Diagnostic performance of cytology for assessment of hepatic lipid content in dairy cattle.

The objective of our study was to characterize the diagnostic performance of cytology for assessing hepatic lipid content (HLC) in dairy cows by comparing microscopic evaluation of lipid vacuolation in touch imprint slide preparations of liver biopsies with quantitative measurement of triglyceride concentration ([TG]; mg/mg of wet weight) in paired biopsy samples. Our study also sought to compare the diagnostic performance of liver cytology, plasma nonesterified fatty acid concentration ([NEFA]), and plasma ß-hydroxybutyrate concentration ([BHB]) derived from a measurement performed on whole blood, for assessing HLC. Chemical extraction of TG from liver tissue remains the gold standard for quantifying HLC, largely because available blood tests, although useful for detecting some types of pathology, such as increased lipid mobilization, ketosis, or hepatocellular injury, are nonspecific as to etiology. Veterinary practitioners can sample bovine liver for cytological evaluation in a fast, minimally invasive, and inexpensive manner. Thus, if highly predictive of HLC, cytology would be a practical diagnostic tool for dairy veterinarians. In our study, liver biopsy samples from Holstein cows (219 samples from 105 cows: 52 from cows 2 to 20 d prepartum, 105 from cows 0 to 10 d in milk, 62 from cows 18 to 25 d in milk) were used to prepare cytology slides and to quantify [TG] using the Folch extraction method followed by the Hantzch condensation reaction and spectrophotometric measurement. An ordinal scale (0-4) based on amount of hepatocellular cytoplasm occupied by discrete clear vacuoles was used by 3 blinded, independent observers to rank HLC in Wright-Giemsa-stained slides. Interobserver agreement in cytology scoring was good. Corresponding plasma [NEFA] and [BHB] measurements were available for 187 and 195 of the 219 samples, respectively. Liver [TG] correlated more strongly with cytology score than with NEFA or BHB, and receiver operating characteristic curve analysis showed that cytology had better diagnostic performance than either NEFA or BHB for correctly categorizing [TG] at thresholds of 5, 10, and 15%. Hepatic lipidosis in high-producing dairy cows is of major clinical and economic importance, and this study demonstrates that cytology is an accurate means of assessing HLC. Additional work is indicated to evaluate the diagnostic utility of liver cytology.

Accuracy and reproducibility of coronary flow rate assessment by real-time contrast echocardiography: in vitro and in vivo studies.

Real-time myocardial contrast echo (MCE) provides the potential to assess myocardial blood flow from time-intensity refilling curves after high-energy bubble destruction. This study validated the accuracy of this approach and the effect of specific examination variables and instrument settings on results. The effects of examination depth and angle as well as dynamic range, pulse repetition frequency, and line density were assessed with the use of in vitro incremental flow rates produced in an in vitro tissue phantom. In vivo recordings of real-time imaging with an infusion of a contrast agent (Optison) were obtained in 7 open-chest dogs with graded left anterior descending artery stenosis at baseline and during adenosine hyperemia, and were compared with flow probe measurements. After bubble destruction, time-intensity data were fitted to an exponential function, and the rate of intensity increase (b) and peak plateau intensity (A) were derived from refilling curves. In vivo real-time values for b, but not A, correlated closely with flow probe measures (r = 0.93). A similar correlation for b was observed in vitro (r = 0.98). The correlation between flow rate and b was influenced by several examination variables, including depth, angle, and instrument settings. Real-time MCE provides accurate quantification of coronary flow by assessing the rate of microbubble refilling. However, this parameter may be affected by several examination and instrument variables. Therefore, real-time MCE refilling measures are best applied by comparing baseline values with those of stress studies.

Refined fetal abdominal growth assessment in normal pregnancy: Part I. Abdominal anteroposterior diameter.

BACKGROUND: The assessment of the adequacy of fetal growth by parameters other than the abdominal anteroposterior diameter (AAPD) of the fetus has been studied extensively. However the designs of these studies and the statistical methods used appears to deserve some criticism, based on present knowledge. Noncross-sectional cases selection, uncertainty of the fetal normality and inadequacy in statistical method, mostly ignored the changing property of each standard deviation (SD) of each gestational age (GA) which was proposed by Altman et. al. in 1993, are the three most common flaws in previous publishes. We tried to use AAPD with a strict study design as well as a reasonable statistical method to evaluate the fetal growth. METHODS: This study was performed in the Division of Maternal Fetal Medicine, National Cheng Kung University Hospital, Taiwan. The prenatal sonographic data of the fetuses were collected prospectively based on the following criteria: (1) accurate dating by knowing the maternal last menstration period (LMP) and early ultrasonography of the fetuses, (2) singleton pregnancy, (3) no fetal structural or chromosomal abnormality confirmed by prenatal ultrasonography and postnatal examination, (4) GA at birth was between 37 and 41 weeks' gestation, (5) no birth asphyxia, (6) appropriate birth body weight, and (7) no maternal medical disease or obstetrical complication which might predictably interfere with fetal growth. The collected data were analyzed by polynomial regression test and the best-fit equation for prediction of fetal growth was selected. The standard deviation (SD) of each GA was modeled before constructing the fetal growth centile charts by Altman's method. RESULTS: A total of 2077 cross-sectional sonographic data meeting the above criteria were collected for statistical analysis. The best-fit equation for the prediction of fetal GA by AAPD is GA = 20.8539 - 3.36743 x AAPD + 0.86927 x (AAPD)2 - 0.03789 x (AAPD)3 +/- k x [1.2533 x (0.36772 + 0.10938 x AAPD)], (r = 0.97287, p < 0.0001). The best-fit equation for prediction of fetal AAPD by GA is AAPD = -2.49495 + 0.38247 x GA - 1.07071 x 0.001 x (GA)2 +/- k x [1.2533 x (0.01760 + 0.01372 x GA)], r = 0.97122, p < 0.0001. The SD of AAPD for each complete GA was not the same. The fetal growth centile charts in the study are presented in this article. CONCLUSIONS: The SD of each complete GA changed with each specific GA. The GA of the fetus can be assessed accurately by measuring the AAPD alone. The utilization of these growth centile charts for evaluation of fetal growth is recommended.

Fetal heart volume assessment by three-dimensional ultrasound.

Heart volume may provide important information on the status of fetal hemodynamics. However, traditionally fetal heart volume has been assessed with the erroneous assumption that the fetal heart is spherical or elliptical. With the advent of three-dimensional ultrasound, accurate assessment of organ volume has become feasible. The objectives of this study were to compare the reproducibility of two-dimensional ultrasound and three-dimensional ultrasound in the assessment of heart volume, and to test whether heart volume assessed by the traditional method of two-dimensional ultrasound equates to that assessed by three-dimensional ultrasound. If it proved to be significantly different, we aimed to find a new constant which, if incorporated into the traditional formula used to determine heart volume, would enable us to achieve more accurate volumes with two-dimensional ultrasound. In total, 50 normal singleton fetuses ranging from 20 to 30 weeks' gestation were included in the study. Both the traditional two-dimensional and the new three-dimensional volume measurements were compared. The results showed that three-dimensional ultrasound has a better reproducibility than two-dimensional ultrasound in heart volume assessment and that heart volume assessed by the traditional formula of two-dimensional ultrasound is significantly larger than that measured by three-dimensional ultrasound (p < 0.001). We therefore propose that, if the traditional two-dimensional equation is to be used, the constant for heart volume could be modified to 0.4563 (SE = 0.0153, n = 50) to achieve more accurate results. With this new constant, the heart volume derived by two-dimensional ultrasound was not found to differ from that measured by three-dimensional ultrasound. From our series, we conclude that three-dimensional ultrasound is theoretically the best method for the assessment of heart volume. However, because of the limitations of three-dimensional ultrasound (i.e. it is not routinely available, it is more expensive and more time-consuming) two-dimensional ultrasound in practical terms should be the method of choice. Although we were able to improve the accuracy of the heart volume measurements using a new constant in the traditional two-dimensional formula, the new constant will not improve variability, which can only be reduced by three-dimensional ultrasound.

Three-dimensional ultrasound assessment of fetal liver volume in normal pregnancy: a comparison of reproducibility with two-dimensional ultrasound and a search for a volume constant.

The purposes of this study are to compare the reproducibility of two-dimensional ultrasound (2DUS) and three-dimensional ultrasound (3DUS) in the assessment of fetal liver volume (LV), and to test whether the fetal LV assessed by the traditional method with 2DUS is equal to that with 3DUS in normal pregnancy. If significantly different, we then try to calculate a new constant of fetal LV for the traditional equation from the LV values obtained with 3DUS. In total, 30 normal singleton fetuses with gestational ages ranging from 20 to 30 weeks were included for the reproducibility test and 55 cases ranging from 20 to 31 weeks gestation were enrolled for finding a new volume constant of LV. The results showed that 3DUS is superior to 2DUS in the reproducibility test of fetal LV assessment. Moreover, the LV assessed with the traditional 2DUS method (identified as LV_42) was significantly smaller than that measured with 3DUS (P < 0.001). If the traditional 2DUS equation is to be used, the multiplying factor in the equation for the calculation of LV should be modified to 0.55 (SE = 0.017, N = 55). With the new volume constant, the new derived LV with 2DUS (identified as LV 55) was not different from that with 3DUS (identified as LV_3D). In conclusion, we recommend that 3DUS, instead of 2DUS, should be used for reaching an accurate assessment of fetal LV. Otherwise, applying our new volume constant may be of help in detecting abnormal fetal liver growth when only 2DUS is available.

[Studies on assessment of intensity of infection of Schistosoma japonicum in cattle].

In order to carry out quantitative epidemiological survey of animal schistosomiasis, a sensitive egg-counting method was studied both in the laboratory and in the field. Fecal material was filtered by a copper gauze (60 meshes/inch) into a nylon-tissue bag with 2 layers, 150 and 260 meshes/inch respectively. Thin smears were made from the residue in the bag. The mean recovery rate of mature schistosome eggs by previously adding 100 eggs to 5g of feces from noninfected cattle was 67.5%, ranging from 53 to 81%. To compare the egg-concentration thin smear method mentioned above, with egg-concentration thick smear method after hyalinization, various numbers of eggs, namely, 25, 50 and 100, were added to 5g of feces. The mean recovery rates of fecal eggs were 57.6%, 57.6% and 69.1% respectively, for the thin smear method and 3.2%, 13.8% and 19.5% for the thick smear method. The coefficients of variability in the former were from 12.9% to 17.4% and in the latter, from 30.7% to 98.8%. The total number of schistosome eggs per 5g of feces found in 34 egg-positive cattle in the field were 434 and 178 by the thin smear method and the thick smear method, respectively. A correlation analysis performed on the numbers of detected eggs in a total volume of fecal sediment and from half a volume of fecal sediment multiplied by two, showed a correlation coefficient of 0.98 (P less than 0.01), indicating that half a volume of fecal sediment may be used instead of a whole volume.(ABSTRACT TRUNCATED AT 250 WORDS)