Combined therapy with deferiprone and desferrioxamine successfully regresses severe heart failure in patients with beta-thalassemia major

Cardiac complications caused by iron deposition are major causes of death in patients with beta-thalassemia major. Deferiprone (L1) was found to have greater efficacy at depleting myocardial iron than desferrioxamine (DFX). Furthermore, combined therapy with L1 and DFX produced an additive or synergistic iron chelating effect. We report the successful treatment of severe heart failure in two patients with beta-thalassemia major with the combined therapy. Magnetic resonance images showed a marked recovery of signal intensity in the heart, indicating a significant reduction of iron load in the heart. No significant adverse effects were noted. Therefore, combined therapy with L1 and DFX should be considered in patients with beta-thalassemia major and cardiac complications.

Nitrification of high strength ammonia wastewater and nitrite accumulation characteristics

Biological nitrogen removal via the nitrite pathway in wastewater treatment is very important in saving the cost of aeration and as an electron donor for denitrification. Wastewater nitrification and nitrite accumulation were carried out in a biofilm airlift reactor with autotrophic nitrifying biofilm. The biofilm reactor showed almost complete nitrification and most of the oxidized ammonium was present as nitrite at the ammonium load of 1.5 to 3.5 kg N/m3 x d. Nitrite accumulation was stably achieved by the selective inhibition of nitrite oxidizers with free ammonia and dissolved oxygen limitation. Stable 100% conversion to nitrite could also be achieved even under the absence of free ammonia inhibition on nitrite oxidizers. Batch ammonium oxidation and nitrite oxidation with nitrite accumulating nitrifying biofilm showed that nitrite oxidation was completely inhibited when free ammonia is higher than 0.2 mg N/L. However, nitrite oxidation activity was recovered as soon as the free ammonia concentration was below the threshold level when dissolved oxygen concentration was not the limiting factor. Fluorescence in situ hybridization analysis of cryosectioned nitrite accumulating nitrifying biofilm showed that the beta-subclass of Proteobacteria, where ammonia oxidizers belong, was distributed outside the biofilm whereas the alpha-subclass of Proteobacteria, where nitrite oxidizers belong, was found mainly in the inner part of the biofilm. It is likely that dissolved oxygen deficiency or limitation in the inner part of the nitrifying biofilm, where nitrite oxidizers exist, is responsible for the complete shut down of the nitrite oxidizers activity under the absence of free ammonia inhibition.

Nitrifying microbial community analysis of nitrite accumulating biofilm reactor by fluorescence in situ hybridization

Biological nitrogen removal via nitrite pathway in wastewater treatment is very important especially in the cost of aeration and as an electron donor for denitrification. Wastewater nitrification and nitrite accumulations were carried out in a biofllm reactor. The biofilm reactor showed almost complete nitrification and most of the oxidized ammonium was present as nitrite at the ammonium load of 1.2 kg N/m3/d. Nitrite accumulation was achieved by the selective inhibition of nitrite oxidizers by free ammonia and oxygen limitation. Nitrite oxidation activity was recovered as soon as the inhibition factor was removed. Fluorescence in situ hybridization studies of the nitrite accumulating biofilm system have shown that genus Nitrosomonas which is specifically hybridized with probe NSM156 was the dominant nitrifying bacteria while Nitrospira was less abundant than those of normal nitrification systems. Further FISH analysis showed that the combinations of Nitrosomonas and Nitrospira cells were identified as important populations of nitrifying bacteria in an autotrophic nitrifying biofilm system.

Combined Fenton-MF process increases acrylonitrile removal

The Fenton oxidation process is possessed of the advantages of both oxidation and coagulation processes. In addition to these functions, Fenton's reagent is also a typical initiator of polymerization. The application of the Fenton-microfiltration process for removal of acrylonitrile (AN), which is the major raw material for manufacturing ABS reins, was investigated. As for Fenton oxidation, in the range of pH 2 to pH 4, AN removal efficiency increased as the pH increased. In experiment of the same initial molar ratio of [FeSO4]0/[H2O2]0, the higher dosage can obtain the higher removal efficiency. At pH 4, the AN removal increased as the [H2O2]0 increased for each [FeSO4]0. Acrylic acid and acrylamide were detected in the solution after Fenton oxidation. On the other hand, acrylamide, polyacrylamide, and polyacrylic acid exist in the precipitate after the Fenton oxidation of AN solution. Moreover, it was also found that the operational mode is an important factor of the combined Fenton-MF process.

Imaging features of ischial bursitis with an emphasis on ultrasonography

OBJECTIVE

The aim of this study was to evaluate the imaging features of ischial bursitis with an emphasis on ultrasonography (US).

DESIGN AND PATIENTS

Our study included 31 patients with a painful mass or tenderness in their buttock who underwent US (n=27), CT (n=1), or MR imaging (n=4). A needle aspiration (n=6) or a bursal excision (n=5) was performed in those patients who had no clinical improvement in spite of the conservative treatment. Evaluation included lesion location, size, wall of the bursae, and intrinsic characteristics on US, CT and MR imaging.

RESULTS

Ischial bursitis was superficial to the ischial tuberosity in all patients (n=31). The lesion ranged from 1.5 cm to 7 cm (average 3.8 cm) in diameter. The bursal wall was identifiable in 25 cases (81%). Internal septa and mural nodules were seen in 12 (39%) and 17 cases (55%), respectively. Sonography showed that fluid within the bursa was hypoechoic (59%), hyperechoic (26%), or of mixed echogenicity (15%). The bursae were compressible by the transducer. Power Doppler examination (n=7) showed hypervascularity of the bursal wall. All lesions imaged with contrast-enhanced CT and MR imaging had an enhancing thin wall and mural nodule.

CONCLUSIONS

Ischial bursitis, superficial to the ischial tuberosity, can be clearly demonstrated on sonography and appears as a thin-walled cystic lesion, with or without internal septa and mural nodules.

Antileukemic activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb

To evaluate the anti-leukemic activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb., cytotoxicity tests with an XTT-based colorimetric assay were used. Five leukemic cell lines, namely L1210, U937, K562, Raji and P3HR1, were cultured with hot water extracts of B. pilosa var. minor or H. cordata. Hot water extracts of B. pilosa var. minor inhibited these five leukemic cells with IC50s between 145 microg/ml and 586 microg/ml. The effect was greatest on four cell lines, namely L1210, P3MR1, Raji and K562, with IC50s below 200 microg/ml and a selective index of more than 5. Hot water extract of H. cordata inhibited these five leukemic cells with IC50s between 478 microg/ml and 662 microg/ml. The selective index was between 1.5 and 2.1. B. pilosa var. minor was more effective than H. cordata in inhibiting most of the leukemic cells in our study. We suggest that B. pilosa L. var. minor (Blume) Sherff may prove to be a useful medicinal plant for treating leukemia.

Kinetics of hydrogen production with continuous anaerobic cultures utilizing sucrose as the limiting substrate

In this study, local sewage sludge was acclimated to establish H2-producing enrichment cultures, which were used to convert sucrose to H2 with continuously stirred anaerobic bioreactors. The steady-state behaviors of cell growth, substrate utilization, and product formation were closely monitored. Kinetic models were developed to describe and predict the experimental results from the H2-producing cultures. Operation at dilution rates (D) of 0.075-0.167 h(-1) was preferable for H2 production, resulting in a H2 concentration of nearly 0.02 mol/l. The optimal hydrogen production rate was 0.105 mol/h occurring at D=0.125 h(-1). The major volatile fatty acid produced was butyric acid (HBu), while acetic acid and propionic acid were also produced in lesser quantities. The major solvent product was ethanol, whose concentration was only 15% of that of HBu, indicating that the metabolic flow favors H2 production. The proposed model was able to interpret the trends of the experimental data. The maximum specific growth rate (mu(max)), Monod constant (Ks), and yield coefficient for cell growth (Y(x/s)) were estimated as 0.172 h(-1), 68 mg COD/l, and 0.1 g/g, respectively. The model study also suggests that product formation in the continuous hydrogen-producing cultures was essentially a linear function of biomass concentration.

Bcl-2 overexpression attenuates resveratrol-induced apoptosis in U937 cells by inhibition of caspase-3 activity

Resveratrol has been shown to induce anti-proliferation and apoptosis of human cancer cell lines. In the present study, we determined the effect of high intracellular levels of the anti-apoptosis protein Bcl-2 on caspase-3 activation, PLC-gamma1 degradation and cytochrome c release during resveratrol-induced apoptosis. For this, we used U937/vector and U937/Bcl-2 cells, which were generated by transfection of the cDNA of the Bcl-2 gene. As compared with U937/vector, U937/Bcl-2 cells exhibited a 4-fold greater expression of Bcl-2. Treatment with 60 or 100 microM resveratrol for 24 h produced morphological features of apoptosis and DNA fragmentation in U937/vector cells, respectively. This was associated with caspase-3 activation and PLC-gamma1 degradation. In contrast, resveratrol-induced caspase-3 activation and PLC-gamma1 degradation and apoptosis were significantly inhibited in U937/Bcl-2 cells. Bcl-2 overexpressing cells exhibited less cytochrome c release and sustained expression levels of the IAP proteins during resveratrol-induced apoptosis. In addition, these findings indicate that Bcl-2 inhibits resveratrol-induced apoptosis by a mechanism that interferes with cytochrome c release and activity of caspase-3 that is involved in the execution of apoptosis.

Neoplastic transformation and tumorigenesis associated with overexpression of phospholipase D isozymes in cultured murine fibroblasts

Phospholipase D (PLD) has been suggested to play an important role in a variety of cellular functions. PLD activity has been shown to be significantly elevated in many tumours and transformed cells, suggesting the possibility that PLD might be involved in tumorigenesis. In this study, we have established stable cell lines overexpressing PLD1 and PLD2 from fibroblast cells. These cells, but not control cells, showed altered growth properties and anchorage-independent growth in soft agar. Both PLD1 and PLD2 also induced an up-regulation of the activity of matrix metalloprotease-9 as detected by zymograms. Furthermore, both PLD1 and PLD2 transformants, but not vector-transfectants, induced undifferentiated sarcoma when transplanted into nude mice. Both PLD1- and PLD2-mediated cell cycle distributions in stable cell lines revealed an increased fraction of cells in the S phase compared with control cells. Interestingly, the level of cyclin D3 protein, known as an activator of G(1) to S phase transition in the cell cycle, was aberrantly high in cells overexpressing PLD1 and PLD2 compared with control cells. These results suggest that overexpression of PLD isozymes may play an important role in neoplastic transformation.

Functioning of the Drosophila orb gene in gurken mRNA localization and translation

The orb gene encodes an RNA recognition motif (RRM)-type RNA-binding protein that is a member of the cytoplasmic polyadenylation element binding protein (CPEB) family of translational regulators. Early in oogenesis, orb is required for the formation and initial differentiation of the egg chamber, while later in oogenesis it functions in the determination of the dorsoventral (DV) and anteroposterior axes of egg and embryo. In the studies reported here, we have examined the role of theorb gene in the gurken (grk)-Drosophila epidermal growth factor receptor (DER) signaling pathway. During the previtellogenic stages of oogenesis, the grk-DER signaling pathway defines the posterior pole of the oocyte by specifying posterior follicle cell identity. This is accomplished through the localized expression of Grk at the very posterior of the oocyte. Later in oogenesis, thegrk-DER pathway is used to establish the DV axis. Grk protein synthesized at the dorsal anterior corner of the oocyte signals dorsal fate to the overlying follicle cell epithelium. We show that orb functions in both the early and late grk-DER signaling pathways, and in each case is required for the localized expression of Grk protein. We have found thatorb is also required to promote the synthesis of a key component of the DV polarity pathway, K(10). Finally, we present evidence that Orb protein expression during the mid- to late stages of oogenesis is, in turn, negatively regulated by K(10).

Kinetic characteristics of bacterial azo-dye decolorization by Pseudomonas luteola

A Pseudomonas luteola strain expressing azoreductase activity was utilized to remove the color of an azo dye (reactive red 22) from contaminated solutions. The effects of substrate concentrations, medium compositions, and operation parameters (e.g., pH, temperature, dissolved oxygen, etc.) on decolorization of the azo dye by a P. luteola strain were systematically investigated to reveal the key factors that dominate the performance of azo-dye decolorization. The metabolites resulting from bacterial decolorization were analyzed by high-performance liquid chromatography (HPLC) and mass spectrometery (MS). The results show that the dissolved oxygen and glucose concentration retarded decolorization of reactive red 22 by P. luteola. The optimal azo-dye decolorization occurred at 37 degrees C, while more rapid decolorization took place over pH 7-9. Yeast extract and tryptone strongly enhanced the decolorization. The Michaelis-Menten model can satisfactorily describe the dependence of specific decolorization rate on the concentration of substrate (reactive red 22 or yeast extract). Decolorization of the azo dye by intact cells of P. luteola was essentially independent of the growth phase, whereas the azoreductase activity of the cell-free extract decreased in the order of late-stationary phase > early-stationary phase > mid-log phase. This suggests that mass transfer of the azo dye across the cell membrane may be the rate-limiting step. The HPLC and MS analyses suggest that both partial reduction and complete cleavage of the azo bond could contribute to decolorization of reactive red 22 by P. luteola.

Evaluation of percutaneous absorption and skin irritation of ketoprofen through rat skin: in vitro and in vivo study

The influences of different mechanisms of penetration enhancers (such as menthol, azone, ethanol and nonivarnide) regarding the percutaneous absorption and skin irritation of ketoprofen formulations through rat skin were investigated by in vitro and in vivo study. The skin irritation degree at the end of the experiment (10 h) was deterinined by pathologic biopsy and colorimetry methods. In vitro, the menthol showed the most potent enhancing effect. Furthermore, the enhancement effect of a combination of menthol and nonivamide was higher than that of their individual use alone. In vivo the formulation containing 0.05% nonivantide, 5% menthol and 20% ethanol showed a higher penetration rate and an acceptable degree of skin irritation compared to a commercial product (Formax plus gel containing 3% ketoprofen), indicating that it could be used in the clinical situation.

Altered expression of phospholipase D1 in spontaneously hypertensive rats

To clarify the involvement of phospholipase D (PLD) in the mechanism underlying genetically-induced hypertension, we investigated the activity and expression levels of PLD in tissues taken from spontaneously hypertensive rats (SHR), and their normotensive controls, Wistar-Kyoto rats (WKY). The ADP-ribosylation factor 3 (ARF3)-dependent PLD activity and protein levels of PLD1 from SHR increased significantly in the brain and liver, but not in the heart and kidney, compared to those of WKY. The activity and expression of PLD were the same between the homogenated whole kidneys of the two strains; however, there were topographical differences in the expression and activity of PLD between the kidneys of the two strains. The activity and expression level of PLD gradually increased from the cortex to the inner medulla of WKY. The enzyme activity, and amount of PLD in the inner stripe of the outer medulla and in the inner medulla, was significantly lower in SHR than in WKY. Taken together, these results suggest that the distinctly distributed patterns of PLD in the kidney may be associated with differential signal transduction pathways that are involved in hypertension in conjunction with an increase of PLD activity in the brain and liver.

Comparative studies on the GABA-transaminase immunoreactivity in rat and gerbil brains

Gamma-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the central nervous system (CNS). Degradation of GABA in the CNS is catalyzed by the action of GABA transaminase (GABA-T). However, the neuroanatomical characteristics of GABA-T in the gerbil, which is a useful experimental animal in neuroscience, are still unknown. Therefore, we performed a comparative analysis of the distribution of GABA-T in rat and gerbil brains using immunohistochemistry. GABA-T immunoreactive neurons were observed in the regions which contained GABAergic neurons of both animals: corpus striatum; substantia nigra, pars reticulata; septal nucleus; and accumbens nucleus. GABA-T + neurons were restricted to layers III and V in the rat. Unlike the rat GABA-T + neurons were observed in layers II, III, and V of the gerbil cerebral cortex. These results suggest that the expression of GABA-T in the gerbil brain may be similar to that in the rat brain, except in the cerebral cortex.

Development of Th1-mediated CD8+ effector T cells by vaccination with epitope peptides encapsulated in pH-sensitive liposomes

There have been many studies for tumor therapy mediated by cytotoxic T lymphocytes (CTL) that recognize tumor-associated antigen. It is generally accepted that CTL responses are induced when antigen is delivered into the cytosol. The pH-sensitive liposomes as vehicles are well known for their capacity to deliver the antigen into the cytosol. In this work, immunization of mice with CTL epitope peptides from Hantaan nucleocapsid protein (M6) or human papilloma virus E7 encapsulated in pH-sensitive liposomes induced effective antigen-specific CTL responses. The CTL responses induced by M6 peptide encapsulated in pH-sensitive liposomes blocked the formation of tumor mass from Hantaan NP transfected B16 melanoma cells in C57BL/6 mice and delayed the growth of preinoculated melanoma cells. During the blockade of the tumor growth, the CTL response was maintained for at least approximately 6 weeks, and the mice secreted Th1 type cytokines such as IL-2 and IFN-gamma. These results suggested that the pH-sensitive liposomes might provide an effective peptide delivery system for CTL-mediated tumor therapy.

Nitrogen removal from sewage by continuous flow SBR system with intermittent aeration

A continuous-flow sequential batch reactor system with intermittent aeration known as the intermittent cycle extended aeration system was used to investigate the efficiencies of nitrogen removal for sewage. In the conventional intermittent cycle extend aeration system with continuous aeration process to treat the synthetic sewage wastewater under 3 cycles per day (cycle time = 8 hours), high COD removal efficiencies were achieved, but high levels of nitrate (22.3-23.6 mg l-1) and decreased pH values were also found in the effluent. In the intermittent aeration, the dissolved oxygen in the reactor was reduced from the range of 3.5-5.0 mg l-1 to 0.5-1.2 mg l-1, the nitrogen in the influent was partially oxidized to nitrite-nitrogen, although nitrate-nitrogen was also present in the effluent. In detailed cyclic study of the reactor with relatively low D.O. (0.3-1.0 mg l-1) and high MLSS (3200 mg l-1 at half full water level), the experimental results of intermittent aeration processes showed higher oxidation rates of ammonia to nitrite (1.44-3.55 mg N g-1 MLSS hr-1) than the conversion rates of nitrite to nitrate (0.00-1.22 mg N g-1 MLSS hr-1). It was thus, concluded that denitrification rates were not affected by the limited supplement of soluble organic carbon in the system. In addition, NOx(-)-N could be removed with a total nitrogen removal rate up to 94.9% when the MLSS was controlled in concentrations of 3200 mg l-1 at half full water level with low D.O. The process of intermittent aeration of ICEAS could provide an economic and effective means for nitrogen removal in treating sewage.

Biodegradation of phenanthrene in river sediment

The aerobic biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower biodegradation rates occurred at higher concentrations. Optimal biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene biodegradation during a 12-day incubation period.

An autoregulatory feedback loop directs the localized expression of the Drosophila CPEB protein Orb in the developing oocyte

The RRM-type RNA binding protein Orb plays a central role in the establishment of polarity in the Drosophila egg and embryo. In addition to its role in the formation and initial differentiation of the egg chamber, orb is required later in oogenesis for the determination of the dorsoventral (DV) and anteroposterior (AP) axes. In DV axis formation, Orb protein is required to localize and translate gurken mRNA at the dorsoanterior part of the oocyte. In AP axis formation, Orb is required for the translation of oskar mRNA. In each case, Orb protein is already localized at the appropriate sites within the oocyte before the arrival of the mRNAs encoding axis determinants. We present evidence that an autoregulatory mechanism is responsible for directing the on site accumulation of Orb protein in the Drosophila oocyte. This orb autoregulatory activity ensures the accumulation of high levels of Orb protein at sites in the oocyte that contain localized orb message.

The unfolded protein response represses nitrogen-starvation induced developmental differentiation in yeast

Diploid budding yeast exhibits two developmental programs in response to nitrogen starvation, pseudohyphal growth, and sporulation. Here we show that both programs are repressed by activation of the unfolded protein response (UPR), a stress-signal transduction pathway responsible for induction of endoplasmic reticulum (ER)-resident chaperones when protein folding in the ER is impaired. Pseudohyphal growth was derepressed in ire1Delta/ire1Delta and hac1Delta/hac1Delta strains. Activation of the UPR or overexpression of the transcription factor Hac1(i)p, the product of an unconventional splicing reaction regulated by the UPR, was sufficient for repression of pseudohyphal growth and meiosis. HAC1 splicing occurred in a nitrogen-rich environment but ceased rapidly on nitrogen starvation. Further, addition of ammonium salts to nitrogen-starved cells was sufficient to rapidly reactivate HAC1 splicing. We propose that high translation rates in a nitrogen-rich environment are coupled to limited protein unfolding in the ER, thereby activating the UPR. An activated UPR then represses pseudohyphal growth and meiosis. Nitrogen starvation slows translation rates, allowing for more efficient folding of nascent polypeptide chains, down-regulation of the UPR, and subsequent derepression of pseudohyphal growth and meiosis. These findings significantly broaden the range of physiological functions of the UPR and define a role for the UPR in nitrogen sensing.

Frequency and characterization of platelet-specific antibodies in patients who received multiple platelet transfusions

BACKGROUND AND PURPOSE

Multiple platelet transfusions may induce alloimmunization. Platelet alloimmunization involves human leukocyte antigen (HLA) antibodies and platelet-specific antibodies, which recognize platelet glycoproteins. No data are available about the frequency and characteristics of platelet-specific antibodies in patients who have received multiple platelet transfusions in Taiwan.

METHODS

From June through December 1998, blood samples from 103 patients who had received multiple platelet transfusions were submitted to our laboratory for examination of platelet antibodies. The samples were first screened for HLA antibodies or platelet-specific antibodies using a solid phase method. Positive sera were further tested using an enzyme-linked immunosorbent assay (ELISA) to identify the specificities of the alloantibodies.

RESULTS

Forty of the 103 patients who had received multiple platelet transfusions were positive for platelet-reactive antibodies. Further study using ELISA showed that 22 patients had both HLA and platelet-specific antibodies, 12 patients had HLA antibodies alone, and five patients produced platelet-specific antibodies in the absence of HLA antibodies. Most platelet-specific antibodies were found among patients who had HLA antibodies: 81% of platelet-specific antibodies were found in HLA-immunized patients. The most frequently involved platelet glycoprotein antigens were Ia/IIa and IIb/IIIa.

CONCLUSIONS

HLA antibodies were the most frequently found platelet-reactive antibodies in Taiwanese patients who had received multiple transfusions, although platelet-specific antibodies were also common. The frequency of platelet-specific antibodies was not as low as previously reported.

Evaluation of pharmacokinetics and pharmacodynamics of captopril from transdermal hydrophilic gels in normotensive rabbits and spontaneously hypertensive rats

The purpose of this investigation was to assess the pharmacokinetics (plasma concentration) and pharmacodynamics (heart rate, blood pressure (BP), and plasma renin activity (PRA)) of captopril experimental gel in normotensive rabbits and spontaneously hypertensive rats (SHRs) by reference to a short duration intravenous administration of the drug. In normotensive rabbits, the blood concentration versus time course of captopril after transdermal administration could be described well by a two-compartment model, and the maximum plasma concentration (5. 68+/-2.05 microg ml(-1)) was achieved in about 7 h. The increase in plasma captopril concentration led to increases in PRA and reductions in BP. A simple E(max) model adequately described the relationship between the percentage change of mean blood pressure (MBP) and the blood concentration of the captopril. The maximum reduction in MBP (E(max)) was 36.23% and the concentration at half maximum effect (EC(50)) was 0.24 microg ml(-1). The captopril was continuously released from the gel formulation and protected the SHRs in lower BP throughout the period of transdermal therapy. These results indicated that the development of captopril transdermal drug delivery system was possible. Further research was warranted on a modified formulation of captopril, which was optimized for transdermal delivery of the drug.

Elevation of the gamma-aminobutyric acid transaminase expression in the gerbil CA1 area after ischemia-reperfusion damage

gamma-Aminobutyric acid-transaminase (GABA-T) plays an important role in the metabolism of GABA, particularly in the neurons or glial cells. The present study was undertaken to determine the alteration of GABA-T expression in the gerbil hippocampus after ischemia-reperfusion. In the sham, GABA-T(+) neurons were scattered in the hippocampus proper and dentate gyrus. The intensity of the GABA-T immunoreactivity had nearly disappeared in the interneurons at 12 h after ischemia. In contrast, 24 h post-ischemia the dramatic augmentation of GABA-T immunoreactivity in the pyramidal cells was observed in the CA1 area but not in the CA2 or CA3 areas. Forty-eight hours after ischemia-reperfusion, its immunoreactivity was preserved in the CA1 neurons. These results suggest that the over-expression of GABA-T in the CA1 area may be related to delayed neuronal death after ischemia-reperfusion insult.

Fed-batch bioreactor strategies for microbial decolorization of azo dye using a Pseudomonas luteola strain

A Pseudomonas luteola strain possessing azoreductase activity was utilized to decolorize a reactive azo dye (C. I. Reactive Red 22) with fed-batch processes consisting of an aerobic cell growth stage and an anaerobic fed-batch decolorization stage. The fed-batch decolorization was conducted with different agitation and aeration rates, initial culture volumes, dye loading strategies, and yeast extract to dye (Y/D) ratios, and the effect of those operation parameters on azo dye decolorization was evaluated. Dissolved oxygen strongly inhibited the azo reduction activity; thus aeration should be avoided during decolorization but slight agitation (around 50 rpm) was needed. With the periodical feeding strategy, the specific decolorization rate (v(dye)) and overall decolorization efficiency (eta(dye)) tended to increase with increasing feeding concentrations of dye, whereas substrate inhibition seems to arise when the feeding concentration exceeded 600 mg dye/L. In the continuous feeding mode, higher initial culture volume resulted in better eta(dye) due to higher biomass loading, but lower v(dye) due to lower dye concentration in the bioreactor. With a volumetric flow rate (F) of 25 mL/h, both v(dye) and eta(dye) increased almost linearly with the increase in the loading rate of dye (F(dye)) over the range of 50-200 mg/h, while further increase in F(dye) (400 mg/h) gave rise to a decline in v(dye) and eta(dye). As the F was doubled (50 mL/h), the v(dye) and eta(dye) increased with F(dye) only for F(dye) < 80 mg/h. The best v(dye) (113.7 mg dye g cell(-)(1) h(-)(1)) and eta(dye) (86.3 mg dye L(-)(1) h(-)(1)) were achieved at F(dye) = 200 mg/h and F = 25 mL/h. The yield coefficient representing the relation between dye decolorized and yeast extract consumed was estimated as 0.8 g/g. With F(dye) = 75 mg/h, the Y/D ratio should be higher than 0.5 to ensure sufficient supply of yeast extract for stable fed-batch operations. However, performance of the fed-batch decolorization process was not appreciably improved by raising the Y/D ratio from 0.5 to 1.875 but was more sensitive to the changes in the dye loading rate.

The short-term effect of pentoxifylline on rabbit choroidal blood flow

This study evaluates the effect of different doses ofpentoxifylline on rabbit choroidal blood flow (CBF). Sixteen albino rabbits of both sexes, weighing 2.0-3.0 kg, were randomly separated into four groups. The first group of rabbits received 2 ml normal saline injection through the ear vein. They served as the control group (group n). Three different doses of pentoxifylline, 1 mg/kg, 5 mg/kg, and 10 mg/kg, were injected intravenously to groups p1, p5 and p10, respectively. By means of a laser Doppler flowmeter, the blood cell flux (PF), velocity, and the concentration of moving blood cells (CMBC) were recorded simultaneously. The laser probe was advanced through the pars plana and positioned near the retinal surface. The mean arterial pressure was recorded at the same time. There was a significant increase in PF at 1, 5 and 10 min in group p10 rabbits compared with the control group (p=0.0005, 0.0416, and 0.0087, respectively). The velocity increased at 5 min in group p5 rabbits (p=0.0082) and at 1, 5 and 10 min in group p10 rabbits (p=0.0188, 0.0080, and 0.0207, respectively) as compared with the controls. The CMBC decreased after injection of pentoxifylline and reached statistical significance at 5 and 10 min in group p5 rabbits (p=0.0019 and 0.0046, respectively) and at 5 min in group p10 rabbits (p=0.0447). These results show that larger doses of pentoxifylline (10 mg/kg) increased the CBF of rabbits. This effect was achieved primarily by an increase in blood cell velocity.