Methods to enhance tolerances of Chlorella KR-1 to toxic compounds in flue gas

Possible methods to minimize the toxic effects of SOx and NOx on the growth of a highly CO2 tolerant and fast-growing microalga, Chlorella sp. KR-1, were investigated. Maintaining the pH of the culturing media at an adequate value was quite important to enhancing the tolerances of the microalgae to SOx and NOx. Controlling the pH by adding an alkaline solution, using a low flow rate of gas fed to the culture, and using a high concentration of inoculating cells were effective methods to maintaining the proper pH of the culture. Controlling the pH was the most effective method but could be applied only for some specific microalgae.

Effect of short-term ethanol on the proliferative response of Swiss 3T3 cells to mitogenic growth factors

Both adaptive and deleterious responses of cells to ethanol are likely triggered by short-term interactions of the cells with ethanol. Many studies have demonstrated the direct effect of ethanol on growth factor-stimulated cell proliferation. Using Swiss 3T3 cells whose growth was inhibited by ethanol in a concentration-dependent manner, we further investigated the molecular mechanisms of acute ethanol treatment by examining its effect on EGF- and PDGF-mediated cellular signaling systems for the mitogenic function. Tyrosine autophosphorylation of the growth factor receptors was partially prevented by ethanol in intact cells. When ethanol was included before or after EGF stimulation, no effect on the receptor signaling was observed. Here we also report that ethanol inhibits activation of ERK induced by both EGF and PDGF. EGF-induced JNK activation was reduced but PDGF-induced rapid JNK activation was delayed by the addition of ethanol. The balance between its inhibitory and stimulatory effect on the signaling molecules might determine the rate of cell growth.

Differential activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinases by methyl methanesulfonate in the liver and brain of rats: implication for organ-specific carcinogenesis

Methyl methanesulfonate (MMS), a direct-acting alkylating agent, is a strong brain carcinogen but a poor hepatocarcinogen in rats. To elucidate the mechanism(s) leading to tissue-specific carcinogenesis in response to MMS, we compared the activation of the stress-activated protein kinases (SAPKs), the c-Jun NH2-terminal kinase (JNK) and p38, in the liver and brain of rats after i.p. injection of MMS. p38 was activated in both the liver and brain, but JNK was activated only in the liver in a dose- and time-dependent manner. The activation of JNK was preceded by the activation of SAPK or extracellular signal-regulated protein kinase kinase 1/mitogen-activated protein kinase kinase 4 in the liver, but no activation of SAPK or extracellular signal-regulated protein kinase kinase 1/mitogen-activated protein kinase kinase 4 was observed in the brain. The activation of JNK in the liver was accompanied by increased phosphorylation of activating transcription factor 2 and followed by an increase in the phosphorylation and level of c-Jun protein, in contrast to no such changes in the brain. To study the physiological consequences of these differential molecular events in the liver and brain, we examined MMS-induced apoptosis, a process shown to involve stress kinase activation. A significant increase in apoptotic cell death was detected in the liver but not in the brain after a MMS injection, which correlated with the patterns of JNK activation in the liver. Taken together, our results demonstrate that a tissue-specific signaling pathway(s) leading to distinct physiological responses in the liver and brain of rats exposed to MMS exists, suggesting a possible explanation for tissue-specific carcinogenic effects exerted by MMS in vivo.

Up-regulation and co-expression of fibroblast growth factor receptors in human gastric cancer

Fibroblast growth factor (FGF), a key regulatory factor of cell growth and differentiation, is involved in embryonic development, angiogenesis, and tumorigenesis. To date, four different FGF receptors (FGFRs) have been cloned and characterized. We examined the expression of four FGFRs in human gastric cancer tissues and cell lines using Northern analysis, ribonuclease protection assay, and immunohistochemistry. The mRNAs of FGFR-1 (10/14), FGFR-2 (9/14), and FGFR-4 (9/14) were up-regulated in cancer compared with normal tissues. FGFR-3 mRNAs were barely detectable in both normal and cancer tissues. These FGFR mRNAs were co-expressed in various combinations of two or three in the same tissue. Immunohistochemistry confirmed specific staining of multiple FGFRs, except FGFR-3, in the cancer specimens. To investigate the functional significance of FGFR co-expression we examined the invasive property of SNU-16 cells, which exhibited gene amplification of FGFR-2, -3, and -4 as well as over-expression of keratinocyte growth factor receptor (KGFR), a splice variant of FGFR-2, and FGFR-4 mRNA. KGF plus acidic FGF (aFGF), KGF, and aFGF treatment enhanced the invasive potential of SNU-16 cells over the control by 100%, 107%, and 47%, respectively, indicating that neither additive nor synergistic effect was induced by stimulation with aFGF plus KGF. These results suggest that co-expression of FGFRs in various combinations may cause subtle changes in the progression of gastric cancer.

Reduction of UV-induced cell death in the human senescent fibroblasts

We studied mechanisms by which senescent cells acquire resistance to UV-induced cellular insults. Human primary foreskin fibroblast culture was used since it undergoes cellular senescence in vitro after a limited number of passages. Senescence was induced by a brief treatment of the early passage cells with 100 microM of H2O2 for 1 h, and subsequent culture for 3 weeks. Hydrogen peroxide-treated cells showed an enhancement of senescence-associated beta-galactosidase activity. In the senescent cells, DNA fragmentation in response to UV-irradiation was found to decrease significantly compared with that in the young cells. The SAPK/JNK activation by UV irradiation was reduced in both non-treated senescent cells and the hydrogen peroxide-induced senescent cells, suggesting that a reduced DNA fragmentation by UV-irradiation in the senescent cells is closely related to the decreased SAPK/JNK activity. Since a cell cycle inhibitor, p21Waf1, has been implicated in protecting cells against apoptotic cell death, we determined p21Waf1 to assess whether its elevation has any impact on the reduction of UV-induced activation of SAPK/JNK in the senescent cells. The expression of p21Waf1 increased in both the nontreated and the hydrogen peroxide-treated senescent cells. Our study also revealed that the blockage of SAPK/JNK activation in the senescent cells was closely related to the increased level of p21Waf1. Our observation might provide clues about molecular mechanism of resistance to DNA fragmentation and the consequent cell death by UV-irradiation.

Senescence-like changes induced by hydroxyurea in human diploid fibroblasts

Hydroxyurea was found to inhibit the growth of human diploid fibroblasts, which resulted in senescence-like changes both in morphology and replicative potential similar to the replicative senescence. SA-beta-gal activity, a typical characteristic of the replicative senescence was also induced through a long-term treatment of the presenescent cells with 400-800 microgM of hydroxyurea for about 3 weeks. In addition, we determined the levels of cyclin-dependent kinase inhibitors, p21(Waf1) and p16(INK4a), and the p53 tumor suppressor in order to monitor its effect on cell cycle and stress responses. We observed a great induction of both p53 and p21(Waf1), but not of p16(INK4a) in the premature senescent cells. UV-irradiation of the premature senescent cells showed a decreased level of DNA fragmentation presumably ascribed to the reduced activation of stress-activated protein kinases. These results suggest that a chronic hydroxyurea treatment induces the cellular senescence in association with the induction of p53 and p21(Waf1).

Hydroxyurea induces a senescence-like change of K562 human erythroleukemia cell

Hydroxyurea, a differentiation-inducing agent of human erythroleukemia K562 cells, is commonly used to treat some types of leukemia. However, the mechanism for its therapeutic effect is not clearly understood yet. In this study, we have observed an interesting effect of hydroxyurea on tumor cells: an induction of senescence-like changes. Human erythroleukemia K562 cells, when treated with hydroxyurea for 7 days or more, underwent a change into phenotypically senescent cells together with a reduction of hemoglobin generation, a differentiation marker. The hydroxyurea-treated cells showed positive senescence associated-beta-galactosidase staining, a senescence index, and the accumulation of cdk (cyclin dependent kinase) inhibitors, such as p16INK4a, p21Waf1, and p27Kip1, implicated in cellular senescence. Nonetheless, these changes were not accompanied by DNA fragmentation. Taken together, we summarize that the long-term treatment of cancer cells with hydroxyurea can induce cellular senescence different from differentiation or programmed cell death.

Up-regulation of caveolin attenuates epidermal growth factor signaling in senescent cells

Senescent human diploid fibroblasts do not respond to growth factors like epidermal growth factor (EGF), although they have a normal level of receptors and downstream signaling molecules. To examine the mechanism of signaling attenuation, we investigated Erk activation after EGF stimulation in senescent cells. Senescent cells did not phosphorylate Erk-1/2 after EGF stimulation, whereas young cells did. In those senescent cells, we found an increased level of caveolin proteins and strong interactions between caveolin-1 and EGF receptor. Electron microscopic analysis demonstrated an increased number of caveolae structures in senescent cells. More interestingly, brain, spleen, and lung from 26-month-old rats showed substantial increases of caveolin proteins. However, in the case of p53-induced senescence, caveolin-1 was not induced, and EGF stimulation phosphorylated Erk-1/2 as much as young control cells. Finally, we overexpressed caveolin-1 in young human diploid fibroblasts in which the activation of Erk-1/2 upon EGF stimulation was significantly suppressed. These results suggest that the unresponsiveness of senescent fibroblasts to EGF stimulation may be due to the overexpression of caveolins, which seems to be independent of growth arrest and other aging phenotypes.

BCG infection during pre-sensitization or even post-sensitization inhibits airway sensitivity in an animal model of allergic asthma

The objective of this study is to investigate whether BCG infection before, during or after sensitization suppresses allergen-induced airway hyperresponsiveness and eosinophilic inflammation in allergic asthma rats, and to determine the required dose of BCG to induce such an inhibition. Eighty-seven Sprague-Dawley (SD) rats were sensitized and provoked with ovalbumin (OA). A pretreatment of 6 x 10(4) or 6 x 10(5) colony forming units (CFUs) of BCG or saline was done at four different times: 3 days before sensitization, at sensitization, 3 days before provocation, or at provocation. The assessment of tracheal smooth muscle (TSM) responsiveness to electrical field stimulation or acetylcholine (ACh) and bronchoalveolar lavage (BAL) were performed 1 day after OA provocation. Doses of 6 x 10(4) CFUs inhibited TSM sensitivity of rats infected 3 days before sensitization or at sensitization, but not 3 days before provocation or at provocation. However, doses of 6 x 10(5) CFUs significantly inhibited not only the airway eosinophilia of rats infected 3 days before sensitization or at sensitization, but also the TSM sensitivity of rats infected 3 days before provocation or at provocation. In conclusion, BCG infection suppresses the development of sensitivity of airway smooth muscle and airway eosinophilic inflammation in allergic asthma rats. Furthermore, a relatively high dose of BCG infection inhibits airway sensitivity, even after allergen sensitization.

Isolation of bacteriophages specific to a fish pathogen, Pseudomonas plecoglossicida, as a candidate for disease control

Two types of bacteriophage specific to Pseudomonas plecoglossicida, the causative agent of bacterial hemorrhagic ascites disease in cultured ayu fish (Plecoglossus altivelis), were isolated from diseased ayu and the rearing pond water. One type of phage, which formed small plaques, was tentatively classified as a member of the family Myoviridae, and the other type, which formed large plaques, was classified as a member of the family Podoviridae. All 27 strains of P. plecoglossicida examined, which were isolated from diseased ayu from geographically different areas in 1991 to 1999, exhibited quite similar sensitivities to either type of phage. One strain of P. plecoglossicida was highly virulent for ayu, and the 50% lethal dose (LD(50)) when intramuscular injection was used was 10(1.2) CFU fish(-1); in contrast, phage-resistant variants of this organism were less virulent (LD(50), >10(4) CFU fish(-1)). Oral administration of phage-impregnated feed to ayu resulted in protection against experimental infection with P. plecoglossicida. After oral administration of P. plecoglossicida cells of this bacterium were always detected in the kidneys of control fish that did not receive the phage treatment, while the cells quickly disappeared from the phage-treated fish. Bacterial growth in freshwater was lower in the presence of phage, and the number of phage PFU increased rapidly. These results suggest that it may be possible to use phage to control the disease caused by P. plecoglossicida.

Continuous ethanol production from concentrated wood hydrolysates in an internal membrane-filtration bioreactor

Continuous culture for the production of ethanol from wood hydrolysate was carried out in an internal membrane-filtration bioreactor. The hydrolysate medium was sterilized at a relatively low temperature of 60 degrees C with the intention of reducing the formation of inhibitory compounds during the sterilization. The maximum ethanol concentration and productivity obtained in this study were 76.9 g/L and 16.9 g/L-h, respectively, which were much higher than those (57.2-67 g/L and 0.3-1.0 g/L-h) obtained in batch cultures using hydrolysate media sterilized at 60 degrees C. The productivity was also found to be much higher than that (6.7 g/L-h) obtained in a continuous cell retention culture using a wood hydrolysate sterilized at 121 degrees C. These results show that the internal membrane-filtration bioreactor in combination with low-temperature sterilization could be very effective for ethanol production from wood hydrolysate.

Establishment of a phagocytic cell line from Bombina orientalis

Continuous serum-free culture of Bok-2 cells was generated from primary culture of the tail bud stage embryos of the toad, Bombina orientalis. Bok-2 cells can be maintained in modified L-15 serum-free medium prepared by mixing L-15 medium, lactalbumin enzymatic hydrolysate, sucrose and sodium bicarbonate. Bok-2 cells have an ameboid behavior and morphology. When Bok-2 and viable Candida albicans were co-cultured, Bok-2 cells showed an immune response characterized by chemotaxis, phagocytosis and partial clearing activity of Candida cells and colonies. And Bok-2 cells also showed phagocytosis of latex beads without serum treatment and displayed numerous pseudopodia, membrane evagination for phagocytosis and phagosome activity. On the basis of these results, Bok-2 cells were identified as professional phagocytes.

Selective degradation of unfolded proteins by the self-compartmentalizing HtrA protease, a periplasmic heat shock protein in Escherichia coli

HtrA, which has a high molecular mass of about 500 kDa, is a periplasmic heat shock protein whose proteolytic activity is essential for the survival of Escherichia coli at high temperatures. To determine the structural organization of HtrA, we have used electron microscopy and chemical cross-linking analysis. The averaged image of HtrA with end-on orientation revealed a six-membered, ring-shaped structure with a central cavity, and its side-on view showed a two-layered structure. Thus, HtrA behaves as a dodecamer consisting of two stacks of hexameric ring. HtrA can degrade thermally unfolded citrate synthase and malate dehydrogenase but cannot when in their native form. HtrA degraded partially unfolded casein more rapidly upon increasing the incubation temperature. However, it hydrolyzed oxidized insulin B-chain, which is fully unfolded, at nearly the same rate at all of the temperatures tested. HtrA also rapidly degraded reduced insulin B-chain generated by treatment of insulin with dithiothreitol but not A-chain or intact insulin. Moreover, HtrA degraded fully unfolded alpha-lactalbumin, of which all four disulfide bonds were reduced, but not the native alpha-lactalbumin and its unfolded intermediates containing two or three disulfide bonds. These results indicate that unfolding of the protein substrates, such as by exposure to high temperatures or reduction of disulfide bonds, is essential for their access into the inner chamber of the double ring-shaped HtrA, where cleavage of peptide bonds may occur. Thus, HtrA with a self-compartmentalizing structure may play an important role in elimination of unfolded proteins in the periplasm of Escherichia coli.

Complications of endomyocardial biopsy in children

OBJECTIVES

To evaluate the incidence of, and risk factors for, complications of endomyocardial biopsy in children.

BACKGROUND

Endomyocardial biopsy (EMB) is a low risk procedure in adults, but there is a paucity of data with regard to performing this procedure in children.

METHODS

Retrospective review of the morbidity and mortality of 1,000 consecutive EMB procedures.

RESULTS

One thousand EMB procedures (right ventricle 986, left ventricle 14) were performed on 194 patients from July 1987 through March 1996. Indications for EMB included heart transplant rejection surveillance (846) and the evaluation of cardiomyopathy or arrhythmia for possible myocarditis (154). Thirty-seven (4%) procedures were performed on patients receiving intravenous inotropic support. There was one biopsy related death, secondary to cardiac perforation, in a two-week-old infant with dilated cardiomyopathy. There were nine perforations of the right ventricle, eight occurring in patients with dilated cardiomyopathy and one in a transplant recipient. The transplant patient did not require immediate intervention; two patients required pericardiocentesis alone, and six underwent pericardiocentesis and surgical intervention. All nine perforations were from the femoral venous approach (p < 0.01). Multivariate analysis demonstrated that the greatest risk of perforation occurred in children being evaluated for possible myocarditis (p = 0.01) and in those requiring inotropic support (p < 0.01). Other complications included arrhythmia (5) and single cases of coronary-cardiac fistula, flail tricuspid leaflet, pneumothorax, hemothorax, endocardial stripping and seizure.

CONCLUSIONS

Risk of endomyocardial biopsy is highest in sick children with suspected myocarditis on inotropic support. However, EMB can be performed safely with very low morbidity in pediatric heart transplant recipients.

Comparative enzymatic hydrolysis of phytate in various animal feedstuff with two different phytases

Bacillus amyloliquefaciens DS11 phytase (DS11 phytase) and Aspergillus ficuum phytase (AF phytase) activities were investigated by measuring the release of phosphate from phytate in animal feedstuff such as wheat bran, corn meal, soybean meal and rice flour at pH 5 and 7. In all the tested feedstuff, the enzymatic activity of DS11 phytase was more active at pH 7, but that of AF phytase was more active at pH 5. From these results, the phytate in the gastrointestinal tract could be degraded in the small intestine or stomach by DS11 or AF phytase, respectively. In conclusion, the results presented in this paper indicated that different combination ratios of DS11 and AF phytase, depending on the kind of feedstuff, might effectively induce more enzymatic activity both in the stomach and small intestine in terms of the pH of the gastrointestinal tract.

Common mutation of plasminogen detected in three Asian populations by an amplification refractory mutation system and rapid automated capillary electrophoresis

Congenital deficiency and dysfunction of plasminogen (PLG) are associated with a mild thrombotic tendency. To facilitate the genetic diagnosis of dysPLGemia, we combined an amplification refractory mutation system and rapid automated capillary electrophoresis. Two different fluorescence-labeled PLG-specific primers for exon XV were designed so that each DNA amplified by PCR showed fluorescence of a different wavelength. Single peaks were detected for the normal and the mutant Ala601 -Thr alleles, respectively. A study of 90 normal Caucasians revealed no individuals with the mutation, whereas its gene frequency was 0.021 in Japanese. This mutation was also detected in Korean and Chinese populations at gene frequencies of 0.016 and 0.015, respectively. All of the Korean and Chinese cases with the mutation had at least one haplotype I of the PLG gene, as did most Japanese cases. The high frequency of the Ala601-Thr mutation among these Asian populations may be due to the founder effect.

Regulation of selection of liver nodules initiated with N-nitrosodiethylamine and promoted with nodularin injections in fischer 344 male rats by reciprocal expression of transforming growth factor-beta1 and its receptors

To investigate how glutathione-S-transferase placental form (GST-P)+ hyperplastic nodules (HNs) are selected and to determine the driving force for progression or regression of HNs, changes in transforming growth factor-beta1 (TGF-beta) and its receptors were examined during hepatocarcinogenesis initiated by N-nitrosodiethylamine (DEN) and promoted by nodularin. The induction of TGF-beta1 expression in the GST-P+ HNs was dependent on nodularin injections for 10 wk, which started the third week after DEN initiation. The kinetics of TGF-beta1 induction during carcinogenesis were quite different from that of simple regeneration after partial hepatectomy (PH): hepatocytes initiated with DEN alone induced TGF-beta1 expression for 24 d, and subsequent stimulation by PH on the fourteenth day after DEN initiation super-induced TGF-beta1 mRNA (50 times that of the control level), as opposed to a transient expression for less than 5 d by PH alone. GST-P+ HNs did not express TGF-beta receptors I (RI) and II (RII) during the early stage of carcinogenesis, whereas the surrounding hepatocytes strongly expressed both of these receptors. On cessation of nodularin injection, however, the expression of RI and RII in the HNs changed significantly: RII+ nodules appeared, and the number and area of RII+/- nodules were significantly increased at 10 wk after the cessation. These findings indicate that induction of TGF-beta expression in GST-P+ HNs might be a strong selection pressure that allows outgrowth of RII- nodules during liver carcinogenesis.

Effect of nodularin on the expression of glutathione S-transferase placental form and proliferating cell nuclear antigen in N-nitrosodiethylamine initiated hepatocarcinogenesis in the male Fischer 344 rat

The tumor-promoting effect of nodularin during carcinogenesis was investigated. Male Fischer 344 rats were injected with nodularin for 10 weeks from week 3 after N-nitrosodiethylamine initiation without partial hepatectomy. Rats were further maintained for 10 weeks after the cessation of nodularin and were periodically killed. In contrast to the minimal foci in the DEN and nodularin alone groups, treatment with DEN and nodularin produced four kinds of nodules with eosinophilic, clear, mixed and basophilic cells. After the cessation of nodularin, the maximally increased number, but not the area, of glutathione S-transferase placental form-positive [GST-P(+)] nodules at week 12 decreased significantly and the appearance of two types of hyperplastic nodules was noted by GST-P immunostaining; homogeneously stained dense nodules (DN) and heterogeneously stained pale nodules (PN), which appeared only after the cessation of nodularin. DN were well circumscribed by enzyme-altered cells, as opposed to poorly in PN. Moreover, normal-appearing hepatocytes replaced the enzyme-altered cells in PN. In contrast to the higher PCNA index in GST-P(+) DN, the background level returned to that of the control at week 15. PCNA indices in DN were significantly higher than in PN, which were still higher than the control, indicating that nodularin affected the PCNA index differentially in the altered and unaltered hepatocytes. However, nodularin without DEN initiation significantly increased the PCNA index through initial cell death and subsequent hepatocyte proliferation. These results suggest that: (i) nodularin has a promoting effect by inducing hepatocyte proliferation in both enzyme-altered hyperplastic nodules and the surrounding parenchyma; (ii) proliferation is transient in background cells but not in enzyme-altered hepatocytes; (iii) GST-P(+) DN can be regarded as progressive and GST-P(+) PN as regressive, revealed by both immunohistochemistry and PCNA index.

Two-phase methanization of food wastes in pilot scale

A 5 ton/d pilot scale two-phase anaerobic digester was constructed and tested to treat Korean food wastes in Anyang city near Seoul. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert materials such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons, and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 d space time at pH of about 6.5. The second, methanization reactor converted the acids into methane with pH between 7.4 and 7.8. The space time for the second reactor was 15 d. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady-state operation with the maximum organic loading rate of 7.9 kg volatile solid (VS)/m3/d and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about 230 m3 of biogas with 70% (v/v) of methane and 80 kg of humus. This process is extended to full-scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

Comparison of verapamil and felodipine treatment on lipid and glucose metabolism in obese female SHHF/Mcc-facp rats

Calcium channel blockers, verapamil or felodipine, were given to genetically obese 6 and 11-month-old female SHHF/Mcc-facp (SHHF: Spontaneous Hypertension Heart Failure) rats for 8 weeks to investigate their effects on glucose and lipid metabolism and obesity. Both antihypertensive agents significantly decreased systolic blood pressure. In 11-month-old rats, verapamil treatment significantly decreased body weight after 4 weeks whereas with felodipine it was only significantly reduced after 8 weeks. In 6-month-old rats, verapamil significantly curtailed body weight gain. Subcutaneous fat depots were smaller, and abdominal fat depots were larger in verapamil rats compared to felodipine or control rats. Oral glucose tolerance tests in the 6-month-old verapamil and the 11-month-old felodipine groups showed improved glucose tolerance compared to their respective control groups. After 8 weeks of treatment, fasting plasma glucose levels were lower in 6-month-old verapamil rats compared to felodipine and control rats and were decreased by both verapamil and felodipine treatments as compared to control in 11-month-old rats. During the oral glucose tolerance test in 6-month-old rats, both fasting plasma insulin and the area under the insulin curve were increased in verapamil compared to both control and felodipine groups. When compared to controls, plasma cholesterol was increased by verapamil in both age groups, but was significantly decreased by felodipine after 8 weeks of treatment in the 11-month-old group. Plasma triglycerides increased in all control rats compared to initial levels; however, verapamil and felodipine groups showed lower triglycerides in both age groups. In 6-month-old rats, the percentages of plasma HDL significantly increased in both treatment groups as compared to control. This study shows that verapamil and felodipine depressed body weight gain in the young rats, reduced body weight in the old rats, improved lipid parameters and glucose tolerance, but had the opposite effects on body fat distribution and insulin levels in obese female SHHF rats.

A randomized comparison of prism adaptation and augmented surgery in the surgical management of esotropia associated with hypermetropia

OBJECTIVE

To compare both motor and sensory surgical outcomes for patients with esotropia associated with hypermetropia managed with an augmented surgery based on the average of the near deviation with and without correction vs preoperative prism adaptation.

METHODS

Forty-three patients with esotropia associated with hypermetropia entered a randomized prospective evaluation of augmented surgery (group A, 27 patients) versus prism adaptation (group P, 16 patients). The formula for augmenting the amount of the rectus muscle recession was based on the average of the near deviation with and without correction in group A, and the prism-adapted angle of deviation in group P.

RESULTS

In group A, postoperative deviations of 8 prism diopters (delta) or less at distance and at near were achieved in 24 patients (88%), and in 22 patients (81%), respectively. In nine prism responder patients, postoperative deviations of 8 delta or less at distance and at near were achieved in eight patients (89%). In seven nonresponder patients, postoperative deviations of 8 delta or less at distance and at near were achieved in six patients (86%). No significant difference between the two groups in terms of near and distance deviation at 1 and 3 months postoperatively were noted.

CONCLUSION

No significant difference existed in the motor outcomes between the two groups, or between the prism responder and prism nonresponder groups. Further detailed studies must be made in a large number of patients.

Hydrogen peroxide mediates doxorubicin-induced transglutaminase 2 expression in PC-14 human lung cancer cell line

Increased expression of Transglutaminases 2 (TGase 2, TGase C) was observed in PC-14 human lung cancer cells in association with doxorubicin resistance and the reduction of the enzyme expression was correlated with the increasing cytotoxicity of the drug (Han and Park, 1999). Hydrogen peroxide was suggested to be a key mediator for doxorubicin-induced DNA fragmentation leading to apoptosis. A possible role of hydrogen peroxide as a putative mediator of TGase 2 expression in the doxorubicin sensitive PC-14 cells was examined. TGase 2 expression was increased in PC-14 cells treated with doxorubicin in a dose-dependent manner resulting in the concomitant increase of reactive oxygen species. The rise of TGase 2 expression by doxorubicin treatment was inhibited by N-acetylcysteine or glutathione treatment, while direct addition of hydrogen peroxide to PC-14 cells induced TGase 2 expression. These results suggest that generation of hydrogen peroxide induced by doxorubicin treatment is one of the key factors in an enhancement of TGase 2 expression in PC-14 cells.