Enhancement of denitrification in a down-flow hanging sponge reactor by effluent recirculation.

A down-flow hanging sponge reactor, constructed by connecting three identical units in series, was applied to the treatment of artificial wastewater containing phenol and ammonia under high salinity conditions (10.9 g-Cl(-)/L). The theoretical hydraulic retention time (HRT) of each unit was 4 h (total HRT = 12 h). To enhance denitrification by effluent recirculation, the effluent recirculation ratio was increased in increments ranging from 0.0 to 2.0. The concentration of total ammonia nitrogen (TAN), NO2-N, and NO3-N in the final effluent as a proportion of the TAN in the influent was determined to calculate the unrecovered, or denitrification, proportion. The denitrification proportion of the reactor was equivalent to 19.1 ± 14.1% with no effluent recirculation; however, this was increased to 58.6 ± 6.2% when the effluent recirculation ratio was increased to 1.5. Further increasing the effluent recirculation ratio to 2.0 resulted in a decrease in the denitrification proportion to 50.9 ± 9.3%. Activity assays of nitrification and denitrification, as well as 16S rRNA gene sequence analysis, revealed that denitrification occurred primarily in the upper sections of the reactor, while nitrification increased in the lower sections of the reactor. Gene sequence analysis revealed that denitrification by Azoarcus-like species using phenol as an electron donor was dominant.

[Ultrasonographic assessment of carotid atherosclerosis emphasizing the variety of intimal-medial thickness and the relationship with coronary risk factors].

Intimal-medial thickness (IMT) of the extracranial carotid arteries measured by B-mode ultrasonography has been used as a marker of systemic and coronary atherosclerosis. Previous studies have indicated that maximum and mean carotid IMT are significantly correlated with the extent and severity of coronary artery disease (CAD), but the clinical usefulness of these markers is limited because they are neither specific nor sensitive enough to identify patients with or without significant CAD. The correlation of a new IMT marker, variance of IMT, with coronary risk factors and coronary atherosclerosis was investigated in 200 patients who underwent carotid ultrasonography and coronary angiography. IMT was measured in 16 sites of the extracranial carotid arteries for the calculation of mean, maximum and variance of IMT. Univariate analysis showed that these three indexes were significantly correlated with age, serum lipoprotein (a) and hypertension. However, age was correlated weakly with variance of IMT. There were significant gender differences in the mean and maximum IMT but not in the variance. There were also significant correlations of mean IMT with smoking, and maximum and variance of IMT with high-density lipoprotein. Multiple logistic regression analysis in 100 age and sex matched patients indicated that the only significant predictor for CAD in this subgroup was variance of IMT (odds ratio = 1.6). These results indicated that each risk factor causes different morphologic manifestations in the carotid atherosclerotic lesion. Variance of IMT, which represents the irregularity of carotid IMT, was correlated well with CAD and appears to be useful for assessing systemic and coronary atherosclerosis.

[Cardiac sarcoidosis with myopathy and advanced A-V nodal block in a woman with a previous diagnosis of sarcoidosis].

In 1992, a 49-year-old woman was admitted to the hospital because of exertional dyspnea. Three years earlier sarcoidosis had been diagnosed, and the patient was found to have bilateral hilar lymphadenopathy. The eye, skin, and knee joint were also involved. During the second hospital stay, atrial flutter with advanced A-V nodal block, scattered defects on a 201T1 scintigram, and marked cardiomegaly on chest roentgenogram led to the diagnosis of cardiac sarcoidosis. Signs and symptoms of cardiac failure subsided after placement of an artificial cardiac pacemaker, but the patient still complained of mild muscle weakness in the lower extremities on exertion. 67Ga scintigraphy revealed marked accumulation in the lower extremities, and muscle biopsy of the left gastrocnemius revealed numerous epithelioid cell granulomas with muscle fiber degeneration. Oral corticosteroid therapy was effective. A review of the 24 cases of sarcoid myopathy reported in Japan indicated that the male-to-female ratio is 1:3.8. As compared to patients in whom myopathy led to the diagnosis of sarcoidosis, those in whom myopathy developed after sarcoidosis was diagnosed were (1) relatively older, (2) more likely to have multiple organ involvement, and (3) more likely to have cardiac sarcoidosis. Corticosteroids were beneficial in about three quarters of these 16 cases, who received corticosteroid therapy.