Differential effects of nitric oxide on erythroid and myeloid colony growth from CD34+ human bone marrow cells

Nitric oxide (NO) is a reactive molecule with numerous physiologic and pathophysiologic roles affecting the nervous, cardiovascular, and immune systems. In previous work, we have demonstrated that NO inhibits the growth and induces the monocytic differentiation of cells of the HL- 60 cell line. We have also demonstrated that NO inhibits the growth of acute nonlymphocytic leukemia cells freshly isolated from untreated patients and increases monocytic differentiation antigens in some. In the present work, we studied the effect of NO on the growth and differentiation of normal human bone marrow cells in vitro. Mononuclear cells isolated from human bone marrow were cultured in semisolid media and treated with the NO-donating agents sodium nitroprusside (SNP) or S- nitroso-acetyl penicillamine (SNAP) (0.25 to 1 mmol/L). Both agents decreased colony-forming unit-erythroid (CFU-E) and colony-forming unit- granulocyte macrophage (CFU-GM) formation by 34% to 100%. When CD34+ cells were examined, we noted that these cells responded to SNP and SNAP differently than did the mononuclear cells. At a concentration range of 0.25 to 1 mmol/L, SNP inhibited the growth of CFU-E by 30% to 75%. However, at the same concentration range, SNP increased the number of CFU-GM by up to 94%. At concentrations of 0.25 to 1 mmol/L, SNAP inhibited the growth of CFU-E by 33% to 100%. At a concentration of 0.25 mmol/L, SNAP did not affect CFU-GM. At higher concentrations, SNAP inhibited the growth of CFU-GM. Although SNP increased intracellular levels of cGMP in bone marrow cells, increasing cGMP in cells by addition of 8-Br-cGMP (a membrane permeable cGMP analogue) did not reproduce the observed NO effects on bone marrow colonies. These results demonstrate that NO can influence the growth and differentiation of normal human bone marrow cells. NO (generated in the bone marrow microenvironment) may play an important role modulating the growth and differentiation of bone marrow cells in vivo.     

To stand back or step in? Exploring the responses of employees who observe workplace bullying

Bullying remains a pervasive problem in healthcare, and evidence suggests systems in place are not utilised due to perceptions of ineffectiveness and inequity. This study examines bystander responses to bullying and factors that influence decisions to intervene. We explore relationships between bystanders’ perceptions of psychological safety across three levels (organisation, supervisor and colleague) and reactions to witnessing bullying. We suggest psychological safety would be positively associated with the decision to intervene. Findings indicate the most pervasive reaction to witnessing incidents of bullying is to discuss with colleagues, a low‐involvement reaction. We find perceptions of supervisory and organisational safety/support are positively related to high‐involvement decisions such as formal reporting of the incidents, highlighting the importance of support from those in power. However, perceptions of collegial support may lead to low‐involvement responses, which risk reinforcing and underpinning dysfunctional organisational dynamics by providing informal social and emotional responses that may substitute more formal organisational responses to this persistent problem. This study highlights the importance of support from individuals in power if bystanders are to feel comfortable making high‐involvement interventions.     

Interleukin-10 promoter polymorphisms in rheumatoid arthritis and Felty's syndrome

OBJECTIVE: To examine whether promoter polymorphisms associated with variation in interleukin-10 (IL-10) production are relevant to the development of rheumatoid arthritis (RA) or Felty's syndrome (FS). METHODS: DNA was obtained from 44 FS patients, 117 RA patients and 295 controls. The promoter region between -533 and - 1120 was amplified by polymerase chain reaction, and polymorphisms detected by restriction enzyme digest or sequence-specific oligonucleotide probing. RESULTS: We found no significant difference in allele or haplotype frequencies between the groups. CONCLUSION: There is no association between FS or RA and these recently identified IL-10 promoter polymorphisms. Other genetic or environmental factors could explain the alterations in IL-10 levels seen in these conditions.      

Lowering cholesterol: effects on trauma death, cancer death and total mortality

Randomised trials of cholesterol reduction (26 trials, 50 000 patients, net cholesterol reduction ～10%) have demonstrated a clear reduction in the incidence of coronary heart disease (CHD) after just a few years of treatment. Overall, the reduction in CHD death was only half as large as the reduction in non-fatal myocardial infarction (MI), although both were statistically significant (2P < 0.005). In these trials, 60% of all deaths were from CHD, and since treatment reduced these by about 10%, the expected reduction in total deaths was about 6%. This expected reduction falls within the 95% confidence interval of the observed effect of cholesterol reduction on total mortality in these trials. There were small excesses of deaths from cancer and deaths from trauma among patients allocated active treatment. However, in no single trial, nor in the trials collectively, were these increases statistically significant. Furthermore, the increases did not appear to be specific to any one agent nor were the increases consistent between trials of the same agent. These observations are consistent with the hypothesis that the small excesses of cancer and trauma deaths observed in the cholesterol reduction trials occurred by chance.     

A review of cervical spine injury associated with maxillofacial trauma at a UK tertiary referral centre

IntroductionThe aim of this study was to determine the incidence and patterns of cervical spine injury (CSI) associated with maxillofacial fractures at a UK trauma centre.MethodsA retrospective analysis was conducted of 714 maxillofacial fracture patients presenting to a single trauma centre between 2006 and 2012.ResultsOf the 714 maxillofacial fracture patients, 2.2% had associated CSI including a fracture, cord contusion or disc herniation. In comparison, 1.0% of patients without maxillofacial trauma sustained a CSI (odds ratio: 2.2, p=0.01). The majority (88%) of CSI cases of were caused by a road traffic accident (RTA) with the remainder due to falls. While 8.8% of RTA related maxillofacial trauma patients sustained a CSI, only 2.0% of fall related patients did (p=0.03, not significant). Most (70%) of the CSIs occurred at C1/C2 or C6/C7 levels. Overall, 455, 220 and 39 patients suffered non-mandibular, isolated mandibular and mixed mandibular/non-mandibular fractures respectively. Their respective incidences of CSI were 1.5%, 1.8% and 12.8% (p=0.005, significant). Twelve patients with concomitant CSI had their maxillofacial fractures treated within twenty-four hours and all were treated within four days.ConclusionsThe presence of maxillofacial trauma mandates exclusion and prompt management of cervical spine injury, particularly in RTA and trauma cases involving combined facial fracture patterns. This approach will facilitate management of maxillofacial fractures within an optimum time period.     

Effects of blood pressure lowering with perindopril and indapamide therapy on dementia and cognitive decline in patients with cerebrovascular disease

BACKGROUND: High blood pressure and stroke are associated with increased risks of dementia and cognitive impairment. This study aimed to determine whether blood pressure lowering would reduce the risks of dementia and cognitive decline among individuals with cerebrovascular disease. METHODS: The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) was a randomized, double-blind, placebo-controlled trial conducted among 6105 people with prior stroke or transient ischemic attack. Participants were assigned to either active treatment (perindopril for all participants and indapamide for those with neither an indication for nor a contraindication to a diuretic) or matching placebo(s). The primary outcomes for these analyses were dementia (using DSM-IV criteria) and cognitive decline (a decline of 3 or more points in the Mini-Mental State Examination score). RESULTS: During a mean follow-up of 3.9 years, dementia was documented in 193 (6.3%) of the 3051 randomized participants in the actively treated group and 217 (7.1%) of the 3054 randomized participants in the placebo group (relative risk reduction, 12% [95% confidence interval, -8% to 28%]; P =.2). Cognitive decline occurred in 9.1% of the actively treated group and 11.0% of the placebo group (risk reduction, 19% [95% confidence interval, 4% to 32%]; P =.01). The risks of the composite outcomes of dementia with recurrent stroke and of cognitive decline with recurrent stroke were reduced by 34% (95% confidence interval, 3% to 55%) (P =.03) and 45% (95% confidence interval, 21% to 61%) (P<.001), respectively, with no clear effect on either dementia or cognitive decline in the absence of recurrent stroke. CONCLUSIONS: Active treatment was associated with reduced risks of dementia and cognitive decline associated with recurrent stroke. These findings further support the recommendation that blood pressure lowering with perindopril and indapamide therapy be considered for all patients with cerebrovascular disease.