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Biomedical subjects

Z Abedin

Publications and source records attributed to Z Abedin.

17 recordsLinked to original sources

Effect of long-term application of biosolids for land reclamation on surface water chemistry.

Biosolids are known to have a potential to restore degraded land, but the long-term impacts of this practice on the environment, including water quality, still need to be evaluated. The surface water chemistry (NO3-, NH4+, and total P, Cd, Cu, and Hg) was monitored for 31 yr from 1972 to 2002 in a 6000-ha watershed at Fulton County, Illinois, where the Metropolitan Water Reclamation District of Greater Chicago was restoring the productivity of strip-mined land using biosolids. The mean cumulative loading rates during the past 31 yr were 875 dry Mg ha(-1) for 1120-ha fields in the biosolids-amended watershed and 4.3 dry Mg ha(-1) for the 670-ha fields in the control watershed. Biosolids were injected into mine spoil fields as liquid fertilizer from 1972 to 1985, and incorporated as dewatered cake from 1980 to 1996 and air-dried solids from 1987 to 2002. The mean annual loadings of nutrients and trace elements from biosolids in 1 ha were 735 kg N, 530 kg P, 4.5 kg Cd, 30.7 kg Cu, and 0.11 kg Hg in the fields of the biosolids-amended watershed, and negligible in the fields of the control watershed. Sampling of surface water was conducted monthly in the 1970s, and three times per year in the 1980s and 1990s. The water samples were collected from 12 reservoirs and 2 creeks receiving drainage from the fields in the control watershed, and 8 reservoirs and 4 creeks associated with the fields in the biosolids-amended watershed for the analysis of NO3- -N (including NO2- N), NH4+-N, and total P, Cd, Cu, and Hg. Compared to the control (0.18 mg L(-1)), surface water NO3- -N in the biosolids-amended watershed (2.23 mg L(-1)) was consistently higher; however, it was still below the Illinois limit of 10 mg L(-1) for public and food-processing water supplies. Biosolids applications had a significant effect on mean concentrations of ammonium N (0.11 mg L(-1) for control and 0.24 mg L(-1) for biosolids) and total P (0.10 mg L(-1) for control and 0.16 mg L(-1) for biosolids) in surface water. Application of biosolids did not increase the concentrations of Cd and Hg in surface water. The elevation of Cu in surface water with biosolids application only occurred in some years of the first decade, when land-applied sludges contained high concentrations of trace metals, including Cu. In fact, following the promulgation of 40 CFR Part 503, the concentrations of all three metals fell below the method detection level (MDL) in surface water for nearly all samplings. Nitrate in the surface water tends to be higher in spring, and ammonium, total P, and total Hg in summer and fall. Mean nitrate, ammonium, and total phosphorus concentrations were found to be greater in creeks than reservoirs. The results indicate that application of biosolids for land reclamation at high loading rates from 1972 to 2002, with adequate runoff and soil erosion control, had only a minor impact on surface water quality.

Metals↗

Angina pectoris before and after myocardial infarction. Angiographic correlations.

Clinical, hemodynamic, and angiographic data were examined in 97 consecutive patients who underwent catheterization within two years of documented acute transmural myocardial infarction. The patients were divided according to the absence or presence of angina pectoris prior to myocardial infarction (groups 1 and 2). Group 1 had more females, was younger, and had a greater prevalence of one-vessel coronary artery disease. Of the patients surviving the myocardial infarction until hospital discharge, group 1 had fewer cases of postinfarction angina pectoris. The following were not statistically different for the two groups: mean time from infarction to catheterization, location of infarction, heart failure, coronary risk factors, mean left ventricular end-diastolic pressure, and mean ejection fraction. The angiographic significance of angina following infarction was analyzed in the 94 survivors. Patients with angina after infarction had a greater prevalence of two- and three-vessel coronary artery disease compared with patients without angina following infarction. Group 1 patients who had developed angina after infarction also had a greater prevalence of two- and three-vessel disease than patients who had no postinfarction angina. One-vessel disease was found in 82 percent of patients who had no angina before and after infarction. Infarction as the first manifestation of coronary artery disease (group 1) is often associated with one-vessel disease, especially if angina does not appear after infraction. Angina before or after infarction suggests two- and three-vessel disease.

Adult↗

Serum and urinary beta-galactosidase and beta-glucuronidase activity in patients with acute myocardial infarction.

To determine the effect of acute myocardial infarction (AMI) on serum and urinary activity of beta-galactosidase and beta-glucuronidase (lysosomal enzymes) 40 patients were studied. Eighteen patients had acute myocardial infarction and 22 were assigned as controls. Three of the 18 patients with acute myocardial infarction died within 5 to 10 days after hospitalization. Although the serum and urinary beta-glucuronidase and serum beta-galactosidase activity was higher in patients with acute myocardial infarction when compared with the control subjects these differences did not achieve statistical significance. However, the mean values of urinary beta-galactosidase in the control and acute MI groups were 158.68 and 333.3 nmol/mg creatinine/hr, respectively (p less than 0.046). These findings indicate that there is a significant increase in the urine beta-galactosidase activity during the early phases of acute myocardial infarction.

Female↗

Cardiac toxicity of perchloroethylene (a dry cleaning agent).

Perchloroethylene analysis was performed on plasma of a 24-year-old white man who presented with a history of premature ventricular beats, dizziness, and headaches. There was no clinical, electrocardiographic, radiologic, or echocardiographic evidence of heart disease. The occurrence of premature ventricular beats and the patient's symptoms were more pronounced when the plasma level of perchloroethylene was high (3.8 ppm). Removal of exposure to perchloroethylene relieved the patient's symptoms and the premature beats completely disappeared.

Adult↗

Origin and length of left main coronary artery: its relation to height, weight, sex, age, pattern of coronary distribution, and presence or absence of coronary artery disease.

The distance from the base of the left coronary sinus to the origin of the left main coronary artery was measured in 54 patients. The length of the left main coronary artery and the pattern of arterial dominance were determined in the last 37 patients. These variables were correlated with height, weight, age, sex, and presence or absence of coronary artery disease. Average distance from the basis of the left coronary sinus to the origin of the left main coronary artery was 19.4 +/- 2.7 mm. Average length of the left main coronary artery was 9.7 +/- 4.3 mm. There was a large inherent variability between distance from the base of left coronary sinus to the origin of the left main coronary artery and height of the subjects. Other variables did not show positive correlation. Similar large variability was noticed between of the left main coronary artery and height of the subjects. Thus, from these observations it was not possible to predict the distance from the base of the left coronary sinus to the origin of the left main coronary artery or the length of the left main coronary artery using height or any other variable. The importance of these findings in relation to coronary angiography is discussed.

Adult↗

Ventricular tachyarrhythmias following surgery for myocardial revascularization. A follow-up study.

Of 1,599 patients who underwent surgery for direct myocardial revascularization in 1973 at Cleveland Clinic Hospital, 19 patients (1.2 percent) developed primary ventricular fibrillation or ventricular tachycardia during the immediate postoperative period. Occurrence of postoperative ventricular tachyarrhythmias could not be predicted by assessment of preoperative symptoms or by evaluation of the extent of coronary artery disease and left ventricular function. There was no increase in early or late mortality or morbidity (including postoperative myocardial infarction) among patients who developed postoperative primary ventricular tachyarrhythmias.

Angina Pectoris↗

Clinical, electrocardiographic, and radiological evaluation of pulmonary hypertension in patients with mitral stenosis.

Fifty-one patients with dominant rheumatic mitral stenosis were studied by clinical, electrocardiographic, and radiological criteria for evaluation of pulmonary hypertension. Predicted pulmonary artery pressure from these criteria were then compared with the pulmonary artery pressure measured during cardiac catheterization. In the first 31 patients, the assessment of pulmonary hypertension using combined clinical, electrocardiographic, and radiological methods gave better results than any one single method alone. On the basis of these observations, a composite criterion was arrived at. This new criterion was then prospectively applied to the next 20 consecutive patients with dominant mitral stenosis. In 14 of the 20 patients, the predicted pulmonary artery mean pressures were in the same range as the measured mean pulmonary artery pressures when the new composite criterion was used.

Adolescent↗

Changing P wave polarity. Intermittent posterior internodal conduction.

Spontaneous changes of P-wave polarity without change in heart rate were noted on the resting electrocardiogram of a patient admitted because of chest pain. Intracardiac and His bundle electrograms were compatible with a sequence of activation from high to low right atrium with both positive and negative P waves in lead aVR. The decrease in the P-His interval with positive P waves in lead aVR is consistent with selective conduction via the posterior internodal pathway.

Aged↗

Myocardium of hypothermic rats with and without administration of dextran. Electrocardiographic and electron microscopic studies.

Electrocardiographic and electron microscopic alterations in the myocardium were investigated in rats subjected to hypothermia with and without injection of dextran. Twenty-two animals were divided into four groups and studied. The first group of five rats served as the control group. The second group of six rats, which were subjected to total body hypothermia developed arrhythmia (from first degree atrioventricular block to complete heart block) at a mean rectal temperature of 18 degrees C., with prolongation of P,P-R, and QRS duration, as well as a marked separation of intercalated discs, articularly at the level of the fascia adherens. The third group of six rats was subjected to hypothermia and to an injection of dextran. The resulting threshold temperature tthe temperature at which the arrhythmia appeared) was lower (16 degrees C.) than in the preceding group (p less than 0.005), but neither advanced atrioventricular block nor remarkable subcellular structural changes developed. The fourth group of five rats was sacrificed 18 to 24 hours following recovery from hypothermia and, at that time, showed no significant electrocardiographic or electron microscopic alterations.

Animals↗