Goodbye SIRS? Innate, trained and adaptive immunity and pathogenesis of organ dysfunction

The novel concepts within Sepsis‑3 criteria include a focus on dysregulated host responses, removal of the systemic inflammation response syndrome (SIRS) criteria from sepsis diagnosis, the use of Sepsis-related (Sequential) Organ Failure Assessment (SOFA) scores to define organ dysfunction, and the explicit recognition of the septic shock as a subset of sepsis. Protection against infection requires a surveillance system, an effector response against "perceived" pathogens, a method for regaining immune homeostasis following an immune response, and generation of immunological memory. In comparison to normally regulated responses to infection, the innate immune system shows profoundly abnormal neutrophil and macrophage function. Similarly, the adaptive immune system is typically depleted numerically of lymphocytes and functionally with T and B cell exhaustion. Although there are numerous proposed mechanisms by which these dysregulated immune responses may be associated with organ failure, it is unclear what the unifying organ failure mechanisms in sepsis are. Furthermore, in sepsis survivors, the epigenetic changes on immune cells and widespread changes to lymphocyte populations may increase the risk of adverse events such as rehospitalisation and mortality. Finally, our current gaps in understanding of the immune response trajectory and the associated modifiable mechanisms in sepsis leave us a long way from successful immunomodulation for these patients. This article is freely available.

Inflammatory Cytokine TNFα Promotes the Long-Term Expansion of Primary Hepatocytes in 3D Culture

In the healthy adult liver, most hepatocytes proliferate minimally. However, upon physical or chemical injury to the liver, hepatocytes proliferate extensively in vivo under the direction of multiple extracellular cues, including Wnt and pro-inflammatory signals. Currently, liver organoids can be generated readily in vitro from bile-duct epithelial cells, but not hepatocytes. Here, we show that TNFα, an injury-induced inflammatory cytokine, promotes the expansion of hepatocytes in 3D culture and enables serial passaging and long-term culture for more than 6 months. Single-cell RNA sequencing reveals broad expression of hepatocyte markers. Strikingly, in vitro-expanded hepatocytes engrafted, and significantly repopulated, the injured livers of Fah^-/- mice. We anticipate that tissue repair signals can be harnessed to promote the expansion of otherwise hard-to-culture cell-types, with broad implications.

Tissue Repair in the Mouse Liver Following Acute Carbon Tetrachloride Depends on Injury-Induced Wnt/β-Catenin Signaling

In the liver, Wnt/β-catenin signaling is involved in regulating zonation and hepatocyte proliferation during homeostasis. We examined Wnt gene expression and signaling after injury, and we show by in situ hybridization that Wnts are activated by acute carbon tetrachloride (CCl₄ ) toxicity. Following injury, peri-injury hepatocytes become Wnt-responsive, expressing the Wnt target gene axis inhibition protein 2 (Axin2). Lineage tracing of peri-injury Axin2⁺ hepatocytes shows that during recovery the injured parenchyma becomes repopulated and repaired by Axin2⁺ descendants. Using single-cell RNA sequencing, we show that endothelial cells are the major source of Wnts following acute CCl₄ toxicity. Induced loss of β-catenin in peri-injury hepatocytes results in delayed repair and ultimately injury-induced lethality, while loss of Wnt production from endothelial cells leads to a delay in the proliferative response after injury. Conclusion: Our findings highlight the importance of the Wnt/β-catenin signaling pathway in restoring tissue integrity following acute liver toxicity and establish a role of endothelial cells as an important Wnt-producing regulator of liver tissue repair following localized liver injury.

Single-cell transcriptomics of 20 mouse organs creates a Tabula Muris

Here we present a compendium of single-cell transcriptomic data from the model organism Mus musculus that comprises more than 100,000 cells from 20 organs and tissues. These data represent a new resource for cell biology, reveal gene expression in poorly characterized cell populations and enable the direct and controlled comparison of gene expression in cell types that are shared between tissues, such as T lymphocytes and endothelial cells from different anatomical locations. Two distinct technical approaches were used for most organs: one approach, microfluidic droplet-based 3'-end counting, enabled the survey of thousands of cells at relatively low coverage, whereas the other, full-length transcript analysis based on fluorescence-activated cell sorting, enabled the characterization of cell types with high sensitivity and coverage. The cumulative data provide the foundation for an atlas of transcriptomic cell biology.

Self-renewing diploid Axin2(+) cells fuel homeostatic renewal of the liver

The source of new hepatocytes in the uninjured liver has remained an open question. By lineage tracing using the Wnt-responsive gene Axin2, we identify a population of proliferating and self-renewing cells adjacent to the central vein in the liver lobule. These pericentral cells express the early liver progenitor marker Tbx3, are diploid, and thus differ from mature hepatocytes, which are mostly polyploid. The descendants of pericentral cells differentiate into Tbx3-negative, polyploid hepatocytes and can replace all hepatocytes along the liver lobule during homeostatic renewal. Adjacent central vein endothelial cells provide Wnt signals that maintain the pericentral cells, thereby constituting the niche. Thus, we identify a cell population in the liver that subserves homeostatic hepatocyte renewal, characterize its anatomical niche, and identify molecular signals that regulate its activity.

Wnt signaling mediates self-organization and axis formation in embryoid bodies

Embryonic stem cells (ESCs) form descendants of all three germ layers when differentiated as aggregates, termed embryoid bodies. In vivo, differentiation of cells depends on signals and morphogen gradients that provide instructive and positional cues, but do such gradients exist in embryoid bodies? We report here the establishment of anteroposterior polarity and the formation of a primitive streak-like region in the embryoid body, dependent on local activation of the Wnt pathway. In this region, cells undergo an epithelial-to-mesenchymal transition and differentiate into mesendodermal progenitors. Exogenous Wnt3a protein posteriorizes the embryoid body, resulting in predominantly mesendodermal differentiation. Conversely, inhibiting Wnt signaling promotes anterior character and results in neurectodermal differentiation. The activation of Wnt signaling and primitive streak formation requires external signals but is self-reinforcing after initiation. Our findings show that the Wnt pathway mediates the local execution of a gastrulation-like process in the embryoid body, which displays an unexpected degree of self-organization.

Prevalence and pattern of cognitive impairment in a community cohort of men in South Wales: methodology and findings from the Caerphilly Prospective Study

BACKGROUND/AIMS

The prevalence of dementia and cognitive impairment not dementia was investigated in the Caerphilly Prospective Study cohort (men currently aged 65-84 years).

METHODS

Of 1,633 men eligible for cognitive screening, 1,225 (75%) were seen, with those failing the screening criteria (CAMCOG <83 or decline in CAMCOG >9) being neurologically examined.

RESULTS

For dementia, diagnosed by DSM-IV criteria, the population prevalence was 5.2% rising to 6.1% in the screened population. For cognitive impairment not dementia, the prevalence in the screened population was 15.6% giving an overall prevalence of cognitive impairment of 21.8%. Prevalence rose fivefold between ages of 65 and 84 years to reach over 50%.

CONCLUSION

These figures are likely to underestimate actual prevalence in this population, and developing effective interventions should be a public health priority.

[A concept of nephrologic care at the end of life]

BACKGROUND

A care pathway for the end-of-life had been implemented onto the two renal wards. An audit was performed to highlight potential issues and areas for development.

METHOD

The audit consisted of a base review of documentation from the medical notes of 10 patients who had died an 'expected' death prior to commencing the renal Integrated Care Pathway (ICP) for the end of life and then 10 patients who had died whilst using the ICP documentation. A questionnaire was also given out to nursing staff who had used the ICP documentation. The results were collated and analysed.

RESULTS

In the base review 100% of the documentation looked at did not provide a regular documented assessment of symptoms that are common in the terminal phase of life. The ICP provided a documented assessment of all of these main symptoms. The base review indicated a good response by doctors to meet the potential needs of the patient, but the ICP improved on this. This was through the use of a pre-emptive prescription. 80% of all patients were pain free, not agitated, had no nausea or vomiting or respiratory secretions. The 2 patients that had pain received further analgesia and were then pain free at the next assessment. One of the most positive aspects of the audit was that 90% of relatives were aware that the patient was dying and 100% had the plan of care discussed with them.

CONCLUSION

Implementing the ICP has generated the opportunity to deliver a hospice model of care to a busy renal unit. It has allowed best practice, and a measurable standard of care, in the final stages of patients' lives. Staff find the documentation easy to use and also see it as enhancing patient care.

An unconventional nuclear localization motif is crucial for function of the Drosophila Wnt/wingless antagonist Naked cuticle

Wnt/beta-catenin signals orchestrate cell fate and behavior throughout the animal kingdom. Aberrant Wnt signaling impacts nearly the entire spectrum of human disease, including birth defects, cancer, and osteoporosis. If Wnt signaling is to be effectively manipulated for therapeutic advantage, we first must understand how Wnt signals are normally controlled. Naked cuticle (Nkd) is a novel and evolutionarily conserved inducible antagonist of Wnt/beta-catenin signaling that is crucial for segmentation in the model genetic organism, the fruit fly Drosophila melanogaster. Nkd can bind and inhibit the Wnt signal transducer Dishevelled (Dsh), but the mechanism by which Nkd limits Wnt signaling in the fly embryo is not understood. Here we show that nkd mutants exhibit elevated levels of the beta-catenin homolog Armadillo but no alteration in Dsh abundance or distribution. In the fly embryo, Nkd and Dsh are predominantly cytoplasmic, although a recent report suggests that vertebrate Dsh requires nuclear localization for activity in gain-of-function assays. While Dsh-binding regions of Nkd contribute to its activity, we identify a conserved 30-amino-acid motif, separable from Dsh-binding regions, that is essential for Nkd function and nuclear localization. Replacement of the 30-aa motif with a conventional nuclear localization sequence rescued a small fraction of nkd mutant animals to adulthood. Our studies suggest that Nkd targets Dsh-dependent signal transduction steps in both cytoplasmic and nuclear compartments of cells receiving the Wnt signal.

Genetic evidence that Drosophila frizzled controls planar cell polarity and Armadillo signaling by a common mechanism

The frizzled (fz) gene in Drosophila controls two distinct signaling pathways: it directs the planar cell polarization (PCP) of epithelia and it regulates cell fate decisions through Armadillo (Arm) by acting as a receptor for the Wnt protein Wingless (Wg). With the exception of dishevelled (dsh), the genes functioning in these two pathways are distinct. We have taken a genetic approach, based on a series of new and existing fz alleles, for identifying individual amino acids required for PCP or Arm signaling. For each allele, we have attempted to quantify the strength of signaling by phenotypic measurements. For PCP signaling, the defect was measured by counting the number of cells secreting multiple hairs in the wing. We then examined each allele for its ability to participate in Arm signaling by the rescue of fz mutant embryos with maternally provided fz function. For both PCP and Arm signaling we observed a broad range of phenotypes, but for every allele there is a strong correlation between its phenotypic strength in each pathway. Therefore, even though the PCP and Arm signaling pathways are genetically distinct, the set of signaling-defective fz alleles affected both pathways to a similar extent. This suggests that fz controls these two different signaling activities by a common mechanism. In addition, this screen yielded a set of missense mutations that identify amino acids specifically required for fz signaling function.

Strategies used by hospital nurses to cope with a national crisis: a manager's perspective

This article explores the anxiety level of, and coping strategies used by, hospital nurses, during a national state of emergency. The study was guided by a stress and coping framework, developed by Lazarus & Folkman, and was conducted at a large teaching hospital, located in the centre of Israel, during the Iraqi crisis in January and February, 1998. Data were collected from a sample of 100 female nurses, and a descriptive correlational design was used. The findings indicated that approximately 33% of the nurses expressed feelings of stress, tension and a sense of discomfort. The dominant coping strategy used by the nurses was direct-active, which was found to be the most effective strategy. As they were unable to remove or control the stressor, stress management intervention by nursing managers focused mainly on communicating with staff and providing social support - informational and emotional--to buffer the stressful experience. Providing support and help in finding practical solutions is important for maintaining emotional stability of staff, thereby helping them to improve their nursing interventions in assisting people to cope with stressful situations.

A descriptive evaluation with follow-up of the clinical significance of atypical immature squamous metaplasia of the cervix

OBJECTIVES

We set out to determine the clinical significance of atypical immature squamous metaplasia (AIM).

METHODS

We performed in a military, hospital-based colposcopy clinic a descriptive, retrospective review of patients who had a diagnosis of AIM. Patients were examined at 3- to 4-month intervals for at least 1 year after a diagnosis of AIM was established. A gynecological pathologist reviewed all histological and cytological specimens. Initial histological or cytological specimens were tested for the presence of HPV DNA using in situ hybridization.

RESULTS

High-risk HPV DNA types 16 or 18 were detected in 3% of patients with AIM. Concurrent cervical intraepithelial neoplasia 3 (CIN3) was noted in 3% of patients with AIM. One-third of patients with initially diagnosed AIM had complete resolution of this lesion after 1 year of follow-up.

CONCLUSIONS

This descriptive, retrospective review shows that AIM does not appear to be associated with high-risk HPV DNA or with CIN3. In this limited study, a concurrent diagnosis of AIM likely does not influence the 1-year behavior of CIN. The degree of CIN should dictate treatment recommendations. A larger prospective trial is needed.

Frizzled and Dfrizzled-2 function as redundant receptors for Wingless during Drosophila embryonic development

In cell culture assays, Frizzled and Dfrizzled2, two members of the Frizzled family of integral membrane proteins, are able to bind Wingless and transduce the Wingless signal. To address the role of these proteins in the intact organism and to explore the question of specificity of ligand-receptor interactions in vivo, we have conducted a genetic analysis of frizzled and Dfrizzled2 in the embryo. These experiments utilize a small gamma-ray-induced deficiency that uncovers Dfrizzled2. Mutants lacking maternal frizzled and zygotic frizzled and Dfrizzled2 exhibit defects in the embryonic epidermis, CNS, heart and midgut that are indistinguishable from those observed in wingless mutants. Epidermal patterning defects in the frizzled, Dfrizzled2 double-mutant embryos can be rescued by ectopic expression of either gene. In frizzled, Dfrizzled2 mutant embryos, ectopic production of Wingless does not detectably alter the epidermal patterning defect, but ectopic production of an activated form of Armadillo produces a naked cuticle phenotype indistinguishable from that produced by ectopic production of activated Armadillo in wild-type embryos. These experiments indicate that frizzled and Dfrizzled2 function downstream of wingless and upstream of armadillo, consistent with their proposed roles as Wingless receptors. The lack of an effect on epidermal patterning of ectopic Wingless in a frizzled, Dfrizzled2 double mutant argues against the existence of additional Wingless receptors in the embryo or a model in which Frizzled and Dfrizzled2 act simply to present the ligand to its bona fide receptor. These data lead to the conclusion that Frizzled and Dfrizzled2 function as redundant Wingless receptors in multiple embryonic tissues and that this role is accurately reflected in tissue culture experiments. The redundancy of Frizzled and Dfrizzled2 explains why Wingless receptors were not identified in earlier genetic screens for mutants defective in embryonic patterning.

A Drosophila Axin homolog, Daxin, inhibits Wnt signaling

The vertebrate Axin protein, the product of the mouse fused gene, binds to beta-catenin to inhibit Wnt signaling. We have identified a homolog of Axin in Drosophila, Daxin. Using double-stranded RNA interference, we generated loss-of-function phenotypes that are similar to overexpression of the Drosophila Wnt gene wingless (wg). Overexpression of Daxin produces phenotypes similar to loss of wg. In addition, we show that Daxin overexpression can modify phenotypes elicited by wg and another Drosophila Wnt gene, DWnt-2. Using immunoprecipitation of endogenous Daxin protein from embryos we show that Daxin interacts with Armadillo and Zeste-white 3. The loss-of-function and overexpression phenotypes show that Daxin, like its mammalian counterpart, acts as a negative regulator of wg/Wnt signaling.

Benign keratotic squamous epithelial neoplasm of the palate: a unique lesion

BACKGROUND

This case report describes a unique palatal tumor with features of a dermal neoplasm. Microscopically, the lesion appeared similar to a trichoepithelioma and trichoadenoma.

METHODS

Light microscopic and immunohistochemical studies were performed to arrive at the final diagnosis.

RESULTS

The lesion arose from the surface epithelium and had features of a dermal tumor.

CONCLUSIONS

The case report describes a unique benign palatal neoplasm.

A volumetric MRI study of Gilles de la Tourette's syndrome

The neuroanatomic or neuropathologic basis of Gilles de la Tourette's syndrome (GTS) remains unknown. Recent studies have suggested abnormalities of cerebral asymmetry and basal ganglia volumes. We studied 17 patients with GTS and eight normal controls using volumetric MRI techniques for measuring the caudate nucleus, amygdala, and corpus callosum. One subject with GTS was subsequently excluded because he was left handed. No absolute differences in caudate nucleus volumes between patient and control groups were evident. There was an increase in corpus callosum (CC) cross-sectional area and a loss of the normal asymmetry of the caudate nucleus in the patient group. A loss of the normal correlation between cross-sectional area of the CC and whole brain index (WBI) in the patient group also was found. The amygdala measurements had a poor interrater reliability.

Parkinson's disease symptoms--patients' perceptions

Self-assessment is significant for the accurate evaluation of patient' needs. This study examined the frequency and severity of symptoms reported by 39 patients with Parkinson's disease and compared them with symptoms suggested by the literature and by specialists as bothering Parkinson's patients. Four categories of symptoms were examined: (a) motor disability or activity loss, (b) mental change, (c) psychosocial difficulties, and (d) nonspecific symptoms. The findings show that there was correspondence between expert judgements and subjects' reports regarding symptoms such as dyskinesia/tremor as well as walking, freezing gait, and changing position. Symptoms such as dressing self, getting in/out of bed, morning stiffness and deficit in cognitive sequencing, which experts described as characteristic of Parkinson's disease patients, bothered subjects less. In general, patients mental and psychosocial symptoms were higher in their frequencies and perceived severity than problems of performing activities of daily living.

Linking employment to attachment: the mediating effects of maternal separation anxiety and interactive behavior

This study examined the effects of maternal employment and separation anxiety on maternal interactive behavior and infant attachment. 73 mother-infant pairs participated in a laboratory free-play session when infants were 5 and 10 months of age and in the Strange Situation when the infants were 18 months of age. Maternal feelings about being separated from her infant were assessed by questionnaire at 5 months. Employed mothers returned to work before the infants' fifth month, and nonemployed mothers did not work outside the home through their infants' tenth month. Employed mothers who reported high levels of separation anxiety were more likely to exhibit intrusive behaviors at 10 months. While employment was not directly related to attachment, we found infants of high-anxiety employed mothers to develop anxious-avoidant attachments. The results suggest that maternal separation anxiety and interactive style may be important mediators between employment and later infant outcome.

Conditions of continuity and discontinuity in infant negative emotionality: newborn to five months

This study investigated infant and caregiving-environment variables associated with continuity and discontinuity in infant negative emotionality between the newborn period and 5 months of age. Comparisons were made between groups of infants who evidenced similar levels of crying as neonates but differed by 5 months of age. For initially high-crying infants, mother personality traits, marital quality, and infant variables measured neonatally discriminated stable from changing infants. Ratings of mother sensitivity and infant responsiveness made at 5 months of age also related to continuity and discontinuity in negative emotionality over the first 5 months.

The Kendrick Battery: sensitivity to survival effects

In an effort to establish the sensitivity of the Kendrick Battery (KB) to mortality effects among institutionalized aged, the residualized pre-death KB scores (Digit Copying, Object Learning Subtests), as well as measures of affect (Zung Depression), and organicity (Luria Pathognomic Scale, Orientation Test) were compared in a sample of fifty-three elderly persons (M age = 82.7, SD = 7.76). Forty-two were female, eleven were male. Twenty-two of these individuals had subsequently died during an eighteen-month period following assessment. Six years after testing, thirty-six of these individuals had died. Step-wise discriminant analyses at each occasion yielded functions defined by the KB subtests, measures of organicity and depression, age of institutionalization, sex, and length of institutionalization that differentiated survivors and nonsurvivors. These data suggested that the Kendrick Battery subtests, measures of depression and organicity, in combination with length of institutionalization and age of admittance predict death among the elderly, for the most part, replicating previous research.

Construct validity of the Kendrick Battery with institutionalized aged

In this study, we attempted to explore the construct validity of the Kendrick Battery by using an American sample and psychometric tests as indexes of diffuse organicity, depression, and normality. Institutionalized residents (N = 53) were tested twice (6-week interval). When organicity was defined by disorientation and memory deficits, then both the Object Learning test and the Digit Copying test were accurate in differentiating preestablished criterion groups. When organicity was defined more broadly, including sensorimotor function, the Digit Copying test alone was more accurate when depression was defined in terms of irritability, restlessness, and despair. These data suggest that although the Kendrick scales appeared to be sensitive to organicity and depression in this sample, their validity varied with the criteria for each when such were defined psychometrically.