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.

Bilateral Basal Ganglia Hemorrhage in a Patient with Confirmed COVID-19

Bilateral basal ganglia hemorrhage is exceedingly rare. To our knowledge, our patient is the first reported case of a confirmed coronavirus disease 2019 (COVID-19) patient who had bilateral basal ganglia hemorrhage. In the absence of other risk factors for bilateral deep cerebral involvement, we suspect that COVID-19 may be contributing to these rare pathologies. Most published data represent a correlation between COVID-19 and neurologic complications, and more research is still needed to prove causation.

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.

Functional characterization of the G162R and D216H genetic variants of human CYP17A1

Cytochrome P450 17A1 (CYP17A1) is a dual-function enzyme catalyzing reactions necessary for cortisol and androgen biosynthesis. CYP17A1 is a validated drug target for prostate cancer as CYP17A1 inhibition significantly reduces circulating androgens and improves survival in castration-resistant prostate cancer. Germline CYP17A1 genetic variants with altered CYP17A1 activity manifesting as various endocrinopathies are extremely rare; however, characterizing these variants provides critical insights into CYP17A1 protein structure and function. By querying the dbSNP online database and publically available data from the 1000 genomes project (http://browser.1000genomes.org), we identified two CYP17A1 nonsynonymous genetic variants with unknown consequences for enzymatic activity and stability. We hypothesized that the resultant amino acid changes would alter CYP17A1 stability or activity. To test this hypothesis, we utilized a HEK-293T cell-based expression system to characterize the functional consequences of two CYP17A1 variants, D216H (rs200063521) and G162R (rs141821705). Cells transiently expressing the D216H variant demonstrate a selective impairment of 16α-hydroxyprogesterone synthesis by 2.1-fold compared to wild-type (WT) CYP17A1, while no effect on 17α-hydroxyprogesterone synthesis was observed. These data suggest that substrate orientations in the active site might be altered with this amino acid substitution. In contrast, the G162R substitution exhibits decreased CYP17A1 protein stability compared to WT with a near 70% reduction in protein levels as determined by immunoblot analysis. This variant is preferentially ubiquitinated and degraded prematurely, with an enzyme half-life calculated to be ∼2.5 h, and proteasome inhibitor treatment recovers G162R protein expression to WT levels. Together, these data provide new insights into CYP17A1 structure-function and stability mechanisms.

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.

Oceanic protists with different forms of acquired phototrophy display contrasting biogeographies and abundance

This first comprehensive analysis of the global biogeography of marine protistan plankton with acquired phototrophy shows these mixotrophic organisms to be ubiquitous and abundant; however, their biogeography differs markedly between different functional groups. These mixotrophs, lacking a constitutive capacity for photosynthesis (i.e. non-constitutive mixotrophs, NCMs), acquire their phototrophic potential through either integration of prey-plastids or through endosymbiotic associations with photosynthetic microbes. Analysis of field data reveals that 40-60% of plankton traditionally labelled as (non-phototrophic) microzooplankton are actually NCMs, employing acquired phototrophy in addition to phagotrophy. Specialist NCMs acquire chloroplasts or endosymbionts from specific prey, while generalist NCMs obtain chloroplasts from a variety of prey. These contrasting functional types of NCMs exhibit distinct seasonal and spatial global distribution patterns. Mixotrophs reliant on 'stolen' chloroplasts, controlled by prey diversity and abundance, dominate in high-biomass areas. Mixotrophs harbouring intact symbionts are present in all waters and dominate particularly in oligotrophic open ocean systems. The contrasting temporal and spatial patterns of distribution of different mixotroph functional types across the oceanic provinces, as revealed in this study, challenges traditional interpretations of marine food web structures. Mixotrophs with acquired phototrophy (NCMs) warrant greater recognition in marine research.

Intraoperative use of a transarticular circular fixator construct to facilitate reduction and stabilisation of a proximal tibial physeal fracture in a dog

CASE REPORT

A 4-month-old female intact American Pit Bull Terrier was presented for right pelvic limb lameness 1 day after the dog had been hit by an all-terrain vehicle. Orthogonal radiographs of the right stifle revealed a Salter-Harris type IV fracture through the proximal tibial physis extending caudodistally through the proximal tibial metaphysis. The distal tibia was markedly displaced cranially, laterally and proximally, resulting in complete overriding of the fracture segments. An open approach was made in order to facilitate direct reduction, but the fracture could not be sufficiently distracted and the epiphyseal segment remained fixed caudal to the remainder of the tibia. Concerns regarding possible iatrogenic trauma to the epiphysis prompted the use of a transarticular circular fixator construct to distract the fracture segments to facilitate reduction. Distraction that facilitated reduction was performed using three TrueLok Rapid Quick Adjust Struts that were positioned between the two ring components. The struts also allowed for multiplanar adjustment of alignment, which allowed the fracture to be maintained in anatomic reduction as divergent interfragmentary Kirschner wires were placed. Radiographic union was confirmed 19 days after surgery.

CONCLUSION/CLINICAL SIGNIFICANCE

Transient intraoperative application of a circular construct incorporating the TrueLok components facilitated accurate fracture reduction without inflicting further iatrogenic trauma to the epiphysis, after traditional direct reduction techniques proved ineffective, and afforded a successful clinical outcome in the dog reported here.

The influence of taste in willingness-to-pay valuations of sirloin steaks from postextraction algal residue-fed cattle

Consumer preferences and willingness-to-pay (WTP) for beef sirloin steaks with differing production, physical, and credence attributes related to the use of postextraction algal residue (PEAR), a novel feed ingredient, were estimated. Ninety-six consumers participated in a sensory tasting panel before completing a choice set survey; 127 consumers completed only the choice set survey without sampling products. Steaks from grain- and PEAR-fed steers had similar Warner-Bratzler shear force (WBSF) scores (1.89 kg and 2.01 kg, respectively; = 0.77) and had lower WBSF scores than steaks from grass-fed steers (3.37 kg; < 0.05). Eicosapentaenoic acid (20:5) was not different among steaks from grain- and PEAR-fed steers ( = 0.39) but was greater compared with steaks from grass-fed cattle ( ≤ 0.03). Panelists in the sensory portion of the study evaluated beef samples for like/dislike of overall sample, overall flavor, beefy flavor, and juiciness. Panelist rating of overall like, overall flavor like, and beefy flavor like were not different between the PEAR- and grain-fed treatments ( > 0.26). Panelists rated the juiciness like/dislike of steaks from PEAR-fed cattle the highest ( < 0.01) among the 3 samples. Sensory tasting of the products was observed to alter the preferences of consumers. Consumers who completed only the survey negatively perceived beef from PEAR-fed cattle compared with beef from grain-fed cattle, with a WTP discount of -US$1.17/kg. However, with sensory tasting, the WTP for beef from PEAR-fed cattle was not discounted relative to beef from grain-fed cattle ( = 0.21). The nontasting consumers had much higher stated WTP values for credence attributes. Factors that influence the eating experience (tenderness and quality grade) dominated as the most important attributes on WTP among the tasting group. The use of no hormones and no antibiotics in production had a premium of $2.34/kg among the nontasting group, but with tasting, the premium was $1.19/kg. If PEAR-fed beef came to market, there would be no need to differentiate it from grain-fed beef unless retailers wanted to market it as a differentiated product. If it were marketed as a differentiated product, retailers would need to hold promotional tastings to change consumer's preconceived notions about the product.

Physiological changes in the pallidum in a progressive model of Parkinson's disease: Are oscillations enough?

Neurophysiological changes in the basal ganglia thalamo-cortical circuit associated with the development of parkinsonian motor signs remain poorly understood. Theoretical models have ranged from those emphasizing changes in mean discharge rate to increased oscillatory activity within the beta range. The present study characterized neuronal activity within and across the internal and external segments of the globus pallidus as a function of motor severity using a staged, progressively severe 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinsonism in three rhesus monkeys. An increase in coherence between neuronal pairs across the external and internal globus pallidus was present in multiple frequency bands in the parkinsonian state; both the peak frequency of oscillatory coherence and the variability were reduced in the parkinsonian state. The incidence of 8-20Hz oscillatory activity in the internal globus pallidus increased with the progression of the disease when pooling the data across the three animals; however it did not correlate with motor severity when assessed individually and increased progressively in only one of three animals. No systematic relationship between mean discharge rates or the incidence or structure of bursting activity and motor severity was observed. These data suggest that exaggerated coupling across pallidal segments contribute to the development of the parkinsonian state by inducing an exaggerated level of synchrony and loss of focusing within the basal ganglia. These data further point to the lack of a defined relationship between rate changes, the mere presence of oscillatory activity in the beta range and bursting activity in the basal ganglia to the motor signs of Parkinson's disease.

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.

Epigenetic marks provide information that is not encoded in the primary DNA sequence itself but in modifications of genomic DNA and of the associated proteins. Methylation of genomic DNA at cytosine residues is an important epigenetic modification that is associated with developmental processes, carcinogenesis and other diseases. Genome-wide extent of, and reasons for inter-individual differences in cytosine methylation, and their association with phenotypic variation are poorly characterised. To address these questions we have determined and compared the genome-wide methylation patterns in heart tissue of two inbred rat strains, the spontaneously hypertensive rat, an animal model of human disease and a control rat strain. Comparison of methylation differences between genetically identical animals from the same strain and differences between animals from different strains allowed us to quantify association of epigenetic and genetic differences. We show that differences in an individual's germline DNA sequence are important determinants of the variability in methylation between individuals. Comparison with previous reports implicates common mechanisms for regulation of cytosine methylation that are highly conserved across species. Finally, we find correlation between a proposed blood biomarker for heart failure and variation in DNA methylation, suggesting a link between germline DNA sequence variation, methylation and a disease-related phenotype.

KAP regulates ROCK2 and Cdk2 in an RNA-activated glioblastoma invasion pathway

Aberrant splicing of the cyclin-dependent kinase-associated phosphatase, KAP, promotes glioblastoma invasion in a Cdc2-dependent manner. However, the mechanism by which this occurs is unknown. Here we show that miR-26a, which is often amplified in glioblastoma, promotes invasion in phosphatase and tensin homolog (PTEN)-competent and PTEN-deficient glioblastoma cells by directly downregulating KAP expression. Mechanistically, we find that KAP binds and activates ROCK2. Thus, RNA-mediated downregulation of KAP leads to decreased ROCK2 activity and this, in turn, increases Rac1-mediated invasion. In addition, the decrease in KAP expression activates the cyclin-dependent kinase, Cdk2, and this directly promotes invasion by increasing retinoblastoma phosphorylation, E2F-dependent Cdc2 expression and Cdc2-mediated inactivation of the actomyosin inhibitor, caldesmon. Importantly, glioblastoma cell invasion mediated by this pathway can be antagonized by Cdk2/Cdc2 inhibitors in vitro and in vivo. Thus, two distinct RNA-based mechanisms activate this novel KAP/ROCK2/Cdk2-dependent invasion pathway in glioblastoma.

Acute focal bacterial nephritis due to methicillin-resistant Staphylococcus aureus in an immunocompetent adult

Acute focal bacterial nephritis (AFBN) is a rare, acute focal infection of the renal parenchyma without liquefaction. The pathogenesis is thought to be due to hematogenous infection or ascending infection from the lower urinary tract. Escherichia coli has been the major pathogen isolated in prior cases, but other Gram-negative enteric pathogens and Staphylococcus aureus have been reported as well. It is well described in children and adults with diabetes and organ transplantation, but has not been previously reported in healthy adults. We report a case of an immunocompetent adult female who presented with a methicillin-resistant Staphylococcus aureus bacteremia after a skin and soft tissue infection that resulted in AFBN.

Autophagy is redundant for the host defense against systemic Candida albicans infections

Autophagy has been demonstrated to play an important role in the immunity against intracellular pathogens, but very little is known about its role in the host defense against fungal pathogens such as Candida albicans. Therefore, the role of autophagy for the host defense against C. albicans was assessed by complementary approaches using mice defective in autophagy, as well as immunological and genetic studies in humans. Although C. albicans induced LC3-II formation in macrophages, myeloid cell-specific ATG7(-/-) mice with defects in autophagy did not display an increased susceptibility to disseminated candidiasis. In in vitro experiments in human blood mononuclear cells, blocking autophagy modulated cytokine production induced by lipopolysaccharide, but not by C. albicans. Furthermore, autophagy modulation in human monocytes did not influence the phagocytosis and killing of C. albicans. Finally, 18 single-nucleotide polymorphisms in 13 autophagy genes were not associated with susceptibility to candidemia or clinical outcome of disease in a large cohort of patients, and there was no correlation between these genetic variants and cytokine production in either candidemia patients or healthy controls. Based on these complementary in vitro and in vivo studies, it can be concluded that autophagy is redundant for the host response against systemic infections with C. albicans.

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.

Evaluation of a digital microfluidic real-time PCR platform to detect DNA of Candida albicans in blood

Species of Candida frequently cause life-threatening infections in neonates, transplant and intensive care unit (ICU) patients, and others with compromised host defenses. The successful management of systemic candidiasis depends upon early, rapid diagnosis. Blood cultures are the standard diagnostic method, but identification requires days and less than half of the patients are positive. These limitations may be eliminated by using real-time polymerase chain reaction (PCR) to detect Candida DNA in the blood specimens of patients at risk. Here, we optimized a PCR protocol to detect 5-10 yeasts in low volumes of simulated and clinical specimens. We also used a mouse model of systemic candidiasis and determined that candidemia is optimally detectable during the first few days after infection. However, PCR tests are often costly, labor-intensive, and inconvenient for routine use. To address these obstacles, we evaluated the innovative microfluidic real-time PCR platform (Advanced Liquid Logic, Inc.), which has the potential for full automation and rapid turnaround. Eleven and nine of 16 specimens from individual patients with culture-proven candidemia tested positive for C. albicans DNA by conventional and microfluidic real-time PCR, respectively, for a combined sensitivity of 94%. The microfluidic platform offers a significant technical advance in the detection of microbial DNA in clinical specimens.

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.

Interactions between focused synaptic inputs and diffuse neuromodulation in the spinal cord

Spinal motoneurons (MNs) amplify synaptic inputs by producing strong dendritic persistent inward currents (PICs), which allow the MN to generate the firing rates and forces necessary for normal behaviors. However, PICs prolong MN depolarization after the initial excitation is removed, tend to "wind-up" with repeated activation and are regulated by a diffuse neuromodulatory system that affects all motor pools. We have shown that PICs are very sensitive to reciprocal inhibition from Ia afferents of antagonist muscles and as a result PIC amplification is related to limb configuration. Because reciprocal inhibition is tightly focused, shared only between strict anatomical antagonists, this system opposes the diffuse effects of the descending neuromodulation that facilitates PICs. Because inhibition appears necessary for PIC control, we hypothesize that Ia inhibition interacts with Ia excitation in a "push-pull" fashion, in which a baseline of simultaneous excitation and inhibition allows depolarization to occur via both excitation and disinhibition (and vice versa for hyperpolarization). Push-pull control appears to mitigate the undesirable affects associated with the PIC while still taking full advantage of PIC amplification.

Courteous service: Its assessment and modification in a human service organization

We evaluated strategies to increase behaviors associated with courteous provision of service by 3 staff members of a human service agency. Training included written instructions, practice, and performance feedback. A lottery procedure was introduced to maintain courteous service after training. The results of a multiple baseline design across the 3 participants showed marked increases in courteous behaviors following training. These effects were maintained at 3-, 5-, and 8-month follow-ups. Consumers' satisfaction with service also increased. These findings suggest that simple training and reinforcement procedures can enhance courtesy afforded those who receive service from public and nonprofit organizations.

Efavirenz directly modulates the oestrogen receptor and induces breast cancer cell growth

OBJECTIVES

Efavirenz-based HIV therapy is associated with breast hypertrophy and gynaecomastia. Here, we tested the hypothesis that efavirenz induces gynaecomastia through direct binding and modulation of the oestrogen receptor (ER).

METHODS

To determine the effect of efavirenz on growth, the oestrogen-dependent, ER-positive breast cancer cell lines MCF-7, T47D and ZR-75-1 were treated with efavirenz under oestrogen-free conditions in the presence or absence of the anti-oestrogen ICI 182,780. Cells treated with 17β-oestradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure the ER binding affinity of efavirenz.

RESULTS

Efavirenz induced growth in MCF-7 cells with an estimated effective concentration for half-maximal growth (EC(50)) of 15.7 μM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to the ER [inhibitory concentration for half maximal binding (IC(50)) of ∼52 μM] at a roughly 1000-fold higher concentration than observed with 17β-oestradiol.

CONCLUSIONS

Our data suggest that efavirenz-induced gynaecomastia may be caused, at least in part, by drug-induced ER activation in breast tissues.

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.

Decrease in apparent alpha1-adrenoceptor-G protein coupling during maturation in rat aorta

We have previously shown that the adrenoceptor agonist norepinephrine (NE) is more potent in eliciting contraction in aortas from 1-month-old Fischer 344 rats than it is in older animals. In the present study, we examined alpha1-adrenoceptor-guanine nucleotide regulatory binding protein (G protein) coupling in aortic membranes in order to investigate the mechanism for the age-dependent reduced responsiveness of aorta to NE. We used the guanosine 5'(betagamma-imido)triphosphate (Gpp[NH]p)-induced shift in agonist binding affinity as a measure of the efficiency of alpha11-adrenoceptor-G protein coupling. The binding of NE was assessed by measuring the displacement of 2-[beta-(4-hydroxy-3-[125I]iodophenyl)ethylaminomethyl] tetralone ([125]-HEAT) by NE in aortic membranes. In 1-, 6-, and 24-month-old rat aortas, two apparent binding sites were detected in the competition isotherms for NE. This heterogeneous binding pattern was independent of Gpp(NH)p at all ages, and is likely to be due to a heterogeneous receptor population (alpha(1a), alpha(1b), and alpha(1d) subtypes). In 1-month-old rats, the high affinity binding of NE to alpha,-adrenoceptors was sensitive to Gpp(NH)p, indicating a significant interaction between the receptor and G protein. This Gpp(NH)p-sensitive high affinity binding was not observed in aortas from 6- or 24-month-old animals. Despite the lack of Gpp(NH)p-sensitive high affinity binding of agonist in 6- or 24-month-old aortas, NE was still able to induce maximal contraction in these aortas, albeit, with a relatively low potency. A partial reduction in alpha1-adrenoceptor-G protein coupling between 1 and 6 months of age can explain the observed decrease in ago- nist potency and the loss of Gpp(NH)p-sensitive high affinity binding of NE. This phenomenon can be explained as a reduction of allosteric coupling between the bindings of ligand and G protein to the receptor, that has been formulated in the ternary complex model. Computer simulation using the simple ternary complex model shows that manipulating the reciprocal coupling factor alone can lead to a loss of Gpp(NH)p-sensitive high affinity agonist binding, along with a reduction in agonist potency for contraction without altering the maximal response. Thus, a change in the relative expression of different alpha,-adrenoceptor subtypes, which we have previously observed in the aorta, and which possess diverse intrinsic allosteric couplings, may be speculated to be the mechanism for the apparent reduction of alpha,-adrenoceptor-G protein coupling during maturation.

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.

Bias voltages at microelectrodes change neural interface properties in vivo

Rejuvenation of iridium microelectrode sites, which involves applying a 1.5 V bias for 4 s, has been shown to reduce site impedances of chronically implanted microelectrode arrays. This study applied complex impedance spectroscopy measurements to an equivalent circuit model of the electrode-tissue interface. Rejuvenation was found to cause a transient increase in electrode conductivity through an IrO2 layer and a decrease in the surrounding extracellular resistance by 85 +/- 1% (n=73, t-test p < 0.001) and a decrease in the immediate site resistance by 44 +/- 7% (n=73, t-test p<0.001). These findings may be useful as an intervention strategy to prolong the lifetime of chronic microelectrode implants for neuroprostheses.

Combination antifungal therapy: what can and should we expect?

Invasive fungal infections are associated with significant morbidity and mortality among immunocompromised patients. Recent advances in antifungal development have afforded us more pharmacologic compounds to choose from when managing these fungal infections. The role of combination antifungal therapy has been well established for fungal infections such as cryptococcal meningitis. The availability of new antifungals, increased incidence of mould infections and high mortality among certain affected populations, such as hematopoietic stem cell transplant recipients, has stimulated interest in the clinical use of combination antifungal therapy. In this paper, we review supporting evidence for the use of combination antifungals in the treatment of cryptococcal meningitis, invasive candidiasis, invasive aspergillosis and zygomycosis. Several controlled clinical trials have demonstrated benefits of combination antifungal approaches for patients with cryptococcal meningitis and invasive candidiasis, but variable effects when using different agents in combination have been reported. Randomized prospective studies of combination antifungal therapy in mould infections are lacking but some series provide supportive evidence for this approach. We also describe limitations of the data and these study designs, including the fact that we still need randomized controlled multicenter studies of combination antifungal therapy for mould infections. Trials in this area should be performed with efficiency and economics in mind, and could potentially use surrogate markers as end points. Therefore, we suggest future investigations of combination antifungal therapy should include a randomized, comparative trial of primary therapy for invasive aspergillosis.

Transforming growth factor beta and monocyte chemotactic protein-1 are elevated in cerebrospinal fluid of immunocompromised patients with HIV-1 infection

Monocyte infiltration of the brain is central to the pathogenesis of HIV-1 encephalitis. The cytokines promoting recruitment of monocytes into the central nervous system during HIV-1 infection are not established. In this study, we evaluated human cerebrospinal fluid from patients with HIV-1 infection for transforming growth factor beta1 (TGFbeta1) and monocyte chemotactic protein-1 (MCP-1) using a quantitative sandwich enzyme-linked immunoassays. Cytokine levels were compared to those from patients with multiple sclerosis and normal controls. In cerebrospinal fluid of patients with HIV-1 infection and CD4<500 cells/mm3, both TGFbeta1 and MCP-1 were significantly elevated compared to those with CD4>500 cells/mm3, multiple sclerosis, and controls.

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.

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.

Bax regulates c-Myc-induced mammary tumour apoptosis but not proliferation in MMTV-c-myc transgenic mice

The expression of the proto-oncogene c-myc is frequently deregulated, via multiple mechanisms, in human breast cancers. Deregulated expression of c-myc contributes to mammary epithelial cell transformation and is causally involved in mammary tumorigenesis in MMTV-c-myc transgenic mice. c-Myc is known to promote cellular proliferation, apoptosis, genomic instability and tumorigenesis in several distinct tissues, both in vivo and in vitro. Expression of the proapoptotic regulatory gene bax is reduced or absent in human breast cancers, and c-Myc has been shown to regulate the expression of Bax, as well as cooperate with Bax in controlling apoptosis in a fibroblast model. Additionally, loss of bax reduces c-Myc-induced apoptosis in lymphoid cells and increases c-Myc-mediated lymphomagenesis in vivo. In order to assess whether loss of bax could influence c-Myc-induced apoptosis and tumorigenesis in the mammary gland in vivo, we generated MMTV-c-myc transgenic mice in which neither, one, or both wild-type alleles of bax were eliminated. Haploid loss of bax in MMTV-c-myc transgenic mice resulted in significantly reduced mammary tumour apoptosis. As anticipated for an apoptosis-regulatory gene, loss of the wild-type bax alleles did not significantly alter cellular proliferation in either mammary adenocarcinomas or dysplastic mammary tissues. However, in contrast to c-Myc-mediated lymphomagenesis, loss of one or both alleles of bax in MMTV-c-myc transgenic mice did not significantly enhance mammary tumorigenesis, despite evidence that haploid loss of bax might modestly increase mammary tumour multiplicity. Our results demonstrate that Bax contributes significantly to c-Myc-induced apoptosis in mammary tumours. In addition, they suggest that in contrast to c-Myc-induced lymphomagenesis, mammary tumorigenesis induced by deregulated c-myc expression requires some amount of Bax expression.

Molecular genetic and proteomic analysis of synchronous malignant gliomas

Described is a patient with concurrent discrete gliomas: a pleomorphic xanthoastrocytoma with anaplastic features and an anaplastic oligoastrocytoma. The distinct and morphologically dissimilar tumors demonstrated similar genetic abnormalities by loss of heterozygosity and comparative genome hybridization. Clonality and proteomic analyses highlighted an independent origin for the two tumors. Proteomic methods may prove useful in cases where the differential diagnosis and pathogenetic origin of tumors are uncertain, as well as more globally for its ability to provide insight into specific expression of proteins that may serve as unique markers of tumorigenesis or as novel targets of therapy.

Thermodynamic model of electric-field-induced pattern formation in binary dielectric fluids

An electric-field-induced phase transition and pattern formation in a binary dielectric fluid layer are studied using a coarse-grained free-energy functional. The electrostatic part of the free energy is a nonlinear functional of the dielectric function, which depends in turn on the local colloidal concentration. We determine the phase coexistence curve and find that beyond a critical electric field the system phase separates. Accompanying the phase separation are patterns similar to those observed in a spinodal decomposition of an ordinary binary fluid. The temporal evolution of the phase separating patterns are discussed both analytically and numerically by integrating a Cahn-Hilliard type of equation.

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.

An improved resazurin-based cytotoxicity assay for hepatic cells

A simple resazurin-based cytotoxicity assay is presented for screening of cytotoxicity in hepatocytes and liver cell lines. Human hepatoma (HepG2) cells in 96-well culture plates were exposed to known toxic (cisplatin, 5-fluorouracil, ethionine, flufenamic acid, and diflunisal) and control (transplatin, 5-chlorouracil, methionine, and acetylsalicylic acid) compounds for 1-3 days, and resazurin (5 micromol/L) was added. A conventional short-term (1 h) assay was first performed, where cytotoxicity is indicated by decreased reduction of resazurin to its fluorescent product resorufin. Our improved assay consists of additionally measuring fluorescence 2-4 days later, when cytotoxicity is indicated by a striking increase in the concentration of resorufin, resulting from two distinct processes. First, viable liver-derived cells slowly convert resorufin to nonfluorescent metabolites. Fluorescence of control cell wells decreased to background during a 2- to 4-day exposure to resazurin. This metabolism of resorufin was largely blocked by dicumarol and to lesser extents by disulfiram and SKF525a. Second, dead or dying cells slowly convert resazurin to resorufin but do not further metabolize resorufin; thus this fluorescent metabolite accumulates to high levels in wells with dead cells by 2 to 4 days. A similar increase in fluorescence associated with cytotoxicity was observed in primary cultures of rat hepatocytes using the long-term resazurin-based assay. In addition to an improved signal relative to the short-term assay, the inversion of the fluorescent signal from high = alive short-term to high = dead long-term allows determination of two independent cytotoxicity endpoints after addition of one innocuous vital dye.

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.

Nile Red binding to HepG2 cells: an improved assay for in vitro studies of hepatosteatosis

Nile Red is a fluorescent dye used extensively to study fat accumulation in many types of cells; unfortunately protocols that work well for most cells are not effective for studying drug-induced lipid accumulation in cultured liver cells and hepatocyte-derived cell lines. Using human hepatoma (HepG2) cells, we have developed a simple Nile Red binding assay as a screen for steatosis-inducing compounds. Increases in Nile Red binding in response to known hepatotoxic compounds were observed after incubating treated cells with 1 microM Nile Red for several hours, washing away free Nile Red, and then allowing redistribution, and/or clearance of the lipid-indicator dye. Several compounds known to cause hepatic fat accumulation in vivo were examined and most robustly increased Nile Red binding in HepG2 cells. These include estrogen and other steroids, ethionine, cyclosporin A, and valproic acid. Required concentrations for increased Nile Red binding were generally three-fold or more lower than the cytotoxic concentration determined by a resazurin reduction assay in the same cells. Qualitatively similar Nile Red binding results were obtained when primary canine or rat hepatocytes were used. Morphological differences in Nile Red staining were observed by confocal fluorescence microscopy in HepG2 cells after treatment with different compounds and likely reflect distinct toxicological mechanisms.

Uses of DHEA in aging and other disease states

Dehydro-3-epiandrosterone is a steroid hormone synthesized in large quantities by the adrenal gland whose physiologic role remains unclear. The effects of DHEA could be estrogenic or androgenic, depending on the hormonal milieu. Low levels of DHEA are associated with aging, cardiovascular disease in men, and an increased risk of pre-menopausal breast and ovarian cancer. High levels of DHEA might increase the risk of postmenopausal breast cancer. Therapeutically DHEA might be useful for improving psychological well-being in the elderly, reducing disease activity in people with mild to moderate systemic lupus erythematosus and myotonic dystrophy, improving mood in those clinically depressed, and improving various parameters in women with adrenal insufficiency. Although many other claims have been made for DHEA in diverse conditions, such as aging, dementia, and AIDS, no well-designed clinical trials have clearly substantiated the utility and safety of long-term DHEA supplementation.

Rifampin is a selective, pleiotropic inducer of drug metabolism genes in human hepatocytes: studies with cDNA and oligonucleotide expression arrays

We used expression microarrays to test the effects of rifampin on the overall pattern of mRNA expression of multiple metabolic enzymes in primary human hepatocytes. Two microarrays were utilized, a cDNA-based array and one that is oligonucleotide-based. The cDNA-based expression arrays showed that rifampin caused a 7.7 +/- 6.6-fold induction in CYP2A6 and a 4.0 +/- 2.0-fold increase in the CYP2C family of enzymes while having little effect on CYP2E1 or CYP2D6. Many non-P450 enzymes were also induced including FMO-4 and -5, UGT-1A, MAO-B, and GST-P1. The oligonucleotide-based array made it possible to detect different levels of induction within the CYP2C family, with rifampin causing a 6.5-fold increase in expression of CYP2C8 and a 3.7-fold increase in CYP2C9 while having no effect on the level of CYP2C18 mRNA. Rifampin also induced other CYP enzymes including CYP2B6 and all three members of the CYP3A family, with CYP3A4 showing the highest level of induction at 55.1-fold. RNase protection assays were used to validate results from the arrays and a comparison of all three methods of mRNA detection showed qualitatively similar results. These data make it clear that rifampin treatment brings about broad changes in the pattern of gene expression, rather than increased expression of a small number of metabolic enzymes. Clinicians and researchers who use and study rifampin and other drugs that induce drug metabolism should be alert to the possibility of multiple effects.

Detection of proliferating S-phase brain tumor cells by in situ DNA replication

OBJECT

Current methods used to describe the proliferative status of brain tumors rely on labor-intensive, potentially costly procedures. This article provides a description of a rapid, inexpensive, uncomplicated technique used to identify proliferating cells in tissue obtained at the time of resection.

METHODS

Touch preparations of 16 fresh astrocytic tumors and four fresh healthy temporal neocortical tissue samples were obtained at the time of surgery. Slides were placed in hypotonic potassium chloride to permeabilize their membranes, incubated in nucleotide precursors, and labeled with bromodeoxyuridine; they were later examined with the aid of a fluorescence microscope. The percentage of tumor cells in the S phase increased in conjunction with the grade of tumor and corresponded with the findings of immunohistochemical staining for the cell-cycle marker MIB-1. These results were confirmed in cell culture by using normal human astrocytes and two glioma cell lines. Slides can be analyzed in as little as 30 minutes after removal of tissue during surgery.

CONCLUSIONS

In this study the authors describe a simple method by which cells in the S phase of the cell cycle. which are contained in fresh tumor obtained at the time of surgery, can be labeled. This method may prove a useful adjunct to frozen-section analysis and may permit discrimination of neoplastic tissues from other tissues observed in small specimen samples.

Carcinoid tumor development in an intramedullary spinal cord mature teratoma

The case of a 43-year-old woman with a several month history of severe back pain is reported. CT and MR imaging revealed an intramedullary cystic tumor, which was considered a dermoid cyst or teratoma. During surgery, the tumor was found within the base of the filum terminale and completely resected. Microscopic studies revealed a mature teratoma with an intramural carcinoid nodule. Thirteen-month follow-up after surgical resection showed no evidence of tumor recurrence or neoplasms elsewhere.

Cytochrome P450 induction in rat hepatocytes assessed by quantitative real-time reverse-transcription polymerase chain reaction and the RNA invasive cleavage assay

The acceleration of drug discovery due to combinatorial chemistry and high-throughput screening methods has increased the numbers of candidate pharmaceuticals entering the drug development phase, and the capability to accurately predict whether drug candidates will induce various members of the drug-metabolizing cytochrome P450 (CYP) enzyme superfamily is currently of great interest to the pharmaceutical industry. In the present study, we describe the rapid and reliable analysis of CYP induction in a readily obtained model system (cultured rat hepatocytes) using both real-time quantitative reverse transcription-polymerase chain reaction (real-time RT-PCR) and the RNA invasive cleavage assay. The levels of members in the three primary inducible rat CYP subfamilies (CYP1A1, CYP2B1/2, and CYP3A1) were analyzed in untreated and induced (beta-naphthoflavone, phenobarbital, and hydrocortisone) hepatocyte cultures under various media conditions to screen for optimal CYP induction profiles. The fold inductions measured by real-time RT-PCR and the RNA invasive cleavage assay were also compared with enzyme activity measurements in parallel cultures using liquid chromatography/double mass spectrometry-based assays, and the sensitivity and the specificity of the two RNA analysis methods were compared. Using these techniques, various culture conditions were examined for optimizing induction of the three CYP subfamily members. Both real-time RT-PCR and the RNA invasive cleavage assay prove to be effective methods for determining the effects of drugs on specific CYPs in primary rat hepatocytes.

Increased stromal expression of murine urokinase plasminogen activator in a human breast cancer xenograft model following treatment with the matrix metalloprotease inhibitor, batimastat

The matrix metalloprotease (MMP) family of enzymes and the urokinase plasminogen activator (uPA) pathway have both been implicated in tumor invasion and metastasis and in poor prognosis of cancer. We have previously shown that treatment with batimastat, a synthetic MMP inhibitor, leads to significant retardation but not regression of tumor growth in a human breast cancer xenograft model. In addition, batimastat treatment did not inhibit local tumor invasion, nor did it encourage stromal encapsulation of the tumor, suggesting the additional involvement of non-MMP proteolytic mechanisms. To investigate the presence of an alternative extracellular matrix protease whose activity is known to be important in breast cancer, but which is not inhibited by batimastat, expression of murine and human uPA were examined by in situ hybridization and ELISA. No differences were observed between untreated and batimastat-treated tumors regarding human uPA mRNA and protein. In contrast, murine uPA mRNA expression was increased at the tumor-stromal junction in batimastat-treated tumors in comparison with the control tumors. In agreement with these results, batimastat treatment was shown to significantly induce murine uPA protein content in the tumors. Inoculating MDA435/LCC-6 cells into immunodeficient, uPA-deficient mice resulted in tumor growth retardation as compared to tumor growth in littermate wild-type controls, while addition of batimastat treatment to uPA-/- mice did not result in further growth inhibition. The increased expression of stromal uPA may represent a cellular response to MMP inhibition and may demonstrate a new level of plasticity in the malignant progression of the disease. These results may have important implications for the clinical applications of MMP inhibitors, as well as for development of other anti-invasion drugs.

Immunohistochemical localization and comparison of carboxypeptidases D, E, and Z, alpha-MSH, ACTH, and MIB-1 between human anterior and corticotroph cell "basophil invasion" of the posterior pituitary

Basophil invasion, i.e., invasion of basophilic corticotrophs from the residual intermediate lobe into the posterior lobe of the human pituitary gland, is believed to be a physiological phenomenon. This study evaluated the distribution of CPE, CPD, CPZ, alpha-MSH, ACTH, and Ki-67 immunoreactivity between human anterior pituitary and basophil invasion of the neurohypophysis. Mild to moderate immunoreactivities for CPE and CPZ were distributed relatively uniformly in the majority of the anterior pituitary cells and basophil invasion. In contrast, only corticotrophs exhibited intense CPD immunoreactivity. Basophil invasion showed similar immunoreactivities for alpha-MSH, ACTH, CPE, and CPZ as corticotrophs in the anterior pituitary, except for CPD, which was detected much less frequently. In the posterior lobe, CPE, CPD, and CPZ were present within the Herring bodies. Although no MIB-1 immunoreactivity was identified in anterior pituitary cells, limited MIB-1 labeling was detected in basophil invasion in five of ten cases. Highly selective expression of CPD in corticotrophs suggests that CPD plays a particularly important role in prohormone (POMC) processing in corticotrophs, with minimal or no significant roles in non-corticotrophs. Evidence that corticotrophs in basophil invasion are undergoing proliferation and are also phenotypically different from their counterpart in the anterior pituitary has further raised the possibility of some neoplastic potential.

Oligodendroglial ganglioglioma with anaplastic features arising from the thalamus

Anaplastic gangliogliomas with an oligodendroglial component are exceedingly rare tumors of uncertain growth potential. We report a 17-year-old female with a massive ganglioglioma containing anaplastic oligodendroglioma apparently arising from the thalamus. Two weeks after partial resection, she was started on a regimen including escalated doses of topotecan in combination with a fixed-dosage intensification regimen of cisplatin, cyclophosphamide and vincristine with subsequent hyperfractionated external beam radiotherapy. She currently has stable disease.

Strength training by children and adolescents

Pediatricians are often asked to give advice on the safety and efficacy of strength training programs for children and adolescents. This review, a revision of a previous American Academy of Pediatrics policy statement, defines relevant terminology and provides current information on risks and benefits of strength training for children and adolescents.

Five-color-based high-information-content fingerprinting of bacterial artificial chromosome clones using type IIS restriction endonucleases

We have developed a high-information-content fingerprinting (HICF) system for bacterial artificial chromosome (BAC) clones using a Type IIS restriction endonuclease, HgaI, paired with a Type II restriction endonuclease, RsaI. In the method described, unknown five-base overhangs generated with HgaI are partially or fully sequenced by modified fluorescent dideoxy terminators. Using an in-lane size standard labeled with a fifth dye, fragments are characterized by both the size and the sequence of its terminal one to five bases. The enhanced information content associated with this approach significantly increases the accuracy and efficiency of detecting shared fragments among BAC clones. We have compared data obtained from this method to predicted HICF patterns of 10 fully sequenced BACs. We have further applied HICF to 555 BAC clones to assemble contigs spanning 16p11.2 to 16p13.1 of human chromosome 16.

Organized sports for children and preadolescents

Participation in organized sports provides an opportunity for young people to increase their physical activity and develop physical and social skills. However, when the demands and expectations of organized sports exceed the maturation and readiness of the participant, the positive aspects of participation can be negated. The nature of parental or adult involvement can also influence the degree to which participation in organized sports is a positive experience for preadolescents. This updates a previous policy statement on athletics for preadolescents and incorporates guidelines for sports participation for preschool children. Recommendations are offered on how pediatricians can help determine a child's readiness to participate, how risks can be minimized, and how child-oriented goals can be maximized.