We have studied the prevalence of the fra (X) and of the autosomal fragile sites fra (10) (q25) and fra (16) (q22) in patients from an institute for the mentally retarded in Italy. We found six cases (1.9%) of fra (10) (q25) and 9 (2.9%) of fra (16) (q22). The study of the fra (X) was restricted to a subgroup of 91 males who did not have other chromosome anomalies or variants, and led to the discovery of 4 fra (X) cases. These 4 had the Martin-Bell syndrome; 3 of them were epileptic and had a characteristic EEG pattern originating during sleep from the temporal lobe not previously described in fra (X) mental retardation.

Adolescent↗

PubMedDate not supplied

Early and late results of ascending aorta surgery: risk factors for early and late outcome.

This study was designed to evaluate risk factors for in-hospital mortality and midterm survival in patients undergoing ascending aorta surgery at a single institution during an 11-year period. Between 1984 and 1994 a total of 158 patients underwent an ascending aorta procedure at our institution. Their mean age was 59.6 +/- 12.3; 115 (73%) were male, 33 (21%) had a history of congestive heart failure, 61 (39%) had an acute type A dissection, 21 (13%) underwent redo operations, and 55 (35%) were operated on an emergency basis. In-hospital mortality was 9.7% (10/103) for elective procedures and 36.4% (20/55) for emergency operations (p < 0.0001). Multivariable stepwise logistic regression analysis identified the cardiopulmonary bypass time [odds ratio (OR) = 1.01/min, p = 0.0021], emergency operation (OR = 2.27, p = 0.0022), arch replacement (OR = 2.71, p = 0.0067), and the need of femoral vein cannulation at intervention (OR = 1.89, p = 0.0375) as independent predictors of in-hospital death. When this kind of analysis was performed, evaluating only the variables known before surgery, acute type A dissection (OR = 2.21, p = 0.0009) and preoperative NYHA class (OR = 1.88 per class, p = 0.0290) were independent risk factors for in-hospital death. Follow-up ranged from 10 to 126 months (median 42 months), with Kaplan-Meier survivals of 69 +/- 4%, and 60 +/- 5% at 5 and 7 years, respectively; survival rates for hospital survivors were 85 +/- 4% and 67 +/- 7% at 5 and 7 years, respectively. Cox regression analysis has identified arch replacement [relative risk (RR) = 2.48, p < 0.0001], perioperative myocardial infarction (RR = 2.44, p = 0.0003), preoperative NYHA class (RR = 1.97 per class, p = 0.0009), acute type A aortic dissection (RR = 1.44, p = 0.0238), the need of femoral vein cannulation at intervention (RR = 1.55, p = 0.0332), and redo operation (RR = 1.44, p = 0.0851) as independent predictors of reduced survival at follow-up. When this kind of analysis was performed on hospital survivors only, postoperative tracheostomy (p = 0.0003, RR = 3.42), reexploration for bleeding (p = 0.0003, RR = 3.77), and the occurrence of postoperative ventricular arrhythmias (p = 0.0007, RR = 2.45) emerged as risk factors. Multiple factors affect the early and late outcome after ascending aorta surgery; our data suggest that the preoperative clinical status of the patients and the priority of surgery and aortic dissection are the main determinants of the early results; on the other hand, the early postoperative course is the main determinant of the late outcome of hospital survivors.

Aortic Dissection↗

PubMedDate not supplied

Comparison of technetium 99m-tetrofosmin and thallium-201 single photon emission computed tomographic imaging for the assessment of viable myocardium in patients with left ventricular dysfunction.

BACKGROUND: Tetrofosmin is a new technetium 99m-labeled myocardial perfusion agent that has demonstrated favorable imaging characteristics in recent clinical trials. However, it is not certain whether 99mTc-tetrofosmin compared with thallium 201 would underestimate myocardial viability in regions with left ventricular dysfunction. METHODS: To this end 15 patients (mean age 52+/-7 years) with coronary artery disease and left ventricular dysfunction (ejection fraction 35%+/-8%) documented on angiography underwent both quantitative rest-redistribution 201Tl and rest 99mTc-tetrofosmin single photon emission computed tomography imaging. RESULTS; Of 240 total segments on rest-redistribution 201Tl protocol 139 (58%) segments had irreversible 201Tl defects. Of these segments 79 (57%) had only mild to moderate reduction of 201Tl uptake (51% to 85% of normal uptake), whereas the remaining 60 (43%) had severely reduced tracer uptake (< or = 50% of normal uptake). On 99mTc-tetrofosmin protocol 180 (75%) segments had abnormal 99mTc-tetrofosmin uptake; of these segments 120 (67%) had mild to moderate reduction of 99mTc-tetrofosmin uptake, whereas 60 (33%) had severely reduced activity. Among hypokinetic regions concordance between 201Tl and 99mTc-tetrofosmin regarding myocardial viability with a cutoff point of 50% of peak activity was obtained in 28 (90%) of 31 segments (K' = 0.80), leaving only 3 of 31 regions discordant (p = NS). Similarly, among akinetic or dyskinetic regions concordance between the two tracers regarding myocardial viability was achieved in 54 (93%) regions (K' = 0.75), leaving only 4 of the 58 regions discordant (p = NS). CONCLUSIONS: These data show that when the severity of uptake was considered within abnormal segments, a similar amount of 201Tl viable regions were observed by 99mTc-tetrofosmin. Thus these two agents may provide comparable information about myocardial viability when quantitative analysis of defect severity is performed.

Adult↗

PubMedDate not supplied

Accuracy of 99mTc-tetrofosmin myocardial tomography in the evaluation of coronary artery disease.

BACKGROUND: Technetium 99m-labeled myocardial agents have been proposed as an alternative to thallium 201. The aim of this study was to assess retrospectively the accuracy of exercise myocardial 99mTc-tetrofosmin scintigraphy with tomographic imaging (SPECT) in a large group population in the evaluation of coronary artery disease. Furthermore we evaluated the relation between the severity of scintigraphic impaired myocardial perfusion and the angiographic coronary artery stenoses in patients without myocardial infarction and with stenosis localized exclusively in the proximal segment of the 3 main coronary arteries. METHODS AND RESULTS: The study group consisted of 235 consecutive patients, 204 (87%) of whom were men, with a mean age of 57+/-10 years, and with suspected or known coronary artery disease, who underwent 99mTc-tetrofosmin SPECT and coronary angiography. Furthermore, 61 patients in a low-likelihood group for coronary artery disease were also studied. Significant disease was defined by > or = 50% luminal coronary artery stenosis in > or = 1 native coronary artery or major branch or in a saphenous vein graft or arterial mammary graft. The overall sensitivity was 95%, specificity was 76%, and predictive accuracy was 95%. The normalcy rate for the low-likelihood group was 93%. Sensitivity was 71% for the left anterior descending artery, 61% for the left circumflex artery, and 73% for the right coronary artery. Specificity was 94% for the left anterior descending artery, 96% for the left circumflex artery, and 91% for the right coronary artery. Predictive accuracy was 79% for the left anterior descending artery, 78% for the left circumflex artery, and 81 % for the right coronary artery. In patients without myocardial infarction linear regression analysis between scintigraphy and angiography showed a significant correlation in patients with severe proximal coronary artery stenosis (r = 0.53, P < .002), but not in those with moderate proximal stenosis (r = 0.31, P = NS). CONCLUSIONS: This study shows that 99mTc-tetrofosmin SPECT is accurate in the detection of coronary artery disease. The relation of the severity of scintigraphic impaired myocardial perfusion and angiographic coronary artery stenosis, however, may differ significantly in patients with proximal stenosis of different severity.

Aged↗

PubMedDate not supplied

Photon scattering as a probe of microviscosity and channel size in gels such as sickle haemoglobin.

The aggregation of sickle-cell haemoglobin (HbS) is one of the most physiologically important and widely studied macromolecular gelation processes. Both the thermodynamics and kinetics of the process are important in determining the pathological consequences of deoxygenation of the red cells (and both must be understood if a rational strategy is to be developed for pharmacological intervention). We describe here a new and versatile technique for the study of the structure and formation of the HbS aggregates, that should be widely applicable to gel systems generally. We use laser autocorrelation spectroscopy to observe the diffusion of monodisperse polystyrene latex spheres in the interstices of the gel.

Chemical Phenomena↗