Accumulation of Tributyl- and Triphenyltin Compounds in Pacific Oyster, Crassostrea gigas, from the Chinhae Bay System, Korea

The feeding response of juvenile amphipod Gammarus pulex (L.) was investigated following exposure to freshwater pollutants. The method employed is nondestructive, provides a rapid indication of the status of groups of individuals, and is based on a time-response analysis of the consumption of the eggs of Artemia salina and the determination of median feeding times or FT50s. The feeding activity of juvenile G. pulex was found to be a sensitive response criterion for use in assessing the sublethal toxicity of copper, lindane, and 3,4-dichloroaniline (3,4-DCA). Reductions in gammarid feeding activity were identified following 96 hours exposure at 12.1 μg/L copper or 8.4 μg/L lindane and 240 hours exposure at 918 μg/L 3,4-DCA. However, a significant increase was observed in the feeding rate of gammarids that had been exposed for 240 h at 0.09 μg/L lindane in comparison with control values. The increase in feeding rate may be interpreted as a possible stimulatory effect associated with the toxicant action of lindane. Increases in gammarid feeding activity were not determined during the experiments conducted with either copper or 3,4-DCA. A sustained reduction in G. pulex feeding rates may cause growth inhibition and impaired reproduction which have previously been identified as sublethal responses of other freshwater organisms exposed to comparable concentrations of lindane, 3,4-DCA, or copper. The feeding bioassay was also used as a tool in an investigation of species interactions in toxicant systems. The feeding responses of G. pulex, which had been maintained in the presence of Asellus aquaticus (as interacting pairs) and exposed to a range of concentrations of lindane or 3,4-DCA, were recorded and compared. The findings illustrate the complex nature of test systems that integrate the stresses of toxicant and competition. In the lindane test system a reduction in gammarid feeding activity was observed following a 96-h exposure with A. aquaticus at 3.8 and 6.0 μg/L lindane (mean measured concentrations). After a 240-h exposure period a decrease in feeding rate was recorded only for gammarids that had been exposed to 6.5 μg/L lindane, however exposure to very low concentrations of lindane (0.1 and 0.9 μg/L) resulted in a significant increase in gammarid feeding activity. In the experiment conducted with 3,4-DCA the calculation of median feeding times or FT50s of gammarids that had been exposed for 96 and 240 h in the toxicant treatment groups with A. aquaticus was largely precluded (in most groups less than 50% of the A. salina eggs were eaten). However, control group FT50 values were determined on each occasion the bioassay was performed, indicating that a substantial reduction in gammarid feeding activity had occurred in the majority of the 3,4-DCA treatment groups. Received: 3 April 1997/Accepted: 6 August 1997     

Small bowel obstruction in patients with a prior history of cancer.

To assess the efficacy of operative and nonoperative therapy of small bowel obstruction (SBO) in patients with a previous diagnosis of cancer, a review of 54 cases was carried out. The 32 men and 22 women had a mean age of 58 years. At presentation with SBO, 26 patients (48%) had known recurrent cancer. Forty patients were initially treated nonoperatively; 11 (28%) had resolution of their SBO after a mean of 7 days of nasogastric suction. Five of 11 patients developed recurrent SBO prior to death. Thirty-seven patients underwent laparotomy, 14 on the day of admission and 23 after failure of nasogastric suction. Twenty-five of 37 (68%) had obstruction due to recurrent carcinoma. Small bowel obstruction due to recurrent cancer occurred earlier (21 +/- 5 months) than SBO from benign causes (61 +/- 18 months; p < 0.01). Mean survival for patients with malignant obstruction (5 +/- 1 month) was significantly shorter than for those with benign obstruction (50 +/- 10 months; p < 0.001). The 30-day and in-hospital mortality rates for the 25 surgically treated patients with malignant SBO were 24% and 28%, respectively; in 9 of 25 (36%), the obstruction failed to fully resolve. The only factor predictive of in-hospital mortality was obstruction secondary to cancer (p < 0.05). The median posthospital survival for surgically treated patients with malignant SBO was only 2.5 months. We conclude that: (1) patients should be given an initial trial of nonoperative therapy; (2) patients with no known recurrence or a long interval to the development of SBO should be aggressively treated with early surgery if nonoperative treatment fails; and (3) for patients with known abdominal recurrence in whom nonoperative therapy fails, the results of surgical palliation are grim. Innovative approaches are needed to maximize palliation while also limiting morbidity and mortality.     

Effects of chronic cyclosporine administration on renal blood flow and intrarenal blood flow distribution

Cyclosporine-induced decreases in renal blood flow (RBF) and glomerular function are well documented. Glomerular filtration and tubular function may be affected by changes in both total renal blood flow and cortical blood flow distribution (CBFD). The effect of CsA on RBF, CBFD, glomerular filtration rate, and tubular function was studied in conscious ewes receiving a mean CsA dose of 30 mg/kg/day for 28 days with mean CsA trough levels of 344 +/- 45 ng/ml. RBF and CBFD were determined by the injection of 15 microns radioactive microspheres before and after one month of treatment with CsA or its vehicle, olive oil. RBF decreased by 24% from 7.65 +/- 0.87 to 5.79 +/- 0.42 ml/min/g of kidney in CsA-treated ewes (P = 0.014), while no decrease was noted in the control group (7.92 +/- 1.10 vs. 7.62 +/- 0.71). Intracortical blood flow decreased in proportion to the fall in total renal blood flow--thus CsA treatment did not change the cortical distribution of flow. There was a 25% decrease in GFR, as determined by inulin clearance, in the CsA-treated group (80 +/- 6 vs. 62 +/- 3 ml/min; P = 0.027) while there was a nonsignificant increase in control animals (62 +/- 11 vs. 92 +/- 7 ml/min). There was no evidence of tubular dysfunction in either group. There were also no changes in urinary excretion rates of prostaglandins PGE2, 6-keto-PGF1 alpha or thromboxane B2, nor were there changes in plasma renin activity. CsA induced decreases in RBF occur red without redistribution of cortical blood flow, indicating that altered cortical distribution of blood flow is not responsible for the changes in GFR or tubular function that have been reported. The changes in renal blood flow and glomerular filtration rate are independent of changes in renal prostaglandin production, and are likely not associated with altered plasma renin activity.     

Identification of borinic esters as inhibitors of bacterial cell growth and bacterial methyltransferases, CcrM and MenH

As bacteria continue to develop resistance toward current antibiotics, we find ourselves in a continual battle to identify new antibacterial agents and targets. We report herein a class of boron-containing compounds termed borinic esters that have broad spectrum antibacterial activity with minimum inhibitory concentrations (MIC) in the low microgram/mL range. These compounds were identified by screening for inhibitors against Caulobacter crescentus CcrM, an essential DNA methyltransferase from gram negative alpha-proteobacteria. In addition, we demonstrate that borinic esters inhibit menaquinone methyltransferase in gram positive bacteria using a new biochemical assay for MenH from Bacillus subtilis. Our data demonstrate the potential for further development of borinic esters as antibacterial agents as well as leads to explore more specific inhibitors against two essential bacterial enzymes.     

Ad libitum feeding: safely improving the cost-effectiveness of pyloromyotomy

Background/Purpose: Patients undergoing pyloromyotomy traditionally have been placed on complex postoperative feeding regimens. The authors evaluated the substitution of an ad libitum feeding regimen to determine if it could decrease length of hospital stay and cost without increasing the moribidity rate. Methods: Fifty-six consecutive patients undergoing open pyloromyotomy were evaluated. The initial 31 patients were treated with a traditional protocol, whereas the next 25 patients received ad libitum feeding. Time to first full-strength feeding, amount and time of any emesis, and time to discharge were recorded. Hospital costs and number of readmissions were assessed. Results: Patients in the ad libitum group had a statistically significant shorter time to discharge (25.1 hours versus 38.8 hours), which translated into a savings of $1,290 per patient. Whereas more patients in the ad libitum group experienced postoperative emesis (32% v 26%), this was not statistically significant. There was no other morbidity and there were no readmissions in either group. Conclusions: Postoperative ad libitum feedings resulted in significant decreases in hospital stay and associated costs without increasing morbidity. Ad libitum feeding is safe, simple, and cost effective, and may offer an avenue for short-stay pyloromyotomy in selected patients.     

Antimutagenic, antioxidant and free radical scavenging activity of ethyl acetate extracts from white, yellow and red onions.

The beneficial effects of red, yellow and white onion extracts have been assessed by antioxidant activity and antimutagenic activity. And the effects compared to BHT and ascorbic acid. Total phenolic compounds and flavonoids in onion extracts were determined. Yellow onion extract had more organic acid and free sugar than those detected in the white and red onion extract. The scavenging activity of DPPH radical and H(2)O(2) were increased depending on the concentration. The antioxidant activities using beta-carotene-linoleate system and reducing power were increased but the effect was small to that of BHT and ascorbic acid. After digested, extracts showed antimutagenic activities, and it seems that they inhibit the mutagenicity for digesting. This study demonstrated that the antimutagenicities and antioxidant properties of ethyl acetate extract against mutagens were related to their phenols and flavonoids, which are heat stable and losses digestive juices are relatively low.