Nitric oxide mediates the inhibition of neutrophil migration induced by systemic administration of LPS

To investigate the role of NO in the inhibition of neutrophil migration by circulating endotoxin, mice were pretreated with NO synthase inhibitors or with a free radical scavenger (D-penicillamine), before intravenous LPS injection. LPS dose-dependently inhibited the thioglycollate-induced neutrophil migration into the peritoneal cavities. Aminoguanidine, a selective inducible NO synthase inhibitor, abolished the inhibition of neutrophil migration and the increase in serum nitrate levels induced by a nonlethal dose of LPS. During lethal endotoxemia aminoguanidine partially abolished the neutrophil migration inhibition. Additionally, D-penicillamine prevented the inhibition of neutrophil migration caused by LPS. However, Nitro-L-Arginine, a selective constitutive NO synthase inhibitor, did not prevent neutrophil migration inhibition. Aminoguanidine treatment did not affect the systemic increased levels of TNF-, IL-1, and IL-10, suggesting that NO is the final mediator involved in the inhibition of neutrophil migration. Our results suggest that NO released by the inducible NO synthase mediates the inhibition of neutrophil migration mediated by circulating LPS.     

Immunologic events in pigeon breeders'' disease

The immunologic and physiologic status of a group of symptomatic and asymptomatic pigeon breeders was studied in an attempt to define the immunologic events occurring in pigeon breeders' disease. Antibody activity to antigen(s) present in pigeon dropping extract (PDE) and pigeon serum (PS) was detected in the serum of both symptomatic and asymptomatic breeders. Antibody activity, however, tended to be greater in the symptomatic pigeon breeders. When subjects were challenged with PS via aerosol, serum complement activity became depressed only in asymptomatic patients. Cellular hypersensitivity to antigens present in PDE was detected in vitro in peripheral lymphocyte populations of 4 of 5 symptomatic breeders and in none of the asymptomatic breeders; cellular hypersensitivity to antigens in PS was not demonstrated in any of the individuals tested. These findings indicate that cell-mediated hypersensitivity, as well as humoral immunologic processes, may be involved in the pathogenesis of the hypersensitivity pneumonitis found in pigeon breeders.     

Chemical Characterization of Macrophage Cytotoxicity Factor,Macrophage Migration Inhibitory Factor,T-Helper Cell-Replacing Factor and Colony-Stimulating Factor from Culture Supernatants of Concanavalin A-Stimulated Murine Spleen Cells

Supernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins. Chromatography of pools containing MCF, MIF and TRF on Sephadex did not lead to a separation of the three activities which were all found in a molecular weight range of 25.000-55.000. Isoelectric focusing of these pools in pH range from 4 to 9 gave two peaks for MCF at pH 8.2 and 7.2, whereas MIF activity focused from pH 4.5 to 5.5. TRF activity was found in a single sharp peak at pH 5.3. The results demonstrate that the four biological activities can be distinguished on a chemical basis and are accessible for purification and chemical characterization.     

Undocumented Migrants Reintroducing COVID-19, Yunnan Province,China

To limit the spread of severe acute respiratory syndrome coronavirus 2, the government of China has been monitoring infected travelers and minimizing cold-chain contamination. However, other factors might contribute to recurring outbreaks. We analyze the role of undocumented migrants as potential transmitters of severe acute respiratory syndrome coronavirus 2 in China.     

Migration Patterns for Revision Total Hip Arthroplasty in the United States as Reported in the American Joint Replacement Registry

BackgroundRevision total hip arthroplasty (revTHA) is associated with higher rates of complications and greater costs than primary procedures. The aim of this study is to evaluate the effect of hospital size, teaching status, and indication for revTHA, on migration patterns in patients older than 65 years old.MethodsAll THAs and revTHAs reported to the American Joint Replacement Registry from 2012 to 2018 were included and merged with the Centers for Medicare and Medicaid Services database. Migration rate was defined as a patient’s THA and revTHA procedures that were performed at separate institutions by different surgeons. Migratory patterns were recorded based on hospital size, teaching status, and indication for revTHA. Analyses were performed by statisticians.ResultsThe number of linked procedures included was 11,906. Migration rates in revTHA due to infection were higher for small hospitals than large hospitals (46.6% vs 28.6%, P < .0001). Migration rates were higher comparing non-teaching with teaching hospitals (55% vs 34%, P < .0001). This difference was significant for periprosthetic fractures (70.6% vs 37.2%, P = .005), instability (56.5% vs 35.5%, P = .04), and mechanical complications (88.9% vs 34.7%, P < .05). Most patients migrated to medium or large hospitals rather than small hospitals (89% vs 11%, P < .0001) and to teaching rather than non-teaching institutions (82% vs 18%, P < .0001).ConclusionHospital size and teaching status significantly affected migration patterns for revTHA. Migration rates were significantly higher in small non-teaching hospitals in revTHA due to infection, periprosthetic fracture, instability, and mechanical complications. Over 80% of patients migrated to larger teaching hospitals.     

镰刀菌对太子参品质影响及DON毒素在其煎煮过程中迁移规律研究

目的:探究镰刀菌对太子参品质的影响和太子参中脱氧雪腐镰刀菌烯醇(DON)毒素在其煎煮过程中的迁移规律。方法:采用反式培养法,探讨镰刀菌侵染太子参后DON毒素积累变化及对太子参质量的影响,计算水煎煮后汤液DON毒素的迁移率。结果:受镰刀菌侵染后,太子参表面会形成1层白色菌丝和黑色沉积物,DON毒素在太子参中随时间推移显著增加;受镰刀菌侵染的太子参中总皂苷和多糖含量分别为对照组的1.5、2.0倍,而太子参环肽B含量显著降低。镰刀菌侵染太子参20 d后,DON毒素质量分数达到45.40μg·kg–1,DON毒素煎煮后转移率为12.50%~27.90%。结论:研究结果为制定中药材DON毒素限量标准及临床安全用药提供了参考。     

Early postoperative colonic ventriculoperitoneal shunt migration with trans-anal protrusion: A unique case report

Introduction and importanceColonic ventriculoperitoneal shunt (VPS) migration with trans-anal protrusion remains uncommon. Patients may be asymptomatic, and diagnosis may only be made on visualization of the prolapsed catheter from the anus. This unique case of early post-operative trans-anal shunt protrusion highlight the possibility of this rare complication specially when shunt revision accompanies bowel surgery.Case presentationThe authors present a case of early postoperative colonic shunt migration in a thirteen-year-old female with who underwent Malone Antegrade Continence Enema (MACE) with concomitant revision of the distal part of the peritoneal catheter. She presented two weeks post operatively with shunt catheter protruding from the anus. This was noticed by her carer and she was asymptomatic on her presentation.Clinical discussionDelayed post-operative shunt related bowel perforation and trans-anal shunt protrusion is an uncommon complication after ventriculoperitoneal shunting. Most cases present months after surgery and majority are asymptomatic on presentation. The exact pathophysiology is not established, and mechanisms have been proposed. Early post -operative trans-anal shunt protrusion is rare and suggests inadvertent occult bowel injury especially when shunt placement or revision accompanies extensive bowel surgery.ConclusionThe authors recommended shunt imaging within the first two to three weeks after shunt revision in patient who undergo concomitant bowel surgery with risk of inadvertent bowel injury to identify early colonic migration and avoid its potentially fatal sequelae.     

How people of African Caribbean or Irish ethnicity cope with long-term health conditions in UK community settings: A systematic review of qualitative,quantitative and mixed method studies

Living with a chronic or mental health condition can be challenging and requires considerable adjustment. As ways of coping are culturally influenced, it is important to understand how minority ethnic populations cope, to inform appropriate services. This review aimed to explore the coping strategies used by UK residents from an African Caribbean or Irish background between 1960 and 2020. A systematic literature search on strategies used to cope with chronic health conditions in both populations living in the United Kingdom identified 26 relevant studies. Data were extracted, quality of papers was appraised and critical interpretive synthesis was applied. Two major foci of the studies were coping strategies and barriers to coping. The main coping strategies were denial/scepticism, self-management, spirituality and religion. Within each population, there was variation in ways of coping. The review highlights the complex role of religion in influencing coping strategies. It demonstrates how personal and minority ethnic populations’ experiences of service use are connected with stigma, fear and mistrust, which also act as barriers to seeking help and to coping. Coping with a chronic or mental health condition in the Irish and African Caribbean populations is under-researched. Stigma, fear and mistrust in services act as key barriers to help-seeking and religion is a prominent coping strategy. However, few detailed examples were given on how it was used to assist individuals when managing a chronic or mental health condition. Also due to a lack of research, firm conclusions cannot be drawn for the Irish population.     

Assessment of the effects of exposure to extremely low-frequency magnetic fields on MDCK epithelial cell lines under a controlled environment

To assess the effects of exposure to extremely low-frequency magnetic fields (ELF-MFs) on MDCK cell lines, experiments were performed in a chamber under controlled conditions (temperature, humidity and CO₂). Therefore, the measured physicochemical and electrical changes in the cells are due solely to the magnetic field exposure and not to external factors. A developed sinusoidal magnetic field generator produced the ELF-MFs with a uniform magnetic field and adjustable intensity and frequency. Three experimental indicators were used: (i) transepithelial electrical impedance (TEEI); (ii) cell migration and proliferation; and (iii) expression of the proteins of the tight junctions, and changes in the area and shape of the cell nuclei. No significant effects on TEEI values were observed when 10 and 50 G 60 Hz magnetic fields were applied to confluent cell monolayers. There were no significant differences in migration and proliferation of the cell monolayer exposed to 60 Hz magnetic fields10 and 50 G , but a contact inhibition factor was observed. The expression of the CLDN-1 protein decreased by 90% compared with the control, while ZO-1 protein expression increased by 120%. No significant effects were observed in the area and shape of the cell nuclei. Experimentation in a controlled environment, under physiological conditions, ensures that the observed effects were strictly due to exposure to magnetic fields. Different exposure conditions are necessary to determine the impact on TEEI and cell migration–proliferation indicators.