Rhesus infant nervous temperament predicts peri-adolescent central amygdala metabolism & behavioral inhibition measured by a machine-learning approach

Anxiety disorders affect millions of people worldwide and impair health, happiness, and productivity on a massive scale. Developmental research points to a connection between early-life behavioral inhibition and the eventual development of these disorders. Our group has previously shown that measures of behavioral inhibition in young rhesus monkeys (Macaca mulatta) predict anxiety-like behavior later in life. In recent years, clinical and basic researchers have implicated the central extended amygdala (EAc)-a neuroanatomical concept that includes the central nucleus of the amygdala (Ce) and the bed nucleus of the stria terminalis (BST)-as a key neural substrate for the expression of anxious and inhibited behavior. An improved understanding of how early-life behavioral inhibition relates to an increased lifetime risk of anxiety disorders-and how this relationship is mediated by alterations in the EAc-could lead to improved treatments and preventive strategies. In this study, we explored the relationships between infant behavioral inhibition and peri-adolescent defensive behavior and brain metabolism in 18 female rhesus monkeys. We coupled a mildly threatening behavioral assay with concurrent multimodal neuroimaging, and related those findings to various measures of infant temperament. To score the behavioral assay, we developed and validated UC-Freeze, a semi-automated machine-learning (ML) tool that uses unsupervised clustering to quantify freezing. Consistent with previous work, we found that heightened Ce metabolism predicted elevated defensive behavior (i.e., more freezing) in the presence of an unfamiliar human intruder. Although we found no link between infant-inhibited temperament and peri-adolescent EAc metabolism or defensive behavior, we did identify infant nervous temperament as a significant predictor of peri-adolescent defensive behavior. Our findings suggest a connection between infant nervous temperament and the eventual development of anxiety and depressive disorders. Moreover, our approach highlights the potential for ML tools to augment existing behavioral neuroscience methods.

Energy Balance Modulation Impacts Epigenetic Reprogramming, ERα and ERβ Expression, and Mammary Tumor Development in MMTV-neu Transgenic Mice

The association between obesity and breast cancer risk and prognosis is well established in estrogen receptor (ER)-positive disease but less clear in HER2-positive disease. Here, we report preclinical evidence suggesting weight maintenance through calorie restriction (CR) may limit risk of HER2-positive breast cancer. In female MMTV-HER2/neu transgenic mice, we found that ERα and ERβ expression, mammary tumorigenesis, and survival are energy balance dependent in association with epigenetic reprogramming. Mice were randomized to receive a CR, overweight-inducing, or diet-induced obesity regimen (n = 27/group). Subsets of mice (n = 4/group/time point) were euthanized after 1, 3, and 5 months to characterize diet-dependent metabolic, transcriptional, and epigenetic perturbations. Remaining mice were followed up to 22 months. Relative to the overweight and diet-induced obesity regimens, CR decreased body weight, adiposity, and serum metabolic hormones as expected and also elicited an increase in mammary ERα and ERβ expression. Increased DNA methylation accompanied this pattern, particularly at CpG dinucleotides located within binding or flanking regions for the transcriptional regulator CCCTC-binding factor of ESR1 and ESR2, consistent with sustained transcriptional activation of ERα and ERβ. Mammary expression of the DNA methylation enzyme DNMT1 was stable in CR mice but increased over time in overweight and diet-induced obesity mice, suggesting CR obviates epigenetic alterations concurrent with chronic excess energy intake. In the survival study, CR elicited a significant suppression in spontaneous mammary tumorigenesis. Overall, our findings suggest a mechanistic rationale to prevent or reverse excess body weight as a strategy to reduce HER2-positive breast cancer risk. Cancer Res; 77(9); 2500-11. ©2017 AACR.

Upregulation of autophagy genes and the unfolded protein response in human heart failure

The cellular environment of the mammalian heart constantly is challenged with environmental and intrinsic pathological insults, which affect the proper folding of proteins in heart failure. The effects of damaged or misfolded proteins on the cell can be profound and result in a process termed "proteotoxicity". While proteotoxicity is best known for its role in mediating the pathogenesis of neurodegenerative diseases such as Alzheimer's disease, its role in human heart failure also has been recognized. The UPR involves three branches, including PERK, ATF6, and IRE1. In the presence of a misfolded protein, the GRP78 molecular chaperone that normally interacts with the receptors PERK, ATF6, and IRE-1 in the endoplasmic reticulum detaches to attempt to stabilize the protein. Mouse models of cardiac hypertrophy, ischemia, and heart failure demonstrate increases in activity of all three branches after removing GRP78 from these internal receptors. Recent studies have linked elevated PERK and CHOP in vitro with regulation of ion channels linked with human systolic heart failure. With this in mind, we specifically investigated ventricular myocardium from 10 patients with a history of conduction system defects or arrhythmias for expression of UPR and autophagy genes compared to myocardium from non-failing controls. We identified elevated Chop, Atf3, and Grp78 mRNA, along with XBP-1-regulated Cebpa mRNA, indicative of activation of the UPR in human heart failure with arrhythmias.

Abstract PL03-01: A gnotobiotic mouse model demonstrates that dietary fiber protects against colorectal tumorigenesis in a microbiota- and butyrate-dependent manner

It is controversial whether dietary fiber protects against colorectal cancer because of conflicting results from human epidemiologic studies. However, these studies and mouse models of colorectal cancer have not controlled the composition of gut microbiota, which ferment fiber into short-chain fatty acids such as butyrate. Butyrate is noteworthy because it has energentic and epigenetic functions in colonocytes and tumor-suppressive properties in colorectal cancer cell lines. We colonized BALB/c mice with wild-type or mutant strains of a butyrate-producing bacterium in a gnotobiotic facility, provided them with high- or low-fiber diets that were otherwise identical and isocaloric, and used azoxymethane (AOM) to induce colorectal tumors. Analysis of these gnotobiotic mouse models demonstrated that fiber conferred a significant tumor-suppressive effect but in a microbiota- and butyrate-dependent manner. To confirm that butyrate is a causal factor, the anticancer chemoprotective effect was recapitulated in mice without any butyrate-producing bacteria when they were provided a tributyrin-fortified diet. Our data support a general mechanism that includes microbial fermentation of fiber rather than fiber exclusively speeding colonic transit to minimize the exposure of colonocytes to ingested carcinogens. Our data also support a molecular mechanism that is metaboloepigenetic. Normal colonocytes utilize butyrate as their primary energy source, whereas cancerous colonocytes rely on glucose because of the Warburg effect. Due to this metabolic difference, butyrate accumulated in tumors and functioned as an HDAC inhibitor to increase histone acetylation levels globally and at pro-apototic (Fas) and cell-cycle (p21 and p27) target genes, which culminated in increased apoptosis and decreased cell proliferation. To support the relevance of this mechanism in human cancer, we demonstrate that butyrate and histone acetylation levels are elevated in colorectal adenocarcinomas compared to normal colonic tissues. These results, which link diet and microbiota to a tumor-suppressive metabolite, provide insight into conflicting epidemiologic findings and suggest that probiotic/prebiotic strategies can modulate an endogenous HDAC inhibitor for anticancer chemoprevention without the adverse effects associated with synthetic HDAC inhibitors used in chemotherapy.

Citation Format: Dallas Donohoe, Darcy Holley, Leonard Collins, Stephanie Montgomery, Alan Whitmore, Kaitlin Curry, Sarah Renner, Alicia Greenwalt, Elizabeth Ryan, Virginia Godfrey, Deborah Threadgill, James Swenberg, David Threadgill, Scott Bultman. A gnotobiotic mouse model demonstrates that dietary fiber protects against colorectal tumorigenesis in a microbiota- and butyrate-dependent manner. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr PL03-01.

Non-targeted metabolomics of Brg1/Brm double-mutant cardiomyocytes reveals a novel role for SWI/SNF complexes in metabolic homeostasis

Mammalian SWI/SNF chromatin-remodeling complexes utilize either BRG1 or Brm as alternative catalytic subunits to alter the position of nucleosomes and regulate gene expression. Genetic studies have demonstrated that SWI/SNF complexes are required during cardiac development and also protect against cardiovascular disease and cancer. However, Brm constitutive null mutants do not exhibit a cardiomyocyte phenotype and inducible Brg1 conditional mutations in cardiomyocyte do not demonstrate differences until stressed with transverse aortic constriction, where they exhibit a reduction in cardiac hypertrophy. We recently demonstrated the overlapping functions of Brm and Brg1 in vascular endothelial cells and sought here to test if this overlapping function occurred in cardiomyocytes. Brg1/Brm double mutants died within 21 days of severe cardiac dysfunction associated with glycogen accumulation and mitochondrial defects based on histological and ultrastructural analyses. To determine the underlying defects, we performed nontargeted metabolomics analysis of cardiac tissue by GC/MS from a line of Brg1/Brm double-mutant mice, which lack both Brg1 and Brm in cardiomyocytes in an inducible manner, and two groups of controls. Metabolites contributing most significantly to the differences between Brg1/Brm double-mutant and control-group hearts were then determined using the variable importance in projection analysis. Increased cardiac linoleic acid and oleic acid suggest alterations in fatty acid utilization or intake are perturbed in Brg1/Brm double mutants. Conversely, decreased glucose-6-phosphate, fructose-6-phosphate, and myoinositol suggest that glycolysis and glycogen formation are impaired. These novel metabolomics findings provide insight into SWI/SNF-regulated metabolic pathways and will guide mechanistic studies evaluating the role of SWI/SNF complexes in homeostasis and cardiovascular disease prevention.

Abstract SY04-02: Dietary fiber protects against colorectal tumorigenesis in a microbiota- and butyrate-dependent manner

It is controversial whether dietary fiber protects against colorectal cancer because of conflicting results from human epidemiologic studies. These studies have been complicated by the participants’ genetic heterogeneity and differences in the composition of microbiota within their gastrointestinal tracts. To eliminate these confounding variables, we utilized a gnotobiotic mouse model of colorectal cancer. Our experiments were designed to investigate the function of butyrate because it is a short-chain fatty acid produced by bacterial fermentation of fiber in the colon at high (mM) levels and has potent energetic and epigenetic properties in host colonocytes. Here, we report that fiber did, in fact, have a chemoprotective effect but in a microbiota- and butyrate-dependent manner. The incidence, number, size, and histopathologic progression of AOM/DSS-induced colorectal tumors were significantly diminished when BALB/c mice were provided a high-fiber diet only if they were colonized with defined microbiota that included a butyrate-producing bacteria. This chemoprotective effect was attenuated when mice were colonized with the same microbiota except that the wild-type butyrate producer was replaced by a mutant strain with a 0.8-kb deletion in the butyryl-CoA synthesis operon. To confirm that butyrate is a causal factor, the chemoprotective effect was recapitulated in mice without any butyrate-producing bacteria if they were provided a butyrate-fortified diet. Our data support a general mechanism that includes microbial fermentation of fiber rather than fiber exclusively speeding colonic transit to minimize the exposure of colonocytes to ingested carcinogens. Our data also support a molecular mechanism that is metaboloepigenetic. Normal colonocytes utilize butyrate as their preferred energy source, whereas cancerous colonocytes rely on glucose because of the Warburg effect. Due to this metabolic difference, butyrate accumulated in tumors (as measured by LC-MS) and functioned as an HDAC inhibitor to increase histone acetylation levels and apoptosis. To support the applicability of this model to human cancer, we demonstrate that butyrate also accumulates at higher levels in human colorectal tumors than in normal colonic tissue, and this is associated with higher levels of histone acetylation in tumors. These results link diet and microbiota to a common metabolite that influences epigenetics and cancer predisposition.

Citation Format: Dallas Donohoe, Darcy Holley, Leonard Collins, Stephanie Montgomery, Alan Whitmore, Andrew Hillhouse, Kaitlin Curry, Sarah Renner, Alicia Greenwalt, Elizabeth Ryan, Virginia Godfrey, Mark Heise, Deborah Threadgill, James Swenberg, David Threadgill, Scott Bultman. Dietary fiber protects against colorectal tumorigenesis in a microbiota- and butyrate-dependent manner. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr SY04-02. doi:10.1158/1538-7445.AM2014-SY04-02

A gnotobiotic mouse model demonstrates that dietary fiber protects against colorectal tumorigenesis in a microbiota- and butyrate-dependent manner

Whether dietary fiber protects against colorectal cancer is controversial because of conflicting results from human epidemiologic studies. However, these studies and mouse models of colorectal cancer have not controlled the composition of gut microbiota, which ferment fiber into short-chain fatty acids such as butyrate. Butyrate is noteworthy because it has energetic and epigenetic functions in colonocytes and tumor-suppressive properties in colorectal cancer cell lines. We used gnotobiotic mouse models colonized with wild-type or mutant strains of a butyrate-producing bacterium to demonstrate that fiber does have a potent tumor-suppressive effect but in a microbiota- and butyrate-dependent manner. Furthermore, due to the Warburg effect, butyrate was metabolized less in tumors where it accumulated and functioned as a histone deacetylase (HDAC) inhibitor to stimulate histone acetylation and affect apoptosis and cell proliferation. To support the relevance of this mechanism in human cancer, we demonstrate that butyrate and histone-acetylation levels are elevated in colorectal adenocarcinomas compared with normal colonic tissues.

SIGNIFICANCE

These results, which link diet and microbiota to a tumor-suppressive metabolite, provide insight into conflicting epidemiologic findings and suggest that probiotic/prebiotic strategies can modulate an endogenous HDAC inhibitor for anticancer chemoprevention without the adverse effects associated with synthetic HDAC inhibitors used in chemotherapy.

Restoring ADL function after wrist surgery in children with cerebral palsy: a novel Bilateral robot system design

Cerebral palsy is a leading cause of disability in children and reducing its effects on arm function will improve quality of life. Our goal is to train children with CP after wrist tendon transfer surgery using a robotic therapy system consisting of two robot arms and wrist robots. The therapeutic goal is to determine if the robot training combined with surgery intervention improved functional outcomes significantly more than surgery alone. To accomplish this long-term goal we have developed a Bilateral ADL Exercise Robot, BiADLER aimed at training children with CP in reach to grasp coordination on ADLs. Specifically, the robot will provide active training using an assist-as-needed. This paper presents the design concepts.

Abstract SY08-03: Metaboloepigenetic effects of microbial-produced butyrate in cancer prevention

It is controversial whether dietary fiber protects against colorectal cancer because of conflicting results from human epidemiologic studies. These studies have been complicated by the participants' genetic heterogeneity and differences in the composition of microbiota within their gastrointestinal tracts. To eliminate these confounding variables, we utilized a gnotobiotic mouse model of colorectal cancer. Our experiments were designed to investigate the function of butyrate because it is a short-chain fatty acid produced by bacterial fermentation of fiber in the colon at high (mM) levels and has potent energetic and epigenetic properties in host colonocytes. Here, we report that fiber did, in fact, have a chemoprotective effect but in a microbiota- and butyrate-dependent manner. The incidence, number, size, and histopathologic progression of AOM/DSS-induced colorectal tumors were significantly diminished when BALB/c mice were provided a high-fiber diet only if they were colonized with defined microbiota that included a butyrate-producing bacteria. This chemoprotective effect was attenuated when mice were colonized with the same microbiota except that the wild-type butyrate producer was replaced by a mutant strain with a 0.8-kb deletion in the butyryl-CoA synthesis operon. To confirm that butyrate was a causal factor, the chemoprotective effect was also observed in mice without any butyrate-producing bacteria if their diet was fortified with a butyrate derivative. Our data support a general mechanism that includes microbial fermentation of fiber rather than fiber exclusively speeding colonic transit to minimize the exposure of colonocytes to ingested carcinogens. Our data also support a molecular mechanism that is metaboloepigenetic. Normal coloncytes utilize butyrate as their preferred energy source, whereas cancerous colonocytes rely on glucose because of the Warburg effect. Due to this metabolic difference, butyrate accumulated in tumors (as measured by LC-MS/MS) and functioned as an HDAC inhibitor to increase global histone acetylation levels and apoptosis. To support the applicability of this model to human cancer, we demonstrate that butyrate also accumulates at higher levels in human colorectal tumors than in normal colonic tissue, and this is associated with higher levels of histone acetylation in tumors. These results link diet and microbiota to a common metabolite that influences epigenetics and cancer predisposition.

To investigate the metaboloepigenetic mechanism in more detail, we evaluated the effect of butyrate in colorectal cancer cell lines in the presence of the Warburg effect and when it was prevented from occurring by growing the tumor cells in low glucose or depleting lactate dehydrogenase levels (siLDHA). Low doses of butyrate (0.5-1 mM) inhibited cell proliferation in the presence of the Warburg effect by acting as an epigenetic factor (by inducing histone acetylation) but stimulated proliferation in the absence of the Warburg effect by acting as an energy source. Low doses of butyrate also stimulated the proliferation of non-cancerous colonocytes, which do not undergo the Warburg effect without any experimental manipulation. Higher doses of butyrate (2-5 mM), which exceed the metabolic capacity of the cell to oxidize butyrate (but are still physiologically relevant), induced histone acetylation and apoptosis regardless of the Warburg effect. At the lower doses, where butyrate was metabolized, it was converted to acetyl-CoA, and this was important not only for energetics but also for epigenetics because it served as a HAT co-factor to stimulate histone acetylation. Although the acetyl-CoA/HAT and HDAC inhibition mechanisms both stimulate histone acetylation, they were differentially utilized and upregulated different target genes. The acetyl-Co-A/HAT mechanism was predominant in normal cells and at low butyrate doses regardless of the Warbug effect and upregulated cell proliferation genes, whereas the HDAC inhibition mechanism was predominant in cancerous colonocytes and at high butyrate doses regardless of the Warburg effect and upregulated pro-apoptotic genes. These data have important implications in vivo. Because mucus produced by goblet cells within the crypts flows upward into the lumen, an endogenous butyrate gradient is believed to exist with lower concentrations at the base of crypts (<1 mM) than in the lumen (2-5 mM). Therefore, butyrate may contribute to normal colonic homeostasis by promoting the proliferation of stem cells and transit amplifying cells near the base while inducing apoptosis in cells exfoliating into the lumen. And due to the Warburg effect in tumor cells, butyrate is not readily metabolized, accumulates, and functions primarily as an HDAC inhibitor regardless of position within the epithelium. These results indicate that metabolic transformation (i.e., the Warburg effect) can drive aberrant epigenetic (histone acetylation) and transcriptome profiles in tumor cells compared to their cell of origin.

Citation Format: Dallas Donohoe, Stephanie Montgomery, Leonard Collins, Darcy Holley, Virgina Godfrey, James Swenberg, Scott Bultman. Metaboloepigenetic effects of microbial-produced butyrate in cancer prevention. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY08-03. doi:10.1158/1538-7445.AM2013-SY08-03

Functional redundancy of SWI/SNF catalytic subunits in maintaining vascular endothelial cells in the adult heart

RATIONALE

Mating type switching/sucrose non-fermenting (SWI/SNF) chromatin-remodeling complexes utilize either BRG1 or BRM as a catalytic subunit to alter nucleosome position and regulate gene expression. BRG1 is required for vascular endothelial cell (VEC) development and embryonic survival, whereas BRM is dispensable.

OBJECTIVE

To circumvent embryonic lethality and study Brg1 function in adult tissues, we used conditional gene targeting. To evaluate possible Brg1-Brm redundancy, we analyzed Brg1 mutant mice on wild-type and Brm-deficient backgrounds.

METHODS AND RESULTS

The inducible Mx1-Cre driver was used to mutate Brg1 in adult mice. These conditional-null mutants exhibited a tissue-specific phenotype and unanticipated functional compensation between Brg1 and Brm. Brg1 single mutants were healthy and had a normal lifespan, whereas Brg1/Brm double mutants exhibited cardiovascular defects and died within 1 month. BRG1 and BRM were required for the viability of VECs but not other cell types where both genes were also knocked out. The VEC phenotype was most evident in the heart, particularly in the microvasculature of the outer myocardium, and was recapitulated in primary cells ex vivo. VEC death resulted in vascular leakage, cardiac hemorrhage, secondary death of cardiomyocytes due to ischemia, and ventricular dissections.

CONCLUSIONS

BRG1-catalyzed SWI/SNF complexes are particularly important in cardiovascular tissues. However, in contrast to embryonic development, in which Brm does not compensate, Brg1 is required in adult VECs only when Brm is also mutated. These results demonstrate for the first time that Brm functionally compensates for Brg1 in vivo and that there are significant changes in the relative importance of BRG1- and BRM-catalyzed SWI/SNF complexes during the development of an essential cell lineage.

Opportunity of detecting pre-hypertension: worldwide data on blood pressure overswinging

Overswinging or CHAT (brief for Circadian Hyper-Amplitude-Tension), that is an excessive circadian variation in blood pressure (BP), has been associated with a large increase in cardiovascular disease risk, present even in the absence of an elevated BP itself. This usually asymptomatic condition is usually overlooked by current practice based on spot-checks, because to be diagnosed, measurements need to be taken around-the-clock, preferably for 7 days at the outset. Once diagnosed, however, a usual circadian BP pattern can be restored by means of certain non-pharmacologic or pharmacologic interventions timed appropriately. Thereby, it is possible to reduce the risk of cardiovascular morbidity and mortality, cerebral ischemic events and nephropathy in particular. For the preparation of guidelines regarding the diagnosis of BP disorders and for the institution of primary as well as secondary preventive measures, it is important to know what the incidence of CHAT is on a global basis. We found 191 cases of CHAT among 1602 mostly 7-day/24-h BP profiles, obtained from several centers in different countries participating in an ongoing project on the BIOsphere and the COSmos (BIOCOS). CHAT incidence is about the same between men and women, but it is diagnosed more often among patients with borderline hypertension or with glucose intolerance. It is also more common among MESOR-hypertensive than among MESOR-normotensive individuals. Priority should be given to the development of an unobtrusive and affordable device to automatically monitor BP and to analyze the data as-one-goes, so that cardiovascular disease risk can be prevented.

In vitro cytolytic activity of lymphocytes from tumor-draining lymph nodes is associated with increased numbers of CD8+ cells and increased cytokine production

A murine footpad tumor model was used to determine the cytotoxic activity, tumor specificity, phenotypic profile, and cytokine production of stimulated cells from draining lymph nodes (DLN). Popliteal DLN from 5-day-old P-815 footpad tumors were stimulated with 10(-7) M phorbol 12, 13-dibutyrate +5 x 10(-7) M ionomycin for 16 hr and cultured in IL-2 (20 units/ml) for 7 or 14 days without autologous tumor. Most cells in both groups were CD3+ (93% at Day 7, 99% at Day 14); however, the percentage of CD8+ cells increased as the cell population matured in the presence of low-dose IL-2. On Day 7, the phenotypic profile was 62% CD4+ and 29% CD8+, whereas on Day 14 it was 16% CD4+ and 81% CD8+. Similarly, in vitro cytokine production increased with time in culture. After 7 days, the level of tumor necrosis factor-alpha (TNF-alpha) was 220 pg/mL and the interferon-gamma (IF-gamma) production was 150 pg/ml. At Day 14 the TNF level had increased to 500 pg/ml, and IF production had increased to 350 pg/ml. These increases in the CD8+ population and in cytokine production correlated with the increase in the percentage of target cells killed by the DLN cells. Cytolytic activity against P-815 was only 13% on Day 7 but 39% on Day 14. Neither group of effector cells (Day 7 or Day 14) had any cytolytic activity against the syngeneic tumor cell line L-1210, demonstrating the tumor specificity of the DLN cells. We describe a model for generating tumor-specific cytotoxic T-cells that have significant cytokine production, which may account for previously described in vivo activity.

Routine use of transesophageal echocardiography and color flow imaging in the evaluation and treatment of children with congenital heart disease

We reviewed our experience with transesophageal echocardiography (TEE) and color flow imaging in 157 consecutive patients with known or suspected heart disease to ascertain the impact of this technology on patient care. TEE was performed for diagnostic purposes (22/157), during interventional cardiac catheterizations (13/157), and during operative procedures (122/157). Diagnostic studies were performed after transthoracic echocardiography (TTE) in 21 of 22 patients. TEE was performed because TTE was inconclusive (15/21) or failed to provide sufficient detail of an abnormality (6/21). TEE detected an abnormality in 6 of 15 inconclusive TTEs. TEE was helpful during interventional cardiac catheterizations, particularly during umbrella closure of septal defects and in patients with complex venous and atrial anatomy undergoing transseptal puncture. TEE studies performed before cardiac operations significantly changed the diagnosis in only 5 of 122 (4%) patients, but the information changed the surgical approach in 4 of 5 of these patients. Postoperative TEE assessment more frequently changed care and resulted in further surgical management in 9 of 122 (7%) or a change in medical management in 6 of 122 (5%) patients. TEE was discontinued because of complications before studies were completed in only 4 of 157 (3%) patients. TEE and color flow imaging is a useful adjunct to care of children with known or suspected congenital heart disease.

Effects of cervical adjustments on lateral-flexion passive end-range asymmetry and on blood pressure, heart rate and plasma catecholamine levels

The biomechanical and physiological effects of a single, unilateral lower cervical spinal adjustment delivered to the most restricted side of cervical lateral-flexion passive end-range were examined. Only healthy, asymptomatic male subjects who exhibited goniometrically verified lateral-flexion passive range of motion asymmetries of 10 degrees or greater on the morning of the experiment were chosen for the study. Posttreatment goniometric measurements revealed that in sham-adjusted controls, mean lateral-flexion asymmetries had not changed significantly during the 4-hr time period examined. However, in subjects who received lower cervical adjustments, dramatic ameliorations of asymmetry magnitude were observed which persisted throughout the entire 4-hr posttreatment time period. On the other hand, in the face of this rather robust biomechanical effect, heart rate and blood pressure measurements obtained at -60 and -15 min prior to treatments, and at 5, 30, 60, 120 and 240 min following treatments, revealed no significant differences between adjusted and sham-adjusted subjects at any of the time periods examined. Consistent with this, analysis of the plasma concentrations of norepinephrine, epinephrine and dopamine in serial blood samples collected at these same times also failed to reveal significant differences between treatment groups at any of the time periods examined. The results of this investigation indicate that lower cervical adjustments are capable, at least in asymptomatic subjects, of inducing relatively robust biomechanical effects related to passive cervical end-range capability without simultaneously inducing significant alterations in the overall activity of the sympathetic nervous system.

Relation between apnoea duration and type and neurological status of preterm infants

The incidence, duration, and type of apnoea were determined in 28 preterm infants born at 27 to 34 weeks' gestation, using polygraphic records of abdominal breathing movements and nasal airflow. Of the 1520 episodes of apnoea of 10 or more seconds duration, 1002 (66%) lasted 10 to 14 seconds, 311 (20%) lasted 15 to 20 seconds, and 207 (14%) lasted more than 20 seconds. Overall, 69% were central in type, 20% were mixed, and 11% were purely obstructive. With increasing duration of apnoea, the proportion of episodes of central apnoea decreased (69 to 29%) while that of mixed apnoea increased (20 to 60%). Eight infants had obstructive apnoea of more than 20 seconds duration. When they were compared with the 10 infants of similar gestational age and birthweight who had central or mixed apnoea, they had a higher incidence of intraventricular haemorrhage, hydrocephalus, positive pressure ventilation via an endotracheal tube, and abnormal neurological development during the first year of life.

A mechanical aid for the treatment of carcinoma of the breast

A relatively inexpensive mechanical aid is described which, in primary or adjuvant irradiation for breast carcinoma, allows easy and stable reproducibility of the abducted arm position, unobstructed access for lateral tangential portals, and leveling of the anterior chest for regional nodal irradiation. The device may be constructed de novo or from a commonly available treatment-table accessory.