Impact of maternal risk factors on the structure and function of the heart in newborns

Introduction

Maternal factors such as smoking during pregnancy, advanced age, and obesity are associated with increased risk of complex congenital heart defects in the offspring. It is unknown whether maternal risk factors may also cause subtle abnormalities in cardiac structure and function.

Purpose

To investigate whether the following maternal factors: advanced age, high body mass index (BMI), and smoking during pregnancy are associated with changes in left ventricle (LV) dimensions and systolic function in the newborn child.

Methods

Data was obtained as part of a population-based cohort study with prenatal inclusion and postnatal transthoracic echocardiography (TTE) of newborns within 60 days of birth. The TTE protocol included measurements of: Interventricular septal thickness at end-diastole (IVSd), LV posterior wall thickness at end-diastole (LVPWd), LV internal diameter at end-diastole (LVIDd) and LV internal diameter at end-systole (LVIDs). Fractional shortening (FS) was calculated by use of Teicholz's formula.

Children of mothers with data available on age, BMI, and smoking status, respectively, were divided into the following groups depending on whether their mothers were: of young age <25 years, 25–29 years, 30–34 years (reference group), 35–39 years, and advanced age ≥40 years; underweight BMI <18.5, normal range BMI 18.5–24.9 (reference group), preobese BMI 25–29.9, and obese BMI ≥30; smoking or nonsmoking (reference group).

Associations between different groups with each maternal risk factor and newborn LV parameters were analysed using a multiple linear regression model.

Results

Children of mothers with advanced age at the time of childbirth (n=1,411) had significantly smaller LVIDd and LVIDs (Table 1) compared to children of mothers in their early thirties (n=10,045). Children of preobese (n=4,707) and obese mothers (n=2,138) had significantly smaller LVIDd and LVIDs than children of mothers in the normal BMI range (n=17,654). Children of mothers who smoked during pregnancy (n=808) had significantly larger LVPWd than children of non-smoking mothers (n=24,072). A significant difference in FS was only seen in children of obese mothers.

Subanalyses of the quantity of maternal smoking (available data in n=548 [67.8%] of mothers who smoked during pregnancy) showed that children of heavy smoking mothers (≥15 cigarettes/day, n=101), had significantly thicker IVSd and LVPWd compared with children of nonsmoking mothers, whereas no significant effect was identified in newborns of mothers smoking less than 15 cigarettes per day (Table 2).

Conclusions

Systematic population-based echocardiography of newborns showed that an increased maternal BMI and maternal age above 40 years were associated with smaller LV cavity dimensions in the offspring and that heavy smoking during pregnancy was associated with increased LV myocardial thickness. FS was only affected in children of obese mothers. The long-term effects of these novel findings are unknown.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Herlev-Gentofte Hospital Internal Funding for Cardiological Research andThe Novo Nordisk Foundation

The experience of using prompting technology from the perspective of people with Dementia and their primary carers

OBJECTIVES

People who are living with dementia typically experience difficulties in completing multi-step, everyday tasks. However, digital technology such as touchscreen tablets provide a means of delivering concise personalised prompts that combine audio, text and pictures. This study was one component of a broader, mixed methods study that tested how an application (app) -based prompter running on a touchscreen tablet computer could support everyday activities in individuals with mild to moderate dementia. In this study we set out to understand the experiences of people living with dementia and their primary carer in using the prompter over a four-week period.

METHOD

We collected qualitative data using semi-structured interviews from 26 dyads, composed of a person living with dementia and their carer. Dyads were interviewed at the start and end of this period. Transcripts were then analysed using thematic analysis.

RESULTS

The study identified three overarching themes related to: participants' attitudes towards the technology; their judgements about how useful the prompter would be; and the emotional impact of using it.

CONCLUSION

Consistent with the Technology Acceptance Model, carers and participants were influenced by their approaches to technology and determined the usefulness of the prompter according to whether it worked for them and fitted into their routines. In addition, participants' decisions about using the prompter were also determined by the extent to which doing so would impact on their self-identity.

Spontaneous closure of ventricular septal defects in newborns the first year of life

Background

Ventricular septal defect (VSD) is one of the most common congenital heart defects. Some VSDs close spontaneously while persistence of the VSD may result in heart failure and, at long term, irreversible pulmonary hypertension. Consequently, identification of factors associated with spontaneous closure are important to ensure relevant clinical follow up of those at risk of a persistent VSD.

Purpose

We aimed to assess the rate of spontaneous closure in a population-based cohort of newborns with VSD and to identify significant predictors for spontaneous closure.

Methods

The study is part of a large-scale population-based study, focusing on cardiac structure and function, including newborns born from 1st April 2016 to 31st October 2018. Newborns with a VSDs at baseline were followed with echocardiography at 3, 6 and 12 months (+30 days) of age. Cox proportional hazard model was used to determine significant predictors of spontaneous closure

Results

Based on echocardiographies of 25.750 newborn, 850 newborns (3.3%) with a VSD were identified. The majority of newborns with VSDs were born at term (88.7%) and the mean age at inclusion was 11.7±8.1 days. VSDs were more frequent in females (57.1%, p<0.001). Of all VSDs, 787l (92.6%) were of a muscular type, 60 (7.0%) of perimembranous type and 3 (0.4%) were of subarterial type. Multiple VSDs were found in 98 (11.5%) cases and all were of a muscular type. Muscular VSDs were significantly smaller than perimembranous VSDs (1.9±0.7 mm vs. 3.7±1.8 mm, p<0.0001). During the follow up period, seven (0.8%) children underwent surgical repair: five (5 of 56) children with perimembranous VSDs and two (two of three) children with subarterial VSDs. Follow-up was complete in 89.4% of all children. After one year 82.6% (601 of 727) VSDs had closed spontaneously. The prevalence of VSD in one-year old children was thus 0.5%. The majority of VSD closed spontaneously during the first 6 months of life (57.6% (419/727)). Muscular VSDs showed significantly higher rate of spontaneous closure compared with perimembranous VSDs (86.9% (582 /670) vs. 46.2% (25/54), p=0.0001) during the first year of life. No subarterial VSDs closed spontaneously during follow-up. Muscular type (p=0.002), size (p<0.001) and presence of one VSD as opposed to multiple (p<0.0025) were associated to spontaneous closure. Sex did not significantly influence spontaneous closure rate (p=0.65).

Conclusion

In a population study including more than 25,000 newborns we found that the vast majority, i.e. almost 9/10 of all VSDs, closed spontaneously during the first year of life, ultimately resulting in a prevalence of VSD in one-year old children of 0.5%. The identified factors associated with spontaneous closure – anatomical location, size and presence of multiple VSDs are of use for future management of VSDs in newborns.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The Danish Heart Foundation

Association between maternal diabetes and cardiac left ventricular structure and function in the neonate: a study from the Copenhagen Baby Heart Study

Background

Prenatal exposure to maternal diabetes has been associated with increased risk of congenital heart defects.

Purpose

To evaluate whether maternal diabetes is associated with more subtle morphological and functional cardiac changes in neonates without congenital heart defects.

Methods

We included 17,869 newborns sampled from the Copenhagen Baby Heart Study, all of whom underwent transthoracic echocardiography within 30 days of delivery. We investigated the association between exposure to maternal diabetes (pre-existing diabetes [type 1 or type 2 diabetes] or gestational diabetes [GDM]) and the neonates' echocardiographic indices of left ventricular structure (left posterior wall thickness in end-diastole [LVPWd], interventricular septum thickness in end-diastole [IVSd], left ventricular internal diameter in end-systole [LVIDs] and end-diastole [LVIDd]), systolic function (fractional shortening [FS], stroke volume [SV]) and diastolic function (mitral valve peak early and atrial filling velocities, deceleration time of early filling, and E/A-ratio), using linear and logistic regression. Models were adjusted for maternal age, infant sex, infant birth weight for gestational age and gestational age in days. In additional analyses, we evaluated the relationship between HbA1C levels in first and third trimester and left ventricular structure and function.

Results

We found that infants exposed to pre-existing maternal diabetes (n=x) had, on average, a thicker LVPWd (mean difference 0.12 mm [95% CI: 0.06–0.19]), a smaller LVIDs (−0.27 mm [95% CI: −0.46, −0.07]) and LVIDd (−0.43 mm [95% CI: −0.66, −0.19]), and decreased SV (−0.50 ml [95% CI: −0.77, −0.23]). We found no significant differences in IVSd, FS, and measures of diastolic function for infants exposed to pre-existing maternal diabetes compared with infants not exposed to diabetes. Infants exposed to GDM (n=) also had thicker LVPWd (0.06 mm [95% CI: −0.28, −0.01]) and smaller LVIDs (−0.15 mm [95% CI: −0.28, −0.01]); however, on average, IVSd, LVIDd, and measures of systolic and diastolic function did not differ for infants born to mothers with and without GDM. We observed no consistent association between HbA1C levels measured early and late in pregnancy in mothers with diabetes and indices of left ventricular structure and function.

Conclusion

In conclusion, we found that exposure to maternal pre-existing diabetes, and to a lesser degree GDM, was associated with changes in neonatal left ventricular structure and function, including a thicker left ventricular posterior wall, smaller left ventricular internal diameters, and lower stroke volumes.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Rigsbospitalet Research Foundation

The role of filaggrin mutations during pregnancy and postpartum: atopic dermatitis and genital skin diseases

Mutations in the epidermal filaggrin gene (FLG) are associated with skin barrier dysfunction (dry skin, less acidic skin, and fissured skin), and atopic dermatitis (AD) with a severe and persistent course. Because pregnancy and delivery further impairs normal skin barrier functions (immune suppression, mechanical stress), we studied the possible role of FLG mutations on the risk of AD flares, genital infections, and postpartum problems related to perineal trauma. FLG-genotyping was performed in a population-based sample of 1837 women interviewed in the 12th and 30th weeks of pregnancy and 6 months postpartum as part of the Danish National Birth Cohort study 1996-2002. We found that FLG mutations also influence pregnancy-related skin disease; thus, women with FLG mutations had an increased risk of AD flares during pregnancy (OR 10.5, 95% CI 3.6-30.5) and of enduring postpartum physical problems linked to perineal trauma during delivery (OR 11.1, 95% CI 1.1-107.7).

The anticholinesterase activity of some antiadrenaline agents

The contractions of the isolated guinea-pig vas deferens in response to stimulation of the sympathetic hypogastric nerve were potentiated by low concentrations and inhibited by high concentrations of the antiadrenaline agents tolazoline, yohimbine, ergotamine, phenoxybenzamine and piperoxan. Eserine potentiated the contractions of the vas deferens produced by hypogastric nerve stimulation. The cholinesterase activity of an extract of vas deferens was decreased by the antiadrenaline agents. The potentiation of responses to sympathetic stimulation by antiadrenaline drugs, which also possess anticholinesterase activity, can be explained on the basis of a cholinergic sympathetic mechanism.

Urinary cytokines for assessing inflammation in HIV-associated wasting

The relationship between cytokines and HIV-related weight loss has not been well established. Unlike most cytokines that are secreted in a paracrine manner, IL-6, sTNFR-II, and IL-1ra are readily detected in the systemic circulation and serve as markers of the inflammatory response. Twenty-four-hour urine concentrations of these proteins are believed to provide an integrative assessment of their systemic levels over the preceding hours. We sought to determine whether spot measurements of IL-6, sTNFR-II, and IL-1ra could be related to subsequent 24 h concentrations and prior weight loss. Eighteen subjects with severe wasting (average BMI=18+/-3 kg/m2with 19+/-13 kg of weight loss) and six HIV-negative healthy subjects were tested. Compared to values in controls, 24-h urinary concentrations of the three proteins adjusted for creatinine excreted were elevated in 44%, 89%, and 72% of patients, respectively. Twenty-four-hour concentrations were highly correlated with the spot concentrations (r=0.80, 0.87, 0.84, respectively, P<0.001). IL-1ra concentrations (24 h and spot) were correlated with weight loss in the previous 6 months, lifetime rate of weight loss and the 6 month rate of weight loss (spot: r=0.66, 0.73, 0.68, respectively, P< or =0.001). These data suggest that spot urinary collections can be used to estimate 24 h excretion rates. This strategy may be useful in assessing the inflammatory response in HIV-associated wasting.

SB-253514 and analogues; novel inhibitors of lipoprotein-associated phospholipase A2 produced by Pseudomonas fluorescens DSM 11579. I. Fermentation of producing strain, isolation and biological activity

Two new classes of inhibitors of LpPLA2 have been identified in fermentations of Pseudomonas fluorescens. The two structurally isomeric series differ in the geometry of closure of the bicyclic carbamate and comprise a range of compounds varying only in length of their lipophilic sidechain. The most abundant species were extracted from the cells and purified by silica and C18 chromatography. Members of the more stable class were shown to be potent and selective competitive inhibitors of LpPLA2.

A report system for PET assessment of myocardial viability

Coronary bypass surgery can improve the prognosis of patients with heart failure due to coronary artery disease. However, these patients have a high operative risk and should be operated on only if they have a sizeable amount of viable tissue (i.e. asynergic myocardium) that can recover contractile function following coronary revascularization. In the clinical setting, regional wall motion is usually evaluated by two-dimensional echocardiography, whereas retained metabolic activity assessed by positron emission tomography (PET) and 18F-fluorodeoxyglucose is a well-established means for the evaluation of myocardial viability. Unfortunately, the two-dimensional echocardiography and PET reports are often different, and this renders the matching of information difficult and the estimation of the risk-benefit ratio of the operation unreliable. In this paper, we present a report system for the evaluation of myocardial viability with PET. We divided the left ventricle into 16 segments following the proposal of the American Society of Echocardiography for wall motion analysis by two-dimensional echocardiography. Following this partition, three portions of the left ventricle are identified along the long axis: basal, mid and apical. Each plane of the basal and mid portions is automatically divided into six segments with the super-imposition of a radial divider over the short-axis images. Similarly, each plane of the apical portion is automatically divided, but into four segments. This partition of the left ventricle permits a precise match between the information on wall motion obtained with two-dimensional echocardiography and that on viability obtained with PET.

Transmural myocardial blood flow distribution in hypertrophic cardiomyopathy and effect of treatment

Verapamil alleviates symptoms in patients with hypertrophic cardiomyopathy (HCM), but the underlying mechanism of improvement remains speculative. Baseline and dipyridamole myocardial blood flow (MBF) were measured in 15 HCM patients (14 men, 42 +/- 10 years), before and after 4 weeks of verapamil SR 480 mg daily, using 15O labelled water the positron emission tomography (PET). Subendocardial (endo) and subepicardial (epi) MBF was measured in the septum (thickness 25.4 +/- 5.8 mm). Pre-treatment baseline whole heart MBF was 1.02 +/- 0.28 ml/min/g and 1.01 +/- 0.30 ml/min/g on treatment (p = ns). Dipyridamole MBF was 1.39 +/- 0.31 ml/min/g off treatment and 1.23 +/- 0.34 ml/min/g on treatment (p = ns). Coronary flow reserve (dipyridamole/resting MBF) was 1.45 +/- 0.52 and 1.30 +/- 0.51, respectively (p = ns). At baseline, the septal endo/epi MBF ratio was uniform off and on treatment (1.13 +/- 0.18 vs 1.18 +/- 0.21, p = ns). Before treatment, the endo/epi ratio following dipyridamole decreased to 0.93 +/- 0.24 (p < 0.01 vs baseline) and 5/15 (33%) patients had a ratio < 0.8 which would suggest subendocardial underperfusion. During treatment, the endo/epi ratio following dipyridamole was no more different from baseline (1.06 +/- 0.24, p = ns vs baseline) and 2/14 (14%) patients had an endo/epi < 0.8. PET can be successfully used to determine transmural MBF in vivo in patients with hypertrophied ventricles. Despite symptomatic improvement, high dose verapamil therapy does not increase total MBF in patients with HCM but may improve septal transmural MBF distribution during dipyridamole in some patients.

ATP-Citrate lyase as a target for hypolipidemic intervention. 2. Synthesis and evaluation of (3R,5S)-omega-substituted-3-carboxy-3, 5-dihydroxyalkanoic acids and their gamma-lactone prodrugs as inhibitors of the enzyme in vitro and in vivo

A series of (3R,5S)-omega-substituted-3-carboxy-3, 5-dihydroxyalkanoic acids have been synthesized and evaluated as inhibitors of the recombinant human form of ATP-citrate lyase. The best of these have Ki's in the 200-1000 nM range. As the corresponding thermodynamically favored gamma-lactone prodrugs, a number of compounds are able to inhibit cholesterol and fatty acid synthesis in HepG2 cells and reduce plasma triglyceride levels in vivo. The best of these, compound 77, is able to induce clear hypocholesterolemic and hypotriglyceridaemic responses when administered orally to rat and dog. These results provide evidence to support the hypothesis that compounds which inhibit ATP-citrate lyase have the potential to be a novel class of hypolipidemic agent, which possess combined hypocholesterolemic and hypotriglyceridemic activities.

The role of ATP citrate-lyase in the metabolic regulation of plasma lipids. Hypolipidaemic effects of SB-204990, a lactone prodrug of the potent ATP citrate-lyase inhibitor SB-201076

ATP citrate (pro-S)-lyase (EC 4.1.3.8), a cytosolic enzyme that generates acetyl-CoA for cholesterol and fatty acid synthesis de novo, is a potential target for hypolipidaemic intervention. Here we describe the biological effects of the inhibition of ATP citrate-lyase on lipid metabolism in Hep G2 cells, and plasma lipids in rats and dogs, by using SB-204990, the cell-penetrant gamma-lactone prodrug of the potent ATP citrate-lyase inhibitor SB-201076 (Ki=1 microM). Consistent with an important role of ATP citrate-lyase in the supply of acetyl-CoA units for lipid synthesis de novo, SB-204990 inhibited cholesterol synthesis and fatty acid synthesis in Hep G2 cells (dose-related inhibition of up to 91% and 82% respectively) and rats (76% and 39% respectively). SB-204990, when administered orally to rats, was absorbed into the systemic circulation; pharmacologically relevant concentrations of SB-201076 were recovered in the liver. When administered in the diet (0.05-0. 25%, w/w) for 1 week, SB-204990 caused a dose-related decrease in plasma cholesterol (by up to 46%) and triglyceride levels (by up to 80%) in rats. This hypolipidaemic effect could be explained, at least in part, by a decrease (up to 48%) in hepatic very-low-density lipoprotein (VLDL) production as measured by the accumulation of VLDL in plasma after injection of Triton WR-1339. SB-204990 (25 mg/kg per day) also decreased plasma cholesterol levels (by up to 23%) and triglyceride levels (by up to 38%) in the dog, preferentially decreasing low-density lipoprotein compared with high-density lipoprotein cholesterol levels. Overall these results are consistent with the concept that ATP citrate-lyase is an important enzyme in controlling substrate supply for lipid synthesis de novo and a potential enzyme target for hypolipidaemic intervention.

Characterization of pituitary adenylate cyclase-activating polypeptide 38 (PACAP38)-, PACAP27-, and vasoactive intestinal peptide-stimulated responses in N1E-115 neuroblastoma cells

In this study, the effects of three related peptides, pituitary adenylate cyclase-activating polypeptide 38 (PACAP38), PACAP27, and vasoactive intestinal peptide (VIP), on cyclic AMP (cAMP) accumulation and intracellular Ca2+ concentration ([Ca2+]i) were compared in N1E-115 cells. PACAP38 and PACAP27 stimulated cAMP accumulation up to 60-fold with EC50 values of 0.54 and 0.067 nM, respectively. The effect of VIP on cAMP accumulation was less potent. The binding of 125I-PACAP27 to intact cells was inhibited by PACAP38 and PACAP27 (IC50 values of 0.44 and 0.55 nM, respectively) but not by VIP. In fura-2-loaded cells, both PACAP38 and PACAP27 increased [Ca2+]i with EC50 values around 10 nM. The interactions of these three peptides with ionomycin, a Ca2+ ionophore, and 4 beta-phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, were also determined. Ionomycin increased the cAMP accumulation caused by all three peptides. With low concentrations of PACAP38 or PACAP27, the effect of PMA was inhibitory, whereas at higher concentrations of PACAP (> 1 nM), the effect of PMA was stimulatory. Similar to other agents that elevate cAMP, PACAP38 was an effective stimulator of neurite outgrowth. These results show that (a) PACAP27 and PACAP38 stimulate cAMP accumulation and increase [Ca2+]i through the type I PACAP receptors in N1E-115 cells, (b) ionomycin enhances cAMP accumulation by all three peptides, and (c) activation of protein kinase C has a dose-dependent stimulatory or inhibitory effect on the PACAP38- or PACAP27-stimulated cAMP accumulation.

Health-related quality of life of adults surviving malignancies in childhood

While sophisticated data on specific problems are available, very little is known about the overall quality of life of long-term survivors of malignancies in childhood. We used a previously validated 15-dimensional questionnaire to examine the perceived health-related quality of life of 168 survivors, currently aged 16-35 years, who had been treated for a malignancy at a single institution between 1961 and 1993. All had been off therapy for at least 1 year (median, 12 years). In statistical terms, the quality of life score of the survivors was significantly better than that of 129 normal controls [0.966 versus 0.941 (theoretical maximum 1), respectively; P < 0.001]; however, a difference of this magnitude is most likely not clinically significant. There were no associations between original diagnosis and present quality of life, but the numbers in each diagnostic group were small. The survivors reported significantly better levels of vitality, distress, depression, discomfort, elimination and sleeping dimensions than the controls. Although we are presently not able to identify all the contributing factors, we speculate that the high perceived quality of life of long-term survivors of childhood malignancies is at least in part a consequence of denial mechanisms which compensate or even overcompensate the objectively measurable late effects of childhood cancer.

Myocardial beta-adrenoceptor density and plasma catecholamines in syndrome X

Recent research has cast doubt on the ischemic hypothesis of etiology of syndrome X (anginal pain, ischemic-like changes in the stress electrocardiogram, but normal coronary arteriogram). Abnormalities of pain perception have been shown and abnormal sympathetic nervous system activation has also been implicated. The aim of this study was to test the hypothesis that downregulation of myocardial beta adrenoceptors is demonstrable in patients with syndrome X. Such downregulation would be consistent with raised myocardial catecholamine concentrations. We performed positron emission tomography with (11)C-CGP-12177 to measure beta-adrenoceptor density. Plasma catecholamines were sampled simultaneously and assayed using high-performance liquid chromatography. Twenty syndrome X patients (11 female, age 57 +/- 9 SD years, range 33 to 69) and 18 matched controls (9 women, age 50 +/- 13 years, range 25 to 65; p = NS vs patients) were studied. Myocardial beta-adrenoceptor density did not differ between syndrome X patients and controls: 8.0 (1.9) pmol/g for patients versus 8.3 (2.1) pmol/g for controls; p = 0.62. No differences were found between patients and controls for plasma norepinephrine (2.82 [1.07] and 2.76 [1.18] nM, respectively; p = 0.89) or for epinephrine (0.29 [0.14] and 0.30 [0.20] nM, respectively; p = 0.84). In patients with syndrome X, beta-adrenoceptor density is normal and, by inference, myocardial catecholamines would also be normal. This weakens the case for a generalized enhancement of sympathetic activation in this disorder, although increased sympathetic reactivity during actual episodes of chest pain remains a possibility.

Uptake of [N-methyl-11C]propionyl-L-carnitine (PLC) in human myocardium

We studied the uptake of propionyl-L-carnitine from plasma by the myocardium in 10 human subjects using positron emission tomography. Propionyl-L-carnitine was labeled in the N-methyl position with carbon-11 (T1/2 = 20.4 min) and administered i.v. in trace amounts. The uptake of the radiolabel by the myocardium was then scanned over a period of 1 1/2 h. The activity-time course of the tracer in blood and plasma and the exchange of the label in plasma between propionyl carnitine, acetyl carnitine and free carnitine was followed during the scans. Myocardial blood flow was also measured in the same subjects. The results show an exchange of the tracer between the myocardium and plasma, and they show an apparently irreversible component of uptake, a result consistent with the incorporation of the label into relatively large intracellular carnitine pools.

Dobutamine stress: effects on regional myocardial blood flow and wall motion

OBJECTIVES

This investigation studied the relation between regional myocardial blood flow and left ventricular function during dobutamine stress in patients with coronary artery disease.

BACKGROUND

Dobutamine stress is becoming more frequently used as an alternative to dynamic exercise in patients with ischemic heart disease.

METHODS

We studied 12 patients with coronary artery disease. Dobutamine was infused from 5 micrograms/kg body weight per min up to 40 micrograms/kg per min or until chest pain or other intolerable side effects. Regional myocardial blood flow was measured with positron emission tomography and oxygen-15-labeled water. Regional wall motion was assessed in three short-axis slices by magnetic resonance imaging. Each slice was subdivided into four regions: septal, anterior, lateral and inferior. A total of 140 regions were suitable for comparison.

RESULTS

During stress, new wall motion abnormalities developed in 27 regions. Myocardial blood flow (mean +/- SD) increased in 113 regions that did not develop wall motion abnormalities (0.98 +/- 0.26 [baseline] vs. 1.98 +/- 0.87 [dobutamine] ml/min per g, p < 0.001), whereas it did not change significantly in regions with stress-induced wall motion abnormalities (1.00 +/- 0.28 [baseline] vs. 1.30 +/- 0.62 [dobutamine] ml/min per g, p = NS). An absolute decrease in myocardial blood flow below the value at rest was observed in seven segments that developed wall motion abnormalities during stress.

CONCLUSIONS

The normal functional response to dobutamine stress is paralleled by an increase in coronary flow, whereas mechanical dysfunction is accompanied by a blunted increase, or even a paradoxic decrease, in regional coronary flow.

CRIB and SNAP: assessing the risk of death for preterm neonates

The performance of three scoring systems for assessing mortality risk for neonates--clinical risk index for babies (CRIB), score for neonatal acute physiology (SNAP), and SNAP's perinatal extension (SNAP-PE)--were tested in the same set of patients. In 222 neonates weighing less than 1500 g at birth, CRIB scores were significantly better for assessing mortality risk than SNAP (p = 0.017) or SNAP-PE (p < 0.001), areas under receiver operating characteristic curves being 0.89 (SE 0.02), 0.82 (0.03), and 0.79 (0.03), respectively. Male sex was independently associated with poor prognosis after taking the CRIB score into account with a risk ratio of 2.75. We conclude that CRIB is the most useful score for comparing the performance of neonatal intensive-care units. New treatment methods, however, may require modifications to the system.

Familial pericentric inversion inv(8)(p23q11)

We describe two families in whom a pericentric inversion, inv(8)(p23q11), is segregating. No examples of unbalanced karyotypes were encountered. The families originated from neighbouring parishes in western Finland. In one family a mild form of mental retardation segregated. However, this phenotype did not cosegregate with the inversion karyotype. There was no evidence of a higher than average abortion rate in the inversion carriers. Carrier matings produced 19 children with a balanced inversion and 14 children with a normal karyotype, concordant with a 1:1 segregation ratio. Of 13 karyotyped men at risk, 10 were inversion carriers. However, this difference was not statistically different from the expected 1:1 ratio. In females, the inversion carrier to normal ratio was 10:11.

Diffuse reduction of myocardial beta-adrenoceptors in hypertrophic cardiomyopathy: a study with positron emission tomography

OBJECTIVES

This study was conducted to determine the myocardial beta-adrenoceptor density as a marker of sympathetic function in patients with hypertrophic cardiomyopathy and normal control subjects.

BACKGROUND

Although some cases of hypertrophic cardiomyopathy are familial with an autosomal dominant pattern of inheritance, there remains a substantial proportion of cases in which neither a family history nor genetic abnormalities can be demonstrated. Additional abnormalities, both genetic and acquired, may be important in the phenotypic expression of this condition. Clinical features of the disease and metabolic studies suggest an increased activity of the sympathetic nervous system.

METHODS

Eleven patients with hypertrophic cardiomyopathy, none of whom had previously received beta-blocking drugs, and eight normal control subjects underwent positron emission tomography to evaluate regional left ventricular beta-adrenoceptor density and myocardial blood flow using carbon-11-labeled CGP 12177 and oxygen-15-labeled water as tracers. Plasma catecholamines were also measured.

RESULTS

Mean (+/- SD) myocardial beta-adrenoceptor density was significantly less in the hypertrophic cardiomyopathy group than in the control group (7.70 +/- 1.86 vs. 11.50 +/- 2.18 pmol/g tissue, p < 0.001). Myocardial blood flow was similar in both groups (0.91 +/- 0.22 vs. 0.91 +/- 0.21 ml/min per g, p = NS). The distribution of beta-adrenoceptor density was uniform throughout the left ventricle in both groups. In the hypertrophic cardiomyopathy group, there was no correlation between regional wall thickness and myocardial beta-adrenoceptor density. There were no significant differences in either plasma norepinephrine or epinephrine concentrations between the two groups.

CONCLUSIONS

There is a diffuse reduction in myocardial beta-adrenoceptor density in patients with hypertrophic cardiomyopathy in the absence of significantly elevated circulating catecholamine concentrations. This most likely reflects downregulation of myocardial beta-adrenoceptors secondary to increased myocardial concentrations of norepinephrine and is consistent with the hypothesis that cardiac sympathetic drive is increased in this condition.

Selection of a dye for use in semen transport studies in the cow

A series of experiments was carried out to select a dye and diluent that would facilitate identification of bovine inseminate in the uterus of the live cow when using hysteroscopic techniques. Of the dyes tested, Aniline Blue and the permitted food dye Green S as 1% solutions were the most suitable when added to semen with milk buffer diluent. Neither stained the uterine mucosa nor adversely affected the equipment, and both were visually distinctive during hysteroscopy. Using 1% concentrations of these dyes, sperm motility scores were acceptable before and after slow and fast freezing processes.

Inescapable shock, neurotransmitters, and addiction to trauma: toward a psychobiology of post traumatic stress

Chronic post traumatic stress has been described as a "physioneurosis" (Kardiner 1941), that is, a mental disorder with both psychological and physiological components. The behavioral sequelae of inescapable shock in animals and of massive psychic trauma in people show a striking parallel. Inescapable shock in animals leads to both transient catecholamine depletion and subsequent stress-induced analgesia. We postulate that the numbing and catatenoid reactions following trauma in humans correspond to the central nervous system (CNS) catecholamine depletion that follows inescapable shock in animals. We further explore the evidence for a human equivalent of "stress-induced analgesia" in animals, which is known to be mediated by endogenous opioids. Although reexposure to trauma may produce a paradoxical sense of calm and control due to endogenous opioid release, a cessation of traumtic stimulation will be followed by symptoms of opioid withdrawal and physiological hyperreactivity mediated by CNS noradrenergic hypersensitivity. This hyperreactivity can, in turn, be temporarily modified by reexposure to trauma. This factor could account for voluntary reexposure to trauma in many traumatized individuals and would provide a complementary formulation to the conventional psychodynamic concept of attempted mastery of the psychosocial meaning of the trauma.

Monitoring pre-service reproductive status in dairy cows

Combinations of oestrus detection, ovarian palpation and milk progesterone assays were used to monitor pre-service reproductive status of cows in two dairy herds over two successive years. Non-cyclical cows were identified as having no luteal tissue in their ovaries on two occasions 10 days apart. Absence of luteal tissue was determined by the presence of basal mild progesterone initially followed either by a repeat of this result or by failure to palpate a corpus luteum per rectum. In the period 32 to 56 days post partum the number of non-cyclical cows on farm A years 1 and 2 was eight out of 31 (25 . 5 per cent), and 10 out of 62 (16 . 1 per cent) and on farm B years 1 and 2 was 10 out of 68 (14 . 7 per cent) and 11 out of 85 (12 . 9 per cent) respectively. The farm A herd was high yielding, (average lactation 6380 litres), whereas the farm B herd was of average yield (4717 litres). In both herds 60 day milk yield was not related to cyclical status of pre-service cows. There was however a trend toward a greater proportion of young cows being non-cyclical. With the exception of a prolonged calving to conception interval for farm A in year 1, whether a pre-service cow was cyclical or not had no effect on when the cow was first served or on when the animal conceived. The routine incorporation of pre-service monitoring to herd fertility control programmers may however be of value in recognising the incidence of non-cyclical cows and giving an early indication of oestrus detection efficiency.

Progesterone assays and rectal palpation in pre-service management of a dairy herd

Fifty-one dairy cows were examined three times at weekly intervals during weeks 5 to 7 after calving. Rectal palpation of the ovaries and plasma progesterone assay were used to determine cyclic ovarian function. Eight of 51 cows exhibited true anoestrus by day 49 after calving. Only 23 of 43 cycling cows were served by day 77, the end of the target period for first service. In 77 per cent of 142 examinations, rectal palpation and progesterone assay gave compatible results. Most incompatibility occurred early or late inthe cycle, or in association with cystic structures in the ovaries. Eleven of the 51 cows had cysts in the ovaries but cyclicity and fertility were not adversely affected.

beta-adrenergic receptor and adenylate cyclase in transverse tubules of skeletal muscle

Experiments were carried out to clarify the sites of action of beta-adrenergic agonists in skeletal muscle microsomes. Microsomes were fractionated into longitudinal reticulum, terminal cisternae, and isolated transverse tubules. Transverse tubules were selectively labeled and tracked with [3H]ouabain. beta-adrenergic receptor was identified by [3H]dihydroalprenolol binding. Assays of beta-adrenergic receptor, adenylate cyclase, and protein kinase-stimulated phosphorylation showed: 1) beta-adrenergic receptor was detected in transverse tubules with a receptor density of 0.61 pmol/mg of protein. No significant binding was detected in longitudinal reticulum or in terminal cisternae. 2) Isoproterenol-stimulated adenylate cyclase was present in microsomes but was similarly confined to the transverse tubular fraction. The activity of F- stimulated cyclase in transverse tubules was 2.3 nmol/mg of protein/min. 3) No phosphorylation of microsomes by cyclic AMP and protein kinase could be detected. We conclude that the action of epinephrine on skeletal muscle is mediated through receptors and adenylate cyclase in the external membrane.

A study of cyclic nucleotide metabolism and the histology of rat liver during 3'-methyl-4-dimethylamino-azobenzene carcinogenesis. II. Cyclic AMP metabolism

We have studied cAMP metabolism in rat livers undergoing carcinogenesis induced by dietary 3'-methyl-4-dimethylaminoazobenzene. A correlation between the biochemical and the histological changes described in the companion paper has been made. In this study, we saw 100% incidence of cholangiocarcinoma by 10 weeks. During weeks 1--10, the biochemistry of tumor-free areas of the livers only was studied; during weeks 11-13, the increased size of the tumors made possible a biochemical study of the tumor tissue as well as the non-tumor tissue, and a comparison between the two was made. Alterations in all parameters of cAMP metabolism were seen from the earliest stages of treatemnt. Most striking were those of adenylate cyclase activity which preceded and accompanied tumor formation, and were seen in both non-tumor and tumor tissue. In the first few weeks of treatment, small acidophilic glycogen-deficient hepatocytes appeared in the periportal areas of the liver lobules. During this time, there was an increase in maximal isoproterenol stimulation of adenylate cyclase and to a lesser extent in the basal activity of the enzyme; increases in phosphodiesterase activity were seen, and were greatest in weeks 1, 2; cAMP levels were diminished in weeks 1, 2 and slightly but not significantly elevated at week 3. From week 4 onwards an even smaller glycogen-deficient cell population appeared in perilobular areas amongst the acidophilic hepatocytes, and tumors began to appear elsewhere in the livers; at this time, there were further marked increases in the basal activity and isoproterenol responsiveness of adenylate cyclase, and the appearance of increased Gpp(NH)p responsiveness of the enzyme; the increase in phosphodiesterase activities seen at week 3 (smaller than that seen in weeks 1, 2) was sustained but did not further increase; cAMP levels were now significantly elevated also, but they did not rise steadily as did the activity of adenylate cyclase. There was a marked difference between the adenylate cyclase activities in non-tumor tissue from tumor-bearing and non-tumor-bearing livers in weeks 4--10, but there was no difference between the phosphodiesterase activities or cAMP levels in these two groups. Adenylate cyclase activity was extremely high in both non-tumor tissue of tumor-bearing livers from weeks 4--10 and tumors from weeks 11--13. Although phosphodiesterase activities were most elevated in the tumors, there were extremely high cyclic AMP levels in these tissues. The difference between the cAMP levels of tumor and non-tumor tissue was striking. Our findings are discussed with respect to the two-state model of carcinogenesis...

Hormone receptors and cyclic nucleotide metabolism in cancer cells

The possibility of a relationship between cyclic AMP formation and metabolic processes in tumours has been investigated. Changes in basal activity and hormone-responsiveness of adenylate cyclase were demonstrated in plasma membranes and intact cells from pre-cancerous liver of rats fed a diet containing the carcinogen 3'-methyl-4-dimethylaminoazobenzene. Basal adenylate cyclase activity in hyperplastic parathyroid gland membranes was 200% higher than that in parathyroid adenoma membranes, corresponding with their relative rates of parathyroid hormone secretion in vitro. Membrane adenylate cyclase activity in hypernephromas was consistently 100--300% higher than in adjacent human renal cortex. Furthermore the adenylate cyclase activity of the tumour membranes was not influenced by a wide range of hormones which were effective stimulants in 'normal' renal cortex membranes. Conversion of 25-hydroxycholecalciferol to 1,25-dihydrocholecalciferol could not be demonstrated in either hypernephroma or adjacent renal cortical tissue. However, three of the four hypernephromas tested secreted a bone-resorbing factor. Cyclic AMP formation was increased by salmon, human and porcine calcitonins in both plasma membranes and intact cells from a poorly differentiated epidermoid cell carcinoma which was itself secreting calcitonin in culture. This phenomenon might be related to a feedback regulation of calcitonin production in this cell line. The observations are consistent with the concept of a relationship between cyclic AMP formation and certain metabolic functions (e.g. hormone production) in tumour cells.