Cellular resolution anatomical and molecular atlases for prenatal human brains

Increasing interest in studies of prenatal human brain development, particularly using new single-cell genomics and anatomical technologies to create cell atlases, creates a strong need for accurate and detailed anatomical reference atlases. In this study, we present two cellular-resolution digital anatomical atlases for prenatal human brain at postconceptional weeks (PCW) 15 and 21. Both atlases were annotated on sequential Nissl-stained sections covering brain-wide structures on the basis of combined analysis of cytoarchitecture, acetylcholinesterase staining, and an extensive marker gene expression dataset. This high information content dataset allowed reliable and accurate demarcation of developing cortical and subcortical structures and their subdivisions. Furthermore, using the anatomical atlases as a guide, spatial expression of 37 and 5 genes from the brains, respectively, at PCW 15 and 21 was annotated, illustrating reliable marker genes for many developing brain structures. Finally, the present study uncovered several novel developmental features, such as the lack of an outer subventricular zone in the hippocampal formation and entorhinal cortex, and the apparent extension of both cortical (excitatory) and subcortical (inhibitory) progenitors into the prenatal olfactory bulb. These comprehensive atlases provide useful tools for visualization, segmentation, targeting, imaging, and interpretation of brain structures of prenatal human brain, and for guiding and interpreting the next generation of cell census and connectome studies.     

A cross-sectional study of knife injuries at a London major trauma centre

INTRODUCTION

No national recording systems for knife injuries exist in the UK. Understanding the true size and nature of the problem of knife injuries is the first stage in reducing the burden of this injury. The aim of this study was to survey every knife injury seen in a single inner city emergency department (ED) over a one-year period.

METHODS

A cross-sectional observational study was performed of all patients attending with a knife injury to the ED of a London major trauma centre in 2011. Demographic characteristics, patterns of injury, morbidity and mortality data were collected.

RESULTS

A total of 938 knife injuries were identified from 127,191 attendances (0.77% of all visits) with a case fatality rate of 0.53%. A quarter (24%) of the major trauma team’s caseload was for knife injuries. Overall, 44% of injuries were selfreported as assaults, 49% as accidents and 8% as deliberate self-harm. The highest age specific incident rate occurred in the 16–24 year age category (263/100,000). Multiple injuries were seen in 19% of cases, of which only 81% were recorded as assaults. The mean length of stay for those admitted to hospital was 3.04 days. Intrathoracic injury was seen in 26% of cases of chest trauma and 24% of abdominal injuries had a second additional chest injury.

CONCLUSIONS

Violent intentional injuries are a significant contributory factor to the workload of the major trauma team at this centre. This paper contributes to a more comprehensive understanding of the nature of these injuries seen in the ED.     

Hydroxyurea-induced augmentation of fetal hemoglobin production in patients with sickle cell anemia

Five patients with sickle cell anemia were treated with hydroxyurea (HU), in hopes of augmenting their production of fetal hemoglobin. Laboratory responses in two patients treated for more than 2 years were encouraging and there were suggestions of clinical improvement. Long- term HU therapy should be considered for severely affected adults with sickle cell anemia who are willing to accept what is probably a small risk of carcinogenesis. Preliminary chromosomal analysis and knowledge of the clastogenic properties of HU suggest that conception and pregnancy should be avoided. Pharmacokinetic studies will probably be necessary to adjust individual dosage schedules so that cytotoxicity is avoided. F cell responses can be seen in 2 to 3 weeks if the HU dose is optimal, but establishment of a large number of F cells in the circulation may take a month or longer.     

Cytokine activation during attacks of the hyperimmunoglobulinemia D and periodic fever syndrome

The hyperimmunoglobulinemia D and periodic fever (hyper-IgD) syndrome is typified by recurrent febrile attacks with abdominal distress, joint involvement (arthralgias/arthritis), headache, skin lesions, and an elevated serum IgD level (> 100 U/mL). This familial disorder has been diagnosed in 59 patients, mainly from Europe. The pathogenesis of this febrile disorder is unknown, but attacks are joined by an acute-phase response. Because this response is considered to be mediated by cytokines, we measured the acute-phase proteins C-reactive protein (CRP) and soluble type-II phospholipase A2 (PLA2) together with circulating concentrations and ex vivo production of the proinflammatory cytokines interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6, and tumor necrosis factor alpha (TNF alpha) and the inhibitory compounds IL-1 receptor antagonist (IL-1ra), IL-10, and the soluble TNF receptors p55 (sTNFr p55) and p75 (sTNFr p75) in 22 patients with the hyper-IgD syndrome during attacks and remission. Serum CRP and PLA2 concentrations were elevated during attacks (mean, 213 mg/L and 1,452 ng/mL, respectively) and decreased between attacks. Plasma concentrations of IL-1 alpha, IL-1 beta, or IL-10 were not increased during attacks. TNF alpha concentrations were slightly, but significantly, higher with attacks (104 v 117 pg/mL). Circulating IL-6 values increased with attacks (19.7 v 147.9 pg/mL) and correlated with CRP and PLA2 values during the febrile attacks. The values of the antiinflammatory compounds IL-1ra, sTNFr p55, and sTNFr p75 were significantly higher with attacks than between attacks, and there was a significant positive correlation between each. The ex-vivo production of TNF alpha, IL-1 beta, and IL-1ra was significantly higher with attacks, suggesting that the monocytes/macrophages were already primed in vivo to produce increased amounts of these cytokines. These findings point to an activation of the cytokine network, and this suggests that these inflammatory mediators may contribute to the symptoms of the hyper-IgD syndrome.     

Asynchronous globin chain synthesis in rabbit reticulocyte lystates induced by hemin-controlled repressor

To define further the role of hemin-controlled repressor (HCR) in globin synthesis, we studied its effect on the synthesis of individual globin chains in a rabbit reticulocyte lysate cell-free system. In the presence of HCR there was a marked globin chain imbalance, resulting in a lowered alpha/beta ratio. These findings in vitro may have relevance to certain clinical heme deficiency states in which a similar globin chain imbalance has been observed.     

Heterogeneity of B cell involvement in acute nonlymphocytic leukemia

In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis.     

Macrophage factor X activator formation: metabolic requirements for synthesis of components

The in vitro production of factor VII-like material and of tissue factor activity by murine thioglycollate exudate macrophages was measured by amidolytic assays. Tissue factor activity was inducible by endotoxin, and its induction was inhibited by 1 microgram/mL of actinomycin D, 10 micrograms/mL of cycloheximide, and 0.2 micrograms/mL of tunicamycin. Soluble factor VII-like material was secreted by macrophages into culture supernatants. The amount produced was not influenced by further activation of the cells by endotoxin, nor was its production inhibited significantly by 1 microgram/mL actinomycin D or 0.2 micrograms/mL tunicamycin. The production of the factor VII-like material was inhibited by 10 micrograms/mL of cycloheximide, and its appearance in culture supernatants was enhanced significantly by the addition of vitamin K1. When lysates of activated macrophages were suspended in ultracentrifuged culture supernatants, a particulate factor X activator was formed. Centrifugation at 100,000 g pelleted the factor X activator and left no factor VII-like material in the supernatant. The data indicate that thioglycollate-induced exudate macrophages make and excrete factor VII-like material, and this production is not modulated by further activation. However, activation of the macrophages induces tissue factor production. The factor X activator appears to result from the interaction and complexing of the soluble factor VII-like material and the membrane-bound tissue factor.     

Hematologic and immunomodulatory effects of an interleukin-1 receptor antagonist coinfusion during low-dose endotoxemia in healthy humans

Endotoxin is a component of gram-negative bacteria that causes hematologic and immunologic changes through its induction of cytokines. Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring inhibitor of IL-1 that competes with IL-1 for occupancy of cell-surface receptors but possesses no agonist activity. We investigated the ability of human recombinant IL-1Ra to block the effects of low-dose endotoxin. Fourteen healthy male volunteers between 18 and 30 years old were injected intravenously with 3 ng/kg Escherichia coli endotoxin. Concurrent with the injections, nine volunteers received a 3-hour continuous intravenous infusion of IL-1Ra. The other five subjects were given a 3-hour infusion of saline. Volunteers injected with endotoxin experienced a threefold increase in circulating neutrophils over baseline. This neutrophilia was significantly reduced by 48% in subjects administered endotoxin plus IL-1Ra (P = .0253). Ex vivo mitogen-induced peripheral blood mononuclear cell proliferation decreased by greater than 60% at 3 and 6 hours after endotoxin injection (P = .0053). This endotoxin-induced reduction in mitogen response was reversed in subjects coinjected with IL-1Ra (P = .0253). Endotoxin-induced symptoms, fever, and tachycardia were unaffected by IL-1Ra. IL-1 appears to be an important mediator in endotoxemia because some of its hematologic and immunomodulatory effects can be blocked by IL-1Ra.