Bioremediation of contaminated surface water by immobilized Micrococcus roseus

The problems caused by contaminated surface water have gradually become more serious in recent years. Although various remediation technologies were investigated, unfortunately, no efficient method was developed. In this paper, a new bioremediation technology was studied using Micrococcus roseus, which was immobilized in porous spherical beads by an improved polyvinyl alcohol (PVA) - sodium alginate (SA) embedding method. The experimental results indicated that COD removal rate could reach 64.7 % within 72 hours when immobilized M. roseus beads were used, which was ten times as high as that of free cells. The optimum inoculation rate of immobilized M. roseus beads was 10 % (mass percent of the beads in water sample, g g(-1)). Suitable aeration was proved necessary to enhance the bioremediation process. The immobilized cells had an excellent tolerance to pH and temperature changes, and were also more resistant to heavy metal stress compared with free cells. The immobilized M. roseus beads had an excellent regeneration capacity and could be reused after 180-day continuous usage. The Scanning Electronic Microscope (SEM) analysis showed that the bead microstructure was suitable for M. roseus growth, however, some defect structures should still be improved.

Anemia during pregnancy in a Chinese population

OBJECTIVES

To study prevalence, risk factors, and birth outcomes of women with anemia during pregnancy in a Chinese population.

METHODS

A retrospective cohort study was performed based on 16936 pregnancies delivered between January 1989 and December 1990 in Suzhou, China. Anemia was defined as hemoglobin less than 10 g/dl. Multivariate logistic regression was used to estimate odds ratio, 95% confidence interval, and to control for confounding variables.

RESULTS

The prevalence of anemia was 10.3% at the first trimester, 18.9% at the third trimester. Overall, 26.2% pregnant women experienced anemia in pregnancy. Anemia during early pregnancy was not associated with increased risk of adverse perinatal outcomes. However, anemia in later pregnancy was inversely associated with preterm birth and low birth weight.

CONCLUSIONS

Anemia during pregnancy does not increase the risk of poor birth outcomes.

[Relationship of age, sex, body weight, smoking, blood lipids and fibrinolytic activities in healthy subjects]

Relationship of plasma activities of tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1(PAI-1) with age, sex, body weight, smoking, blood lipids were studied in 131 healthy subjects. The results demonstrated that plasma PAI-1 activity increased with age and body weight. PAI-1/t-PA ratio was higher in smoking than in non-smoking subjects. With multivariate analyses, plasma PAI-1 activity was positively correlated with age, body weight index(BMI) in males, and positively correlated with low-density-lipoprotein-cholesterol(LDL) in females, and negatively correlated with plasma tPA activity. Plasma triglyceride, high-density-lipoprotein-cholesterol did not show a correlation to PAI-1 or tPA activity. It is indicated that age, BMI, blood lipids may contribute to moderate fibrinolytic activities and that smoking may affect fibrinolytic function.

[Plasma Lp (a) levels and correlation of Lp (a) with fibrinolysis activation in chronic renal failure]

Plasma Lp (a) concentration and activation of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1(PAI-1) were determined in 50 patients with chronic renal failure (CRF) and in 50 healthy subjects. The results demonstrated that plasma concentration of Lp(a) was significantly higher and plasma t-PA activation was significantly lower in CRF patients than in healthy subjects. With multivariate analyses, plasma Lp(a) concentration was positively correlated with the total amount of 24 h uric protein, plasma BUN and uric protein concentration. Moreover, a negative significant correlation between plasma Lp(a) levels and t-PA activation was observed. Plasma Lp(a) levels did not show a correlation to PAI-1 activation. It is indicated that renal function may contribute to moderate plasma Lp(a) concentration and elevated Lp(a) levels may be related with fibrinolytic impairment.

Preeclampsia and cerebral palsy in low-birth-weight and preterm infants: implications for the current "ischemic model" of preeclampsia

OBJECTIVE

One of the prevailing hypotheses for the pathogenesis of preeclampsia is the "ischemic model." It assumes that reduced uteroplacental perfusion is the primary step and the point of convergence of diverse pathogenic processes in the development of preeclampsia. One might expect a fetus under such "ischemic conditions" to be at an increased risk of later development of cerebral palsy (CP). The objective of this study was to test the hypothesis that maternal preeclampsia increases the risk of CP in preterm and low-birth-weight infants.

METHODS

A meta-analysis was performed based on published articles identified by searching computerized databases (MEDLINE, EMBASE, CINAHL, Current Contents, Biological Abstracts, and Dissertation Abstracts) from 1966 through 1999. Ten observational studies on the association between preeclampsia and CP were identified based on prespecified inclusion criteria. Two independent reviewers extracted data and assessed the methodological quality of eligible articles. Odds ratios (OR) of CP for preeclampsia from individual studies were pooled.

MAIN OUTCOME MEASURE

Cerebral palsy.

RESULTS

In case-control studies, preeclampsia was associated with a statistically significant decreased risk of CP [pooled adjusted OR, 0.50; 95% confidence interval (CI), 0.33-0.81; p < 0.01). In cohort studies, preeclampsia was associated with a nonstatistically significant reduced risk of CP (pooled OR, 0.91; 95% CI, 0.35-2.41; p > 0.05).

CONCLUSIONS

Preeclampsia may be associated with a decreased risk of CP in preterm and low-birth-weight infants. This challenges the currently held belief that reduced uteroplacental perfusion is the unique pathophysiological process in preeclampsia.

Effect of therapeutic ionizing radiation on the human brain

We test a hypothesis that fractionated radiation therapy within a therapeutic dose range is associated with a dose-related change in normal brain, detectable by quantitative magnetic resonance imaging. A total of 33 patients were examined by quantitative magnetic resonance imaging to measure brain tissue spin-lattice relaxation time (T1) before treatment, and at various times during and after radiation therapy. A T1 map was generated at each time point, and radiation therapy isodose contours were superimposed on the corresponding segmented T1 map. Changes in white matter and gray matter T1 were analyzed as a function of radiation therapy dose and time since treatment, controlling for patient age and tumor site. In white matter, a dose level of more than 20 Gy was associated with a dose-dependent decrease in T1 over time, which became significant 6 months after treatment. There was no significant change in T1 of gray matter over time, at radiation therapy doses of less than 60 Gy. However, GM in close proximity to the tumor had a lower T1 before therapy. Our results represent the first radiation dose-response data derived from pediatric brain in vivo. These findings confirm that white matter is more vulnerable to radiation-induced change than is gray matter, and suggest that T1 mapping is sensitive to radiation-related changes over a broad dose range (20 to 60 Gy). Human white matter T1 is not sensitive to radiation therapy of less than 20 Gy, and gray matter T1 is unchanged over the dose range used to treat human brain tumor. The reduction of gray matter T1 near the tumor could result from compression of cortical parenchyma near the growing tumor mass, or from tumor cell invasion directly into the parenchyma. If brain T1 is a surrogate for radiation effect, reducing the volume of normal white matter receiving more than 20 Gy could be an important treatment planning goal.

Gestational diabetes mellitus: prevalence, risk factors, maternal and infant outcomes

OBJECTIVES

To study prevalence, risk factors, and maternal and infant outcomes of women with gestational diabetes mellitus (GDM).

METHODS

A retrospective cohort study was performed based on 111563 pregnancies delivered between 1991 through 1997 in 39 hospitals in northern and central Alberta, Canada. Multivariate logistic regression was used to estimate the odds ratios with 95% confidence intervals, and to control for confounding variables.

RESULTS

The prevalence of GDM was 2.5%. Risk factors for GDM included age >35 years, obesity, history of prior neonatal death, and prior cesarean section. Teenage mothers and women who drank alcohol were less likely to have GDM. Mothers with GDM were at increased risk of presenting with pre-eclampsia, premature rupture of membranes, cesarean section, and preterm delivery. Infants born to mothers with GDM were at higher risk of being macrosomic or large-for-gestational-age.

CONCLUSIONS

Specific conditions predispose to GDM which itself is associated with a significantly increased risk of maternal and fetal morbidity.