not translate into diminished but rather enhanced cachexia-associated fat loss. Defective myeloid cell-mediated inflammation was associated with decreased macrophage abundance in visceral adipose tissue, suggesting a role for local macrophages in the regulation of cancer-induced fat loss. CONCLUSIONS: Myeloid cell-mediated inflammation displays a rather unexpected beneficial function in a murine HCC model. These results demonstrate that immune cells are capable of protecting the host against cancer-induced tissue wasting, adding a further layer of complexity to the pathogenesis of cachexia and providing a potential explanation for the contradictory results of clinical studies with anti-inflammatory drugs.

Endocannabinoids in Body Weight Control.

Maintenance of body weight is fundamental to maintain one's health and to promote longevity. Nevertheless, it appears that the global obesity epidemic is still constantly increasing. Endocannabinoids (eCBs) are lipid messengers that are involved in overall body weight control by interfering with manifold central and peripheral regulatory circuits that orchestrate energy homeostasis. Initially, blocking of eCB signaling by first generation cannabinoid type 1 receptor (CB1) inverse agonists such as rimonabant revealed body weight-reducing effects in laboratory animals and men. Unfortunately, rimonabant also induced severe psychiatric side effects. At this point, it became clear that future cannabinoid research has to decipher more precisely the underlying central and peripheral mechanisms behind eCB-driven control of feeding behavior and whole body energy metabolism. Here, we will summarize the most recent advances in understanding how central eCBs interfere with circuits in the brain that control food intake and energy expenditure. Next, we will focus on how peripheral eCBs affect food digestion, nutrient transformation and energy expenditure by interfering with signaling cascades in the gastrointestinal tract, liver, pancreas, fat depots and endocrine glands. To finally outline the safe future potential of cannabinoids as medicines, our overall goal is to address the molecular, cellular and pharmacological logic behind central and peripheral eCB-mediated body weight control, and to figure out how these precise mechanistic insights are currently transferred into the development of next generation cannabinoid medicines displaying clearly improved safety profiles, such as significantly reduced side effects.

Cannabinoid Receptor Signaling in Central Regulation of Feeding Behavior: A Mini-Review.

Cannabinoids are lipid messengers that modulate a variety of physiological processes and modify the generation of specific behaviors. In this regard, the cannabinoid receptor type 1 (CB1) represents the most relevant target molecule of cannabinoids so far. One main function of central CB1 signaling is to maintain whole body energy homeostasis. Thus, cannabinoids functionally interact with classical neurotransmitters in neural networks that control energy metabolism and feeding behavior. The promotion of CB1 signaling can increase appetite and stimulate feeding, while blockade of CB1 suppresses hunger and induces hypophagia. However, in order to treat overeating, pharmacological blockade of CB1 by the inverse agonist rimonabant not only suppressed feeding but also resulted in psychiatric side effects. Therefore, research within the last decade focused on deciphering the underlying cellular and molecular mechanisms of central cannabinoid signaling that control feeding and other behaviors, with the overall aim still being the identification of specific targets to develop safe pharmacological interventions for the treatment of obesity. Today, many studies unraveled the subcellular localization of CB1 and the function of cannabinoids in neurons and glial cells within circumscribed brain regions that represent integral parts of neural circuitries controlling feeding behavior. Here, these novel experimental findings will be summarized and recent advances in understanding the mechanisms of CB1-dependent cannabinoid signaling being relevant for central regulation of feeding behavior will be highlighted. Finally, presumed alternative pathways of cannabinoids that are not driven by CB1 activation but also contributing to control of feeding behavior will be introduced.

Expression and functional relevance of cannabinoid receptor 1 in Hodgkin lymphoma.

BACKGROUND: Cannabinoid receptor 1 (CB1) is expressed in certain types of malignancies. An analysis of CB1 expression and function in Hodgkin lymphoma (HL), one of the most frequent lymphomas, was not performed to date. DESIGN AND METHODS: We examined the distribution of CB1 protein in primary cases of HL. Using lymphoma derived cell lines, the role of CB1 signaling on cell survival was investigated. RESULTS: A predominant expression of CB1 was found in Hodgkin-Reed-Sternberg cells in a vast majority of classical HL cases. The HL cell lines L428, L540 and KM-H2 showed strong CB1-abundance and displayed a dose-dependent decline of viability under CB1 inhibition with AM251. Further, application of AM251 led to decrease of constitutively active NFκB/p65, a crucial survival factor of HRS-cells, and was followed by elevation of apoptotic markers in HL cells. CONCLUSIONS: The present study identifies CB1 as a feature of HL, which might serve as a potential selective target in the treatment of Hodgkin lymphoma.

Antibodies to cannabinoid type 1 receptor co-react with stomatin-like protein 2 in mouse brain mitochondria.

Anti-cannabinoid type 1 receptor (CB1 ) polyclonal antibodies are widely used to detect the presence of CB1 in a variety of brain cells and their organelles, including neuronal mitochondria. Surprisingly, we found that anti-CB1 sera, in parallel with CB1 , also recognize the mitochondrial protein stomatin-like protein 2. In addition, we show that the previously reported effect of synthetic cannabinoid WIN 55,212-2 on mitochondrial complex III respiration is not detectable in purified mitochondrial preparations. Thus, our study indicates that a direct relationship between endocannabinoid signaling and mitochondrial functions in the cerebral cortex seems unlikely, and that caution should be taken interpreting findings obtained using anti-CB1 antibodies.

Cannabinoids attenuate norepinephrine-induced melatonin biosynthesis in the rat pineal gland by reducing arylalkylamine N-acetyltransferase activity without involvement of cannabinoid receptors.

Cannabinoids modulate neuronal and neuroendocrine circuits by binding to cannabinoid receptors acting upon cAMP/Ca(2+)-mediated intracellular signaling cascades. The rat pineal represents an established model to investigate intracellular signaling processes because a well defined input, the neurotransmitter norepinephrine, is transformed via cAMP/Ca(2+)-dependent mechanisms into an easily detectable output signal, the biosynthesis of melatonin. Here we investigated the impact of cannabinoids on norepinephrine-regulated melatonin biosynthesis in the rat pineal. We demonstrated that treatment of cultured rat pineals with 9-carboxy-11-nor-delta-9-tetrahydrocannabinol (THC), cannabidiol or cannabinol significantly reduced norepinephrine-induced arylalkylamine N-acetyltransferase (AANAT) activity and melatonin biosynthesis. These effects were not mimicked by the cannabinoid receptor agonist WIN55,212-2 and were not blocked by cannabinoid 1 and 2 receptor antagonists. The cannabinoids used did not affect norepinephrine-induced increases in cAMP/Ca(2+) levels. Notably, cannabinoids were found to directly inhibit AANAT activity in lysates of the pineal gland. This effect was specific in so far as cannabinoids did not influence the activity of hydroxyindole-O-methyltransferase (HIOMT), the last enzyme in melatonin biosynthesis. Taken together, our data strongly suggest that cannabinoids inhibit AANAT activity and attenuate melatonin biosynthesis through intracellular actions without involvement of classical cannabinoid receptor-dependent signaling cascades.