Reduced B cell HLA-DR expression and natural killer cell counts in patients prone to sepsis after injury.

OBJECTIVE: To examine the influence of natural killer (NK) cells and HLA-DR molecules on B cells in the development of severe sepsis after injury. DESIGN: Prospective study. SETTING: Medical school, Germany. SUBJECTS: 46 severely injured (Injury Severity Score >16) patients. INTERVENTIONS: Blood samples were taken immediately after admission and subsequently for 14 days. MAIN OUTCOME MEASURES: HLA-DR expression on B cells and counts of B and NK cells measured by flow cytometry, and morphological estimation of large granular lymphocytes by microscopy. RESULTS: HLA-DR expression on circulating B cells was significantly reduced from days 6-14 after admission in 13 patients with subsequent severe sepsis compared with 33 patients who did not develop sepsis. In septic patients NK cell counts were significantly decreased from day 4 onwards (p < 0.05). CD16+/CD56+ cells correlated with the morphology of large granular lymphocytes. CONCLUSION: In severely injured patients reduced counts of NK cells and HLA-DR molecules on B lymphocytes seem to be part of an immune deviation that is associated with the development of severe sepsis.     

Influence of granulocyte-macrophage colony-stimulating factor (GM-CSF) on whole blood endotoxin responsiveness following trauma, cardiopulmonary bypass, and severe sepsis.

Major surgery, multiple injury, and severe sepsis lead to an impaired immune response. The suppressed status of the immune system is reflected by a reduced TNFalpha production of whole blood after stimulation with endotoxin in vitro and by a decreased HLA-DR expression on monocytes. In the present study, the effect of the immunostimulating hematopoetic growth factor GM-CSF on whole blood cultures of multiple injury, cardiac surgery, and severe sepsis patients was investigated. Endotoxin-induced TNFalpha production and HLA-DR expression was reduced in blood cultures of these patients compared to healthy donors. Preincubation with GM-CSF in vitro increased cytokine production in volunteers' and all patients' blood specimens in a dose-dependent manner. The elevation of cytokine response in cardiopulmonary bypass patients' blood, caused by in vitro preincubation with GM-CSF, equaled that of normal patients, whereas GM-CSF caused a lower rise of TNFalpha-producing capacity in blood of multiple-injury and sepsis patients. Further, GM-CSF treatment in vitro increased the down-regulated HLA-DR expression on monocytes prepared after cardiac surgery to a degree comparable to preoperative levels. Finally, GM-CSF incubation in vitro elevated TNFalpha synthesis in normal monocytes and in cells treated with a combination of the anti-inflammatory mediators IL-10, TGFbeta, and PGE2. These experiments show that hyporesponsiveness of whole blood induced by trauma, sepsis, or cardiac surgery is not irreversible but can be, at least in vitro, overridden by the immunostimulating compound GM-CSF.     

Towards the control of the reactivity in high temperature bulk anionic polymerization of styrene, 1. Influence of n,s-dibutylmagnesium on the reactivity of polystyryllithium species

The influence of n,s-dibutylmagnesium on the kinetics of styrene polymerization initiated by s-butyllithium was investigated in cyclohexane at 50°C. The presence of n,s-dibutylmagnesium, in molar ratios ranging from 0 to 20 with respect to polystyryllithium, leads to a drastic and continuous reduction of the reactivity of the propagating species. The living character of the polymerization, especially the control of the molar mass is preserved over the entire range studied. The experimental molar masses are in agreement with the formation of one polystyrene chain per lithium and 0.5 to 0.8 chains per magnesium atom, indicating that both alkyllithium and dialkylmagnesium species are involved in the polymerization process through the formation of “ate” complexes. The UV-visible study of the PSLi/n,s-dibutylmagnesium systems shows that several types of “ate” complexes with different stoichiometry are formed depending on the proportion of the two metal derivatives.     

Working from home: mismatch between access and need in relation to work–home interference and fatigue

Objectives:Working from home (WfH) is a promising practice that may enable employees to successfully and sustainably combine work and private life. Yet, not every employer facilitates WfH and not every employee has similar needs concerning the practice. The current study aims to examine the association of a WfH mismatch with work–home interference (WHI) and fatigue.Methods:Data on WfH, WHI, and fatigue of a quasi-representative sample of 2374 Dutch employees in 2012/13 and a follow-up measurement one year later were used. Cross-sectional and longitudinal regression analyses were conducted to investigate the cross-sectional and temporal associations between WfH mismatch on the one hand and (changes in) time-based and strain-based WHI and fatigue on the other hand.Results:In the cross-sectional analyses, WfH mismatch was significantly associated with higher time-based WHI (B=0.13), strain-based WHI (B=0.17) and more fatigue (B=0.32). WfH mismatch was not associated with changes in these outcomes after one year of follow-up.Conclusions:A tailored WfH organizational policy, in which employees’ need for working from home is taken into account, may be a fruitful approach to utilize WfH as a way for employees to successfully and sustainably combine work and private life to its full potential.     

Reduced MHC class II antigen expression on rat heart and kidney cells after in vitro exposure to longwave ultraviolet irradiation

The pretreatment of both kidney and heart donor with the photosensitizer 8-methoxy-psoralen followed by in vitro longwave ultraviolet graft irradiation (PUVA therapy) significantly prolonged graft survival times in rats even across a strong major histocompatibility complex (MHC) barrier. Immunohistological studies using monoclonal antibodies (Mab) to rat MHC class I and II antigens showed a significant reduction of class II antigen expression after PUVA therapy in both Sprague-Dawley rat kidneys and hearts. Using MHC class I Mab there were no differences in distribution pattern in untreated as well as in PUVA treated organs. Thus, our results represent the first in vivo evidence that photochemotherapy-induced graft survival time prolongation is closely connected with its ability to reduce MHC class II antigen expression.     

Effects of insulin infusion on plasma phosphate in diabetic patients.

A clinical association between insulin therapy and hypophosphatemia has frequently been made but a dose-response relationship has not been reported. Furthermore, the rapidity by which hypophosphatemia may be induced following an increment in plasma-free insulin concentration is not well defined. Therefore this study compared the effects of different rates of insulin infusion on the changes in plasma phosphate concentration in ketotic, hyperglycemic diabetic man. Sixteen prospective studies were performed in four insulin-dependent ketotic diabetic subjects. Insulin was infused according to one of four different protocols: high dose (1.0 U/kg/hr), low dose (0.1 U/kg/hr), very low dose (0.01 U/kg/hr) and control (saline only). Plasma phosphate, glucose, and free insulin concentrations were measured sequentially during the 60 min infusion periods. We observed that plasma phosphate concentrations declined significantly only with low-dose and high-dose insulin infusions. The magnitude and rapidity of fall of the mean phosphate concentration were greatest with high-dose insulin infusion. Significant hypophosphatemia can be observed within 30 min following the onset of insulin therapy.     

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不同痘病毒属病毒抗原剂量对实验鸡免疫效果的比较性研究

本研究以两种灭活痘病毒属病毒（vaccinia virus，7．0×10^6PFU和cowpox virus，9．2×10^7PFU）为免疫原，分别考察SNNNT（抗原浓度相差约100倍）实验鸡的免疫效果和相应卵黄抗体效价（免疫荧光法和抗体中和效价）。我们的研究结果，结合文献研究显示，抗原剂量对于特异性卵黄抗体的产生和表达水平具有重要影响。提高免疫原的浓度通常有助于提高抗体效价。但由于不同抗原的免疫原性差异，也有可能导致免疫抑制。针对不同免疫原似乎存在最佳免疫剂量范围。     

Epidemiology of Open Tibia fractures presenting to a tertiary referral centre in Southern Malawi: a retrospective study

BackgroundRoad traffic accidents in Malawi have increased in recent years resulting in a high incidence of trauma seen in the hospitals as well as a high prevalence of musculoskeletal impairment in the community. Open fractures are a common consequence of road traffic accidents and the tibia is the most common long bone open fracture.ObjectiveEpidemiology of open tibia fractures at the largest tertiary level hospital in Malawi and incidence of infections of open fractures managed at the institution.MethodologyThis was a retrospective study of consecutive open tibia fracture patients seen and admitted to Queen Elizabeth Central Hospital''s (QECH) orthopedic department from 1st January 2019 to 31st December 2019. Patients with life-threatening head, chest, or abdominal injuries were excluded as management takes priority over any limb-threatening injury.ResultsThere were 72 open tibia fractures screened, and 60 of these met our entry criteria; 6 patients did not, while 6 patient files were missing. The median age of patients was 36 years, IQR (27–44.75) with Males making up 82%(n=49) of open fractures. Most of the open tibia fractures were caused by road traffic accidents 63%(n=38), followed by assaults 18%(n=11), falls 17%(n=10), and industrial accidents 2%(n=1). 26.7% (n=16) of open tibia fractures developed an infection. We found that patients'' average length of stay was 16. 9(IQR 9.5–31.25) days. Most of the injuries (68.3%, n=41) were moderate to high energy injuries being Gustilo et al. grade II and III open tibia fractures.ConclusionThis study identified that open tibia fractures were common in our hospital and that were often high energy injuries requiring an extended hospital stay to manage. The infection rate noted was higher than that reported on average in lower- and middle-income countries. There is a need to do more robust prospective studies in the area to gather more information.