Small intestinal metastasis from esophageal carcinoma associated with small intestinal obstruction: report of a case

The small intestine is rarely involved with metastatic tumors from outside the abdomen, and few case reports have been documented in the literature. We describe herein what to our knowledge is the third case of a solitary metastasis from squamous cell carcinoma (SCC) of the esophagus being found in the jejunum, causing small intestinal obstruction.     

Development of microbubble aerator for waste water treatment using aerobic activated sludge

In large-scale waste water treatment plants, the aerobic biochemical reactor is the most important process, where the oxygen supply into the microorganisms often limits the overall waste water treatment rate. On the other hand, several kinds of microbubble distributors have been developed to enrich the oxygen dissolution in water. Therefore, the application of microbubbles for a waste water treatment system was investigated in this study.The oxygen absorption performance of typical microbubble generators was compared with typical bubble generators. To evaluate each bubble generator, the liquid-phase volumetric oxygen transfer coefficient, gas hold-up and power consumption per unit liquid volume were measured in a bubble column attached to each bubble generator. All the microbubble generators allowed the oxygen to dissolve faster than the typical aerators. The spiral liquid flow type microbubble generator had the highest oxygen transfer coefficient even at a low air flow rate although it used more energy than the typical distributors.To improve an industrial waste water treatment system, a novel aeration system utilizing a spiral liquid flow type microbubble generator was proposed in this study. The present system has some advantages such as compact size, portability and fast oxygen dissolution rate. To ensure the performance for organic waste water treatment, the effects of the aeration rate, dissolved oxygen concentration and device properties on the specific consumption rate of model organic waste were investigated. For the novel aeration system, the most suitable conditions to treat organic waste were found.     

Synthesis and properties of superabsorbent hydrogels based on guar gum and succinic anhydride

Synthesis of novel superabsorbent hydrogels has been investigated with the reaction of guar gum and succinic anhydride (SA), using of 4‐dimethylaminopyridine as esterification promoter and water or dimethylsulfoxide (DMSO) as reaction solvent, followed by NaOH neutralization. Hydrogels prepared in water exhibited somewhat higher water absorbency than those prepared in DMSO; its maximum water absorbency in pure water and aqueous 0.9% NaCl solution was ca. 200 g/g and 80 g/g, respectively. These values were considerably higher than those of hydrogels obtained from starch in a similar way. The products in this study biologically degraded up to 70–80% after 10 days in activated sludge, which shows their excellent biodegradability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Antitumor agents. 180. Chemical Studies and cytotoxic evaluation of cumingianosides and cumindysoside A, antileukemic triterpene glucosides with a 14,18-cycloapotirucallane skeleton

Treatment of cumingianosides and cumindysoside A, which possess a 14,18-cycloapotirucallane skeleton, with p-toluenesulfonic acid in CH2Cl2 yielded new triterpene glucosides. Cumingianoside A (1) gave 10 and 11, along with cumingianoside Q (5). The structures of 10 and 11 were determined on the basis of spectral examination and contained a dammar-13(17)-ene and a 17(R),23(R)-epoxydammarane skeleton, respectively. Cumingianoside C (2) afforded, together with cumingianoside P (6), products 12 and 13, which were similar to 10 and 11, respectively. With a short reaction time at room temperature, cumingianoside E (3) yielded cumingianoside D (4). In contrast, when 3 was treated with p-toluenesulfonic acid in CH2Cl2 overnight at 5 degrees C, it gave two products, 9 and 14. Extensive spectroscopic examination revealed that 9 possessed a dammar-12-ene skeleton, while 14 was a pentacyclic tetranortriterpene glucoside with a novel skeleton. Cumindysoside A (8) gave a product (15) similar to 14. The cytotoxicities of 9-15 were evaluated against a panel of 58 human tumor cell lines. Compounds 11-15 exhibited potent cytotoxicity with log GI50 values ranging from -7.11 to -4.94, especially against leukemia and colon-tumor cell lines.     

Postsurgical oral administration of uracil and tegafur inhibits progression of micrometastasis of human breast cancer cells in nude mice

We recently established a metastasis model in nude mice using the MKL-4 cell line, a contransfectant of the MCF-7 human breast cancer cell line with fgf-4 and lacZ in which micrometastases in several organs can be quantitatively observed. First, to develop a new postsurgical metastasis model, we investigated the timing of occurrence of micrometastasis and the influence of tumor removal on the progression of micrometastasis in this model. Micrometastases into lymph nodes and lungs were detected 3 weeks after the cell injections. Tumor removal 3 weeks after the injections significantly enhanced the progression of micrometastasis into lymph nodes and bone. Second, to study the effect of a mixed compound, UFT (a molar ratio of uracil:tegafur of 4:1), which has been widely used in the postsurgical adjuvant setting in Japan, 15 or 20 mg/kg UFT were administered p.o. for 4 weeks to tumor-bearing mice or to mice in which transplanted tumors were resected 3 weeks after the injections. Either dose of UFT significantly inhibited the tumor growth as well as the progression of micrometastasis into lymph nodes, lungs, liver, and brain. In addition, enhanced progression of micrometastasis in all explored organs by the tumor removal was significantly inhibited by the administration of either dose of UFT. In conclusion, this new postsurgical metastasis model may be useful for evaluating the efficacy of agents used in the postoperative adjuvant setting. UFT may be an effective drug for inhibiting the progression of micrometastasis after surgery.     

LQ optimal control for a class of pulse width modulated systems

We consider linear quadratic optimal control for a class of pulse width modulated systems. The problem is motivated from a practical application—digital control of switching power converters. The control synthesis problem is posed based on a sampled data model of the original switching dynamics and a linear quadratic criterion that takes the intersampling behavior into account.     

A study of an automated porphyria diagnosis system using urinary porphyrin profile analysis

Porphyrins are essential substances for the biosynthesis of heme. Porphyria results from a disorder in the metabolism of porphyrin. Patients suffering from Porphyria exhibit changes in their porphyrin profiles as measured in excretia and organs. A highly sensitive and simple analytical method using high-performance liquid chromatography (HPLC) for all porphyrin metabolites in urine was established. This method is able to separate porphyrins such as uroporphyrin, carboxylic acid porphyrins of hepta-, hexa-, penta-, and coproporphyrin isomers of I and III in a sample of human urine. In this study, the combination of HPLC with a computer system for automated porphyria diagnosis was investigated. The profile of all urinary porphyrins from patients with various Porphyria were measured by HPLC and diagnosed by the computer diagnostic system. This system enabled the estimation of 5 types of porphyrias with a high accuracy of diagnosis.     

A low-power four-transistor SRAM cell with a stacked vertical poly-silicon PMOS and a dual-word-voltage scheme

To realize high-density SRAMs, we developed a four-transistor SRAM cell with a newly developed stacked vertical poly-silicon PMOS. The vertical poly-silicon PMOS has a gate surrounding a body that forms a channel and yields a drive current of 20 /spl mu/A at 25/spl deg/C. Vertical poly-silicon PMOSs are used as transfer MOSs and are stacked over the bulk NMOSs, used as driver MOSs, to reduce the size of a four-transistor SRAM cell. As a result, the size of the proposed four-transistor SRAM cell was 38% of that of a six-transistor SRAM cell. We also developed an electric-field-relaxation scheme to reduce cell leakage and a dual-word-voltage scheme to improve cell stability. By applying these two schemes to the proposed four-transistor SRAM cell, we achieved a 90% reduction in cell leakage and an improvement in cell stability.     

Atherosclerosis regression in the elderly--correlation between centrally depressed lesions and risk factors

Atherosclerotic plaque with central depression (depressed lesion) may indicate regression of atherosclerosis in the aorta. Aortic depressed lesions have a solitary elevated area of plaque with a sharply-bordered roung depression in its center and no area ulceration. This may be interpretable as a sign of regression of atherosclerosis. To clarify the pathogenesis of depressed lesion, we studied clinical risk factors such as hypercholesterolemia in patients with depressed lesions that were confirmed at autopsy. The patients were divided into 3 groups according to their total cholesterol level at autopsy: a high-risk group (> or = 220 mg/dl), a moderate-risk group (180-220 mg/dl), and a low-risk group (< or = 180 mg/dl). Depressed lesions were found in 16.4% of those in the high-risk group, in 14.6% of those in the moderate-risk group and in 69.0% of those in the low-risk group. Severe aortic atherosclerosis was found in 69.8% of the patients; 50.9% of those with severe disease were in the-low risk group. Depressed lesions were also found in those with low levels of low-density lipoprotein cholesterol (< or = 140 mg/dl), 58.8% of whom were found to have severe atherosclerosis. There was no relationship between total cholesterol level and the presence of depressed lesions. However, a clinical prevention trial may result in sufficient control of ahterosclerosis among those in the high-risk group and may also lead to regression of aortic lesions.     

Effect of a combination of hexamethylphosphoramide and alkyl alcohol on the stereospecificity of radical polymerization of N-isopropylacrylamide

Radical polymerization of N-isopropylacrylamide (NIPAAm) was investigated at low temperatures in the presence of both hexamethylphosphoramide (HMPA) and alkyl alcohols. Although HMPA and alkyl alcohols separately induced syndiotactic specificity in NIPAAm polymerization in toluene at low temperatures, a combination of HMPA and less bulky alkyl alcohols, such as methanol and ethanol, was found to induce isotactic specificity at −80 °C. NMR analysis of mixtures of NIPAAm, ethanol and HMPA suggested the formation of a 1:1:1 complex through O-H•••O=C and N-H•••O=P hydrogen bonding. It is believed that the steric effect of HMPA enhanced by cooperative hydrogen bonding was responsible for the combined effect of HMPA and alkyl alcohols in inducing isotactic specificity.