The Current State of Workforce Diversity and Inclusion in Pediatric Critical Care

Literature suggests the pediatric critical care (PCC) workforce includes limited providers from groups underrepresented in medicine (URiM; African American/Black, Hispanic/Latinx, American Indian/Alaska Native, Native Hawaiian/Pacific Islander). Additionally, women and providers URiM hold fewer leadership positions regardless of health-care discipline or specialty. Data on sexual and gender minority representation and persons with different physical abilities within the PCC workforce are incomplete or unknown. More data are needed to understand the true landscape of the PCC workforce across disciplines. Efforts to increase representation, promote mentorship/sponsorship, and cultivate inclusivity must be prioritized to foster diversity and inclusion in PCC.

A lack of race and ethnicity data in the treatment of hereditary hemorrhagic telangiectasia: a systematic review of intravenous bevacizumab efficacy

BACKGROUND

For extreme hereditary hemorrhagic telangiectasia (HHT) disease, treatments such as intravenous bevacizumab are often utilized. However, whether its efficacy is similar across diverse races and ethnicities is unclear.

METHODS

In this systematic review, we performed a search for English-language articles identified through PubMed, Embase, and Scopus databases whose research occurred in the United States (US). Search terms related to HHT, epistaxis, and intravenous bevacizumab. We searched specifically for the intervention of intravenous bevacizumab because the term serves as a suitable surrogate to convey a patient who has both a diagnosis of HHT and established care. We focused on number of patients recruited in intravenous bevacizumab trials who were identified by race or ethnicity.

RESULTS

Our search identified 79 studies, of which four were conducted in the US. These four were selected for our systematic review. In these studies, 58 total patients were evaluated (ranging from 5 to 34 participants), whereby, information on age and gender were included. However, none of the US-based studies shared race or ethnicity data.

CONCLUSION

Inability to find studies regarding intravenous bevacizumab use in patients with HHT in which race and ethnicity are reported limits our ability to understand the therapy's efficacy in specific populations. Without emphasis on race and ethnicity in such trials, showing the potential of HHT-related diversity in individuals with this disease may reaffirm implicit bias around HHT diagnosis and treatment. Future work on HHT should emphasize sociodemographic data collection and reporting in an effort to understand this disease in diverse populations.

The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

The epididymal amyloid matrix: structure and putative functions

BACKGROUND

We previously demonstrated the normal mouse epididymal lumen contains a non-pathological amyloid matrix that surrounds spermatozoa and plays important roles in sperm maturation and protection.

OBJECTIVE

The objective herein was to present a review of this work, including studies showing the amyloid structures of four members of the CRES (cystatin-related epididymal spermatogenic) subgroup are integral and essential components of the amyloid matrix.

METHODS

We used conformation-dependent reagents that recognize the cross-β-sheet structure characteristic of amyloid, including thioflavin S (ThS), thioflavin T (ThT), anti-amyloid antibodies, and X-ray diffraction, as well as negative-stain transmission electron microscopy (TEM) to visualize amyloid structures in the epididymal lumen. Antibodies that specifically detect each CRES subgroup family member were also used in indirect immunofluorescence analysis.

RESULTS AND DISCUSSION

The epididymal lumen contains an amyloid matrix that surrounds maturing spermatozoa and represents a functional amyloid. Alterations in the structure of the amyloid matrix by the loss of the CRES subgroup members or the overexpression of cystatin C result in epididymal pathologies, including infertility. Preliminary data suggest the epididymal amyloid matrix is structurally and functionally similar to bacterial biofilms.

CONCLUSION

Together, these results suggest the amyloid matrix serves important roles in epididymal function including sperm maturation and protection.

Functional connectivity of human chewing: an fcMRI study

Mastication is one of the most important orofacial functions. The neurobiological mechanisms of masticatory control have been investigated in animal models, but less so in humans. This project used functional connectivity magnetic resonance imaging (fcMRI) to assess the positive temporal correlations among activated brain areas during a gum-chewing task. Twenty-nine healthy young-adults underwent an fcMRI scanning protocol while they chewed gum. Seed-based fcMRI analyses were performed with the motor cortex and cerebellum as regions of interest. Both left and right motor cortices were reciprocally functionally connected and functionally connected with the post-central gyrus, cerebellum, cingulate cortex, and precuneus. The cerebellar seeds showed functional connections with the contralateral cerebellar hemispheres, bilateral sensorimotor cortices, left superior temporal gyrus, and left cingulate cortex. These results are the first to identify functional central networks engaged during mastication.

Brain activity and human unilateral chewing: an FMRI study

Brain mechanisms underlying mastication have been studied in non-human mammals but less so in humans. We used functional magnetic resonance imaging (fMRI) to evaluate brain activity in humans during gum chewing. Chewing was associated with activations in the cerebellum, motor cortex and caudate, cingulate, and brainstem. We also divided the 25-second chew-blocks into 5 segments of equal 5-second durations and evaluated activations within and between each of the 5 segments. This analysis revealed activation clusters unique to the initial segment, which may indicate brain regions involved with initiating chewing. Several clusters were uniquely activated during the last segment as well, which may represent brain regions involved with anticipatory or motor events associated with the end of the chew-block. In conclusion, this study provided evidence for specific brain areas associated with chewing in humans and demonstrated that brain activation patterns may dynamically change over the course of chewing sequences.

Prophylactic feeding tubes for patients with locally advanced head-and-neck cancer undergoing combined chemotherapy and radiotherapy-systematic review and recommendations for clinical practice

GOALS

This work aimed to determine the benefits and risks of prophylactic feeding tubes for adult patients with squamous cell carcinoma of the head and neck who receive combined chemotherapy and radiotherapy with curative intent and to make recommendations on the use of prophylactic feeding tubes and the provision of adequate nutrition to this patient population.

METHODS

A national multidisciplinary panel conducted a systematic review of the evidence and formulated recommendations to guide clinical decision-making. The draft evidence summary and recommendations were distributed to clinicians across Canada for their input.

MAIN RESULTS

No randomized controlled trials have directly addressed this question. Evidence from studies in the target population was limited to seven descriptive studies: two with control groups (one prospective, one retrospective) and five without control groups. Results from ten controlled studies in patients treated with radiotherapy alone were also reviewed.

CONCLUSIONS

The available evidence was insufficient to draw definitive conclusions about the effectiveness of prophylactic feeding tubes in the target patient population or to support an evidence-based practice guideline. After review of the evidence, of guidelines from other groups, and of current clinical practice in Canada, the multidisciplinary panel made consensus-based recommendations regarding comprehensive interdisciplinary clinical care before, during, and after cancer treatment. The recommendations are based on the expert opinion of the panel members and on their understanding of best clinical practice.

Streptococcus pneumoniae bacteraemia in children

Occult bacteraemia is the most frequent invasive disease caused by Streptococcus pneumoniae in children less than 3 years of age. Despite the relative frequency of this infection, its management is still a challenging task for paediatricians because fever is often the only symptom and a considerable overlap exists in the clinical presentation of children with fever without a focus due to viral illness and children with occult bacteraemia. Management protocols take into account the age of the patient, the clinical score for severity and the results of laboratory tests such as the white blood cell count, the C-reactive protein and the blood procalcitonin level in order to define accurately who will benefit from an antibiotic treatment. Despite appropriate healthcare facilities and access to care the case fatality rate in developed countries is around 9% in children aged less than 1 year. Prevention with the 7-valent conjugate vaccine against S. pneumoniae will decrease morbidity and mortality associated with invasive disease due to these bacteria. However, replacement by non-vaccine serotypes has been noted in countries where the vaccine is widely used and this concern needs to be monitored carefully over the next few years.

[Pediatrics. Conjugate anti-pneumoccoccal vaccine: what are the results four years after introduction?]

Considerable morbidity and mortality are related to pneumococcal disease predominantly in high risk populations: infants and young children, the elderly and the immunocompromised. A recent heptavalent conjugate anti-pneumococcal vaccine, introduced in the routine immunization program in the United States in 2001, has been shown to be spectacularly effective in the prevention of invasive disease in the very young in contrast to the pre-existing polysaccharide vaccine. As a consequence, horizontal transmission throughout the community is decreased with a reduction in disease rates in non-vaccinated adults. Finally the conjugate vaccine also provides an effective tool for reduction of drug-resistant pneumococcal strains. A review of the existing anti-pneumococcal vaccines, their direct and indirect effects and their recommended use in Switzerland.

Human Midbrain Sensitivity to Cognitive Feedback and Uncertainty During Classification Learning

Mesencephalic dopaminergic system (MDS) neurons may participate in learning by providing a prediction error signal to their targets, which include ventral striatal, orbital, and medial frontal regions, as well as by showing sensitivity to the degree of uncertainty associated with individual stimuli. We investigated the mechanisms of probabilistic classification learning in humans using functional magnetic resonance imaging to examine the effects of feedback and uncertainty. The design was optimized for separating neural responses to stimulus, delay, and negative and positive feedback components. Compared with fixation, stimulus and feedback activated brain regions consistent with the MDS, whereas the delay period did not. Midbrain activity was significantly different for negative versus positive feedback (consistent with coding of the “prediction error”) and was reliably correlated with the degree of uncertainty as well as with activity in MDS target regions. Purely cognitive feedback apparently engages the same regions as rewarding stimuli, consistent with a broader characterization of this network.

From laminin to lamin: regulation of tissue-specific gene expression by the ECM

Mammary epithelial cells need a laminin-rich extracellular matrix (ECM) to achieve a functionally differentiated phenotype that includes secretion of milk-specific proteins such as beta-casein. There is good evidence that ECM-induced expression of beta-casein involves an 'ECM-response element' in the promoter of the casein gene that is activated by integrin-mediated signalling. This article proposes that ECM-induced structural changes in the cytoskeleton, histone organization and the nuclear matrix contribute to this tissue-specific gene expression.

Interactive memory systems in the human brain

Learning and memory in humans rely upon several memory systems, which appear to have dissociable brain substrates. A fundamental question concerns whether, and how, these memory systems interact. Here we show using functional magnetic resonance imaging (FMRI) that these memory systems may compete with each other during classification learning in humans. The medial temporal lobe and basal ganglia were differently engaged across subjects during classification learning depending upon whether the task emphasized declarative or nondeclarative memory, even when the to-be-learned material and the level of performance did not differ. Consistent with competition between memory systems suggested by animal studies and neuroimaging, activity in these regions was negatively correlated across individuals. Further examination of classification learning using event-related FMRI showed rapid modulation of activity in these regions at the beginning of learning, suggesting that subjects relied upon the medial temporal lobe early in learning. However, this dependence rapidly declined with training, as predicted by previous computational models of associative learning.

Biotech frontiers

Researchers have wrought many new treatments for two growing fields of medicine: cardiovascular services and neurosciences.

Amphipathic variable region heavy chain peptides derived from monoclonal human Wegener's anti-PR3 antibodies stimulate lymphocytes from patients with Wegener's granulomatosis and microscopic polyangiitis

Amphipathic variable-region heavy chain 11-mer peptides from monoclonal human IgM antiproteinase-3 antibodies were studied for peripheral blood lymphocyte stimulation in 21 patients with Wegener's granulomatosis (WG) or microscopic polyangiitis (MPA), connective tissue disease controls and normal control subjects. Positive T-cell activation was observed in most experiments with WG patients' lymphocytes using amphipathic VH-region peptides from four different human monoclonal anti-PR3 antibodies. Control peptides of the same length but without amphipathic characteristics along with other amphipathic peptides not derived from monoclonal anti-PR3 sequence were employed as controls. No significant lymphocyte stimulation was observed with normal controls, but positive stimulation with amphipathic VH peptides was also recorded in other connective tissue disease controls mainly patients with rheumatoid arthritis. Amphipathic peptides not derived from anti-PR3 sequence did not stimulate WG lymphocytes. Our findings indicate that lymphocyte reactivity as an element of cell-mediated immunity may be activated by amphipathic VH-region amino acid sequences of autoantibodies which are themselves associated with diseases such as WG.

Model reactions of Cr (VI) with DNA mediated by thiol species

Model reactions were devised to investigate the capacity of physiologically interesting thiol compounds to mediate reactions between CrO4(2-) (Cr (VI)) and DNA. The sulfhydryl containing reagents included cysteine, glutathione, apo-metallothionein (apoMT). Zinc finger 3 of transcription factor IIIA (Zn-F3) of Xenopus laevis was investigated as a potential redox active site of reaction of Cr (VI) and thiol compounds. The DNA samples were calf thymus DNA and two oligomers, one of them specific for binding Zn-F3. Results showed that in the presence of Cr (VI) apoMT readily participated in damaging DNA in a reaction that appeared to be hydroxyl radical dependent. It also became cross-linked to oligomer and native DNA samples. In comparison, the other two thiol donors were largely inactive in these assays even though they, like apoMT, were able to reduce Cr (VI) to Cr (III) under the conditions of the experiments. Direct attempts to cross link thiols with DNA in the presence of Cr3+ were unsuccessful at pH 7.4. Together, the results indicate that apoMT can effectively collaborate with Cr (VI) in reactions that are deleterious to DNA.

Genomics: implications for health systems

In anticipation of and following the announcement of the completion of the mapping of the human genome, numerous articles have appeared in scientific, industry, and consumer journals and magazines on the topic of genomics. Building off the excitement surrounding this scientific milestone, many of these articles--irrespective of the audience--look to the future and anticipate how this knowledge breakthrough will change the way classes of diseases are diagnosed, treated, and even prevented over the next several generations. However, literature that explores the potential effect of genomics on health system care delivery is virtually nonexistent. As such, this article begins to prepare health system executives for the future by speculating how genomics may affect their organizations and suggesting strategies for future success.

Proapoptotic anti-inflammatory drugs

The very fact that apoptosis and nonsteroidal anti-inflammatory drugs (NSAIDs) can be linked in the same title should tell you that something unusual is happening. The image of NSAIDs among physicians is certainly discordant with that associated with cancer treatment, which usually involves administration of drugs with serious or even life-threatening toxicity. In contrast, the drugs discussed in this review, including selective cyclooxygenase-2 inhibitors, lipoxygenase inhibitors, and novel NSAID derivatives (eg, sulindac sulfone and R-flurbiprofen), offer the promise of oral, nontoxic agents able to control the progression of established prostate cancer and possibly to prevent the development of prostate cancer de novo. NSAIDs were initially developed to suppress inflammation and pain by inhibiting the production of prostaglandin E2 and its metabolites. At first glance, the fact that NSAIDs are active against prostate cancer in laboratory and clinical studies might suggest that prostaglandins play a pivotal role in prostate cancer biology. However, the story is much more complex than that. Although cyclooxygenase-mediated production of prostaglandins appears to play an important role in the biology of prostate cancer, the NSAIDs and derivatives with promising activity against prostate cancer manifest several mechanisms of action that can include direct inhibition of eicosanoid formation, indirect inhibition of eicosanoid formation by inhibiting expression of enzymes involved in eicosanoid synthesis, or by interfering with the function of cyclic guanosine monophosphate.

Effects of repeated withdrawal from continuous amphetamine administration on brain reward function in rats

RATIONALE

The study of the effects of repeated amphetamine administration and withdrawal on brain reward function has relevance to both amphetamine dependence and non-drug-induced depressions.

OBJECTIVES

The purpose of this study was to investigate the effects of continuous amphetamine administration and withdrawal on brain stimulation reward thresholds, and the changes that occur with repeated amphetamine exposures.

METHODS

Rats were prepared with bipolar electrodes in the lateral hypothalamus and trained in a discrete-trial reward threshold procedure. Then, rats underwent two separate periods of amphetamine administration via subcutaneous osmotic mini-pumps.

RESULTS

Continuous amphetamine administration was associated with lowering in brain reward thresholds and decreases in response latencies, while withdrawal was associated with threshold elevations. These effects changed with subsequent amphetamine administration and withdrawal.

CONCLUSIONS

The results of this study indicated that with the amphetamine administration regime used here, rats developed increased sensitivity to the effects of acute amphetamine administration and tolerance to the effects of amphetamine withdrawal.

Maf transcriptionally activates the mouse p53 promoter and causes a p53-dependent cell death

An increase in the level of the tumor suppressor protein p53 can induce cell cycle arrest or cell death. Although mechanisms for regulating the life span of p53 have been described, there is growing evidence that transcriptional regulation of the p53 gene contributes significantly to controlling p53 protein levels and therefore the fate of a cell. However, the signal transduction pathways that lead to transcriptional activation of the p53 gene are poorly understood. The oncoprotein v-Maf and its cellular counterparts belong to the large combinatorially complex basic leucine zipper family of transcription factors, which include the AP1 family. To date few cellular targets of c-Maf have been identified. It is demonstrated here that v-Maf can bind as a homodimer to a variant Maf recognition element located between -66 and -54 upstream in the mouse p53 promoter. V-Maf and its cellular counterparts are shown to activate p53 expression through this site. The ability of v-Maf to activate p53 expression is modulated by AP1 family members. In addition, overexpression of v-Maf in primary cells leads to a p53-dependent cell death. Thus, Maf and members of the AP1 family are able to regulate p53 expression through this site in the p53 promoter.