β-Ketoadipic acid production from poly(ethylene terephthalate) waste via chemobiological upcycling

The upcycling of poly(ethylene terephthalate) (PET) waste can simultaneously produce value-added chemicals and reduce the growing environmental impact of plastic waste. In this study, we designed a chemobiological system to convert terephthalic acid (TPA), an aromatic monomer of PET, to β-ketoadipic acid (βKA), a C6 keto-diacid that functions as a building block for nylon-6,6 analogs. Using microwave-assisted hydrolysis in a neutral aqueous system, PET was converted to TPA with Amberlyst-15, a conventional catalyst with high conversion efficiency and reusability. The bioconversion process of TPA into βKA used a recombinant Escherichia coli βKA expressing two conversion modules for TPA degradation (tphAabc and tphB) and βKA synthesis (aroY, catABC, and pcaD). To improve bioconversion, the formation of acetic acid, a deleterious factor for TPA conversion in flask cultivation, was efficiently regulated by deleting the poxB gene along with operating the bioreactor to supply oxygen. By applying two-stage fermentation consisting of the growth phase in pH 7 followed by the production phase in pH 5.5, a total of 13.61 mM βKA was successfully produced with 96% conversion efficiency. This efficient chemobiological PET upcycling system provides a promising approach for the circular economy to acquire various chemicals from PET waste.

Microbial production of 2-pyrone-4,6-dicarboxylic acid from lignin derivatives in an engineered Pseudomonas putida and its application for the synthesis of bio-based polyester

Lignin valorization depends on microbial upcycling of various aromatic compounds in the form of a complex mixture, including p-coumaric acid and ferulic acid. In this study, an engineered Pseudomonas putida strain utilizing lignin-derived monomeric compounds via biological funneling was developed to produce 2-pyrone-4,6-dicarboxylic acid (PDC), which has been considered a promising building block for bioplastics. The biosynthetic pathway for PDC production was established by introducing the heterologous ligABC genes under the promoter P_tac in a strain lacking pcaGH genes to accumulate a precursor of PDC, i.e., protocatechuic acid. Based on the culture optimization, fed-batch fermentation of the final strain resulted in 22.7 g/L PDC with a molar yield of 1.0 mol/mol and productivity of 0.21 g/L/h. Subsequent purification of PDC at high purity was successfully implemented, which was consequently applied for the novel polyester.

Improving the catalytic performance of xylanase from Bacillus circulans through structure-based rational design

Endo-1,4-β-xylanase is one of the most important enzymes employed in biorefineries for obtaining fermentable sugars from hemicellulosic components. Herein, we aimed to improve the catalytic performance of Bacillus circulans xylanase (Bcx) using a structure-guided rational design. A systematic analysis of flexible motions revealed that the R49 component of Bcx (i) constrains the global conformational changes essential for substrate binding and (ii) is involved in modulating flexible motion. Site-saturated mutagenesis of the R49 residue led to the engineering of the active mutants with the trade-off between flexibility and rigidity. The most active mutant R49N improved the catalytic performance, including its catalytic efficiency (7.51-fold), conformational stability (0.7 °C improvement), and production of xylose oligomers (2.18-fold higher xylobiose and 1.72-fold higher xylotriose). The results discussed herein can be applied to enhance the catalytic performance of industrially important enzymes by controlling flexibility.

Chemo-Biological Upcycling of Poly(ethylene terephthalate) to Multifunctional Coating Materials

Chemo-biological upcycling of poly(ethylene terephthalate) (PET) developed in this study includes the following key steps: chemo-enzymatic PET depolymerization, biotransformation of terephthalic acid (TPA) into catechol, and its application as a coating agent. Monomeric units were first produced through PET glycolysis into bis(2-hydroxyethyl) terephthalate (BHET), mono(2-hydroxyethyl) terephthalate (MHET), and PET oligomers, and enzymatic hydrolysis of these glycolyzed products using Bacillus subtilis esterase (Bs2Est). Bs2Est efficiently hydrolyzed glycolyzed products into TPA as a key enzyme for chemo-enzymatic depolymerization. Furthermore, catechol solution produced from TPA via a whole-cell biotransformation (Escherichia coli) could be directly used for functional coating on various substrates after simple cell removal from the culture medium without further purification and water-evaporation. This work demonstrates a proof-of-concept of a PET upcycling strategy via a combination of chemo-biological conversion of PET waste into multifunctional coating materials.

Improving the organic solvent resistance of lipase a from Bacillus subtilis in water-ethanol solvent through rational surface engineering

Given that lipase is an enzyme applicable in various industrial fields and water-miscible organic solvents are important reaction media for developing industrial-scale biocatalysis, a structure-based strategy was explored to stabilize lipase A from Bacillus subtilis in a water-ethanol cosolvent. Site-directed mutagenesis of ethanol-interacting sites resulted in 4 mutants, i.e., Ser16Gly, Ala38Gly, Ala38Thr, and Leu108Asn, which were stable in 50% ethanol and had up to 1.8-fold higher stability than the wild-type. In addition, Leu108Asn was more thermostable at 45 °C than the wild type. The results discussed in this study not only provide insights into strategies for enzyme engineering to improve organic solvent resistance but also suggest perspectives on pioneering routes for constructing enzyme-based biorefineries to produce value-added fuels and chemicals.

Entecavir and tenofovir reduce hepatitis B virus-related hepatocellular carcinoma recurrence more effectively than other antivirals

Nucleos(t)ide analogues (NAs) have been shown to decrease the risk of hepatocellular carcinoma (HCC) recurrence. This study evaluated whether high-potency NAs (entecavir and tenofovir disoproxil fumarate [TDF]) reduce the risk of tumour recurrence more potently than low-potency NAs after curative treatment of hepatitis B virus (HBV)-related HCC. This study included 607 consecutive HBV-related HCC patients treated with surgical resection or radiofrequency ablation. The patients were categorized into three groups according to antiviral treatment: group A (no antiviral; n = 261), group B (low-potency NA; n = 90) and group C (high-potency NA; n = 256). The primary end-point was recurrence-free survival (RFS). During the duration of follow-up, the median RFS was 29.4, 25.1, and 88.2 months in groups A, B and C, respectively (P < .001, log-rank test). The multivariate Cox analysis indicated that group C had a significantly longer RFS than both group A (adjusted hazard ratio [HR] = 0.39, P < .001) and group B (adjusted HR = 0.47, P < .001). When baseline characteristics were balanced using inverse probability weighting, group C still had a significantly longer RFS than group A (adjusted HR = 0.46, P < .001) and group B (adjusted HR = 0.59, P = .007). Group C had significantly lower risk of viral breakthrough than group B (HR = 0.19, P < .001). Viral breakthrough was an independent risk factor for shorter RFS among groups B and C (adjusted HR = 2.03, P = .007, time-dependent Cox analysis). Antiviral agents with high genetic barrier to resistance (entecavir and TDF) reduced the risk of HCC recurrence compared with other antivirals and no antiviral treatment, especially in patients with high baseline viral load.

Evaluation of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in rat models with hepatocellular carcinoma with liver cirrhosis

Liver cirrhosis is a predominant risk factor for hepatocellular carcinoma (HCC). However, the exact mechanism of the progression from cirrhosis to cancer remains unclear. The uptake of 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) is widely used as a marker of increased glucose metabolism to monitor the progression of cancer with positron emission tomography (PET)/computed tomography (CT). Here we investigated the feasibility of using (18)F-FDG PET/CT in the diethylnitrosamine (DEN) mediated experimental hepatocellular carcinoma model. Rats received weekly intraperitoneal injections of DEN for 16 weeks for induction of HCC. We recorded starting from 0 days or 0 weeks after the last DEN injection. The weight and survival rate of rats were then measured. Also, an (18)F-FDG PET scan and serum analysis were performed at minus 2, 0, plus 2, and plus 4 weeks after the last DEN injection. The body weight of rats was maintained between 350 g and 370 g during 14 and 20 weeks, and the rats were euthanized at 35 days after the last DEN injection. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphate (ALP) were significantly higher at zero weeks after the last DEN injection. The (18)F-FDG uptake for the quantitative evaluation of HCC was done by measuring the region of interest (ROI). At minus two weeks after the last DEN injection, the ROI of rats had significantly increased compared to the normal group, in a time-dependent manner. These results suggest that FDG uptake serves as a good screening test to evaluate the feasibility of DEN-induced HCC.

Vertebral compression fractures may increase mortality in male patients with chronic obstructive pulmonary disease

BACKGROUND

Vertebral compression fracture (VCF) is frequent in chronic obstructive pulmonary disease (COPD) patients. However, little is known about whether VCF affects mortality in COPD patients.

OBJECTIVE

To investigate whether VCFs might increase death in COPD patients.

METHODS

In this retrospective cohort study, we enrolled 254 COPD patients with a recent history of hospitalisation due to respiratory problems. Patients were assessed for VCF using quantitative morphometric analyses of lateral chest radiographs; 211 patients received follow-up examinations for 2 years.

RESULTS

Of the 211 COPD patients analysed, 60 (28.4%) had VCF at enrolment. During the follow-up period, 33/60 (55.0%) patients with and 46/151 patients (30.5%) without VCF died (P = 0.003, log-rank test). Cox proportional hazard analysis revealed that VCF is an independent risk factor for death after adjusting for age, sex, body mass index, smoking, dyspnoea scale, forced expiratory volume in 1 sec (FEV1) and comorbidities (hazard ratio for VCF = 1.79, 95%CI 1.11-2.89, P = 0.02).

CONCLUSION

VCF might be an independent risk factor for death in male COPD patients.

The 'either test positive' strategy for latent tuberculous infection before anti-tumour necrosis factor treatment

SETTING

A ttertiary referral centre in South Korea.

OBJECTIVES

The 'either test positive' strategy, incorporating both the tuberculin skin test (TST) and the T-SPOT(®).TB(T-SPOT) assay, was evaluated as a novel method for diagnosing latent tuberculous infection (LTBI) before treatment with anti-tumour necrosis factor (TNF) in patients with immune-mediated inflammatory diseases.

DESIGN

From June 2008 to April 2012, 430 patients received anti-TNF treatment at our institution. TST and T-SPOT were performed simultaneously at baseline. LTBI was defined as a positive TST or a positive T-SPOT result.

RESULTS

The positivity rates for the TST and T-SPOT assays were respectively 19.1% (82/430) and 44.2% (190/430), yielding an LTBI-positive rate of 48.6% (209/430). LTBI treatment was initiated in 46.0% (198/430) of patients and was completed by 89.4% (177/198). During follow-up (median 884 days), 0.9% (4/430) of the patients developed active tuberculosis (TB). All four TB patients were TST-negative at baseline, although two received LTBI treatment based on the baseline positive T-SPOT assay results.

CONCLUSIONS

The either test positive strategy is a valid method for diagnosing LTBI before anti-TNF treatment, although it is not clear whether it is superior to other strategies.

Dysregulation of miR-106a and miR-591 confers paclitaxel resistance to ovarian cancer

Background:

MicroRNAs are noncoding regulatory RNAs strongly implicated in carcinogenesis, cell survival, and chemosensitivity. Here, microRNAs associated with chemoresistance in ovarian carcinoma, the most lethal of gynaecological malignancies, were identified and their functional effects in chemoresistant ovarian cancer cells were assessed.

Methods:

MicroRNA expression in paclitaxel (PTX)-resistant SKpac sublines was compared with that of the PTX-sensitive, parental SKOV3 ovarian cancer cell line using microarray and qRT–PCR. The function of differentially expressed microRNAs in chemoresistant ovarian cancer was further evaluated by apoptosis, cell proliferation, and migration assays.

Results:

Upregulation of miR-106a and downregulation of miR-591 were associated with PTX resistance in ovarian cancer cells and human tumour samples. Transfection with anti-miR-106a or pre-miR-591 resensitized PTX-resistant SKpac cells to PTX by enhancing apoptosis (23 and 42% increase), and inhibited their cell migration (43 and 56% decrease) and proliferation (64 and 65% decrease). Furthermore, ZEB1 was identified as a novel target gene of miR-591, and BCL10 and caspase-7 were target genes of miR-106a, as identified by immunoblotting and luciferase assay.

Conclusion:

MiR-106a and miR-591 have important roles in conferring PTX resistance to ovarian cancer cells. Modulation of these microRNAs resensitizes PTX-resistant cancer cells by targeting BCL10, caspase-7, and ZEB1.

BrRZFP1 a Brassica rapa C3HC4-type RING zinc finger protein involved in cold, salt and dehydration stress

C3HC4-type RING zinc finger proteins are known to be essential in the regulation of plant processes, including responses to abiotic stress. Here, we identify, clone and examine the first C3HC4-type RING zinc finger protein (BrRZFP1) from Brassica rapa under stress conditions. Phylogenetic analysis of BrRZFP1 revealed strong sequence similarity to C3HC4-type zinc finger proteins from Arabidopsis that are induced by abiotic stresses. Diverse environmental stresses, including salt and cold, were found to induce BrRZFP1 transcripts greater than eightfold in B. rapa. Additional strong induction was shown of the stress hormone abscisic acid, together suggesting that BrRZFP1 could play a role as a general stress modulator. Similar profiles of induction for each of these stresses was found in both root and shoot tissues, although at much higher levels in roots. Constitutive expression of BrRZFP1 in Nicotiana tabacum was conducted to further analyse how changes in gene expression levels would affect plant stress responses. BrRZFP1 overexpression conferred increased tolerance to cold, salt and dehydration stresses. This was observed in several assays examining growth status throughout development, including increased germination, fresh weight and length of shoots and roots, as well as enhanced chlorophyll retention. These results suggest that the transcription factor BrRZFP1 is an important determinant of stress response in plants and that changes in its expression level in plants could increase stress tolerance.

The fate of injured corticospinal tracts in patients with intracerebral hemorrhage: diffusion tensor imaging study

BACKGROUND AND PURPOSE

Little is known about the fate of the injured CST for a large number of patients with ICH. Using DTT, we investigated the longitudinal changes of injured CSTs in patients with an ICH.

MATERIALS AND METHODS

We recruited 45 patients with CST injury by an ICH in the supratentorial subcortical area. Two longitudinal DTTs were acquired: 1 within 30 days and the other after 3 months from onset. DTTs for the CST were classified into 3 types: type A, the CST was preserved around the hematoma; type B, the CST was interrupted around the hematoma; and type C, the CST did not reach the hematoma.

RESULTS

At the first DTT, the motor functions of type C were worse than those of types A and B (P < .01), and motor functions of type A were better than those of type C at the second DTT (P < .01). Of 14 type A, 2 changed to type B (14.3%) and 12 did not change (85.7%); of 12 type B, 11 changed to type A (91.7%) and 1 changed to type C (8.3%); of 19 type C, 3 changed to type A (15.8%) and 16 did not change (84.2%).

CONCLUSIONS

We found that the injured CST could change from the early stage to the chronic stage during the motor recovery phase in patients with an ICH. These results would be helpful in prediction of longitudinal DTT changes from the early stage to the chronic stage following ICH.

Clinical features of subjects with an isolated FEV1 reduction

BACKGROUND

The clinical significance of an isolated reduction in forced expiratory volume in 1 second (FEV(1); i.e., low FEV(1), but normal forced vital capacity [FVC] and FEV(1)/FVC) has not been established.

OBJECTIVE

To examine the clinical features of subjects with an isolated FEV(1) reduction.

METHODS

Clinical, spirometry and radiological data were retrospectively collected from 15,192 subjects attending a medical check-up at the Health Promotion Center of the Asan Medical Center, Korea. Predicted spirometry values were calculated from the Korean reference equations, and the lower limit of normal was set at the 5th percentile. Subjects were divided into four groups: isolated FEV(1) reduction, normal (normal FVC, FEV(1) and FEV(1)/FVC), obstructive (low FEV(1)/FVC) and restrictive (low FVC and normal FEV(1)/FVC). The groups were compared in terms of clinical characteristics.

RESULTS

Of the 15,192 subjects, 323 (2.1%) had an isolated FEV(1) reduction, 10,591 (69.7%) were normal, 951 obstructive (6.3%) and 3327 (22.0%) restrictive. The isolated FEV(1) reduction group had a higher proportion of subjects with smoking history (63.2% vs. 45.7%), radiology abnormalities (15.5% vs. 4.3%) and history of respiratory disease (8.4% vs. 3.0%) than the normal group (all P < 0.001).

CONCLUSION

An isolated FEV(1) reduction suggests abnormal spirometry, and further study is needed to evaluate whether these cases belong to the obstructive or restrictive group.

Association of restrictive ventilatory dysfunction with insulin resistance and type 2 diabetes in koreans

AIMS

To investigate associations of obstructive and restrictive patterns of ventilatory dysfunction with insulin resistance and type 2 diabetes mellitus (DM) in Koreans.

METHODS

We cross-sectionally examined clinical, laboratory, and pulmonary function data on 35,456 Korean adults (age 18-93 years, 40% women) recorded during regular health check-ups. Insulin resistance (IR) was determined from fasting serum insulin concentration and homeostasis model assessment (HOMA).

RESULTS

Individuals with type 2 DM and those with pre-diabetes (impaired fasting glucose levels) showed a higher prevalence of both restrictive (18% and 11%, respectively, VS. 8%; P<0.01) and obstructive (4.3% and 3.2%, respectively, VS. 2.3%; P<0.01) ventilatory dysfunction than did individuals with normal fasting glucose levels. Compared to subjects with normal ventilatory function, those with restrictive or obstructive ventilatory dysfunction were older, had higher systolic and diastolic blood pressure, and had elevated glucose and HbA1c levels. However, serum triglyceride, fasting insulin, and HOMA-IR were higher only in subjects with restrictive ventilatory dysfunction, and not in those with obstructive ventilatory dysfunction. On logistic regression analysis, the age and gender-adjusted odds ratio (OR) of restrictive ventilatory dysfunction for type 2 DM was 1.59 (95% confidence interval, 1.43-1.78). The increased OR remained significant after controlling for exercise, drinking, and smoking habits, presence of hypertension, body mass index, and waist circumference (OR=1.38 [1.23-1.55]). However, further adjustment for HOMA-IR attenuated the OR (1.11 [0.97-1.26]), making the OR statistically insignificant. In contrast, obstructive ventilatory dysfunction was not independently related to type 2 DM status.

CONCLUSION

Restrictive ventilatory dysfunction is independently associated with type 2 DM, probably VIA insulin resistance.

Clinical features of acute renal failure associated with hepatitis A virus infection

Acute hepatitis A (AHA) is one of the most common infectious diseases; it is usually a self-limiting disease affecting the liver. Although extrahepatic manifestations are not common, some cases have been reported associated with acute renal failure. We reviewed the clinical features of patients with AHA complicated by acute renal failure (ARF group) and compared them with patients with noncomplicated AHA (non-ARF group). The medical records of 208 consecutive patients with AHA who were diagnosed between January 2003 and October 2008 were reviewed. We identified 15 patients (7.2%) with ARF associated with AHA. There were no differences between the ARF and non-ARF group with regard to gender and age. The peak value of alanine aminotransferase (ALT) (median: 6060 IU/L vs 1792 IU/L, P < 0.001), prothrombin time (PT) (International normalized ratio, median 1.72 vs 1.10, P < 0.001), and total bilirubin level (median: 9.6 mg/dL vs 6.3 mg/dL, P = 0.04) were significantly higher in the ARF than in the non-ARF group. Twelve patients (80%) recovered completely with haemodialysis (seven patients, 46.7%) or only conservative management (five patients, 33.3%), while one patient underwent liver transplantation because of fulminant hepatic failure, and two patients died because of fulminant hepatic failure. There were no deaths among patients with noncomplicated AHA in the non-ARF group. Five patients underwent kidney biopsy; two patients were diagnosed with acute tubular necrosis, two patients with acute interstitial nephritis with IgA nephropathy and one patient with acute tubulointerstitial nephritis. All patients in the ARF group had microscopic haematuria and proteinuria (100%vs 31.1%, P < 0.001). Urine sodium levels were more than 10 mEq/L in 10 patients. The findings of high urinary sodium concentrations, microscopic haematuria and proteinuria did not support the diagnosis of hepatorenal syndrome (HRS). Patients with AHA with ARF had higher ALT levels, more prolonged PTs, and higher total bilirubin levels. The prognosis for these patients was poorer than for those without ARF. However, the patients with ARF and nonfulminant AHA had recovered with proper treatment and should not be confused with patients that have HRS.

The effect of co-existing solutes on arsenate removal with hydrotalcite compound

Hydrotalcite (HTAL-Cl), an inorganic anion exchanger, is of use as an adsorbent for the removal of arsenate (As(V)) in water systems. The adsorption properties of HTAL-Cl for As(V) and the effects of co-existing anions on the As(V) removal performance were investigated in this work. Under the conditions of pH>or=4, the adsorption capacity for As(V) gradually decreased with an increase of pH, but As(V) was removed effectively within the range of pH = 5-8. Co-existing anions interfered As(V) removal, and the effect decreased in the order of HPO(4)(2-) > HCO(3)(-) > SO(4)(2-) > Cl(-). In binary solute systems containing phosphate and As(V), the maximum adsorption capacity of HTAL-Cl was 0.95 mmol g(-1) for phosphate and 0.65 mmol g(-1) for As(V): the total of these values corresponded to the maximum adsorption capacity for As(V) in single solute systems. The adsorption isotherms in these binary solute systems were approximated by the following modified Langmuir equations:As(V): q(As) = 18.7 radicalC(As)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)), phosphate : q(P) = 33.1 radicalC(P)/(1 + 21.5 radicalC(P) + 12.8 radicalC(As)). The column adsorption experiments showed that the adsorbed As(V) was released by the phosphate adsorption, because phosphate was adsorbed more strongly on HTAL-CL than As(V).

Combined use of QuantiFERON-TB Gold assay and chest computed tomography in a tuberculosis outbreak

OBJECTIVE

To evaluate the value of the QuantiFERON-TB Gold (QFT-G) assay and chest computed tomography (CT), in addition to the conventional use of the tuberculin skin test (TST) and chest radiography (CXR), in a contact investigation of a tuberculosis (TB) outbreak.

DESIGN

In a contact investigation of a TB outbreak in a high school, TST and CXR were performed on all 1044 employees and students. QFT-G was performed on TST-positive subjects, and CT on QFT-G-positive subjects and students with TST > or =20 mm.

RESULTS

TST was positive in 388 subjects (37.2%), while QFT-G was positive in 7.6% (30/394). CXR showed abnormal findings suggestive of TB in 10 (1.0%) subjects, all of whom were TST-positive and six of whom were QFT-G-positive. Findings suggestive of active TB were noted in 17 (32.7%) of 52 subjects by CT. Collectively, among 21 (1.1%) TB patients, all were TST-positive, 12 (57.1%) were QFT-G-positive and active TB was diagnosed by CT, and not by CXR, in 11 subjects.

CONCLUSION

Compared to the conventional approach, the additional use of QFT-G in TST-positive subjects and chest CT in subgroups with a high probability of infection was found to be more effective in the differentiation between active TB, latent TB and non-infected subjects in a contact investigation.

Performance of electron beam irradiation for treatment of groundwater contaminated with acetone

The purposes of this study were to evaluate the efficiency of acetone removal by electron beam irradiation in groundwater and the effect of various conditions. According to the results, the removal kinetics of acetone were pseudo first-order, and the removal efficiencies were expressed to the (%) removal and G-values. By adding sulfite, it was confirmed that acetone was mainly degraded by the reaction with the hydrated electrons. The presence of nitrate caused the removal of acetone to decrease. But there was no significant effect of alkalinity on the removal of acetone. The effect of the initial pH values (pH 5 to 9) on the acetone removal efficiency was negligible, but the pH value decreases due to the formation of acidic compounds after irradiation. Consequently, the radiation-induced removal reactions of acetone followed the pseudo-first-order kinetic model; in addition to the initial concentration of acetone, nitrate and the absorbed dose were important factors in removing acetone from an aqueous solution using electron beam irradiation. The effects of general pH and alkalinity on the degrading acetone were negligible.

Distinct locomotive patterns of granulocytes, monocytes and lymphocytes in a stable concentration gradient of chemokines

The pattern of leukocyte locomotion can be changed in many pathological situations, but its accurate analysis is difficult because of technological limitation. In the present study, by using a newly developed time-lapse videomicroscopic technique, we have analyzed the locomotive patterns of leukocytes in a stable concentration gradient of chemokines. Granulocytes, monocytes, and lymphocytes were purified from adult human peripheral blood. Locomotive behavior of the leukocytes was analyzed by an optical assay using a microchannel producing a stable concentration gradient of chemokines. Videomicroscopic analysis showed distinct locomotive patterns of granulocytes, monocytes, and lymphocytes. Granulocytes were intrinsically motile, vigorously moving in random direction without any chemokine stimulation. Upon stimulation with CXCL8/IL-8, the speed of migration was increased from 13.3 +/- 2.8 to 19.4 +/- 2.5 microm/min (P = 0.002, n = 100) and they moved toward the chemokine, although many cells still wandered very much. Stimulation with CCL5/RANTES or CXCL12/SDF-1alpha induced similar changes in locomotive pattern. On the other hand, most lymphocytes did not polarize or move spontaneously without chemokine stimulation. Stimulation with CXCL12 induced directional migration in 37% of the lymphocytes at a speed of 9.6 +/- 1.6 microm/min (n = 100). The movement pattern of monocytes was similar to that of granulocytes in that they tend to become polarized and move spontaneously, but they moved at a very slow speed ranging from 3.9 to 4.2 microm/min even with chemokine stimulation. The new optical assay may be useful for many diagnostic as well as basic studies.

A model of the effect of temperature on the growth of pathogenic and nonpathogenic Vibrio parahaemolyticus isolated from oysters in Korea

Vibrio parahaemolyticus is recognized as the leading cause of human gastroenteritis associated with the consumption of seafood. The objective of this study was to model the growth kinetics of pathogenic and nonpathogenic V. parahaemolyticus in broth and oyster slurry. Primary growth models of V. parahaemolyticus in broth and oyster slurry fit well to a modified Gomperz equation (broth R(2)=0.99; oyster slurry R(2)=0.96). The lag time (LT), specific growth rate (SGR), and maximum population density (MPD) of each primary model were compared. The growth of nonpathogenic V. parahaemolyticus was found to be more rapid than that of pathogenic V. parahaemolyticus, regardless of the model medium. In addition, significant (P<0.05) differences in the growth kinetics between pathogenic and nonpathogenic V. parahaemolyticus in broth were observed at 10 degrees C. When compared to growth in broth, the growth of V. parahaemolyticus was delayed in oyster slurry, and growth was not observed at 10 or 15 degrees C. The Davey and square root models were identified as appropriate secondary models for predicting the LT and SGR, respectively. For the broth model, the average B(f) and A(f) values for LT were found to be 0.97 and 1.3, respectively, whereas the average B(f) and A(f) values for SGR were 1.05 and 1.11, respectively. The model generated in this study predicted an LT that was shorter and an SGR that was similar to those that were actually observed, which indicates that these models provide a reliable and safe prediction of V. parahaemolyticus growth.

Glutamine preferentially inhibits T-helper type 2 cell-mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A(2) activity in a murine asthma model

BACKGROUND

The non-essential amino acid, l-glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A(2) (cPLA(2)) activity. cPLA(2) has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined.

OBJECTIVE

To investigate the effects of Gln on allergic bronchial inflammation and airway hyperresponsiveness (AHR), and to determine the possible action mechanisms of Gln in a murine model of asthma.

METHODS

cPLA(2) phosphorylation was assessed by immunoprecipitation and Western blotting. Smears of bronchoalveolar lavage cells were stained with Diff-Quik solution for differential cell counting. Airway levels of the proteins [T-helper type-1 (Th1) and Th2 cytokines, and mucin] were measured by ELISA. mRNA expression of cytokines was assessed by real-time RT-PCR. AHR was assessed as a change in airway resistance (RL). Histological studies were performed to assess the levels of mucin and pulmonary inflammation.

RESULTS

Systemic Gln administration inhibited cPLA(2) phosphorylation and its enzymatic activity in the lungs. Additionally, Gln effectively suppressed the key features of Th2-dependent asthmatic features, such as airway eosinophilia, mucus formation, and airway type 2 cytokine production, as well as late AHR.

CONCLUSION

Gln was found to be effective in the suppression of Th2-dependent phenotypes and late AHR, and this effect of Gln appeared to be at least partially attributable to its ability to suppress cLPA(2) activity in the airway. Our results suggest that clinical use of Gln for patients with asthma may be beneficial.

Disinfection and oxidation of sewage effluent water using ozone and UV technologies

This study was aimed at exploring the reclamation of sewage treatment plant effluent water (SEW) as an alternative water resource. For the oxidation of SEW, an ozone-UV system, based on the results of the combined ozone/UV process performed in our previous study, was set up under practical conditions, including a series type, continuous mode, semi-pilot scale operation (1.5 m3/d). As a result, the serial contact of the ozone and UV reactors showed lower CODCr and TOC removal efficiencies. However, these were greatly enhanced by recycling the water flow of the ozone-UV system at 40Q, as a result of the improvements in the transferred ozone dose in the ozone reactor and the contact efficiency between photons and ozone in the UV reactor, which approached that achieved in the combined ozone/UV process. For the disinfection of SEW, carried out in a syringe-type batch reactor, the increase of instantaneous ozone demand (ozone ID) led to a higher inactivation efficiency, an increased UV transmittance due to ozonation, and an enhanced inactivation rate of E. coli in the UV reactor. Additionally, it was concluded that the ozone/UV process could overcome the limitations of the ozone alone and UV alone processes for the reclamation of sewage effluent water.

Control of disinfection and halogenated disinfection byproducts by the electrochemical process

The aim of this study was to investigate some aspects of the performance of electrochemical process as an alternative disinfection strategy, while minimising DBPs, for water purification. The study of electrochemical processes has shown free chlorine to be produced, but smaller amounts of stronger oxidants, such as ozone, hydrogen peroxide and OH radicals (*OH), were also generated. The formation of mixed oxidants increased with increasing electric conductivity, but was limited at conductivities greater than 0.6 mS/cm. Using several microorganisms, such as E. coli and MS2 bacteriophage, inactivation kinetic studies were performed. With the exception of free chlorine, the role of mixed oxidants, especially OH radicals, was investigated for enhancement of the inactivation rate. Additionally, the formation and reduction of DBPs was studied by monitoring the concentration of haloacetic acids (HAAs) during the process.

Surgical resection of cavernous angiomas located in eloquent areas--clinical research

BACKGROUND

In patients with lesions at the eloquent areas, the aim of surgical interventions should be a more radical removal of the lesions with preservation of brain function. In this retrospective study, our techniques for localizing lesion and the postoperative results of 26 patients with cavernous angiomas (CA) located at the eloquent areas are summarized.

METHOD

The MR based 3D-rendering images were reconstructed from the 2D MR images by using a computerized program. These images were obtained in all patients for the localization of their lesion. Following craniotomy, to verify the actual location of lesions, we compared the 3D-image to the exposed cortical surface. Simultaneously, intraoperative ultrasonogram (IOUS) was used for the accurate localization of the lesion. In order to minimize the damage to the eloquent area, the minimal corticotomy was planned at the margin of the sulcus nearest to the lesion.

FINDINGS

An accurate localization of the lesion was possible in all 26 patients and the eloquent areas near the lesions were identified on the operation field. Complete removal of the CAs was done in all cases. One patient developed temporary monoparesis postoperatively, but the patient fully recovered in a month. Fourteen patients presented with preoperative seizures, and all patients had excellent seizure outcome after their surgery. The mean duration of the follow-up period was 27 months.

CONCLUSIONS

We could localize the lesion accurately using MRI 3D-rendering images and IOUS during the operation for CA. We planned minimal corticotomy to the lesion and we completely removed the lesion without causing any additional neurological deficit. Although CA can be located in eloquent areas, surgical removal of these lesions is a safe and effective treatment option for lowering the risk of developing symptoms and controlling the seizure.

Sludge thickening performance of mesh filtration process

Small-scale wastewater treatment facilities play an important role in improving the aquatic environment in many countries. Although sludge treatment is essential for overall wastewater treatment, it is difficult for small-scale facilities to use mechanical equipment or other facilities. As the first step of the sludge treatment, it is important to develop a convenient sludge thickening process for small-scale facilities. In this work, we examined the sludge thickening performance of a mesh filtration system: the mesh opening sizes of 100-500 microm, and the sludge (3,000-9,000 mg-SS/L) was obtained from a domestic wastewater treatment facility. The filtration was carried out only under the hydraulic pressure between the water level and the effluent port connected to the mesh filter module. The sludge reduction rates were in the range of 85-95% for 6-7 h; the initial filtration rate was very high, but the rate decreased with a decrease in hydraulic pressure due to the reduction of the water level in the vessel. In addition, the effluents (passed through the mesh) contained very low SS and could be directly discharged into the environment.

Acidogenic fermentation: utilization of wasted sludge as a carbon source in the denitrification process

Laboratory scale batch experiments were conducted at 20 degrees C to investigate the acidogenic fermentation for the conversion of wasted sludge into short chain fatty acids (SCFA) to be utilized as a carbon source in the denitrification process. Hydraulic retention time (HRT), volatile solid (VS) loading rate and pH were studied as these are the important parameters governing the production of volatile fatty acids (VFA). Four different phases were investigated by varying these parameters. HRT was varied from 2.7 to 8.2 days whereas VS loading rate was varied from 1.2 to 3.6 g d(-1). VFA production decreased with the increase in HRT above 2.7 days. 538.37+/-19.39 mg VFA(produced) x d(-1) (0.176+/-0.010 mg VFA(produced) mg(-1) VS(feed) was found as the maximum value of VFA at 2.7 days. The present results based on wasted sludge showed that almost 0.0483+/-0.0016 mg VFA (as COD mg(-1) initial COD) and about 5% of soluble COD production were achieved, which are slightly less than the results reported for primary sludges. The rates of VFA production increased with the increase in VS, however, opposite results were obtained when pH was increased in the reactor. SCFA/FA ratios during fermentation were found in the range of 67-73%. The specific denitrification rates (SDNR) of methanol (2.20+/-0.44 mg NO3-N g(-1) MLVSS x h(-1)) and the fermenter supernatant (2.00+/-0.45 mg NO3-N g(-1) MLVSS x h(-1)) were found to be comparable. Fermenter supernatant, therefore, has the potential to be utilized as a carbon source. However, the results need to be investigated further on a larger scale to ascertain their validity.

Time-dependent fluctuations in single molecule spectroscopy: a generalized Wiener-Khintchine approach

We consider the theory of time-dependent fluctuations in single molecule spectroscopy. In particular, the relation between stationary spectral diffusion processes and photon counting statistics is investigated. Within linear response theory, a general relation between Mandel's Q parameter and a three time dipole correlation function is obtained. For a prototype spectral diffusion process, an exact solution of Q is found which exhibits rich types of physical behaviors.

Colon-specific prodrugs of 5-aminosalicylic acid: synthesis and in vitro/in vivo properties of acidic amino acid derivatives of 5-aminosalicylic acid

5-aminosalicyl-L-aspartic acid (5-ASA-Asp) and 5-aminosalicyl-L-glutamic acid (5-ASA-Glu) were synthesized and their properties as colon-specific prodrugs of 5-aminosalicylic acid (5-ASA) were investigated employing rats as test animals. Incubation of 5-ASA-Asp and 5-ASA-Glu with the homogenates of tissue and contents of stomach or small intestine released no 5-ASA, indicating that they were stable in this condition. Incubation of 5-ASA-Asp with the cecal contents released 5-ASA 37%, whereas 5-ASA-Glu released only 8% of the dose in 16 h. Plasma concentration of 5-ASA-Asp after intravenous administration decreased rapidly and became undetectable in 60 min. No 5-ASA was detected in the blood, which indicated 5-ASA-Asp was stable in the plasma. After oral administration of 5-ASA-Asp, concentration of 5-ASA, its metabolite N-acetyl-5-ASA, and 5-ASA-Asp in the plasma, feces, and urine was determined. In the plasma, 5-ASA-Asp was not detected and the concentration of 5-ASA or N-acetyl-5-ASA was very low. About 33% of the administered dose was recovered as 5-ASA and N-acetyl-5-ASA and 43% as 5-ASA-Asp from feces, and 20% as 5-ASA and N-acetyl-5-ASA and 1% as 5-ASA-Asp from urine in 24 h. These results suggested that most of 5-ASA-Asp was delivered to the large intestine and about half of the administered dose was activated to liberate 5-ASA. After oral administration of free 5-ASA, fecal recovery was only 7% of the dose in 24 h and more than 80% was recovered from urine. Comparing 5-ASA-Asp and free 5-ASA, the amount of 5-ASA available in the large intestine was much larger, while the amount of 5-ASA in urine, which might be related to the systemic toxicity of 5-ASA, was much lower by the administration of 5-ASA-Asp than free 5-ASA.

Synthesis and evaluation of N-acyl-2-(5-fluorouracil-1-yl)-D,L-glycine as a colon-specific prodrug of 5-fluorouracil

N-nicotinyl-2-(5-fluorouracil-1-yl)-D,L-glycine (NFG) and N-isonicotinyl-2-(5-fluorouracil-1-yl)-D,L-glycine (INFG) were synthesized as colon-specific prodrugs of 5-fluorouracil (5-FU). As N-aromatic acyl amides of glycine, they are expected to be stable in the upper intestine and delivered to the colon as an intact form if they are nonabsorbable. Microbial hydrolysis of amide bond in the colon will give 2-(5-fluorouracil)-D,L-glycine, which releases 5-FU by spontaneous decomposition. NFG and INFG were soluble in water and stable in pH 1.2 and 7.4 buffer solutions. The apparent partition coefficient of NFG or INFG in 1-octanol/pH 7.4 phosphate buffer solution at 37 degrees was 0.025 or 0.024, respectively. On incubation with cecal contents of rats, conversion of NFG or INFG proceeded only 9 or 5% in 8 h, respectively, producing 5-FU and a metabolite. The metabolite formation was inhibited in the presence of diazouracil, a dihydrouracil dehydrogenase inhibitor. The HPLC retention time of the metabolite from the incubation of 5-FU, NFG, or INFG with cecal contents was identical to dihydro-5-fluorouracil (dihydro-5FU). When N-nicotinyl-2-hydroxy-D,L-glycine methyl ester (NHGM) was incubated with the cecal contents, the extent of amide bond hydrolysis was 85% in 24 h. The result suggested that steric hindrance imposed by 5-FU at 2-position of glycine retarded the hydrolysis of the amide bond in NFG or INFG and suppressed the prodrug conversion.

Antioxidative and antitumor promoting effects of [6]-paradol and its homologs

Recently, considerable attention is focused on anti-carcinogenic phytochemicals, particularly those derived from medicinal or edible plants. [6]-Paradol, a pungent phenolic compound present in certain Zingiberaceae plants, is known to have antimicrobial and analgesic activities. The compound has been reported to attenuate promotion of skin carcinogenesis and TPA-induced ear edema in female ICR mice, and to induce apoptosis in cultured human promyelocytic leukemia (HL-60) cells. In this study, we performed several biochemical studies to evaluate and compare the cancer chemopreventive potential of [6]-paradol and its synthetic derivatives. [6]-Paradol and its synthetic nonpungent analog, [6]-dehydroparadol significantly decreased the incidence and the multiplicity of skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). Topical application of [6]-paradol and its derivatives inhibited TPA-induced ear edema and H(2)O(2) production and myeloperoxidase activity in the dorsal skin of mice. Induction of TPA-induced mouse epidermal ornithine decarboxylase (ODC) activity and H(2)O(2)- and UV-induced formation of oxidized DNA bases in vitro were also attenuated by the above compounds. These results indicate that [6]-paradol and its derivatives possess the cancer chemopreventive potential.

Induction of apoptosis in p53-deficient human hepatoma cell line by wild-type p53 gene transduction: inhibition by antioxidant

We investigated the role of wild-type (wt)-p53 as an inducer of apoptotic cell death in human hepatoma cell lines. Following the retrovirus-mediated transduction of the wt-p53 gene, Hep3B cells lacking the endogenous p53 expression began to die through apoptosis in 4 h. They showed a maximal apoptotic death at 12 h, whereas HepG2 cells expressing endogenous p53 did not. However, the transduction of the wt-p53 gene elicited growth suppression of both Hep3B and HepG2 cells. P21(WAF1/CIP1), a p53-inducible cell cycle inhibitor, was induced, not only in Hep3B cells undergoing apoptosis, but also in HepG2 cells. The kinetics of the p21(WAF1/CIP1) induction, DNA fragmentation, and growth suppression of the Hep3B cells showed that DNA fragmentation and growth suppression progressed rapidly following p21(WAF1/CIP1) accumulation. N-acetyl-cysteine or glutathione, potent antioxidants, strongly inhibited the DNA fragmentation, but did not reduce the elevated level of p21(WAF1/CIP1). These findings suggested that p21(WAF1/CIP1) was not a critical mediator for the execution of p53-mediated apoptosis, although it contributed to the growth inhibition of cells undergoing apoptosis. Furthermore, p53-mediated apoptosis could be repressed by antioxidants.

Reciprocal expressions of cyclin E and cyclin D1 in hepatocellular carcinoma

Deregulation of the cell cycle by overexpression of G1 cyclins, cyclin E and cyclin D1 genes, has been demonstrated to be a prerequisite for the development of human cancer. Recently, cyclin E is proposed to be sufficient for the progression of the G1 cell cycle without cyclin D1. Here we show that the proposed model system was specifically present in human hepatocellular carcinoma (HCC) unlike other human cancers. Of 31 HCC tissues analyzed, 21 (67.7%) exhibited an overexpression of cyclin E protein. In contrast to cyclin E gene expression, cyclin D1 expression was strongly downregulated in 19 (61.2%) HCCs. Interestingly, 65% of HCC tissues with overexpression of the cyclin E gene exhibited downregulation of cyclin D1, suggesting reciprocal deregulation of these cyclins in the G1 progression of the cell cycle. Southern blot analysis proved the amplification of cyclin E gene in HCC with a high level of overexpression. The present findings suggest that the reciprocal deregulation of cyclin E lacking cyclin D1 expression might play a role in G1 progression and the development of HCC.

Synthesis and properties of dextran-nalidixic acid ester as a colon-specific prodrug of nalidixic acid

Dextran-nalidixic acid ester (dextran-NA) with a varied degree of substitution (DS) was synthesized as a colon-specific prodrug of nalidixic acid (NA). Solubility in water (mg/ml) of dextran-NA with DS (mg NA/100 mg dextran-NA) of 7, 19, or 32 was 57.57 (equivalent to 4.00 mg NA/ml), 0.53 (equivalent to 0.10 mg NA/ml), or 0.03 (equivalent to 0.01 mg NA/ml), respectively, and that for NA was 0.03 at 25 degrees C. To ensure the chemical stability of dextran-NA at conditions similar to those of the stomach and small intestine, dextran-NA was placed in a solution of pH 1.2 hydrochloric acid buffer or pH 6.8 phosphate buffer and incubated at 37 degrees C; no NA was detected during the 6 h of the incubation period, which indicated that dextran-NA might be chemically stable during the transit through the gastrointestinal tract. Degree of depolymerization (%) by dextranase determined by the 2,4-dinitrosalicylic acid (DNS) method at 37 degrees C for dextran-NA with DS of 7, 19, or 32 was 81, 68, or 8, respectively, in 8 h, and that for dextran was 91. When dextran-NA (equivalent to 50 microg of NA) with a DS of 7 or 17 was incubated with cecal contents (100 mg) of rats at 37 degrees C, the extent of NA released in 24 h was 41% or 32% of the dose, respectively. NA was not liberated from the incubation of dextran-NA with the homogenate of tissue and contents of the small intestine.

Salsolinol, a naturally occurring tetrahydroisoquinoline alkaloid, induces DNA damage and chromosomal aberrations in cultured Chinese hamster lung fibroblast cells

Salsolinol (SAL) is a tetrahydroisoquinoline neurotoxin that has been speculated to contribute to pathophysiology of Parkinson's disease and chronic alcoholism. The compound is also found in certain beverages and food stuffs, including soy sauce, beer and bananas. Despite potential human exposure to SAL and its endogenous formation, little is known about the genotoxic or carcinogenic potential of this substance. In the present investigation, SAL induced DNA damage in cultured Chinese hamster lung (CHL) fibroblasts as assessed by single cell gel electrophoresis (Comet). CHL cells treated with SAL also exhibited higher frequencies of chromosomal aberrations than did vehicle-treated controls. Our recent study has revealed that SAL in combination with Cu(II) causes the strand scission in phiX174 supercoiled DNA [Neurosci. Lett. 238 (1997) 95]. In line with this notion, addition of cupric ion potentiated the DNA damaging and clastogenic activity of SAL. Antioxidant vitamins, such as Vitamin C and Vitamin E, and reduced glutathione inhibited clastogenicity of SAL, suggesting the involvement of reactive oxygen species (ROS) in SAL-induced DNA damage and genotoxicity in CHL cells.

Synthesis and properties of dextran-linked ampicillin

Ampicillin was coupled to dextran of average molecular weight 9,000 or 81,200 via the cyanogen bromide method. The degree of drug substituted per glucose unit (DSG) was varied from 0.104 to 0.028 (by weight bases: 22.1-5.9%) depending on the ratio of the reactants. Water solubility of dextran-linked ampicillin increased compared with free ampicillin, and the solubility decreased as the amount of ampicillin substituted increased. Plasma concentration of ampicillin, which appeared after intravenous administration of dextran-linked ampicillin in rats, was higher than when free ampicillin was administered, and the more so, the higher the molecular weight of dextran. Plasma half-life of dextran-linked ampicillin was two times longer than that of free ampicillin in rats. Antibacterial activities of dextran-linked ampicillin were evaluated against Staphylococcus aureus, Bacillus substillis, and Escherichia coli at two concentration levels according to the cup-plate method by measuring the diameter of inhibition zone, which was comparable to that of free ampicillin.

Spontaneous rupture of hydronephrotic kidney during pregnancy: value of serial sonography

Hydronephrosis during pregnancy is common but rarely results in renal rupture. We report an unusual case of spontaneous rupture of a hydronephrotic kidney during pregnancy. Although we could not predict the renal rupture on the basis of sonographic findings, serial sonography was useful in the early detection and management of the rupture.

Mediastinal lymphadenopathy in pulmonary fibrosis: correlation with disease severity

OBJECTIVE

To evaluate the relationship between mediastinal lymph node enlargement and disease severity score in patients with pulmonary fibrosis.

MATERIALS AND METHODS

A retrospective study included 30 patients with pulmonary fibrosis: idiopathic pulmonary fibrosis (n = 25), usual interstitial pneumonia (UIP) associated with collagen vascular disease (n = 4), and UIP associated with hepatitis C (n = 1). Disease severity was determined by a computed tomography (CT) scoring system. Each patient's lobe was scored by two radiologists on a scale of 0-5 for both ground glass opacity (GGO) and fibrosis. The presence, number, and sites of enlarged nodes (short axis > or = 10 mm) were assessed. CT severity scores were compared with total number of enlarged lymph nodes (L/Ns) and short axis diameter of the largest L/N (LLN). According to each severity score, patients were divided into two groups: the GGO-predominant group (n = 10) and the fibrosis-predominant group (n = 20). Total numbers of enlarged L/Ns and short axis diameter of LLN were compared in each group.

RESULTS

Enlarged mediastinal L/Ns were present in 86%. Total severity score, GGO score, and fibrosis score strongly correlated with total number of enlarged L/Ns (p<0.05). Total severity score and GGO score correlated well with short axis diameter of LLN; however, the fibrosis score did not correlate with the short axis diameter of LLN. In respect to total number of enlarged L/Ns, the difference between the GGO group and fibrosis group was not apparent. In respect to the short axis diameter of LLN, the GGO group LLN was larger in diameter than the fibrosis group LLN (p<0.05).

CONCLUSION

The greater the severity score of pulmonary fibrosis, the larger the total number of enlarged L/Ns. Those patients with more GGO had larger lymph nodes.

Induction of apoptosis in p16INK4A mutant cell lines by adenovirus-mediated overexpression of p16INK4A protein

The tumor suppressor gene p16INK4A is a cyclin-dependent kinase inhibitor (CDKI) and an important cell cycle regulator. We have previously constructed a recombinant adenovirus which expresses p16 (Adp16) and shown that infection in a variety of human tumor cell lines with this recombinant virus results in high levels of p16INK4A protein expression resulting in cell cycle arrest and loss of cyclin-cdk activity. Furthermore, adenoviral-mediated overexpression of wild-type p16INK4A is more toxic in cancer cells which express mutant forms of p16INK4A compared to cancer cell lines containing endogenous wild-type p16. TUNEL assay and DAPI staining following infection of MDA-MB 231 breast cancer cells with Adp16 indicate that p16INK4A-mediated cytotoxicity was associated with apoptosis. This is supported by studies demonstrating a decrease in cpp32 and cyclinB1 protein levels and induction of poly (ADP-ribose) polymerase (PARP) cleavage following infection of MDA-MB-231 cells with Adp16. These results suggest that gene therapy using Adp16 may be a promising treatment option for human cancers containing alterations in p16 expression.

Synthesis and in vitro/in vivo evaluation of 5-aminosalicyl-glycine as a colon-specific prodrug of 5-aminosalicylic acid

A simple synthetic route for the preparation of amino acid conjugate of 5-aminosalicylic acid (5-ASA) was exploited and prepared 5-aminosalicyl-glycine (5-ASA-Gly) in good yield. In vitro and in vivo properties of 5-ASA-Gly as a colon-specific prodrug of 5-ASA were investigated using rats as the test animal. Incubation of 5-ASA-Gly with cecal or colonic contents at 37 degrees C released 5-ASA in 65 or 27% of the dose in 8 h, respectively. No 5-ASA was detected from the incubation of 5-ASA-Gly with the homogenates of stomach or small intestine. Plasma concentration of 5-ASA-Gly decreased rapidly after intravenous administration of 5-ASA-Gly, and no 5-ASA was detected in the blood, which indicated 5-ASA-Gly was not degraded in the plasma. After oral administration of 5-ASA-Gly, about 50% of the administered dose was recovered as 5-ASA and N-acetyl-ASA and 3% as 5-ASA-Gly from feces and 14% as 5-ASA-Gly and 28% as 5-ASA and N-acetyl-ASA from urine in 24 h. These results suggested that a large fraction of 5-ASA-Gly was delivered to the large intestine and activated to liberate 5-ASA. For comparison, total recovery of 5-ASA and N-acetyl-5-ASA from feces after oral administration of 5-ASA-Gly was greater than that from sulfasalazine, which is one of the most commonly prescribed prodrugs of 5-ASA.

Glutamate and aspartate impair memory retention and damage hypothalamic neurons in adult mice

We examined the effects of systemic administration of monosodium glutamate (MSG) or aspartate (ASP) on the memory retention and neuronal damage in the brains of adult mice. Compared with the control mice, a single intraperitoneal injection of either 4.0 mg/g MSG or 0.5 mg/g ASP after acquisition trial significantly shortened the response latency in the passive avoidance test, accompanying by the transient weight loss. Histopathological analysis of the brains of these mice revealed that neurons in the arcuate nucleus of hypothalamus were damaged markedly by MSG (4.0 mg/g) or ASP (0.5 mg/g). Other brain areas including cerebral cortex and hippocampus did not show any pathological changes. These findings suggest that systemic administration of MSG or ASP could impair memory retention and damage hypothalamic neurons in adult mice.

Synthesis and in vitro/in vivo evaluation of 5-aminosalicyl-glycine as a colon-specific prodrug of 5-aminosalicylic acid

A simple synthetic route for the preparation of amino acid conjugate of 5-aminosalicylic acid (5-ASA) was exploited and prepared 5-aminosalicyl-glycine (5-ASA-Gly) in good yield. In vitro and in vivo properties of 5-ASA-Gly as a colon-specific prodrug of 5-ASA were investigated using rats as the test animal. Incubation of 5-ASA-Gly with cecal or colonic contents at 37 degrees C released 5-ASA in 65 or 27% of the dose in 8 h, respectively. No 5-ASA was detected from the incubation of 5-ASA-Gly with the homogenates of stomach or small intestine. Plasma concentration of 5-ASA-Gly decreased rapidly after intravenous administration of 5-ASA-Gly, and no 5-ASA was detected in the blood, which indicated 5-ASA-Gly was not degraded in the plasma. After oral administration of 5-ASA-Gly, about 50% of the administered dose was recovered as 5-ASA and N-acetyl-ASA and 3% as 5-ASA-Gly from feces and 14% as 5-ASA-Gly and 28% as 5-ASA and N-acetyl-ASA from urine in 24 h. These results suggested that a large fraction of 5-ASA-Gly was delivered to the large intestine and activated to liberate 5-ASA. For comparison, total recovery of 5-ASA and N-acetyl-5-ASA from feces after oral administration of 5-ASA-Gly was greater than that from sulfasalazine, which is one of the most commonly prescribed prodrugs of 5-ASA.

Phosphatidic acid is important to the translocation of Rab3A from the cytosol to phospholipid membranes

RAB3A, a Ras-related GTP-binding protein, is found in a rat neuronal cytosol in the form of complex with RabGDI or located on the synaptic vesicles and it cycles between the cytosol and the membranes. However, the regulatory mechanism of the translocation of Rab3A has not been clearly understood. To understand the mechanism of the translocation of Rab3A from the cytosol to the membranes, we examined which membranenous phospholipid is required for the translocation of Rab3A. Phosphatidic acid (PA) was found to be required for the translocation of Rab3A to the membranes and GTPgammaS stimulated the translocation of Rab3A.

Synthesis and properties of disodium tetraethyleneglycol-bis-(alpha-carboxybenzylpenicillin)

Disodium tetraethyleneglycol-bis-(alpha-carboxybenzylpenicillin) (TEG-carbenicillin), a tetraethyleneglycol (TEG) diester of carbenicillin, was synthesized to develop a carbenicillin prodrug with enhanced acid stability for oral administration. Antimicrobial activities of TEG-carbenicillin tested against gram-negative Escherichia coli (TG-1) and gram-positive Staphylococcus aureus (ATCC-12228) and Bacillus subtilis (NA-1) were comparable to that of carbenicillin. Stability of the beta-lactam ring of TEG-carbenicillin was determined by iodometry at pH 6.8, pH 4.5, and pH 2.0 at varied time intervals and was compared to that of carbenicillin. In 26 hr, both of the compounds were stable at pH 6.8. At pH 4.5, about 41% of the carbenicillin was decomposed, while TEG-carbenicillin was not appreciably decomposed. At pH 2.0, carbenicillin was decomposed about 61% after 6 hr, while TEG-carbenicillin was decomposed about 21% during the same period.

Extracellular and cytosolic iron superoxide dismutase from Mycobacterium bovis BCG

Two forms of iron superoxide dismutase (SOD) were purified from cell extract (CE) and culture filtrate (CF) of Mycobacterium bovis BCG, respectively. The molecular weight of both enzymes was estimated to be approximately 84,000 by gel filtration, whereas that of their subunits was 21,500, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that each of purified enzymes is composed of four identical subunits. The specific activities of CE SOD and CF SOD were 3,850 and 4,040, respectively. The purified enzymes were not joined by disulfide bonds and were, to some extent, resistant to sodium dodecyl sulfate. Their activities were lost by H2O2, but not by azide and cyanide, indicating iron SODs. Enzyme activities were detectable over a broad range of pHs, from 5.0 to 9.0, and were stable for 6 months at -20 degreesC. Each value of pI was 4.5. In Western blots, both enzymes reacted with sera of tuberculosis patients, but not with normal sera. The N-terminal amino acid sequences of CE SOD and CF SOD were the same, suggesting that there is no N-terminal signal sequence.

Formation, properties and antimicrobial activities of cotton xanthate-Cu(II)-homosulfamine complex

To develop a cotton derivatives with prolonged antimicrobial activities, homosulfamine (Hs) was coupled to cotton xanthate (CX) via chelate bond in the presence of Cu(II) ion by one- and two-bath processes. In one-bath process, CX was treated with Cu(II)-Hs solution. In two-bath process, CX was treated with Cu(II) ion solution to produce CX-Cu(II) complex, which was isolated and treated in turn with Hs solution. Effects of concentration, Cu(II)/Hs ratio, and pH on the binding of Hs were investigated at 10 degrees C. In one-bath process, binding of Hs took place readily with optimum pH around 5-6. The amount of binding increased to give a maximum within 5 min and decreased slowly to establish an equilibrium within an hour. In two-bath process, binding of Hs was much lower than that of one-bath process. Release of Hs from CX-Cu(II)-Hs was investigated by batch and flow method. Antimicrobial activities of CX-Cu(II)-Hs were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli and it showed prolonged activity compared to that of free Hs.

Synthesis and evaluation of 5-aminosalicyl-glycine as a potential colon-specific prodrug of 5-aminosalicylic acid

As a new colon-specific prodrug of 5-aminosalicylic acid (5-ASA), 5-aminosalicyl-glycine (5-ASA-Gly) was prepared by a simple synthetic route in good yield. Apparent partition coefficients of 5-ASA-Gly were lower than those of 5-ASA, which determined in CHCl3/pH 6.8 buffer or n-octanol/pH 6.8 buffer system. Stability of 5-ASA-Gly by peptidases was investigated by incubation of 5-ASA-Gly with the homogenates of tissue and contents of stomach, proximal small intestine or distal small intestine of rats at 37 degrees C. 5-ASA was not detected, indicating that the prodrug was stable in the upper intestine. The amount of 5-ASA liberated from incubation of the prodrug in cecal or colonic contents of rats was about 65% or 27% in 8 hrs, respectively, which indicated that the prodrug activation took place more readily in the rat cecum whose bacterial counts are high like human colon. Results from in vitro experiments suggested 5-ASA-Gly as a promising candidate of a colon-specific prodrug of 5-ASA.

Synthesis and properties of dextran-5-aminosalicylic acid ester as a potential colon-specific prodrug of 5-aminosalicylic acid

Dextran-5-aminosalicylic acid ester (dextran-5-ASA) was synthesized as a colon-specific prodrug of 5-aminosalicylic acid (5-ASA) which is active against inflammatory bowel diseases. Chemical stability of dextran-5-ASA in the bath of pH 1.2 or 6.8 was investigated at 37 degrees C for 6 hrs, and 5-ASA was not released on such conditions. Depolymerization (%) of dextran-5-ASA by dextranase with the degree of substitution (DS) of 18, 23, or 30 was 92, 62 or 45 in 8 hrs respectively, but was not affected by the MW of dextran (9,000, 40,600, 80,200 or 580,000). Distribution of 5-ASA in dextran, determined by gel filtration chromatography, appeared to be relatively uniform. Incubation of dextran-5-ASA (DS 18) in cecal contents of rats released 20% (28 g) and 35% (49 g) of 5-ASA in 8 hrs and 24 hrs, respectively, but no 5-ASA was liberated from small intestinal contents.

Allelic deletions of MCC/APC and p53 are frequent late events in human gastric carcinogenesis

BACKGROUND/AIMS

Frequent allelic deletion affecting the mutated in colon cancer/adenomatous polyposis coli (MCC/APC) and p53 tumor suppressor gene loci has been reported in human cancers. However, simultaneous correlative analyses of these two abnormalities or their timing in gastric tumorigenesis have not been performed.

METHODS

To ascertain the relation between and timing of allelic deletions of MCC/APC and p53 in gastric carcinogenesis, 52 matched sets of normal tissue, gastric carcinoma, and adjacent gastric dysplasia were evaluated.

RESULTS

Allelic deletion was seen in 33% of informative cancers at MCC, in 34% at APC, and in 64% at p53. Losses involving MCC correlated exactly with those affecting APC. Limited mutational analysis failed to reveal point mutations in selected exons of MCC. The frequencies of allelic losses at the two loci did not differ significantly among histological types. There was no allelic loss in gastric dysplasia. Interestingly, allelic deletion at MCC/APC was never detected in tumors negative for allelic deletion of p53.

CONCLUSIONS

These results suggest that allelic deletions involving p53 and MCC/APC are common late events in gastric cancer. They also imply that allelic deletions affecting MCC/APC may not occur independently of those involving p53 in gastric tumorigenesis.