Altered gene expression and spongiotrophoblast differentiation in placenta from a mouse model of diabetes in pregnancy.

AIMS/HYPOTHESIS: Pregnancies complicated by diabetes have a higher risk of adverse outcomes for mothers and children, including predisposition to disease later in life, e.g. metabolic syndrome and hypertension. We hypothesised that adverse outcomes from diabetic pregnancies may be linked to compromised placental function, and sought to identify cellular and molecular abnormalities in diabetic placenta. METHODS: Using a mouse model of diabetic pregnancy, placental gene expression was assayed at mid-gestation and cellular composition analysed at various stages. Genome-wide expression profiling was validated by quantitative PCR and tissue localisation studies were performed to identify cellular correlates of altered gene expression in diabetic placenta. RESULTS: We detected significantly altered gene expression in diabetic placenta for genes expressed in the maternal and those expressed in the embryonic compartments. We also found altered cellular composition of the decidual compartment. In addition, the junctional and labyrinth layers were reduced in diabetic placenta, accompanied by aberrant differentiation of spongiotrophoblast cells. CONCLUSIONS/INTERPRETATION: Diabetes during pregnancy alters transcriptional profiles in the murine placenta, affecting cells of embryonic and maternal origin, and involving several genes not previously implicated in diabetic pregnancies. The molecular changes and abnormal differentiation of multiple cell types precede impaired growth of junctional zone and labyrinth, and of placenta overall. Regardless of whether these changes represent direct responses to hyperglycaemia or are physiological adaptations, they are likely to play a role in pregnancy complications and outcomes, and to have implications for developmental origins of adult disease.

Myocardial muscarinic receptor upregulation and normal response to isoproterenol in denervated hearts by familial amyloid polyneuropathy.

BACKGROUND: Patients with familial amyloid polyneuropathy, a rare hereditary form of amyloidosis, have progressive autonomic neuropathy. The disease usually does not induce heart failure but is associated with sudden death, conduction disturbances, and an increased risk of complications during anesthesia. Although cardiac sympathetic denervation has been clearly demonstrated, the postsynaptic status of the cardiac autonomic nervous system remains unelucidated. METHODS AND RESULTS: Twenty-one patients were studied (age, 39+/-11 years; normal coronary arteries; left ventricular ejection fraction 68+/-9%). To evaluate the density and affinity constants of myocardial muscarinic receptors, PET with (11)C-MQNB (methylquinuclidinyl benzilate), a specific hydrophilic antagonist, was used. Cardiac beta-receptor functional efficiency was studied by the heart rate (HR) response to intravenous infusion of isoproterenol (5 minutes after 2 mg of atropine, 5, 10, and 15 ng/kg per minute during 5 minutes per step). The mean muscarinic receptor density was higher in patients than in control subjects (B'(max), 35.5+/-8.9 versus 26.1+/-6.7 pmol/mL, P=0.003), without change in receptor affinity. The increase in HR after injection of atropine as well as of MQNB was lower in patients compared with control subjects despite a similar basal HR (DeltaHR after atropine, 11+/-21% versus 62+/-17%; P<0.001), consistent with parasympathetic denervation. Incremental infusion of isoproterenol induced a similar increase in HR in patients and control subjects. CONCLUSIONS: Cardiac autonomic denervation in familial amyloid polyneuropathy results in an upregulation of myocardial muscarinic receptors but without change in cardiac beta-receptor responsiveness to catecholamines.

Diagnosis of extensive coronary artery disease: intrinisic value of increased lung 201 T1 uptake with exercise SPECT.

UNLABELLED: Exercise lung 201 TI uptake calculated with planar imaging has an important diagnostic and prognostic value in patients with coronary artery disease (CAD). However, its value with SPECT imaging raises methodological concerns and is controversial. We studied its value for the discrimination between extensive (E) and limited (L) angiographic CAD with exercise SPECT. METHODS: Four methods of lung-to-heart ratio quantification were calculated in patients with a low likelihood (< 5%) of CAD (n = 62). Their dependent variables were defined, and corresponding correction equations were derived. Receiver operating characteristic (ROC) analysis was performed in a pilot group (L-CAD, n = 49; E-CAD, n = 126) to define the optimal method of calculation of the lung-to-heart ratio. Its best threshold providing the best sensitivity for a specificity of 90% was defined. After correction for dependent variables, the 4 methods were also compared by ROC analysis and the optimal corrected method was compared with the optimal uncorrected method using ROC analysis and the best threshold. The consistency of these results in the validation group (L-CAD, n = 41; E-CAD, n = 122) and of the results of visual analysis of lung 201TI uptake were then verified. RESULTS: On ROC analysis in the pilot group, the optimal method of calculation of the lung-to-heart ratio was the mean activity in a region of interest drawn at the base of the lungs to the mean activity over the heart (Lb/H). For the best threshold, Lb/H presented a sensitivity of 34%. Corrected Lb/H still remained the best method of calculation on ROC analysis compared with the other corrected methods. On ROC analysis, there was no difference between corrected and uncorrected Lb/H. For the best threshold, corrected Lb/H presented a similar sensitivity of 37% compared with uncorrected Lb/H. When applied to the validation group (L-CAD, n = 41; E-CAD, n = 122), the best-defined threshold in the pilot group for corrected Lb/H presented a diagnostic value similar to that in the pilot group (sensitivity, 41%; specificity, 90%), but uncorrected Lb/H presented a higher sensitivity (47%; P < 0.04) and a slightly lower specificity (80%). Results of lung 201TI uptake visual analysis were inconsistent between pilot and validation groups (42% versus 58% sensitivity, P = 0.012; 86% versus 66% specificity, P = 0.023). CONCLUSIONS: For evaluation of E-CAD versus L-CAD, quantification of the exercise lung-to-heart 201TI uptake ratio with SPECT is feasible, reproducible, more discriminate than simple visual analysis, and best calculated as Lb/H. It presents an intrinsic diagnostic value even after correction for other clinically valuable dependent variables.

Sympathetic nerve alterations assessed with 123I-MIBG in the failing human heart.

UNLABELLED: Norepinephrine (NE) reuptake function is impaired in heart failure and this may participate in myocyte hyperstimulation by the neurotransmitter. This alteration can be assessed by 123I-metaiodobenzylguanidine (MIBG) scintigraphy. METHODS: To determine whether the impairment of neuronal NE reuptake was reversible after metoprolol therapy, we studied 18 patients (43+/-7 y) with idiopathic dilated cardiomyopathy who were stabilized at least for 3 mo with captopril and diuretics. Patients underwent, before and after 6 mo of therapy with metoprolol, measurements of radionuclide left ventricular ejection fraction (LVEF), maximal oxygen consumption and plasma NE concentration. The cardiac adrenergic innervation function was scintigraphically assessed with MIBG uptake and release measurements on the planar images obtained 20 min and 4 h after tracer injection. To evaluate whether metoprolol had a direct interaction with cardiac MIBG uptake and release, six normal subjects were studied before and after a 1-mo metoprolol intake. RESULTS: In controls, neither cardiac MIBG uptake and release nor circulating NE concentration changed after the 1-mo metoprolol intake. Conversely, after a 6-mo therapy with metoprolol, patients showed increased cardiac MIBG uptake (129%+/-10% versus 138%+/-17%; P = 0.009), unchanged cardiac MIBG release and decreased plasma NE concentration (0.930+/-412 versus 0.721+/-0.370 ng/mL; P = 0.02). In parallel, patients showed improved New York Heart Association class (2.44+/-0.51 versus 2.05+/-0.23; P = 0.004) and increased LVEF (20%+/-8% versus 27%+/-8%; P = 0.0005), whereas maximal oxygen uptake remained unchanged. CONCLUSION: Thus, a parallel improvement of myocardial NE reuptake and of hemodynamics was observed after a 6-mo metoprolol therapy, suggesting that such agents may be beneficial in heart failure by directly protecting the myocardium against excessive NE stimulation.

Clinical impact of combination of scatter, attenuation correction, and depth-dependent resolution recovery for (201)Tl studies.

UNLABELLED: A lack of specificity for myocardial perfusion imaging has been widely reported, mostly related to false-positive defects on the inferior wall. The application of depth-dependent resolution recovery (RR), attenuation correction (AC) using external source devices, and scatter correction has been proposed to resolve this pitfall. METHODS: We studied the clinical benefit of depth-dependent RR, nonuniform AC using a scanning line source, and scatter correction (photon energy recovery [PER]) compared with filtered backprojection alone. Eighty-two patients were included: 40 healthy volunteers with a low likelihood of coronary artery disease (control group) and 42 patients with proven right or circumflex coronary artery disease but without involvement of the left anterior descending artery. Among these 82 patients, the images of 33 were also processed with PER. RESULTS: RR did not alter the performance of filtered backprojection alone. AC + RR greatly improved specificity and the rate of normal (201)Tl SPECT findings in the control population (from 56% to 95% and from 53% to 100%, respectively) but significantly decreased sensitivity (from 92% to 54%). AC + RR generated a false anteroapical defect in 21% of patients and reverse redistribution of the apex in 23%. AC + RR significantly decreased the extent of the stress defect (from 4.09 to 3.21 segments, P < 0.003) and increased the perfusion score of the stress defect (from 0.78 +/- 0.72 to 1.47 +/- 1.11, P < 0.00061). Moreover, AC + RR generated overcorrection on the inferior wall, leading to false estimation of viability for 11 of 15 patients with an old inferior myocardial scar without evidence of residual viability. PER decreased overcorrection on the inferior wall, but without improving sensitivity. PER did not significantly reduce the number of anteroapical false-positives or the number of apical reverse distribution cases. CONCLUSION: AC + RR improved the specificity and normalcy rate of (201)Tl SPECT myocardial perfusion imaging but generated overcorrection on the inferior wall, leading to low sensitivity and to false evaluation of myocardial viability in 73% of the patients with inferior infarction. AC + RR also generated anteroapical artifacts. The addition of scatter correction did not significantly reduce these drawbacks.

Detection of bone metastases in patients with endocrine gastroenteropancreatic tumors: bone scintigraphy compared with somatostatin receptor scintigraphy.

UNLABELLED: Scintigraphy with somatostatin analogs is a sensitive method for the staging and therapeutic management of patients with endocrine gastroenteropancreatic (GEP) tumors. The aim of this study was to compare prospectively somatostatin receptor scintigraphy (SRS) using 111n-pentetreotide with bone scintigraphy using 99mTc-hydroxymethylene diphosphonate for the detection of bone metastases. METHODS: One-hundred-forty-five patients with proven endocrine GEP tumors were investigated. Patients were classified according to the presence of bone metastases as indicated by CT, MRI or histologic data. Group I included 19 patients with confirmed bone metastases, and group II included 126 patients without bone metastases. RESULTS: In group I, SRS was positive in all 19 patients with bone metastases, and bone scintigraphy was positive in 17 patients. Bone metastases were found to occur predominantly in patients with liver metastases. In group 11, 5 patients had recent bone surgery for fracture or arthritis. SRS showed bone uptake in 4 of these patients, and bone scanning showed abnormal uptake in 5. In 7 of the remaining 121 group II patients, SRS was negative and bone scanning showed abnormal bone uptake suggesting bone metastases. The detection of bone metastases was of major prognostic value, because 42% of group 1 patients died during a 2-y follow-up. CONCLUSION: In patients with GEP tumors, the accuracy of SRS appears to be similar to that of bone scintigraphy for the detection of bone metastases.

Comparison of left ventricular responses to the six-minute walk test, stair climbing, and maximal upright bicycle exercise in patients with congestive heart failure due to idiopathic dilated cardiomyopathy.

Submaximal exercise tests have been advocated to assess exercise capacity in chronic heart failure, but hemodynamic responses have not been characterized. To determine left ventricular (LV) responses during submaximal exercise, the LV ejection fraction (EF) and volumes were evaluated by using an ambulatory radionuclide detector in 13 patients with idiopathic dilated cardiomyopathy during upright maximal graded bicycle exercise, stair climbing and a 6-minute walk test. The 3 tests elicited different responses in volumes and, to a lesser degree, in LVEF. The maximal bicycle exercise led to a decrease in LVEF from 22 +/- 9% to 17 +/- 8% (p <0.05), with marked increases in both end-diastolic volume (EDV) (+15 +/- 10%, p <0.001) and end-systolic volume (ESV) (+23 +/- 18%, p <0.001). Stair climbing tended to reduce LVEF (from 24 +/- 11% to 21 +/- 10%, p = 0.05), with a lesser increase in volumes, which was more marked for ESV (+8 +/- 9%, p <0.01) than for EDV (+4 +/- 4%, p <0.01). The 6-minute walk test did not significantly change LVEF (23 +/- 10% vs 22 +/- 10%), but increased both EDV (+10 +/- 6%, p <0.001) and ESV (+8 +/- 8%, p <0.01) moderately and proportionally. Exercise capacity indexes (peak oxygen consumption, maximal bicycle work rate, stair climbing time, and the distance covered during the 6-minute walk test) correlated significantly with one another. There was no correlation between submaximal exercise tolerance indexes and resting or exercise LVEF. This study shows that (1) LVEF changes are inadequate to report on LV volume changes during exercise; (2) the 3 tests induce different LV volume changes; (3) the 6-minute walk test induces significant changes in LV volumes but no change in LVEF.

Left ventricular-arterial system coupling at peak exercise in dilated nonischemic cardiomyopathy.

We assessed the ventricular-arterial coupling at peak exercise in 20 patients with dilated cardiomyopathy (ejection fraction, 27+/-12%) and 7 normal subjects by radionuclide ventriculography during exercise, coupled with respiratory gas analysis. The end-systolic pressure-volume ratio, taken as an index of contractility, and the effective arterial elastance were calculated at rest and at peak exercise. The end-systolic pressure/volume ratio increased from 3.7+/-2.7 to 6.9+/-4.0 mm Hg/mL at peak exercise in the normal subjects, but did not change significantly (from 0.9+/-0.5 to 1.0+/-0.6 mm Hg/mL) in the patients. Arterial elastance did not change significantly in the patients (+17+/-32%, not significant [NS] vs rest) or in the normal subjects (+22+/-28%, NS vs rest). The change in ejection fraction during exercise correlated both with the end-systolic pressure/volume ratio and with effective arterial elastance changes (r=0.60 and 0.68, respectively). We conclude that ventricular arterial coupling is further altered at peak exercise in these patients because of the lack of increase in contractility and not of altered effective arterial elastance response.

Prognostic value of 201Tl myocardial scintigraphy after coronary artery bypass grafting.

BACKGROUND: 201Tl myocardial scintigraphy (201Tl SPECT) is of strong prognostic value in various populations with suspected or known coronary artery disease. However, its value in patients with coronary artery bypass grafting (CABG) is not fully assessed. METHODS: We examined 115 consecutive patients to determine the relation between clinical data/stress 201Tl SPECT performed 5+/-3 years after CABG, and subsequent cardiac events. RESULTS: Thirteen patients (11%) had stress-induced angina, 22 (19%) had electrical positivity, and 97 (84%) had abnormal scintigraphy, including 62 (54%) with reversible defects. During follow-up (35+/-22 months), there were nine cardiac deaths, seven myocardial infarctions, and 20 revascularization procedures. Multivariate Cox analysis identified the delay between CABG and scintigraphy (P<0.01, relative risk (RR) = 1.01), the extent of stress 201Tl defects (P = 0.04, RR = 1.18), and increased stress 201Tl lung uptake (P = 0.03, RR = 3.56) as significant predictors of cardiac deaths/infarctions. Delay between CABG and scintigraphy (P < 0.001, RR = 1.01), the extent of stress 201Tl defects (P = 0.03, RR = 1.15), and that of reversible defects (P = 0.05, RR = 1.13) were the only significant predictors of total events. CONCLUSIONS: Besides the delay between CABG and scintigraphy, the scintigraphic parameters were the only significant and additive predictors of cardiac events in 115 patients with CABG.

Comparative impact of standard approach, FDG PET and FDG dual-head coincidence gamma camera imaging in preoperative staging of patients with non-small-cell lung cancer.

We prospectively compared the impact of the standard approach, of fluorodeoxyglucose positron emission tomography (FDG PET) and of FDG dual-head coincidence gamma camera imaging (DHC) in preoperative staging of patients with non-small-cell lung cancer (NSCLC). In addition to traditional staging, 42 patients were studied with a PET system and a DHC system. The number of lesions detected on DHC and on PET were compared independently of the proof of a tumoural invasion. Then, for the sub-group of lesions with the proof of a tumoural invasion, the sensitivity of the different imaging modalities was compared. Finally, stagings were compared with final staging established by histopathological findings (n=28), additional imaging modalities (n=4), clinical and traditional imaging follow-up over at least 4 months. DHC detected 105 of the 145 lesions considered as pathological on PET (73%, P=0.01), with a concurrence of 89% (NS) in lesions larger than 1.5 cm, and only 17% (P=0.03) in those smaller or equal to 1 cm. Traditional staging detected 87 of the 114 verified tumoural lesions (76%), PET 110/114 (96%, P=0.01 vs traditional staging), DHC 88/114 (77%, NS vs traditional staging, P=0.01 vs PET). PET correctly predicted the N stage in 39/42 (93%) patients, DHC in 38/42 (90%), and computed tomography in 32/42 (76%). PET correctly predicted the M stage in 42/42 (100%) patients, DHC in 41/42 (98%), and traditional staging in 38/42 (90%). Identical NM staging was obtained with DHC and PET in 38/42 (90%) patients. Compared to traditional NM staging, PET correctly up-staged 9/42 (21%) patients and down-staged 3/42 (7%), with one additional false N up-staging. DHC correctly up-staged 7/42 (17%) patients and down-staged 3/42 (7%), with one additional false N down-staging. PET correctly reclassified 4/42 (9.5%) patients from resectable to unresectable and incorrectly reclassified one. DHC correctly reclassified 3/42 (7%) patients without false therapeutic reclassification. Although DHC detected fewer lesions than PET, DHC is a possible alternative to PET since the impact on staging was high as compared with traditional staging and was very similar to that of PET.

TNF as a malaria candidate gene: polymorphism-screening and family-based association analysis of mild malaria attack and parasitemia in Burkina Faso.

We have previously obtained strong evidence for linkage of mild malaria attack to the MHC region, with a peak close to the tumor necrosis factor (TNF) gene. We screened, for polymorphisms, the entire TNF gene in the same sample of 34 families comprising 197 individuals living in a Plasmodium falciparum endemic area and we found 17 polymorphisms. In a longitudinal study, we investigated whether the 11 most frequent and informative polymorphisms were associated with mild malaria attack and maximum parasitemia, which was the highest parasitemia in each individual over 2 years. Mild malaria attack and maximum parasitemia were positively correlated. Transmission disequilibrium tests showed nominal evidence for association between TNF-1031, TNF-308, TNF851 and TNF1304 polymorphisms, and mild malaria attack on the one hand, and between TNF-238, TNF851 and TNF1304 polymorphisms, and maximum parasitemia on the other hand. After accounting for multiple tests, we confirmed the association of TNF-238 with maximum parasitemia and the association of TNF1304 and TNF851 with maximum parasitemia and mild malaria attack. The association tests with mild malaria attack suggest a moderate effect of TNF-308 polymorphism. In conclusion, our study suggests that several TNF variants may be part of the genetic determinants for maximum parasitemia and/or mild malaria attack.

Increased myocardial muscarinic receptor density in idiopathic dilated cardiomyopathy: an in vivo PET study.

BACKGROUND: Congestive heart failure is associated with decreased stimulated myocardial adenylate cyclase activity, increased Gi-binding protein, attenuated parasympathetic tone, and increased modulation of beta-adrenergic inotropic left ventricular stimulation by parasympathetic agonists. Despite these abnormalities, changes in the density or affinity of ventricular muscarinic receptors have not been demonstrated in patients. METHODS AND RESULTS: The density and affinity constants of myocardial muscarinic receptors were evaluated noninvasively by means of positron emission tomography with 11C-MQNB (methylquinuclidinyl benzilate), a specific hydrophilic antagonist, in 20 patients with congestive heart failure due to idiopathic dilated cardiomyopathy (mean left ventricular ejection fraction, 22+/-9%) and compared with values in 12 normal subjects. The mean receptor concentration was significantly higher in patients than in control subjects (B'max, 34.5+/-8.9 versus 25+/-7.7 pmol/mL, P<.005), with no changes in affinity constants. The change in heart rate after injection of 0.6 mg of cold MQNB was lower in patients than in control subjects (34+/-20% versus 55+/-36%, P<.05), and receptor density correlated negatively with maximal heart rate in the patients (r=.45, P<.05). CONCLUSIONS: Congestive heart failure is associated with an upregulation of myocardial muscarinic receptors. This may be an adaptive mechanism to beta-agonist stimulation and should increase the number of potential targets for pharmacological intervention.

Cardiac sympathetic denervation in familial amyloid polyneuropathy assessed by iodine-123 metaiodobenzylguanidine scintigraphy and heart rate variability.

Familial amyloid polyneuropathy (FAP) is a rare and severe hereditary form of amyloidosis, due to nervous deposits of a genetic variant transthyretin produced by the liver and characterized by both sensorimotor and autonomic neuropathy. Left ventricular systolic dysfunction is rare, but conduction disturbances and sudden deaths can occur. The neurological status of the heart has not been elucidated, and an alteration of the sympathetic nerves may be involved. We studied 17 patients (42+/-12 years) before liver transplantation by iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, heart rate variability analysis, coronary angiography, radionuclide ventriculography, rest thallium single-photon emission tomography (SPET) and echocardiography. Coronary arteries, left ventricular systolic function and rest thallium SPET were normal in all patients. Only mild evidence of amyloid infiltration was found at echocardiographic examination. Cardiac MIBG uptake was dramatically decreased in patients compared with age-matched control subjects (heart-to-mediastinum activity ratio at 4 h: 1.36+/-0.26 versus 1.98+/-0.35, P<0.001), while there was no difference in MIBG washout rate. Heart rate variability analysis showed a considerable scatter of values, with high values in four patients despite cardiac sympathetic denervation as assessed by MIBG imaging. The clinical severity of the polyneuropathy correlated with MIBG uptake at 4 h but not with the heart rate variability indices. Cardiac MIBG uptake and the heart rate variability indices did not differ according to the presence or absence of conduction disturbances. Patients with FAP have sympathetic cardiac denervation as assessed by MIBG imaging despite a preserved left ventricular systolic function and cardiac perfusion, without correlation with conduction disturbances. Results of the heart rate variability analysis were more variable and this technique does not seem to be the best way to evaluate the extent of cardiac sympathetic denervation in FAP patients.