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Biomedical subjects

Y Toma

Publications and source records attributed to Y Toma.

49 records · Page 3Linked to original sources

Serum cholinesterase activity in population samples from Iraq.

Serum cholinesterase activity has been determined from normal subjects in a sample of the Iraqi population. The enzyme activity was distributed over a comparatively wide range. There was a highly significant difference between males and females with respect to the enzyme level, although the values were relatively higher than those reported elsewhere. The enzyme activity showed no relationship with age and blood group in both sexes.

Cholinesterases↗

[Two-dimensional echocardiographic evaluation of left atrial shape and size].

We investigated the influence of the miscellaneous structures surrounding the left atrium on left atrial shape and examined the feasibility and problems in evaluating its size using the anteroposterior dimension of the M-mode echocardiogram. Using two-dimensional echocardiography, left atrial anteroposterior short-axis dimension (S), long-axis dimension (L), transverse-axis dimension (T) which cross perpendicularly one another, and area in the long-axis section (AREA) were measured in 84 subjects. The left atrial size was defined as AREA X T. The population of this study consisted of 24 subjects without heart disease, 24 with mitral valve disease and 34 with miscellaneous heart diseases other than mitral valve disease. Some of them were associated with the thin chest, chest deformity by thoracoplasty or the markedly dilatated right atrium. In subjects with the thin chest the left atrium was compressed in the anterior and posterior directions, in patients who underwent thoracoplasty it was elongated in the cranial and caudal directions, and in those with the markedly dilatated right atrium it was compressed in the right and left directions. It can be speculated that surrounding structures have some direct effects on left atrial dynamics. As left atrial size increased, these three dimensions (S, L and T) increased disproportionally. Because the contribution of each dimension to the left atrial volume change is proportional to the ratio of dimensional change and S has the largest ratio, S contributed to left atrial volume change more than the others. That is the reason that left atrial volume was not proportional to S or S3. The relationship between S and AREA during one cardiac systole was almost linear in individual studies. The slope in the S-AREA relation, however, was greater in the cases with a larger value of S. Therefore, when the extent of the change in S is used as an index of atrial volume change, it should be normalized by S. Because the left atrium expanded in any directions, either S or other dimensions reflected its size. In cases with the distorted left atrium, however, evaluation of left atrial size by the use of a single dimension alone was inadequate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Determination of atrial size by esophageal echocardiography.

The sizes of both left atrial (LA) and right atrial (RA) cavities were assessed in 16 patients by esophageal echocardiography and biplane cineangiography. The changes in echocardiographic dimension and cineangiographic volume during 1 cardiac cycle showed excellent correlations in both atria. In the left atrium, the relation between the echocardiographic dimension and the cineangiographic volume was significant (r = 0.83) and was fitted by the following power function: LA volume (ml) = 0.94 X LA dimension (mm) 1.24. In the right atrium, the relation between the dimension and the volume was significant; RA volume (ml) = 0.015 X RA dimension (mm) 2.34 (r = 0.95). Thus, esophageal echocardiography is a useful method for evaluating LA and RA size and simultaneously observing of both atria.

Adult↗

Importance of left atrial function in patients with myocardial infarction.

Left atrial function was evaluated in patients with and without remote myocardial infarction. The simultaneous left atrial pressure recording and left atrial and left ventricular cineangiograms were obtained with a catheter-tip micromanometer. The pressure-volume curve of the left atrium was composed of an A-loop and a V-loop. The ratio of active atrial emptying to left ventricular stroke volume in patients with myocardial infarction was significantly larger than that in normal subjects (42 +/- 12% vs 29 +/- 10%, p less than 0.05). The left atrial work was also significantly greater in patients with myocardial infarction (1690 +/- 717 mm Hg X ml) than in normal subjects (940 +/- 426 mm Hg X ml, p less than 0.05). The ratio of active atrial emptying to left ventricular stroke volume and left atrial work were significantly related in both normal subjects and patients with myocardial infarction (gamma = 0.72, p less than 0.01). The left ventricular ejection fraction correlated inversely with left atrial work (gamma = -0.5, p less than 0.05). Left atrial work also showed a significant linear correlation with left atrial volume before active atrial emptying (gamma = 0.82, p less than 0.01). We conclude that the left atrial contribution to left ventricular function is increased in patients with remote myocardial infarction. This left atrial contribution to the left ventricle is attributed to the Frank-Starling mechanism in the left atrium.

Adult↗

Study of atrial contraction in sick sinus syndrome using conventional and esophageal echocardiography.

To evaluate the active systolic function of both atria in sick sinus syndrome (SSS), conventional and esophageal echocardiograms were recorded in 22 normal subjects (Normal), 5 patients (pts) with sinus bradycardia (Group I), 9 with sinoatrial block or sinus arrest (Group II), 10 with bradycardia-tachycardia syndrome (BTS, Group III) and 6 with transient atrial fibrillation (Group IV). Two pts in Group II and 8 in Group III had a history of syncope. Atrial filling fraction obtained by the left ventricular echogram (AFF by LV echo) and posterior wall excursion of the aorta during atrial contraction (Ea) were determined by the conventional echocardiogram. The excursion of the interatrial septum during atrial contraction (Eb) and the dimensional shortening of the right atrium during atrial contraction (Ec) were determined by the esophageal echocardiogram. Results were as follows: AFF was almost the same in Normal, and Group I, II and IV, but it was significantly lower in Group III. AFF was also decreased in 2 pts in Group II who had a history of syncope. Both Ea and Eb in Group III were significantly lower than those in the other groups. Ec was not significantly different among all groups, although one patient in Group III had markedly decreased Ec. There was a significant correlation between Ea and AFF (r = 0.638, p less than 0.001). We conclude that in a number of cases with SSS, especially BTS, left atrial active contraction is significantly impaired in addition to the electrophysiological abnormality.

Adult↗

Esophageal echocardiographic left ventricular anterolateral wall motion in normal subjects and patients with coronary artery disease.

Esophageal echocardiography was developed for recording left ventricular anterolateral wall (LVAW) echocardiograms and was applied clinically to 14 normal subjects and 21 patients with coronary artery disease. LVAW echocardiograms were obtained satisfactorily in 11 of 14 normal subjects (75%) and 20 of 21 patients (95%) with coronary artery disease. LVAW echocardiograms were obtained by conventional anterior echocardiography in eight of 21 patients (38%) with coronary artery disease. In 11 normal subjects, mm/sec (mean 34.3 +/- 5.2 mm/sec); and diastolic wall thickness ranged from 9-12.5 mm (mean 11.2 +/- 0.7 mm). In 20 patients with coronary artery disease, LVAW motion obtained by esophageal echocardiography was classified into five groups according to the excursion, and the findings were in good agreement (80%) with those obtained by left ventriculography. Classification of LVAW motion by conventional echocardiography agreed with that of left ventriculography in only three of eight patients, although all eight patients had abnormal LVAW motion by the conventional method. In all patients except one, whose LVAW echocardiograms were obtained by conventional echocardiography, excursion was much less than that obtained by esophageal echocardiography. We conclude that the projection of an ultrasonic beam from the intraesophageal transducer is a better approach for accurate measurement of LVAW motion.

Adult↗

[Exercise echocardiography: interventricular septal thickness and motion in patients with effort angina during ergometer exercise (author's transl)].

To detect abnormal interventricular septal (IVS) motion during exercise-induced ischemia, ergometer exercise echocardiography was performed using a specially devised transducer in 12 patients (pts) with effort angina (left anterior descending artery disease) and 10 normal subjects (N) at rest, and during exercise and recovery. During exercise, percent systolic IVS thickening (% delta T) and IVS excursion (Ex) increased from 52 +/- 13% at rest to 73 +/- 19% and from 7.0 /- 1.3 mm at rest to 10.6 +/- 1.9 mm, respectively, in N, and also from 52 +/- 23% to 67 +/- 36% and from 7.3 +/- 1.9 mm to 9.7 +/- 2.1 mm in all of 3 pts with distal left anterior descending artery disease. On the other hand, in 9 pts with proximal left anterior descending artery disease, % delta T and Ex during exercise decreased from 41 +/- 17+ at rest to 26 +/- 25% and from 7.7 +/- 1.2 mm to 5.1 +/- 4.6 mm. The late systolic wall thickening of IVS was observed during peak exercise in 2 of the 9 pts, one of whom exhibited systolic IVS thinning and a decrease in diastolic thickness (from 6 mm to 4.5 mm). In 5 pts with IVS asynergy during exercise diastolic IVS thickness increased maximally from 10.2 +/- 3.3 mm at rest to 11.4 +/- 3.5 mm during recovery (reactive hyperemia). Exercise echocardiography is useful to predict the location of left anterior descending artery disease and to evaluate IVS performance during exercise-induced ischemia.

Adult↗

[Prediction of the location of left anterior descending coronary artery disease by anterior echocardiography and esophageal echocardiography (author's transl)].

In 11 normal subjects and 30 patients (pts) with left anterior descending coronary artery (LAD) lesion, the left ventricular anterolateral wall (LVAW) was investigated by esophageal echocardiography (Eso Echo) and the interventricular septum (IVS) by conventional anterior echocardiography (Ant Echo). The location of LAD obstruction, either proximal (20 pts; P-group) or distal (10 pts; D-group) to the first septal branch, was confirmed by coronary arteriography. Twenty-two of the 30 pts with LAD lesion had anteroseptal myocardial infarction (ASMI) and the remaining 8 had angina pectoris. Of the 30 pts, 20 pts including 13 pts with ASMI had normal systolic excursion of IVS. On the other hand, LVAW excursion was below 8 mm in 28 of the 30 pts with LAD lesion compared to the value of the normal subjects (10.8 +/- 1.7 mm; range = 8--13 mm). The sum of the values of IVS and LVAW excursions in the pts with ASMI was significantly lower in the P-group than those in the D-group (p less than 0.001). In the P-group, the beginning of both systolic IVS and LVAW excursion delayed significantly (IVS: 118 +/- 47 msec, LVAW: 121 +/- 44 msec from Q wave on ECG) than those of normal subjects, while in the D-group only LVAW excursion was delayed (142 +/- 23 msec) compared to that of IVS (84 +/- 32 msec). Thus, the analysis of the motion of IVS and LVAW obtained by Ant Echo and Eso Echo is useful in predicting the presence of absence as well as the location of LAD lesion.

Aged↗

[The effect of the Valsalva and Müller maneuvers on right and left atrial dimensions in man studied by esophageal echocardiography (author's transl)].

The effect of the Valsalva (V) and Müller maneuvers (M) on the right and left atrial dimensions was evaluated by esophageal echocardiography in 8 normal male subjects. During V and M, the right atrial free wall (RAW), interatrial septum (IAS) and left atrial posterior wall were recorded by esophageal echocardiography simultaneously with intraairway pressure (Paw). Right (RAD) and left atrial dimensions (LAD) at atrial end-diastolic were measured at various phases during each maneuver. Mean expiratory effort of +40 mmHg Paw in V and mean inspiratory effort of -40 mmHg Paw in M were maintained for about 10 sec. Both atrial dimensions changed significantly during each maneuver. RAD began to decrease just after the onset of V, while LAD changed little during this phase, after which began to decrease progressively. The leftward displacement of IAS with the simultaneous outward displacement of RAW resulted in an increase of RAD and a decrease of LAD just after the onset of M and the release of V. LAD remained higher than resting value from the second (2--4 sec after the onset) to late phase (just before the release) during M. RAD decreased just after the release of M. Thus, esophageal echocardiography was useful to evaluate both atrial dimensions during V and M.

Adult↗

[Significance of non-invasive parameter (PSP/ESVI) in assessing left ventricular contractility (author's transl)].

Since myocardial pump function is affected by preload or afterload, it is difficult to assess left ventricular (LV) contractility independently from these in clinical cardiology. In this study, we performed inotropic intervention by isoproterenol or propranolol, and changed afterload by angiotensin or nitroprusside, to estimate the usefulness of peak systolic pressure/end-systolic volume index (PSP/ESVI) as a parameter of LV contractility. The data were obtained by cuff method or catheter-tip manometer and echocardiography. We calculated PSP/ESVI in various heart diseases, and results were analyzed for a significant change using the t test. Ejection fraction, mean VCF (mVCF) were calculated simultaneously, and compared with PSP/ESVI. The results were as follows: 1) PSP/ESVI ratio significantly reflected inotropic intervention with isoproterenol and propranolol. 2) PSP/ESVI ratio was less affected by the change of peak systolic pressure than EF or mVCF. 3) There was a significant difference in PSP/ESVI among congestive cardiomyopathy, valvular heart diseases and normal controls. 4) There was also a significant difference in PSP/ESVI between patients of NYHA I and those of NYHA II--IV. 5) PSP/ESVI ratio, measured by non-invasive method, was thought to be a useful parameter to assess LV contractility.

Adolescent↗

Amniotic fluid lactoferrin in intrauterine infection.

Lactoferrin (LF) has been found in most biological fluids including amniotic fluid and cervical mucus in pregnant women and is released from neutrophils in response to inflammation. It is an important component of the host defence against microbial infections due to its antimicrobial properties. Premature labour is caused by amniotic infection and high concentrations of inflammatory cytokines in amniotic fluid with infection are well established. In the present study, LF levels of intrauterine infection in amniotic fluid were measured and the biological significance of LF was investigated. The effects of LF on IL-6 production in cultured amnion cells were also investigated. The concentrations of LF and IL-6 in amniotic fluid with chorioamnionitis (CAM) were 8.76+/-0.65 microg/ml and 6.92+/-4.88 ng/ml (n = 28), respectively, and both were significantly higher (P<0.01) than those without CAM (0.86+/-0.81 microg/ml and 0.34+/-0.25 ng/ml; n = 31). LF and IL-6 levels were significantly higher (P<0.01) with CAM. A significant positive correlation between LF and IL-6 levels in amniotic fluid was found (r = 0.91, P<0.01). To our knowledge, this was the first study of its kind, which shows that IL-6 production induced by lipopolysaccharide in cultured cells was significantly inhibited below physiological concentration of LF in the amnion. In addition, the immunohistochemical localization of LF in fetal membranes was investigated. In the fetal membranes with CAM, strong positive staining was observed in amniotic and chorionic membranes, with leucocyte migration, while weak staining was observed in membranes without CAM. These results show conclusively that LF suppresses amniotic IL-6 production under the conditions of intrauterine infection.

Amnion↗