Tibial Intraosseous Administration of Epinephrine Is Effective in Restoring Return of Spontaneous Circulation in a Pediatric Normovolemic But Not Hypovolemic Cardiac Arrest Model.

OBJECTIVE: We compared the efficacy of tibial intraosseous (TIO) administration of epinephrine in a pediatric normovolemic versus hypovolemic cardiac arrest model to determine the incidence of return of spontaneous circulation (ROSC) and plasma epinephrine concentrations over time. METHODS: This experimental study evaluated the pharmacokinetics of epinephrine and/or incidence of ROSC after TIO administration in either a normovolemic or hypovolemic pediatric swine model. RESULTS: All subjects in the TIO normovolemia cardiac arrest group experienced ROSC after TIO administration of epinephrine. In contrast, subjects experiencing hypovolemia and cardiac arrest were significantly less likely to experience ROSC when epinephrine was administered TIO versus intravenous (TIO hypovolemia: 14% [1/7] vs IV hypovolemia: 71% [5/7]; P = 0.031). The TIO hypovolemia group exhibited significantly lower plasma epinephrine concentrations versus IV hypovolemia at 60, 90, 120, and 150 seconds (P < 0.05). Although the maximum concentration of plasma epinephrine was similar, the TIO hypovolemia group exhibited significantly slower time to maximum concentration times versus TIO normovolemia subjects (P = 0.004). CONCLUSIONS: Tibial intraosseous administration of epinephrine reliably facilitated ROSC among normovolemic cardiac arrest pediatric patients, which is consistent with published reports. However, TIO administration of epinephrine was ineffective in restoring ROSC among subjects experiencing hypovolemia and cardiac arrest. Tibial intraosseous-administered epinephrine during hypovolemia and cardiac arrest may have resulted in a potential sequestration of epinephrine in the tibia. Central or peripheral intravascular access attempts should not be abandoned after successful TIO placement in the resuscitation of patients experiencing concurrent hypovolemia and cardiac arrest.

A Prospective Assessment of a Novel, Disposable Video Laryngoscope With Physician Assistant Trainees Using a Synthetic Cadaver Model.

BACKGROUND: Airway obstruction is the second leading cause of preventable death on the battlefield. Video laryngoscopy has improved airway management in the emergency setting for several decades, and technology continues to improve. Current technology in the supply chain is cost-prohibitive to incorporate at Role 1 facilities, which is where many intubations occur by novice intubators. The i-view is a novel video laryngoscopy device that is handheld, inexpensive, and disposable. The aim of this study was to determine if the i-view is suitable based on performance assessments by physician assistant trainees and survey feedback. MATERIALS AND METHODS: We prospectively enrolled physician assistant students at the Interservice Physician Assistant Program at Joint Base San Antonio-Fort Sam Houston. We provided them structured training on how to use the device, and then, a board-certified emergency medicine physician or certified registered nurse anesthetist assessed their intubations performed on a SynDaver mannequin model. We surveyed the participants afterward. RESULTS: We enrolled 60 Interservice Physician Assistant Program students. Most participants were male (75%) with a median age of 32 years. Service affiliations included Army (50%), Navy (23%), Air Force (18%), and Coast Guard (8%). Most (70%) had previous deployment experience. All the participants successfully cannulated the mannequins and 98% achieved first-attempt success. Most participants (78%) reported a grade 1 view. On postprocedure survey, 91% strongly agreed with using this device in the deployed setting and 89% strongly agreed with finding it easy to use. CONCLUSIONS: All physician assistant trainees successfully and rapidly performed endotracheal intubation using the disposable i-view video laryngoscope. Study participants rated the device as easy to use and desirable for deployment. Further research is necessary to validate this novel device in the clinical setting before recommending dissemination to the deployed military medical force sets, kits, and outfits.

A Comparison of the iGel Versus Cricothyrotomy by Combat Medics Using a Synthetic Cadaver Model: A Randomized, Controlled Pilot study.

Background: Airway obstruction is the second leading cause of potentially preventable death on the battlefield. Prior to 2017, the Committee on Tactical Combat Casualty Care (CoTCCC) recommended the surgical cricothyrotomy as the definitive airway of choice. More recently, the CoTCCC has recommended the iGel™ as the supraglottic airway (SGA) of choice. Data comparing these methods in medics are limited. We compared first-pass placement success among combat medics using a synthetic cadaver model. Methods: We conducted a randomized cross-over study of United States Army combat medics using a synthetic cadaver model. Participants performed a surgical cricothyrotomy using a method of their choosing versus placement of the SGA iGel in random order. The primary outcome was first-pass success. Secondary outcomes included time-to-placement, complications, placement failures, and self-reported participant preferences. Results: Of the 68 medics recruited, 63 had sufficient data for inclusion. Most were noncommissioned officers in rank (54%, E6-E7), with 51% reporting previous deployment experience. There was no significant difference in first-pass success (P = .847) or successful cannulation with regard to the two devices. Time-to-placement was faster with the iGel (21.8 seconds vs. 63.8 seconds). Of the 59 medics who finished the survey, we found that 35 (59%) preferred the iGel and 24 (41%) preferred the cricothyrotomy. Conclusions: In our study of active duty Army combat medics, we found no significant difference with regard to first-pass success or overall successful placement between the iGel and cricothyrotomy. Time-to-placement was significantly lower with the iGel. Participants reported preferring the iGel versus the cricothyrotomy on survey. Further research is needed, as limitations in our study highlighted many shortcomings in airway research involving combat medics.

PREDICTIVE MARKERS FOR POSTSURGICAL MEDICAL MANAGEMENT OF ACROMEGALY: A SYSTEMATIC REVIEW AND CONSENSUS TREATMENT GUIDELINE.

Objective: To clarify the selection of medical therapy following transsphenoidal surgery in patients with acromegaly, based on growth hormone (GH)/insulin-like growth factor 1 (IGF-1) response and glucometabolic control. Methods: We carried out a systematic literature review on three of the best studied and most practical predictive markers of the response to somatostatin analogues (SSAs): somatostatin receptor (SSTR) expression, tumor morphologic classification, and T2-weighted magnetic resonance imaging (MRI) signal intensity. Additional analyses focused on glucose metabolism in treated patients. Results: The literature survey confirmed significant associations of all three factors with SSA responsiveness. SSTR expression appears necessary for the SSA response; however, it is not sufficient, as approximately half of SSTR2-positive tumors failed to respond clinically to first-generation SSAs. MRI findings (T2-hypo-intensity) and a densely granulated phenotype also correlate with SSA efficacy, and are advantageous as predictive markers relative to SSTR expression alone. Glucometabolic control declines with SSA monotherapy, whereas GH receptor antagonist (GHRA) monotherapy may restore normoglycemia. Conclusion: We propose a decision tree to guide selection among SSAs, dopamine agonists (DAs), and GHRA for medical treatment of acromegaly in the postsurgical setting. This decision tree employs three validated predictive markers and other clinical considerations, to determine whether SSAs are appropriate first-line medical therapy in the postsurgical setting. DA treatment is favored in patients with modest IGF-1 elevation. GHRA treatment should be considered for patients with T2-hyperintense tumors with a sparsely granulated phenotype and/or low SSTR2 staining, and may also be favored for individuals with diabetes. Prospective analyses are required to test the utility of this therapeutic paradigm. Abbreviations: DA = dopamine agonist; DG = densely granulated; GH = growth hormone; GHRA = growth hormone receptor antagonist; HbA1c = glycated hemoglobin; IGF-1 = insulin-like growth factor-1; MRI = magnetic resonance imaging; SG = sparsely granulated; SSA = somatostatin analogue; SSTR = somatostatin receptor.

Placental polyamine metabolism differs by fetal sex, fetal growth restriction, and preeclampsia.

Preeclampsia and fetal growth restriction (FGR) are major causes of the more than 5 million perinatal and infant deaths occurring globally each year, and both are associated with placental dysfunction. The risk of perinatal and infant death is greater in males, but the mechanisms are unclear. We studied data and biological samples from the Pregnancy Outcome Prediction (POP) study, a prospective cohort study that followed 4,212 women having first pregnancies from their dating ultrasound scan through delivery. We tested the hypothesis that fetal sex would be associated with altered placental function using multiomic and targeted analyses. We found that spermine synthase (SMS) escapes X-chromosome inactivation (XCI) in the placenta and is expressed at lower levels in male primary trophoblast cells, and male cells were more sensitive to polyamine depletion. The spermine metabolite N1,N12-diacetylspermine (DiAcSpm) was higher in the female placenta and in the serum of women pregnant with a female fetus. Higher maternal serum levels of DiAcSpm increased the risk of preeclampsia but decreased the risk of FGR. To our knowledge, DiAcSpm is the first maternal biomarker to demonstrate opposite associations with preeclampsia and FGR, and this is the first evidence to implicate polyamine metabolism in sex-related differences in placentally related complications of human pregnancy.

Genome-wide oxidative bisulfite sequencing identifies sex-specific methylation differences in the human placenta.

DNA methylation is an important regulator of gene function. Fetal sex is associated with the risk of several specific pregnancy complications related to placental function. However, the association between fetal sex and placental DNA methylation remains poorly understood. We carried out whole-genome oxidative bisulfite sequencing in the placentas of two healthy female and two healthy male pregnancies generating an average genome depth of coverage of 25x. Most highly ranked differentially methylated regions (DMRs) were located on the X chromosome but we identified a 225 kb sex-specific DMR in the body of the CUB and Sushi Multiple Domains 1 (CSMD1) gene on chromosome 8. The sex-specific differential methylation pattern observed in this region was validated in additional placentas using in-solution target capture. In a new RNA-seq data set from 64 female and 67 male placentas, CSMD1 mRNA was 1.8-fold higher in male than in female placentas (P value = 8.5 × 10-7, Mann-Whitney test). Exon-level quantification of CSMD1 mRNA from these 131 placentas suggested a likely placenta-specific CSMD1 isoform not detected in the 21 somatic tissues analyzed. We show that the gene body of an autosomal gene, CSMD1, is differentially methylated in a sex- and placental-specific manner, displaying sex-specific differences in placental transcript abundance.

Genetic analysis of the cardiac methylome at single nucleotide resolution in a model of human cardiovascular disease.

Epigenetic marks such as cytosine methylation are important determinants of cellular and whole-body phenotypes. However, the extent of, and reasons for inter-individual differences in cytosine methylation, and their association with phenotypic variation are poorly characterised. Here we present the first genome-wide study of cytosine methylation at single-nucleotide resolution in an animal model of human disease. We used whole-genome bisulfite sequencing in the spontaneously hypertensive rat (SHR), a model of cardiovascular disease, and the Brown Norway (BN) control strain, to define the genetic architecture of cytosine methylation in the mammalian heart and to test for association between methylation and pathophysiological phenotypes. Analysis of 10.6 million CpG dinucleotides identified 77,088 CpGs that were differentially methylated between the strains. In F1 hybrids we found 38,152 CpGs showing allele-specific methylation and 145 regions with parent-of-origin effects on methylation. Cis-linkage explained almost 60% of inter-strain variation in methylation at a subset of loci tested for linkage in a panel of recombinant inbred (RI) strains. Methylation analysis in isolated cardiomyocytes showed that in the majority of cases methylation differences in cardiomyocytes and non-cardiomyocytes were strain-dependent, confirming a strong genetic component for cytosine methylation. We observed preferential nucleotide usage associated with increased and decreased methylation that is remarkably conserved across species, suggesting a common mechanism for germline control of inter-individual variation in CpG methylation. In the RI strain panel, we found significant correlation of CpG methylation and levels of serum chromogranin B (CgB), a proposed biomarker of heart failure, which is evidence for a link between germline DNA sequence variation, CpG methylation differences and pathophysiological phenotypes in the SHR strain. Together, these results will stimulate further investigation of the molecular basis of locally regulated variation in CpG methylation and provide a starting point for understanding the relationship between the genetic control of CpG methylation and disease phenotypes.

Single nucleotide analysis of cytosine methylation by whole-genome shotgun bisulfite sequencing.

Unlike other methods to assess methylation, whole-genome shotgun bisulfite sequencing is used to generate quantitative genome-wide methylation profiles at single-nucleotide resolution. As described in this unit, this method allows for the quantitative measurement of methylation at each cytosine base by treatment of genomic DNA with sodium bisulfite followed by sequencing and alignment of the reads to a reference genome.

Characterization of management and outcomes of patients with acromegaly in Vancouver over 30 years.

PURPOSE: The purpose of this study was to characterize the management and outcomes of patients with acromegaly seen in single center in Vancouver, British Columbia, Canada over a 30 year period. METHODS: The study involved retrospective data collection from charts of patients diagnosed with acromegaly since 1980: 130 patients (63 male and 67 female) were included in the analysis, with a mean age at diagnosis of 43 years (male) and 47 years (female). RESULTS: The most common presenting features included acral enlargement, coarse facial features, sweating/oily skin and headache. All cases were caused by pituitary adenomas, of which 58.5% were macroadenomas and of these, 30.8% were invasive. The most common co-morbidities were hypertension 31.5%, arthralgia 28%, diabetes 27.7% and sleep apnea 23.8%. The vast majority (88.5%) of patients was treated surgically and of these patients, 21.5% also received radiotherapy and 66.9% received medical therapy. When stringent cure criteria were applied (based on latest growth hormone (GH) and IGF-1 results) the outcomes were 35.4% cured or controlled, 30% remained active, 15.4 discordant results and 19.2 % with no results reported. Twenty eight percent of patients who underwent surgery and 32% of patients who underwent radiotherapy were not cured but symptoms were moderately well controlled with medical therapy. CONCLUSION: Based on the size of population studied, this study showed a prevalence of acromegaly of 29 per million. The cure rate was low following surgery but with adjuvant medical treatment disease control was achieved in most individuals.

The genome sequence of the spontaneously hypertensive rat: Analysis and functional significance.

The spontaneously hypertensive rat (SHR) is the most widely studied animal model of hypertension. Scores of SHR quantitative loci (QTLs) have been mapped for hypertension and other phenotypes. We have sequenced the SHR/OlaIpcv genome at 10.7-fold coverage by paired-end sequencing on the Illumina platform. We identified 3.6 million high-quality single nucleotide polymorphisms (SNPs) between the SHR/OlaIpcv and Brown Norway (BN) reference genome, with a high rate of validation (sensitivity 96.3%-98.0% and specificity 99%-100%). We also identified 343,243 short indels between the SHR/OlaIpcv and reference genomes. These SNPs and indels resulted in 161 gain or loss of stop codons and 629 frameshifts compared with the BN reference sequence. We also identified 13,438 larger deletions that result in complete or partial absence of 107 genes in the SHR/OlaIpcv genome compared with the BN reference and 588 copy number variants (CNVs) that overlap with the gene regions of 688 genes. Genomic regions containing genes whose expression had been previously mapped as cis-regulated expression quantitative trait loci (eQTLs) were significantly enriched with SNPs, short indels, and larger deletions, suggesting that some of these variants have functional effects on gene expression. Genes that were affected by major alterations in their coding sequence were highly enriched for genes related to ion transport, transport, and plasma membrane localization, providing insights into the likely molecular and cellular basis of hypertension and other phenotypes specific to the SHR strain. This near complete catalog of genomic differences between two extensively studied rat strains provides the starting point for complete elucidation, at the molecular level, of the physiological and pathophysiological phenotypic differences between individuals from these strains.

Dissection of chromosome 18 blood pressure and salt-sensitivity quantitative trait loci in the spontaneously hypertensive rat.

Hypertension in humans and experimental models has a strong hereditary basis, but identification of causative genes remains challenging. Quantitative trait loci (QTLs) for hypertension and salt sensitivity have been reported on rat chromosome 18. We set out to genetically isolate and prioritize genes within the salt-sensitivity and hypertension QTLs on the spontaneously hypertensive rat (SHR) chromosome 18 by developing and characterizing a series of congenic strains derived from the SHR and normotensive Brown Norway rat strains. The SHR.BN-D18Rat113/D18Rat82 congenic strain exhibits significantly lower blood pressure and is salt resistant compared with the SHR. Transplantation of kidneys from SHR.BN-D18Rat113/D18Rat82 donors into SHR recipients is sufficient to attenuate increased blood pressure but not salt sensitivity. Derivation of congenic sublines allowed for the separation of salt sensitivity from hypertension QTL regions. Renal expression studies with microarray and Solexa-based sequencing in parental and congenic strains identified 4 differentially expressed genes within the hypertension QTL region, one of which is an unannotated transcript encoding a previously undescribed, small, nonprotein coding RNA. Sequencing selected biological candidate genes within the minimal congenic interval revealed a nonsynonymous variant in SHR transcription factor 4. The minimal congenic interval is syntenic to a region of human chromosome 18 where significant linkage to hypertension was observed in family based linkage studies. These congenic lines provide reagents for identifying causative genes that underlie the chromosome 18 SHR QTLs for hypertension and salt sensitivity. Candidate genes identified in these studies merit further investigation as potentially causative hypertension genes in SHR and human hypertension.

Treatment of a juxtaglomerular tumour with radiofrequency ablation.

Juxtaglomerular tumors, or reninomas, are a rare cause of hypertension, almost always benign and accurately localized by a combination of biochemical tests and imaging. Because the tumors are usually small at presentation, and there are good markers for recurrence, we consider treatment by radiofrequency ablation a useful alternative to nephron-sparing surgery and describe its use in one patient.

Canadian consensus guidelines for the diagnosis and management of acromegaly.

Acromegaly is a chronic condition associated with considerably increased morbidity and mortality if left unchecked. In December 2004, a national meeting was held to discuss the diversity in clinical practice across the country in diagnosing and treating patients with acromegaly, as well as to seek consensus on a number of management principles. The group reviewed recent guidelines and discussed issues of diagnosis, treatment, monitoring and treating comorbidities to seek a Canadian consensus on the management of this rare disorder. Consensus was that diagnosis should include clinical and biochemical findings, but is hinged on establishing GH hypersecretion with IGF-I and OGTT testing. Treatment has traditionally included surgical resection or debulking, along with adjunctive medical therapy (primarily somatostatin analogues), if necessary, to normalize GH levels. The option of primary medical therapy in managing this condition has recently emerged and can be justified for non-surgical candidates or for those in whom surgery is not expected to be curative. Overall, improved screening practices and superior epidemiological data are required, since timely diagnosis and appropriate treatment are crucial for reducing the potentially debilitating effects of this chronic, progressive disease. The current evidence also supports the need for long-term follow-up of disease activity and comorbidities in diagnosed patients. A national meeting was held to discuss the diversity in clinical practice across the country in diagnosing and treating patients with acromegaly, as well as to seek consensus on a number of management principles. After brief reviews of the most recent Canadian guidelines and the 2004 guidelines published by the American Association of Clinical Endocrinologists, the group was asked to specifically examine the issues of diagnosis, treatment, monitoring and treating comorbidities and seek a Canadian consensus on practice. This paper summarizes the working group's findings and the points of consensus that were achieved.

Copy number polymorphism in Fcgr3 predisposes to glomerulonephritis in rats and humans.

Identification of the genes underlying complex phenotypes and the definition of the evolutionary forces that have shaped eukaryotic genomes are among the current challenges in molecular genetics. Variation in gene copy number is increasingly recognized as a source of inter-individual differences in genome sequence and has been proposed as a driving force for genome evolution and phenotypic variation. Here we show that copy number variation of the orthologous rat and human Fcgr3 genes is a determinant of susceptibility to immunologically mediated glomerulonephritis. Positional cloning identified loss of the newly described, rat-specific Fcgr3 paralogue, Fcgr3-related sequence (Fcgr3-rs), as a determinant of macrophage overactivity and glomerulonephritis in Wistar Kyoto rats. In humans, low copy number of FCGR3B, an orthologue of rat Fcgr3, was associated with glomerulonephritis in the autoimmune disease systemic lupus erythematosus. The finding that gene copy number polymorphism predisposes to immunologically mediated renal disease in two mammalian species provides direct evidence for the importance of genome plasticity in the evolution of genetically complex phenotypes, including susceptibility to common human disease.

Quality of life in patients with a pituitary adenoma.

A validated quality of life (QOL) measure, the SF-36 questionnaire, was used to assess patients' perception of the impact of a pituitary adenoma, prior to treatment, on his or her physical and mental functioning. Of 270 new patients evaluated for pituitary disease at the University of Virginia Pituitary Clinic, 168 met the criteria for inclusion (pituitary hormone hypersecretion and/or pituitary adenoma) into this prospective study. Results of the SF-26 questionnaire in 36 patients with acromegaly, 42 patients with Cushing's disease, 39 patients with a prolactinoma and 51 patients with a non functioning macroadenoma prior to treatment were compared with those of the normal population; a comparison of results among patients with different types of pituitary adenomas was also performed. Patients with a pituitary adenoma had a significantly decreased QOL compared with the normal population in both physical and mental measures (p < 0.05). There were different degrees of perceived impairment depending on the type of pituitary adenoma. Patients with acromegaly had impairment in measures of physical function while patient with Cushing's disease had impairment in all but one measures compared with the normal population and with patients with other types of pituitary adenomas. Patients with a prolactinoma had impairment in mental measures and patients with a non-functioning adenoma had impairment in both physical and mental measures compared with the normal population. Patients with a pituitary adenoma have an impaired quality of life that should be routinely assessed in conjunction with endocrine and anatomic studies before and after treatment.

Mutations in ANKH cause chondrocalcinosis.

Chondrocalcinosis (CC) is a common cause of joint pain and arthritis that is caused by the deposition of calcium-containing crystals within articular cartilage. Although most cases are sporadic, rare familial forms have been linked to human chromosomes 8 (CCAL1) or 5p (CCAL2) (Baldwin et al. 1995; Hughes et al. 1995; Andrew et al. 1999). Here, we show that two previously described families with CCAL2 have mutations in the human homolog of the mouse progressive ankylosis gene (ANKH). One of the human mutations results in the substitution of a highly conserved amino acid residue within a predicted transmembrane segment. The other creates a new ATG start site that adds four additional residues to the ANKH protein. Both mutations segregate completely with disease status and are not found in control subjects. In addition, 1 of 95 U.K. patients with sporadic CC showed a deletion of a single codon in the ANKH gene. The same change was found in a sister who had bilateral knee replacement for osteoarthritis. Each of the three human mutations was reconstructed in a full-length ANK expression construct previously shown to regulate pyrophosphate levels in cultured cells in vitro. All three of the human mutations showed significantly more activity than a previously described nonsense mutation that causes severe hydroxyapatite mineral deposition and widespread joint ankylosis in mice. These results suggest that small sequence changes in ANKH are one cause of CC and joint disease in humans. Increased ANK activity may explain the different types of crystals commonly deposited in human CCAL2 families and mutant mice and may provide a useful pharmacological target for treating some forms of human CC.