Use of sexed sorted semen for fixed-time artificial insemination or fixed-time embryo transfer of in vitro-produced embryos in cattle.

Artificial insemination and in vitro embryo production are powerful tools for disseminating superior genetic qualities and improving the reproductive performance of dairy and beef cattle. In conjunction with these biotechnologies, sexed-sorted semen has been used to obtain offspring of a predetermined sex. This study compared the pregnancy rates obtained using in vitro fertilization/timed embryo transfer (IVF/TET) and timed artificial insemination (TAI), both performed using sexed-sorted (Y-chromosome-bearing) semen obtained from the same bull. For the in vitro embryo production, the ovaries of 250 Nelore cows with known histories were collected in the slaughterhouse and used for IVF. After evaluation of the recipients (IVF/TET group; n = 974), the resultant embryos were transferred to the females with corpus luteum (n = 822). The pregnancy-related data for this group were compared with those for the TAI group (n = 974). Ultrasonography was performed at 60 days to determine the pregnancy status and confirm the sex of the fetus. A total of 2008 oocytes produced 1050 embryos, with 52% of them reaching the blastocyst stage. The pregnancy rate and the accuracy in determining the fetal sex were 35.4% (345/974) and 95.07% (328/345), respectively, for the IVF/TET group and 30% (293/974; P < 0.05) and 94.88% (278/293), respectively, for the TAI group. In the present study, we concluded that male calves could be better obtained using IVF/TET rather than TAI; therefore, this strategy can be considered to increase the pregnancy rate of beef cattle.

Safety and feasibility of two-dimensional echocardiography and myocardial perfusion imaging in patients with chest pain.

The accurate identification of patients at high risk for acute coronary syndromes among those seen in the emergency department with possible myocardial ischemia and nonischernic electrocardiograms is a problem. Two-dimensional echocardiography and myocardial perfusion imaging with 99m-technetium sestamibi can identify patients at low and high risk; however, comparative studies are lacking. The authors studied 555 patients considered at low or moderate risk for myocardial ischemia in our emergency department on the basis of the presenting history, and results of physical examination and electrocardiography. These patients underwent echocardiography and myocardial perfusion imaging within 4 hours of presentation. Endpoints included myocardial infarction, percutaneous transluminal coronary angioplasty, and positive results on stress perfusion imaging. Both imaging procedures were performed in the emergency department on 370 patients. Overall agreement between the two techniques was high (concordance, 89%) in the patients who had myocardial infarction or underwent coronary angiography. Agreement between the two techniques is high when used in patients with possible myocardial ischemia. Both techniques helped identify patients at high risk who required admission and those who could be safely discharged.

Usefulness of two-dimensional echocardiography and myocardial perfusion imaging for immediate evaluation of chest pain in the emergency department.

BACKGROUND: Accurate identification of patients in the emergency department at high risk of acute coronary syndrome with possible myocardial ischaemia and a nonischaemic electrocardiogram is problematic. Both two-dimensional echocardiography and myocardial perfusion imaging with technetium-99m-sestamibi can identify patients at low and high risk, however comparative studies are lacking. METHODS AND RESULTS: We studied 655 consecutively patients considered at low or moderate risk for myocardial ischaemia in our Emergency Department (ED). On the basis of the presenting history, physical examination, and electrocardiogram they underwent both echocardiography and myocardial perfusion imaging within 4 h of ED presentation. End points included myocardial infarction, percutaneous transluminal coronary angioplasty (PTCA) and positive stress perfusion imaging. Both imaging procedures were performed in the ED on 470 patients. Overall agreement between the two techniques was high (concordance 90%) in the patients who had myocardial infarction or underwent coronary angiography. CONCLUSIONS: Agreement between the two imaging techniques is high when used in patients with possible myocardial ischaemia. Both techniques identified patients at high risk who required admission and those who could be safely discharged directly from the ED.

[Atrial stunning and pharmacologic cardioversion in idiopathic atrial fibrillation of recent onset]. / Stunning atriale e cardioversione farmacologica di fibrillazione atriale idiopatica di recente insorgenza.

BACKGROUND: Normal atrial mechanic function may not return immediately after the successful cardioversion of atrial fibrillation. It has been suggested that the delayed recovery of atrial contraction (atrial stunning) might be due to: 1. the energy delivered during direct current cardioversion 2. the time from the onset of atrial fibrillation 3. the left atrial size 4. the associated cardiac disease. This study evaluates "atrial stunning" in patients pharmacologically treated, with atrial fibrillation of recent onset, normal atrial size and without heart disease. Doppler echocardiography is well suited for assessment of atrial function due to the ability of recording the peak velocity of atrial contraction (A wave). METHODS: Twenty-five patients with no evidence of heart disease and M-mode left atrial dimension less than 40 mm underwent successful pharmacologic cardioversion (pro-paphenon or flecainide 2 mg/kg/10 min) of atrial fibrillation of recent onset (less than 48 hours). After cardioversion an echocardiographic study was performed within 12 hours (ECO 1), on day 3 (ECO 2), on day 12 (ECO 3), and on day 30 (ECO 4). RESULTS: No significant difference of both left atrial size (37 +/- 3.9 mm; 38.22 +/- 3.8 mm; 38.02 +/- 4.7 mm; 38.2 +/- 4.14 mm) and peak E velocity (57.97 +/- 18.3 mm/sec; 59.4 +/- 18.3 mm/sec; 59.0 +/- 16 mm/sec; 59.07 +/- 16.7 mm/sec) was demonstrated among serial echocardiographic evaluations. Both peak A velocity (mm/sec) and E/A ratio were significantly different in ECO 1 (60.29 +/- 12.3-1.0 +/- 0.37) than in ECO 2 (73.1 +/- 10.7, p < 0.005-0.82 +/- 0.27, p < 0.05); no statistical difference was found between ECO 2 and ECO 3 (76.31 +/- 12-0.78 +/- 0.24 mm/sec)--ECO 4 (76.91 +/- 14.8-0.78 +/- 0.21 mm/sec). CONCLUSIONS: This study suggests that patients with atrial fibrillation of recent onset have a delayed recovery of normal atrial systolic function after pharmacologic cardioversion.

[Planar myocardial scintigraphy with 99mTc sestamibi for the evaluation of the infarct area and the efficacy of the thrombolytic therapy]. / Scintigrafia miocardica planare con tecnezio-99m-sestamibi per la valutazione dell'estensione dell'area infartuale e dell'efficacia della terapia trombolitica.

BACKGROUND: Nuclear cardiology permits the estimation of myocardial infarction size and the result of the thrombolytic therapy. The aim of the study was to demonstrate the feasibility of the planar myocardial scintigraphy with tecnetium-99m-sestamibi in the coronary intensive care unit for the early identification of the infarct size and the results of the thrombolytic therapy. MATERIAL AND METHODS: We studied 15 patients affected by a first acute myocardial infarction (AMI), 10 anterior and 5 inferior wall, treated with thrombolysis (APSAC 30U i.v.) within and interval of 3 hours from the symptoms onset, tecnetium-99m-sestamibi was injected before thrombolysis and after 3 +/- 1 hours the planar imaging was registered with a mobile gamma-camera. Scintigraphic evaluation was repeated after 24 hours and before patient discharge. Within 48 hours from the thrombolytic therapy the coronary angiography was performed for the demonstration of patency of the infarct-related artery. The left ventricle myocardial perfusion was divided in the 3 planar projections into 13 segments. The perfusion in each segment was evaluated with a perfusion score: 0 = normal, 1 = moderately reduced, 2 = severely reduced, 3 = absent. The sum of the hypoperfused segments represented the infarct size. A perfusion score improvement greater than 40% was considered a marker of reperfusion. RESULTS: The infarct size involved 4.2 +/- 1.5 segments in the anterior and 2 +/- 0.8 segments in the inferior wall infarctions (p < 0.05). The scintigraphic imaging made 24 hours after AMI allowed the diagnosis of coronary reperfusion in 10 patients. The coronarography demonstrated the infarct related artery patency in 14 patients. The nuclear imaging at patient discharge provided the diagnosis or reperfusion in 11 cases and demonstrated an improvement of the myocardial perfusion score in 8 cases. CONCLUSIONS: In patients with AMI treated with thrombolysis the scintigraphic imaging with tecnetium-99m-sestamibi is feasible with a mobile gamma-camera in the intensive coronary care unit. The quality of planar imaging is good and allows the evaluation of myocardial infarct size and the efficiency of thrombolytic therapy. An earlier scintigraphic imaging should be taken into consideration for a more timely non-invasive evaluation of patients who need coronary angiography and, if necessary, a rescue-PTCA.

[Correlations between the efficacy of thrombolytic therapy and appearance of abnormal Q waves in the early stages of acute myocardial infarction]. / Correlazione tra efficacia della terapia trombolitica e comparsa di onde Q patologiche nella fase precoce dell'infarto miocardico acuto.

BACKGROUND: The purpose of this study was to determine the time course of the appearance of abnormal Q waves on the electrocardiogram (ECG) over the first 6 hrs of the symptoms of acute myocardial infarction (AMI) and to determine what implications, if any, such Q waves have for the efficacy of thrombolytic therapy. Severe myocardial ischemia can produce early QRS changes in the absence of infarction. Abnormal Q waves on the baseline ECG may not be an accurate marker or irreversibly injured myocardium. METHODS: A study of 232 patients with AMI consecutively admitted to our coronary care units was carried out. Patients with previous AMI were not included. The presence and number of abnormal Q waves, as defined by Selvester, on the initial ECG was determined for each patient. The presence or absence and magnitude of ST segment elevation and depression were recorded and these data were used to estimate the left ventricular infarct size should thrombolytic therapy not be given (Aldrich score). Quantitative thallium-201 tomographic imaging was performed after a mean of 42 +/- 40 days from hospital discharge in 145 patients. RESULTS: In patients admitted within 1 hr of symptoms, 53% had abnormal Q waves on the initial ECG independent of the duration of symptoms before therapy (p < 0.001). Despite this finding, the presence of abnormal Q waves on the admission ECG did not eliminate the effect of thrombolytic therapy on reducing final infarct size (p < 0.001). CONCLUSIONS: Abnormal Q waves are a common finding early in the course of AMI. However, there is no evidence that abnormal Q waves are associated with less benefit in terms of reduction of infarct size after thrombolytic therapy.