Voxel model of a rabbit: assessment of absorbed doses in organs after CT examination performed by two different protocols.

The objective of this work was to assess absorbed doses in organs and tissues of a rabbit, following computed tomography (CT) examinations, using a dedicated 3D voxel model. Absorbed doses in relevant organs were calculated using the MCNP5 Monte Carlo software. Calculations were perfomed for two standard CT protocols, using tube voltages of 110 kVp and 130 kVp. Absorbed doses were calculated in 11 organs and tissues, i.e., skin, bones, brain, muscles, heart, lungs, liver, spleen, kidney, testicles, and fat tissue. The doses ranged from 15.3 to 28.3 mGy, and from 40.2 to 74.3 mGy, in the two investigated protocols. The organs that received the highest dose were bones and kidneys. In contrast, brain and spleen were organs that received the smallest doses. Doses in organs which are stretched along the body did not change significantly with distance. On the other hand, doses in organs which are localized in the body showed maximums and minimums. Using the voxel model, it is possible to calculate the dose distribution in the rabbit's body after CT scans, and study the potential biological effects of CT doses in certain organs. The voxel model presented in this work can be used to calculated doses in all radiation experiments in which rabbits are used as experimental animals.

Liver anatomy, intrahepatic vascular and biliary branching system of the mole rat (Spalax leucodon).

BACKGROUND: There are many studies on the morphology of the liver and its blood vessels in experimental animals, but such studies are lacking in the mole rat (Spalax leucodon). The aim of this paper was a detailed basic study on the topography, morphology, vascular and biliary branching systems of the liver in the mole rat. MATERIALS AND METHODS: Coloured gelatine and mixture of coloured lead oxide and linseed oil were injection contrast masses used to obtain vascular and biliary branching pattern in the liver. It was revealed that the liver of the mole rat had five lobes (left, quadrate, right medial, right lateral and caudate lobes). RESULTS: The left, undivided lobe was the largest lobe of the liver. The quadrate lobe was divided into two components by a deep notch. The gallbladder, of cylindrical shape, was present and attached to the quadrate lobe. The common bile duct was formed by the union of the left and right hepatic ducts. The pancreatic duct joined the common bile duct before it entered the duodenum. In the present study, only the right medial lobe and quadrate lobe always showed a single lobar artery, portal and hepatic veins. The left lobe showed four lobar arteries, portal and hepatic veins. The caudate lobe with its two processes and the right lateral and medial lobes had different arterial and portal blood supply as well as hepatic and biliary drainage of these lobes. The intrahepatic branches of the proper hepatic artery ran parallel to the branches of the common portal vein in the same lobes of the liver. CONCLUSIONS: The results of this study are significant for comparative studies among different species of rodents and other experimental animals. Morphology, vasculature and biliary tract of the liver in the mole rat were similar to that of other experimental animals and identified differences may be related to the adaptation to the mode of life and diet of this rodent.

Age-dependent electrocardiographic and echocardiographic changes in German Shepherd dogs.

By causing numerous changes in the cardiovascular system, ageing leads to a decreased threshold for clinical manifestation of heart disease. The aim of this study was to define the existence of cardiac structural and functional changes in healthy dogs of different age. Radiographic, electrocardiographic (ECG) and echocardiographic examinations of 20 clinically healthy German Shepherd dogs were performed in order to define the values of relevant parameters. Afterwards, the values of cardio examinations were compared between young and old dogs and statistically analyzed. The ECG recordings did not show the appearance of clinically significant arrhythmias, nor was their appearance significantly different between dogs of different age. Statistically significant differences in QRS duration (P<0.05) and R wave amplitude (P<0.05) existed between groups, but all values were within the range of ECG reference values for healthy dogs. Concerning structural changes, the left ventricle wall thickness at end-diastole (LVWd) and end-systole (LVWs), and the relative wall thickness (RWT) between young and old dogs differed significantly (P<0.001, P<0.05, P<0.05, respectively). These differences in heart structure were not accompanied by systolic dysfunction, estimated by a left ventricle shortening fraction. The diastolic wall stress index (WSID) was significantly decreased in old dogs (P<0.05). Young and old dogs showed similar electrical and systolic function. Old dogs had different cardiac structure compared to the young dogs, which could result in diastolic function change.

High clinical accuracy of asymmetric dimethylarginine and symmetric dimethylarginine in patients with ischemic heart disease.

Elevated plasma concentrations of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) were found in various clinical settings including coronary heart disease. To assess ADMA and SDMA diagnostic validity in patients with different stages of ischemic heart disease, we studied these markers in patients having stable angina pectoris (SAP), unstable angina (USAP), and acute myocardial infarction (AMI). The results were compared with the values of healthy individuals. Plasma ADMA and SDMA levels were measured by high-performance liquid chromatography. In all patient groups both markers were significantly elevated in comparison with control ones (p < 0.001). In SAP patients, the median ADMA value was 0.75 (0.31-2.73) µmol/L, and SDMA 1.11 (0.69-0.1.42) µmol/L, in USAP patients, the marker values were 0.94 (0.34-3.13) µmol/L and 1.23 (0.88-4.72) µmol/L, and in AMI patients, 0.98 (0.48-2.01) µmol/L and 1.26 (0.75-2.93) µmol/L, while in healthy subjects they were 0.31 (0.17-0.87) µmol/L and 0.29 (0.20-0.83) µmol/L, respectively. SDMA was found significantly different in SAP and AMI patients (p < 0.05). Diagnostic accuracy was determined by receiver operating characteristic (ROC) curve analysis. The highest area under the ROC (AUC) for ADMA was obtained in AMI patients (0.976), while for SDMA in USAP patients (1.000). There was no significant difference between the AUCs. The greatest sensitivity and specificity were found in the USAP group (95.65 and 96.30 % for ADMA, and 100 % for each characteristic of SDMA). Considering these results, SDMA showed better clinical accuracy in assessing ischemic disease, where it could be used as a valid marker and a therapeutic target.

[Functional status of patients after surgical myocardial revascularization].

UNLABELLED: Determination of patient's functional status in early postoperative period is a delicate task, because of its general health status. Measures that can be used for that purpose are walk tests and functional status questionnaires. OBJECTIVE: To determine correlation of different functional tests administered preoperatively and two minute walk test (2MWT) done postoperatively. To detect predictors of early functional recovery measured with two minute walk test. METHOD: We examined ninety eight patients hospitalized for an elective coronary artery bypass graft surgery in February and March 2008. Functional status was assessed preoperatively using Duke Activity Status Index questionnaire (DASI), generic health related quality of life questionnaire and two minute walk test. Prior to discharge from the hospital, two minute walk test was repeated along with VAS for intensity of pain. Statistical analyze was done using Pearson's correlation coefficient, T test and multivariate regression analysis. RESULTS: Distance walked in 2 minutes decreased significantly postoperatively (p < 0.001). There was significant correlation between DASI and SF -12 preoperatively (r = 0.6 p < 0.001) and DASI preoperatively with 2MWT postoperatively (r = 0.4 p < 0.001). 2MWT postoperatively showed good correlation with intensity of pain (r = -0.42 p < 0.001) and age (r = -0.35 p < 0.001). There were no significant correlation with comorbidity, number of bypasses or postoperative complications. Multivariate regression analysis showed that the age was the strongest independent predictor of functional recovery (beta = - 0.33 < 0.05p) and that values of DASI preoperatively had moderate importance in prediction of functional status(beta = 0.238 p < 0.06). CONCLUSION: 2MWT was sensitive to change postoperatively. Significant correlation of 2MWT postoperatively with DASI preoperatively, age and VAS, as well as prediction capacity of age and DASI, gives us possibility to utilize those parameters in early rehabilitation program in order to achieve maximal functional recovery of patients.

[Eisenmenger's syndrome and pregnancy]. / Eisenmengerov sindrom i trudnoca.

Eisenmenger's syndrome is one of the congenital heart defects which deteriorates in the course of pregnancy. For this reason, it is tried to discourage the patient from becoming pregnant, or to strictly interrupt pregnancy up to the 10th gestation week, or -- if the former proves impossible -- to introduce intensive medical supervision until the end of gravidity. A delivery is described of a 23-year old woman, in whom, when 19 years old, Eisenmenger's syndrome -- developed secondarily on the atrial septal defect -- was diagnosed by catheterization. She was admitted to the Department in the 26th week of pregnancy and as successfully confined in the 38th week by using vacuum extraction. Peripartal antibiotic prophylaxis was applied during labour, although she was given oxygen. No derivatives of ergotamine were administered in order to avoid undesirable effects. The loss of blood was controlled and replaced. She was discharged with a healthy girl on the 9th postpartal day without any complications.