Bone Mass,Bone Microstructure and Biomechanics in Patients with Hand Osteoarthritis

The impact of primary hand osteoarthritis (HOA) on bone mass, microstructure, and biomechanics in the affected skeletal regions is largely unknown. HOA patients and healthy controls (HCs) underwent high-resolution peripheral quantitative computed tomography (HR-pQCT). We measured total, trabecular, and cortical volumetric bone mineral densities (vBMDs), microstructural attributes, and performed micro–finite element analysis for bone strength. Failure load and scaled multivariate outcome matrices from distal radius and second metacarpal (MCP2) head measurements were analyzed using multiple linear regression adjusting for age, sex, and functional status and reported as adjusted Z-score differences for total and direct effects. A total of 105 subjects were included (76 HC: 46 women, 30 men; 29 HOA: 23 women, six men). After adjustment, HOA was associated with significant changes in the multivariate outcome matrix from the MCP2 head (p < .001) (explained by an increase in cortical vBMD (Δz = 1.07, p = .02) and reduction in the trabecular vBMD (Δz = −0.07, p = .09). Distal radius analysis did not show an overall effect of HOA; however, there was a gender-study group interaction (p = .044) explained by reduced trabecular vBMD in males (Δz = −1.23, p = .02). HOA was associated with lower failure load (−514 N; 95%CI, −1018 to −9; p = 0.05) apparent in males after adjustment for functional status. HOA is associated with reduced trabecular and increased cortical vBMD in the MCP2 head and a reduction in radial trabecular vBMD and bone strength in males. Further investigations of gender-specific changes of bone architecture in HOA are warranted. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.     

The angiotensin II type 1-receptor blocker candesartan increases cerebral blood flow, reduces infarct size, and improves neurologic outcome after transient cerebral ischemia in rats.

The goal of the present study was to test the impact of administration time of the angiotensin II type 1-receptor blocker candesartan on cerebral blood flow (CBF), infarct size, and neuroscore in transient cerebral ischemia. Therefore, 1-hour middle cerebral artery occlusion (MCAO) was followed by reperfusion. Rats received 0.5-mg/kg candesartan intravenously 2 hours before MCAO (pretreatment), 24 hours after MCAO, every 24 hours after MCAO, or 2 hours before and every 24 hours after MCAO. Infarct size (mm3) and a neuroscore at day 7 were compared with controls. CBF was quantified by radiolabeled microspheres and laser-Doppler flowmetry. Compared with controls (95 +/- 8), infarct size in candesartan-treated groups was smaller (59 +/- 5, 68 +/- 10, 28 +/- 3, and 15 +/- 3, respectively; P<0.05). Although there was no difference in neuroscore between pretreatment and controls (1.55 +/- 0.18, 1.80 +/- 0.13), other treatment regimens resulted in improved neuroscores (1.33 +/- 0.16, 1.11 +/- 0.11, 0.73 +/- 0.15; P<0.05). CBF in pretreated animals at 0.5 hours after MCAO was significantly higher than in controls (0.58 +/- 0.09 mL x g(-1) x min(-1) and 44% +/- 7% of baseline compared with 0.49 +/- 0.06 mL x g(-1) x min(-1) and 37% +/- 6%, microspheres and laser-Doppler flowmetry; P<0.05). Thus, candesartan reduces infarct size even if administered only during reperfusion. Apart from pretreatment, other treatment regimens result in significantly improved neuroscores. In the acute phase of cerebral ischemia, candesartan increases CBF.     

Abstracts of the contributed papers

Abstracts of the contributed papers     

实验性单纯疱疹性角膜炎的组织病理学研究

目的：动态观察1型单纯疱疹病毒（HSV－1）感染角膜后的组织病理改变。方法：BALB／c小鼠眼角膜接种HSV－1（KOS株）以诱发单纯疱疹性角膜炎（HSK）。分别收集正常眼球及感染后第2、7、14天的感染眼球，组织学观察结膜及角膜的病理过程。结果：感染后第2天，中性粒细胞、淋巴细胞及其他单核细胞浸润结膜并在第7－14天间快速向中央角膜扩散。结论：在HSK发展中，中性粒细胞浸润导致进行性的组织破坏。     

Histological and immunopathological analysis of T-cells mediating murine HSV-1 keratitis

Background: Thymusderived lymphocytes play a critical role in the development of herpes simplex keratitis (HSK). T-cell subsets defined by their expression of various T-cell receptor (TCR) Vß segments were studied following corneal HSV-1 infection (p.i.). Methods: Conjunctiva, corneal limbus and corneal stroma of two inbred BALB/c congenic mouse strains which differ only in the gene products closely linked to the Igh-1 locus on chromosome 12 were analyzed. Results: While C.B-17 mice (Igh-1^b) were resistant to HSK, C.AL-20 mice (Igh-1^d) clinically developed severe necrotizing keratitis by day 11 p.i. The corneal stroma of C.B-17 mice remained clear, while it was increasingly infiltrated by mononuclear cells and neutrophils in C.AL-20 mice by day 11 p.i. In C.B-17 mice, Thy1.2+ cells were found in the conjunctiva between days 2 to 4 p.i., and subsequently decreased. Only a few Thyl.2+ cells were found in the limbus, and no such cells were found in the stroma. In contrast, in C.AL-20 mice the numbers of Thyl.2+ cells (activated CD4+, Vß8+ T cells) profoundly increased in the conjunctiva by day 4 p.i. These cells infiltrated the limbus between days 7 and 11 p.i. and eventually entered the stromal tissue by day 11 p.i. Conclusions: Our data suggest that the HSV-1-induced corneal tissue destruction is mediated by mononuclear cells and neutrophils and that these cells are probably attracted into the cornea by cytokines elaborated by activated CD4+, Vß8+ T cells.Presented as a paper at the ECORA Meeting, 4–7 October 1993, Bonn     

Early and sustained haemodynamic improvement with levosimendan compared to intraaortic balloon counterpulsation (IABP) in cardiogenic shock complicating acute myocardial infarction

OBJECTIVE: To investigate the haemodynamic effects of levosimendan in patients with cardiogenic shock (CS) complicating acute myocardial infarction in comparison to the effects of intra-aortic balloon counterpulsation (IABP). METHODS: 10 patients with intractable CS under standard therapy (including the use of PCI, inotropes, and vasopressors) received i.v. infusion of levosimendan (bolus 12 microg/kg i.v., followed by continuous infusion 0.1 microg/kg/min for 24 h). Haemodynamic effects were compared to the effects of IABP-placement added to standard care in 12 patients with CS. RESULTS: Within 24 h, both levosimendan and IABP produced a significant increase in cardiac index (CI) and cardiac power index and a decrease in systemic vascular resistance (SVR) (CI [l/min/m2] baseline 1.97+/-0.15, at 24 h 2.82+/-0.22 for levosimendan; baseline 1.98+/-0.17, at 24 h 2.66+/-0.08 for IABP; SVR [dyn*s*cm-5] baseline 1353+/-106, at 24 h 846+/-69 for levosimendan; baseline 1311+/-214, at 24 h 853+/-63 for IABP, respectively). After 3 h of treatment, CI and SVR had significantly improved in patients treated with levosimendan but not in the IABP-group (CI [l/min/m2] at 3 h 2.72+/-0.28 (+38%) for levosimendan versus 2.18+/-0.15 (+10%) for IABP). CONCLUSION: Infusion of levosimendan in acute CS results in early and sustained haemodynamic improvement. Short-term haemodynamic effects compare favourably with those seen after invasive IABP placement.     

A fluorescent probe designed for studying protein conformational change

The usefulness of fluorescence in studying protein motions derives from its sensitivity, kinetic resolution, and compatibility with both live cells and physiological assays. Recent advances in microscopy and membrane protein purification have permitted the observation of fluorescence changes that accompany the functional transitions of complex eukaryotic membrane proteins. These techniques rely on probes that can clearly report the environmental changes of specific residues, but most commonly available side-chain-reactive probes are not well suited for this purpose. Here, we introduce a red Cys-reactive probe, aminophenoxazone maleimide (APM), designed with improved chemical and spectral properties for reporting protein conformational change. APM is compact, uncharged, and has a short linker between probe and protein, all of which ensure that it can closely track the motions of the side chain to which it is attached. It undergoes large polarity-dependent changes in Stokes shift, as well as large bathochromic shifts in both excitation maximum (from 521 nm in toluene to 598 nm in water) and emission maximum (580 nm to 633 nm). These polarity-dependent spectral changes offer a potentially simple means of relating fluorescence to local structure and motion, although they are partially offset by some complicating factors in APM fluorescence. We find that, like a rhodamine maleimide, APM senses the conformational changes underlying voltage sensing in the Shaker potassium channel, and it is superior at a site that shows limited reactivity to the rhodamine. The spectral characteristics of APM can also report subtle differences between aqueous positions in purified preparations of the beta2 adrenergic receptor.