Effect of prolonged subcutaneous implantation of peritoneal catheter on peritonitis rate during CAPD: a prospective randomized study

We conducted a prospective randomized controlled study to confirm our earlier observation that prolonged subcutaneous implantation of peritoneal catheter reduced peritonitis rate when compared to retrospective data from patients with catheters placed by conventional access technique. A total of 60 patients were randomized into two groups: 30 patients had catheters left implanted subcutaneously for 6 weeks (I) and the other 30 patients had catheters inserted by conventional technique and had 6 weeks of break-in period (C). Subgroups of 15 patients each with new and conventional techniques used Y-connector (IY, CY) and remaining patients used standard spikes (IS, CS). Mean age was 47.7 years (range 16-71); 61.0% were male and 44.1% diabetics. Peritonitis, exit site infection, simultaneous peritonitis and exit site infection, and complication related to Staphylococcus or Pseudomonas infections were observed for up to 2 years in each patient after initiation of bag exchange or until termination of CAPD by transfer to hemodialysis or by death. Total duration of observation was 493.2 patient-months for new access technique and 409.6 patient-months for conventional technique. Patients in IY group had the lowest incidence of peritonitis (1/14.9 patient-months) and exit site infection (1/16.8 patient-months) among four subgroups. Peritonitis rate in IY was significantly lower compared to CY or CS. The total peritonitis-free period in those patients who did not experience peritonitis during the observation period was also significantly longer in IY (120 patient-months) than in CY (26 patient-months), IS (10.6 patient-months), or CS (10.4 patient-months). Simultaneous peritonitis and exit site infection was observed in none of IY group but 3 episodes in CY, 4 episodes in IS, and 3 episodes in CS. The rates of complications related to Staphylococcus aureus and Pseudomonas infections were also significantly lower in IY than in CY, IS, or CS. Technique survival did not differ between the two groups. The present results confirm our previous observation that the new access technique reduces the incidence of peritonitis probably by reducing infection via periluminal route. The Y-connector system further reduces peritonitis rate by reducing infection via intraluminal route.

Impact of environment and interspecific interactions between spoilage fungi and Aspergillus ochraceus on growth and ochratoxin production in maize grain

Using layers of irradiated but still fertile maize grain, the effects of water activity (0.995, 0.95 a(w)) and temperature (18, 30 degrees C) on interspecific interactions between Aspergillus ochraceus and five other spoilage fungi were examined. Asp. ochraceus was not competitive against Asp. flavus, Asp. niger, or Alternaria alternata at 18 degrees C when water was freely available (0.995 a(w)), while at 0.95 a(w) it was dominant against Asp. candidus, Asp. flavus and Alt. alternata. At 30 degrees C and 0.995 a(w), Asp. ochraceus was dominated by other fungi, except Alt. alternata, and was mutually antagonistic to Asp. candidus and Eurotium amstelodami. However, at 30 degreees C and 0.95 a(w), it was competitive against Asp. candidus and Alt. alternata, but not against the other species examined. The overall Index of Dominance showed that Asp. ochraceus was not competitive under the conditions examined here. At 18 degrees C ochratoxin production by Asp. ochraceus was inhibited significantly by Asp. candidus (0.995 and 0.95 a(w)) and Asp. niger (0.995 a(w)). When grown on maize grain at 30 degrees C, ochratoxin production by Asp. ochraceus was significantly inhibited by other spoilage fungi when both were grown on maize grain, especially by Asp. niger and E. amstelodami (0.995 a(w)) and Asp. flavus at 0.95 a(w). These results suggest that, to a large extent, A. ochraceus is not as competitive as some other spoilage fungi in primary resource capture on maize grain at a(w) of 0.95 or above, although it may modify resource quality and influence secondary colonisation by other species under the conditions tested.

The Effect of Fluid Shear Stress on Endothelial Cell Adhesiveness to Polymer Surfaces with Wettability Gradient

In this study, the adhesive strength of endothelial cells (ECs) attached on polymer surfaces with different hydrophilicity was investigated using wettability gradient polyethylene (PE) surfaces prepared by corona discharge treatment from a knife-type electrode whose power increases gradually along the sample length. The EC-attached wettability gradient surfaces were mounted on parallel-plate flow chambers in a flow system prepared for cell adhesiveness test. Three different shear stresses (150, 200, and 250 dyne/cm(2)) were applied to the flow chambers and each shear stress was maintained for 120 min to investigate the effect of shear stress and surface hydrophilicity on the EC adhesion strength. It was observed that the ECs were adhered more onto the positions with moderate hydrophilicity of the wettability gradient surface than onto the more hydrophobic or hydrophilic positions. The maximum adhesion of the cells appeared at around water contact angles of 55 degrees. The EC adhesion strength was higher on the hydrophilic positions than on the hydrophobic ones. However, the maximum adhesion strength of the cells also appeared at around water contact angles of 55 degrees. More than 90% of the adhered cells remained on that position after applying the shear stress, 250 dyne/cm(2) for 2 h, whereas the cells were completely detached on the hydrophobic position (water contact angle, about 86 degrees ) within 10 min after applying the same shear stress. It seems that surface hydrophilicity plays a very important role for cell adhesion strength. Copyright 2000 Academic Press.

Selective involvement of reactive oxygen intermediates in platelet-activating factor-mediated activation of NF-kappaB

Although it has been suggested that some biological activities of platelet-activating factor (PAF) are mediated by, at least in part, reactive oxygen intermediates (ROI), the precise mechanisms underlying the interaction between the two remains to be elucidated. Antioxidants, such as alpha-tocopherol acid succinate, N-acetyl-L-Cysteine, pyrrolidinedithiocarbamate failed to inhibit PAF-induced immediate systemic reactions such as lethality, symptoms of disseminated intravascular coagulation, and histological changes such as pulmonary edema and hemorrhage in renal medullae 10 min following PAF injection. In contrast. antioxidants significantly inhibited both the in vivo and in vitro PAF-induced NF-kappaB activation and NF-kappaB-dependent TNF-alpha expression. The effects of the antioxidants were due to their inhibition of PAF-induced degradation of IkappaBalpha, a protein responsible for keeping NF-kappaB in an inactive form. A protein tyrosine kinase and N-tosyl-L-phenylalanine chloromethyl ketone sensitive serine protease were involved in both PAF- and H2O2-induced NF-kappaB activation. Collectively, these data indicate that the PAF-induced NF-kappaB activation is selectively mediated through the generation of ROI.

Gene polymorphisms of endothelial nitric oxide synthase and angiotensin-converting enzyme in patients with asthma

BACKGROUND

Nitric oxide, including that produced by endothelial constitutive nitric oxide synthase (ecNOS), may regulate vascular and airway tone in the lungs and may influence various aspects of airway homeostasis. Angiotensin-converting enzyme (ACE) is expressed at high levels in the lungs and plays a role in the metabolism of angiotensin II, bradykinin, and substance P, all of which are potentially involved in the pathogenesis of asthma. An insertion-deletion polymorphism of the ACE gene has been shown to be associated with enzyme activity levels of ACE. To examine the possible involvement of the ecNOS and/or ACE genes as the genetic basis of bronchial asthma, we investigated whether there was any association between bronchial asthma and polymorphisms of the ecNOS and/or ACE genes.

METHODS

A total of 310 patients with bronchial asthma and 121 healthy subjects took part in this study. The ecNOS and ACE genotypes were determined in all subjects by polymerase chain reaction.

RESULTS

1) The distribution of one genotype (bb) of ecNOS was significantly higher in the asthma group than in the control population. 2) The ACE genotype distribution was not significantly different between the control and the asthma groups. 3) In asthmatic patients, the ACE and ecNOS genotype distribution did not differ significantly among groups of patients with different severities of asthma.

CONCLUSIONS

These results suggest that polymorphisms of the ecNOS gene, but not the ACE gene, may be associated with the development of asthma. However, the severity of asthma may not be influenced by polymorphisms of the ecNOS and ACE genes.

Peritoneal transport characteristics, comorbid diseases and survival in CAPD patients

OBJECTIVE

To evaluate the influence of initial peritoneal transport rate, serum albumin concentration, and comorbid diseases on continuous ambulatory peritoneal dialysis (CAPD) patient survival.

DESIGN

A prospective single-center study with a long-term follow-up.

PATIENTS

A total of 213 consecutive CAPD patients, who underwent a peritoneal equilibration test (PET) at a mean of 7 days (range 3 - 30 days) after beginning CAPD, were included in this study. One hundred twenty patients were male, 116 patients had comorbid diseases, and mean age was 49.5 years (range 18 - 76 years).

METHODS

A modified PET was performed using 4.25% glucose dialysis solution. Based on the dialysate-to-plasma creatinine concentration ratio at 4 hours' dwell (D4/P4 Cr, 0.62 +/- 0.14), patients were divided into high (H), high-average (HA), low-average (LA), or low (L) transporters.

RESULTS

Of 213 patients, 16.9% were classified as H transporters, 30.5% as HA, 36.6% as LA, and 16.0% as L transporters. The H transporter group had a higher proportion of men, higher proportion of patients with comorbid diseases, lower initial serum albumin concentration, lower D4/D0 glucose, and lower drained volume. The initial D4/P4 Cr correlated with initial serum albumin (r= -0.35, p < 0.001). The patients with comorbid diseases had lower initial serum albumin and higher initial D4/P4 Cr. On Kaplan-Meier analysis, 2-year patient survival of group H was significantly lower compared to the other groups combined (57.1% vs 79.5%, p = 0.009). On Cox proportional hazards analysis, age, comorbid diseases, initial serum albumin concentration, and initial D4/P4 Cr were found to be independent risk factors for mortality. However, in the patients without comorbid diseases, patient survival was not different between group H and the other transport groups combined (p > 0.05), and only age was found to be an independent risk factor for mortality.

CONCLUSION

These data suggest that a high peritoneal transport rate at initial PET is associated with high mortality, and that this is in part due to an increased prevalence of comorbid disease in H transporters. These H transporters with comorbid diseases represent a subset of patients with an especially poor prognosis. In patients without comorbid diseases, high transport status or low serum albumin concentration was not an independent risk factor for mortality.

Effect of lovastatin on small GTP binding proteins and on TGF-beta1 and fibronectin expression

We have shown that lovastatin, an inhibitor of 3 hydroxy-3-methylglutary coenzyme A (HMG CoA) reductase, delays development and progression of diabetic nephropathy in streptozotocine-induced diabetic rats through suppression of glomerular transforming growth factor (TGF)-beta1 mRNA expression. We have also shown that lovastatin suppresses both control and high glucose (HG)-induced TGF-beta1 and fibronectin mRNA expression and protein synthesis by rat mesangial cell (RMC) and that this down-regulation by lovastatin is reversed by mevalonate. It was postulated that this down-regulation may be linked to signaling of small guanine triphosphate (GTP)-binding proteins and mediated by the limitation of isoprenoids such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP) in RMC. To determine the isoprenoid and small GTP-binding proteins involved in TGF-beta1 and fibronectin expression. FPP or GGPP was added alone or in combination to RMC treated with lovastatin cultured under normal or high glucose condition. Suppression of TGF-beta1 and fibronectin expression by lovastatin was reversed effectively when GGPP was added alone. Partial reversal of lovastatin effect on fibronectin and TGF-beta1 expression was found when FPP was added alone. Adding both GGPP and FPP resulted in complete reversal of lovastatin effect on fibronectin but not TGF-beta1 suggesting that fibronectin and TGF-beta1 are regulated differently. Furthermore, luciferase activity of RMC cotransfected with fibronectin promoter reporter system and plasmid-expressing C3 exoenzyme (a specific inactivator of Rho family GTP binding proteins, pEFC3) was completely suppressed when compared with RMC cotransfected with empty vector, pEF. Because geranylgeranylation is usually involved in post-translational modification and membrane targeting of Rho family small GTP binding proteins, these data indicate that Rho family small GTP-binding proteins rather than Ras family small GTP binding proteins may play a key role in the TGF-beta1 and fibronectin expression in RMC.

Reactive oxygen species as glucose signaling molecules in mesangial cells cultured under high glucose

BACKGROUND

Oxidative stress is one of the important mediators of vascular complications in diabetes including nephropathy. High glucose (HG) generates reactive oxygen species (ROS) as a result of glucose auto-oxidation, metabolism, and formation of advanced glycosylation end products. The concept of ROS-induced tissue injury has recently been revised with the appreciation of new roles for ROS in signaling pathways and gene expression.

METHODS AND RESULTS

High glucose rapidly generated dichlorofluorescein-sensitive cytosolic ROS in rat and mouse mesangial cells. Neither L-glucose nor 3-O-methyl-D-glucose increased cytosolic ROS and cytochalasin B, an inhibitor of glucose transporter, effectively inhibited HG-induced ROS generation, suggesting that glucose uptake and subsequent metabolism are required in HG-induced cytosolic ROS generation. H2O2 up-regulated fibronectin mRNA expression and protein synthesis; this up-regulation was effectively inhibited by protein kinase C (PKC) inhibitor or by depletion of PKC. The HG-induced generation of ROS was, in turn, related to activation of PKC and transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) as well as to the up-regulation of transforming growth factor-beta1 (TGF-beta1), fibronectin mRNA expression and protein synthesis, because antioxidants effectively inhibited HG-induced PKC, NF-kappaB, AP-1 activation, and TGF-beta1 and fibronectin expression in mesangial cells cultured under HG.

CONCLUSIONS

Although signal transduction pathways linking HG, ROS, PKC, transcription factors, and extracellular matrix (ECM) protein synthesis in mesangial cells have not been fully elucidated, the current data provide evidence that ROS generated by glucose metabolism may act as integral signaling molecules under HG as in other membrane receptor signaling.

Phellinsin A, a novel chitin synthases inhibitor produced by Phellinus sp. PL3

Phellinsin A, a novel chitin synthases inhibitor was isolated from the cultured broth of fungus PL3, which was identified as Phellinus sp. PL3. Phellinsin A was purified by solvent partition, silica gel, ODS column chromatographies, and preparative HPLC, consecutively. The structure of phellinsin A was assigned as a phenolic compound on the basis of various spectroscopic analyses including UV, IR, Mass, and NMR. Its molecular weight and formula were found to be 358 and C18H14O8, respectively. Phellinsin A selectively inhibited chitin synthase I and II of Saccharomyces cerevisiae with an IC50 value of 76 and 28 microg/ml, respectively, in our cell free assay system. This compound showed antifungal activity against Colletotrichum lagenarium, Pyricularia oryzae, Rhizoctonia solani, Aspergillus fumigatus, and Trichophyton mentagrophytes.

Nifedipine controlled delivery by sandwiched osmotic tablet system

The sandwiched osmotic tablet system (SOTS), which is composed of a sandwiched osmotic tablet core surrounded by a cellulose acetate membrane with two orifices on both side surfaces, has been successfully prepared with the purpose of delivering nifedipine. The sandwiched osmotic tablet core consists of a middle push layer and two attached drug layers. Influences of tablet formulation variables, orifice size and membrane variables on nifedipine release of SOTS have been studied. It was found that potassium chloride amount of push layer and polyethylene oxide amount of drug layer had markedly positive effects on nifedipine release. A push layer/drug layer co-controlled osmotic delivery mechanism and the optimal core formulation have been proposed. The appropriate orifice size was observed in the range of 0.50-1.41 mm. It was also found that the drug release rate of SOTS could be increased by incorporating hydrophilic plasticizer in the membrane, whereas it decreased with hydrophobic plasticizer. It has been observed that the SOTS gives fairly comparable in vitro release features as that of commercialized push-pull osmotic tablet system, such as an approximately constant rate up to 24 h and independence of release media and agitation rate. Exempting side identification before drilling, it is easier to prepare the SOTS than the push-pull osmotic tablet system.

Effect of combined therapy of oral anti-tubercular agents on theophylline pharmacokinetics

To evaluate the effects of combined therapy of anti-tubercular agents with theophylline during treatment of concurrent pulmonary tuberculosis and chronic obstructive pulmonary disease or asthma, the clearance and half life of theophylline was estimated in a control group not treated with anti-tubercular agents, a group treated with isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and pyrazinamide (PZA), and a group treated with INH, RMP and EMB. Clearances of theophylline in the treated groups were significantly lower than in the control group, and the half-life of theophylline was longer than in the control. These results suggest that patients administered combinations of anti-tubercular agents with theophylline require lower doses of theophylline.

Monolithic osmotic tablet system for nifedipine delivery

The monolithic osmotic tablet system, which is composed of a monolithic tablet coated with cellulose acetate (CA) membrane drilled with two orifices on both side surfaces, has been described. The influences of tablet formulation variables including molecular weight (MW) and amount of polyethylene oxide (PEO), amount of potassium chloride (KCl), and amount of rice starch as well as nifedipine loading have been investigated. The optimal tablet formulation and the osmotic-suspending co-controlled delivery mechanisms have been proposed. Orifice size and membrane variables including nature and amount of plasticizers as well as thickness on drug release have also been studied. The in vitro release profiles of the optimal system have been evaluated in various release media and different agitation rates, and compared with commercialized conventional capsule and push-pull osmotic tablet. It was found that PEO with MW of 300000 g/mol was suitable to be thickening agent, both amount of KCl and amount of PEO had comparable and profoundly positive effects, while nifedipine loading had a strikingly negative influence on drug release. It could be found that the optimal orifice size was in the range of 0.25-1.41 mm. It has also been observed that hydrophilic plasticizer polyethylene glycol (PEG) improved drug release, whereas hydrophobic plasticizer triacetin depressed drug release when they were incorporated in CA membrane. The monolithic osmotic tablet system was found to be able to deliver nifedipine at the rate of approximate zero-order up to 24 h, independent of both environmental media and agitation rate, and substantially comparable with the push-pull osmotic tablet. The monolithic osmotic tablet system was simple to be prepared as exempting from push layer and simplifying in the orifice drilling compared with the push-pull osmotic tablet. The monolithic osmotic tablet system may be used in drug controlled delivery field, especially suitable for water-insoluble drugs.

Grass carp (Ctenopharyngodon idellus) bile may inhibit the release of renal dipeptidase from the proximal tubules by nitric oxide generation

There are many reports on acute renal failure (ARF) after ingestion of grass carp bile (CB; Ctenopharyngodon idellus). Renal dipeptidase (RDPase; EC 3.4.13.19) is a glycosylphosphatidylinositol-anchored ectoenzyme within the renal proximal tubules (PTs) and is proposed as a diagnostic enzyme of renal disease. We examined the release of RDPase following treatment with CB and various nitric oxide (NO) related compounds in porcine PTs. The RDPase release from PTs was inhibited by CB in a concentration-dependent manner and was also inhibited by sodium nitroprusside (direct NO donor) and L-arginine (NO synthase substrate) in the tested range (0-12 mM). CB-treated (0. 1 mg/ml) PTs showed a decreased RDPase activity in comparison with the control group. This inhibition was blocked by 2 mM L-NAME (NO synthase inhibitor) and U73122 (inhibitor of phosphatidylinositol-specific phospholipase C) in a concentration-dependent manner. Eel bile (0-0.1 mg/ml), used as the control, did not significantly affect the RDPase release from PTs. The NO concentration was observed as nitrite, the degradation product of the NO metabolism, increased in proportion to CB and L-arginine. The increase of nitrite to 151.5% by CB treatment (0.1 mg/ml) was blocked by 2 mM L-NAME (95.5%). When the phospholipase C pathway was blocked by 10 and 20 microM U73122, the nitrite generation decreased to 122.7 and 89.4%, respectively. These results strongly suggest that NO generation and the phospholipase C pathway affect the RDPase release from the PTs and that they may be involved in the development of ARF in vivo following CB ingestion. The release of RDPase from PTs could be a useful tool not only for this CB-caused ARF, but also for the elucidation of other biochemical mechanisms.

Sandwiched osmotic tablet core for nifedipine controlled delivery

The sandwiched osmotic tablet core, which is composed of a middle push layer and two attached drug layers, has been prepared and systematically studied with the purpose of delivering water-insoluble nifedipine. The advantage of the sandwiched osmotic tablet system over the commercialized push-pull osmotic tablet system is its simplicity of preparation, as the surface identification was avoided. It was observed that polyethylene oxides (PEO) with molecular weight (MW) of 300,000 and 8,000,000 g/mole were suitable for the thickening agent of drug layer and the expandable hydrogel of push layer, respectively. The weight ratio of 190/190 for drug layer/push layer was also found to be suitable. It has been observed that PEO amount of the push layer and the KCl amount of the drug layer had profoundly positive influence on nifedipine release. A push layer/drug layer co-controlled osmotic delivery mechanism has been proposed and the optimal tablet formulation has been obtained. It was also found that PEO and nifedipine were miscible, which may support the application of PEO in nifedipine dosage forms. Meanwhile, the PEO/nifedipine binary phase diagram has been constructed. The sandwiched osmotic tablet system can deliver nifedipine in an approximate zero-order rate up to 24 hours. It may be potentially used for the delivery of water-insoluble drugs.

Gap measurement by position-sensitive detectors

A system for measuring the gap in a proximity exposure tool of a plasma display panel (PDP) is developed that uses single or dual position-sensitive detectors (PSD's). The resolution of the gap distance is 0.5 mum, with a capture range of 500 mum. Signal processing is simple and fast and easy because analogous PSD's are used as the position sensors. One PSD is used to detect the position of the reference beam, which is reflected from the upper surface of the gap; the other PSD is used to detect the position of the signal beam, which is reflected from the lower surface of the gap. A charge-coupled-device sensor is also employed to monitor the reflected beams and the region of measurement. In the gap-measurement system that uses a single PSD, first the reference beam is incident upon the PSD and then the signal beam is incident upon the same PSD. Then the separation between the two beams is calculated from the position of the reference beam and from the average beam position.

Environment factors influence in vitro interspecific interactions between A. ochraceus and other maize spoilage fungi, growth and ochratoxin production

The effect of water availability (water activity, aw; 0.995-0.90) and temperature (18-30 degrees C) on in vitro interactions between an ochratoxin producing strain of Aspergillus ochraceus and six other spoilage fungi was assessed in dual culture experiments on a maize meal-based agar medium. In primary resource capture of nutrient substrate, A. ochraceus was dominant against many of the interacting species, being able to overgrow and replace A. candidus, and sometimes A. flavus and the Eurotium spp. regardless of aw or temperature. However, with freely available water (0.995 aw) A. alternata and A. niger were dominant, with mutual antagonism between A. ochraceus and A. flavus at 25-30 degrees C. In the driest conditions tested (0.90 aw) there was also mutual antagonism between A. ochraceus and the two Eurotium spp. Overall, under all conditions tested the Index of Dominance for A. ochraceus was much higher than for other competing species combined suggesting that A. ochraceus was a good competitive colonist able to replace a number of other species. However, the growth rate of A. ochraceus was modified and decreased by the interaction with competitors. Interaction between A. ochraceus and species such as A. alternata (18 degrees C/0.995) and Eurotium spp. (0.995-0.95 and 25-30 degrees C) resulted in a significant stimulation of ochratoxin production. The results are discussed in relation to the effect that environmental factors have on the possible competitiveness of A. ochraceus in the maize grain ecosystem and the role of ochratoxin in niche exclusion of competitors.

Chaetoatrosin A, a novel chitin synthase II inhibitor produced by Chaetomium atrobrunneum F449

Chaetoatrosin A, a novel chitin synthase II inhibitor, was isolated from the culture broth of fungus F449, which was identified as Chaetomium atrobrunneum F449. Chaetoatrosin A was purified by solvent partition, silica gel, ODS, preparative TLC, and Sephadex LH-20 column chromatographies, consecutively. The structure of chaetoatrosin A was assigned as 1,8-dihydroxy-3(2-hydroxypropionyl)-6-methoxynaphthalene on the basis of various spectroscopic analyses including UV, IR, mass spectral, and NMR. Its molecular weight and formula were found to be 262 and C14H14O5, respectively. ,Chaetoatrosin A inhibited chitin synthase II by 50% at the concentration of 104 microg/ml in an enzyme assay system. This compound showed antifungal activities against Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Cryptococcus neoformans and Trichophyton mentagrophytes.

ECP level in nasopharyngeal secretions and serum from children with respiratory virus infections and asthmatic children

Infection with respiratory virus has been shown to exacerbate asthma in humans. However, the role of a respiratory virus in the pathogenesis of chronic asthma and/or wheezing in young children has not been clearly defined. It has also been debated whether virus-induced wheezing in young children is one entity and allergic asthma another, or whether they are different expressions of the same disease. The present study was done to compare ECP concentrations in nasopharyngeal secretions and serum from 32 nonasthmatic wheezing children with viral infections (RSV in 15 children; influenza B virus in 17 children detected by immunofluorescence antibody technique), 8 asthmatic children without viral infections, and 13 normal children as the controls to understand the role of eosinophil inflammation. The geometric mean of ECP in nasopharyngeal secretions was significantly higher in asthmatic children than in children with virus-induced wheezing (p < 0.05). ECP levels of nasopharyngeal secretions from children with the virus-induced wheezing were significantly greater than those of the controls. However, there were no significant differences in ECP levels in serum among subjects.

Determination of bisphenol A in sewage effluent and sludge by solid-phase and supercritical fluid extraction and gas chromatography/mass spectrometry

Methods have been developed for the determination of bisphenol A (BPA) residues in municipal sewage and sludge samples. BPA in wastewater samples was enriched with a C18 solid-phase extraction cartridge, eluted with acetone, and converted to the pentafluoropropionyl derivative. For sludge samples, BPA was acetylated and extracted with supercritical carbon dioxide. In both cases, BPA-d16 was used as a surrogate to monitor extraction efficiency. Final analyses of derivatized sample extracts were performed by gas chromatography/mass spectrometry operating in the electron impact mode. For water samples, mean recoveries and standard deviations were 89 +/- 6, 94 +/- 4, and 85 +/- 7% at fortification levels of 1, 0.1, and 0.025 microg/L, respectively, with a method detection limit of 0.006 microg/L. For solid waste samples, mean recoveries and standard deviations were 93 +/- 5 and 92 +/- 6% at fortification levels of 2.5 and 0.25 microg/g, respectively, and the method detection limit was 0.05 microg/g. For the Canadian samples under investigation, concentrations of BPA ranged from 49.9 to 0.031 microg/L in sewage influent and effluent, and from 36.7 to 0.104 microg/g in sludge.

Influence of initial nutritional status on continuous ambulatory peritoneal dialysis patient survival

OBJECTIVES

To evaluate the influence of initial nutritional status on continuous ambulatory peritoneal dialysis (CAPD) patient survival and to identify factors determining initial nutritional status and patient mortality.

DESIGN

Prospective single-center study.

SETTING

Kidney Center, Soon Chun Hyang University Hospital.

PATIENTS

A total of 91 consecutive CAPD patients, who underwent initial nutritional assessment at Soon Chun Hyang University Hospital, Seoul, Korea, between September 1994 and January 1999, was included in this study. All patients were assessed at a mean of 7 days after beginning CAPD (range 3 - 24 days). Forty-eight patients were male, 50 were diabetics, and their mean age was 53.9 years (range 22 - 76 years).

METHODS

Nutritional status was assessed by subjective global assessment (SGA), biochemical and anthropometric measurements, fat-free edema-free (FFEF) body mass by creatinine kinetics, urea kinetic studies, and calculation of the normalized protein equivalent of total nitrogen appearance (nPNA).

RESULTS

By SGA, 55% were classified as having normal nutrition while 45% had signs of malnutrition; 61% of female and 31% of male patients, and 54% of diabetics and 34% of nondiabetics were classified as malnourished. Initial FFEF body mass, blood urea nitrogen (BUN), serum albumin (sAIb), residual renal function (RRF), and weekly total creatinine clearance were significantly lower in the malnourished patients than in the patients with normal nutrition. On multiple regression analysis, only FFEF body mass was an independent determinant of SGA score. On 31 January 1999, 41 patients were still on CAPD, 15 patients had died, and 27 patients had been transferred to hemodialysis. Those who died during observation were older and had lower initial FFEF body mass, % lean body mass, BUN, sAIb, RRF, and SGA score. The 2-year patient survival rate was significantly lower in the malnourished than in normal patients (67.1 % vs 91.7%, p = 0.02). On Cox proportional hazards analysis, initial age, malnutrition assessed by SGA, and FFEF body mass were identified as factors determining death.

CONCLUSION

Malnutrition was present in 45% of patients commencing CAPD when assessed by SGA. Initial FFEF body mass was a determinant of SGA score and predicted death. Malnutrition as assessed by SGA was also an independent predictor of death. Initial nutritional status, therefore, appears to exert a powerful influence on CAPD patient survival.

Interaction of fibroblast cells on poly(lactide-co-glycolide) surface with wettability chemogradient

Chemogradient surfaces whose properties are changed gradually along the sample length are of particular interest for the basic studies of the interaction between biological species and surfaces since the effect of a selected property can be examined in a single experiment on one surface. A wettability chemogradient on the poly(L-lactide-co-glycolide) (PLGA) films by treating them in air with corona from a knife-type electrode whose power increases gradually along the sample length. The PLGA surfaces oxidized gradually with the increasing corona power, and the wettability chemogradient was created on the surfaces as evidenced by the measurement of water contact angles and electron spectroscopy for chemical analysis. The wettability chemogradient PLGA surfaces prepared were used to investigate the interaction of fibroblast cells in terms of the surface hydrophilicity/hydrophobicity of PLGA surface. The cells adhered and grown on the chemogradient surface along the sample length were counted and observed by scanning electron microscopy. It was observed that the cells were adhered, spread, and grown more onto positions with moderate hydrophilicity of the wettability chemogradient PLGA surface than onto the more hydrophobic or hydrophilic positions. The maximum adhesion and growth of the fibroblast cells appeared at around water contact angle of 55 degrees. It seems that the wettability plays important roles for cell adhesion, orientation, spreading and growth on the PLGA surface. It might be that this surface modification technique can be used for improving the adhesion and growth of cell onto PLGA film and scaffolds, and can be applicable in the area of the tissue engineering.

The effect of the chemical structure of the phospholipid polymer on fibronectin adsorption and fibroblast adhesion on the gradient phospholipid surface

The interaction between biocomponents and the polyethylene (PE) surface modified with poly[omega-methacryloyloxyalkyl phosphorylcholine (MAPC)] was considered taking into account the surface characteristics, i.e., density, mobility, and orientation of the poly(MAPC). The PE surface, grafted gradually with the poly(MAPC) was prepared by corona irradiation method. The amount of peroxide produced on the PE surface which was determined with 1,1-diphenyl-2-picryl-hydrazyl, increased with an increase in the energy of the corona. The surface density of the poly(MAPC) was increased with an increase in the amount of the peroxides produced by the corona irradiation. The orientation and mobility of the poly(MAPC) grafted on the PE surface was evaluated with 1,6-diphenyl-1,3,5-hexatriene. The orientation of the poly[6-methacryloyloxyhexyl phosphorylcholine (MHPC)] which has six methylene chains between the phospholipid polar group and the backbone was higher than that of other poly(MAPC)s. The mobility of the poly(MAPC) decreased with an increase in the methylene chain length in the MAPC unit. The fibronectin adsorption on the gradient PE sheet grafted with poly(MAPC) was determined with enzyme-labeled immunoassay. The amount of adsorbed fibronectin on the PE grafted with poly[2-methacryloyloxyethyl phospohorylcholine(MPC)] and poly(MHPC) decreased with an increase in their surface density. Especially, the PE sheet grafted with the poly(MHPC) was effectively reduced compared with other poly(MAPC)s. On the poly[10-methacryloyloxydecyl phosphorylcholine (MDPC)], there is a minimum amount of adsorbed fibronectin. The fibronectin adsorption pattern on the PE sheet grafted with poly(MAPC) was quite different from the chemical structure of the MAPC unit. The human normal diploid fibroblasts (WI-38 cells) were cultured on the gradient PE sheet grafted with poly(MAPC) changing the concentration of seeded WI-38 cells. The adhesion behavior of the WI-38 cells was different depending on the concentration of the seeded WI-38 cells. When the concentration was low, the number of the adherent WI-38 cells had the same tendency as fibronectin adsorption. The gradient PE sheet grafted with the poly(MHPC) effectively reduced WI-38 cells adhesion even when the concentration of the WI-38 cells was high. The biocompatibility of polymer surfaces can be improved by highly oriented phosphorylcholine group.

Orbital floor and infraorbital rim reconstruction after total maxillectomy using a vascularized calvarial bone flap

A number of techniques have been introduced to support the orbital floor after maxillectomy without orbital exenteration. These methods include skin graft or muscular sling, but they have resulted in severe complications, such as enophthalmos, global ptosis, diplopia, and facial deformity. Currently, advanced microvascular reconstruction using bone and soft tissue is performed by many surgeons. This usually results in the filling of the postmaxillectomy defect, but the lack of support for the orbital rim and floor by the bone flap may still cause the complications mentioned above. Vascularized calvarial bone flap was chosen in this study for reconstruction of the orbital floor and infraorbital rim to function as a buttress, to reconstruct recipient sites of poor vascular bed after radiation therapy, and to withstand further postoperative radiation. By providing a solid floor and rim, these complications can be prevented with satisfactory function and aesthetically acceptable results. From September of 1995 to July of 1998, we performed vascularized bone flap for the reconstruction of the orbital floor and infraorbital rim in four cases after total maxillectomy involving the orbital floor. With a follow-up period from 19 to 35 months (mean, 27 months), we obtained significant improvement of functional and aesthetically acceptable results without global ptosis, enophthalmos, diplopia, or severe facial contour deformity.

Peritoneal transport of glucose in rat

OBJECTIVE

To evaluate the convective transport characteristics of glucose and the effect of high glucose and insulin during experimental peritoneal dialysis in rat.

METHODS

Male Sprague-Dawley rats weighing 300-400 g were used in this study. Mannitol (5%) was used as osmotic agent. Glucose was added to dialysis solution to yield a concentration of 100 mg/dL (group 1) or 300 mg/dL (group 2). Mannitol solution (5%) containing the same concentration of electrolytes and lactate but without glucose was used as control (group 3). In group 2, blood sugar was maintained at approximately 300 mg/dL by continuous intravenous infusion of 25% glucose solution and 0.9% NaCl solution. A 2-hour dwell study was performed with 30 mL of test solutions. Intraperitoneal volume was calculated by volume marker (18.5 kBq of 131I-human radioiodinated serum albumin, RISA) dilution with corrections made for the elimination of RISA from the peritoneal cavity (K(E)) and sample volume. The diffusive mass transport coefficient (K(BD)) and sieving coefficient (S(BRF)) were calculated by using the Babb-Randerson-Farrell model. S was also calculated directly by using isocratic methods (S(I)). The peritoneal fluid absorption rate (K(E)) was taken into account for the calculation of S(I).

RESULTS

Intraperitoneal volume was significantly higher in group 2 compared with groups 1 and 3. Peritoneal fluid absorption rate, K(E), was similar in all three groups. S(BRF) and S(I) for glucose were significantly lower in group 2 compared with groups 1 and 3. S(BRF) for glucose in group 2 was below zero and S(I) near zero. K(BD) for glucose was significantly higher in group 2 than in groups 1 and 3. Plasma and dialysate concentrations of insulin increased during the initial hour and then decreased to the baseline value in groups 1 and 3, while in group 2 it continuously increased.

CONCLUSION

Significantly lower sieving coefficients for glucose in the high glucose and high insulin group suggest that transport mechanisms other than simple passive transport are involved in peritoneal glucose transport, and that high glucose per se and/or high insulin may be important factors that determine glucose transport characteristics.

De novo induction of island capsule flap by using two silastic sheets: Part 1. Generation

A new experimental model for de novo generation of an axial pattern island flap has been designed in a rat model. The purpose of this study was to make a sufficient vascular carrier, as an island capsule flap, with only vascular pedicles and addition of collagen fibers induced by foreign-body reaction. The femoral arteriovenous bundle was isolated and sandwiched between two 2.5 x 1.5 cm Silastic sheets. Eight weeks later, as a delay procedure, femoral vessels were ligated at the distal end of the Silastic sheets and the four margins of the sheets were divided except for the vascular pedicle. This capsule flap was raised as a secondary island flap connected only by its vascular pedicle, then it was sutured back in place. Ten days after the delay procedure, the upper Silastic sheet was removed and a full-thickness skin graft was performed on the capsular island flap. Animals were killed at 80 days. A total of 40 axial pattern capsulocutaneous flaps from 20 Sprague-Dawley rats were successfully achieved. Pathologic study revealed neovascularization, and abundantly impregnated vascular structures near the pedicle were observed with randomly developed collagen fibers. The skin graft took 100 percent on this newly formed capsular flap; therefore, the capsule structure was able to survive on its own and support skin grafts. This experiment, by using an isolated femoral artery and vein as the main pedicle, led to the formation of a capsule flap through a normal foreign body reaction between two Silastic sheet implants. This new flap can be used as a reliable vascular carrier for various needs with minimal donor morbidity.

Preparation and characterization of Japanese encephalitis virus vaccine loaded poly(L-lactide-co-glycolide) microspheres for oral immunization

Japanese encephalitis virus (JEV) vaccine loaded biodegradable poly(L-lactide-co-glycolide) (PLGA) microspheres (MSs) were prepared by W/O/W solvent evaporation method to study the possibility for oral vaccination. The influence of several preparation parameters as stirring rate, types and concentration of emulsifier, PLGA concentration, etc. has been observed on size, size distribution and biodegradation. The mean MSs size decreased when the agitation speed and the concentration of emulsifier were increased, and when the PLGA concentration was decreased. The surface morphology of porous and nonporous JEV vaccine loaded PLGA MSs was prepared from polyvinylalcohol and sodium dodecyl sulfate as used emulsifiers, respectively. From the assay of lactic acid and scanning electron microscope observation, it can be suggested that the rate of biodegradation of nonporous MSs was slower than that of porous surface morphology due to lower the surface area. Mechanisms of the formation of porous and nonporous surface by different types of emulsifier, and the biodegradation of MSs have been proposed. Also, the size and size distribution of JEV vaccine loaded PLGA MSs were discussed to apply oral vaccination through the Peyer's patches across the gastrointestinal tract.

Release of renal dipeptidase from rabbit renal proximal tubules and its inhibition by gentamicin

Effects of several drugs on rabbit renal proximal tubules were examined for the applicability of renal dipeptidase (RDPase, EC 3. 4. 13. 11) release as a model system to study nephrotoxicity. The proximal tubule prepared by the method of Taub (1990) released RDPase spontaneously in the control experiment which was confirmed by Western blotting. RDPase was also released from cisplatin, lipopolysaccharide (LPS), and indomethacin-treated tubules. Gentamicin inhibited RDPase release in a concentration-dependent manner. This RDPase release system may not be a general model to screen nephrotoxicity but could be a useful source of RDPase purification in a simple and inexpensive way.

Optimization of urinary FDG excretion during PET imaging

Accumulation of fluorodeoxyglucose (FDG) activity in the urine interferes with the visualization of pelvic and, sometimes, abdominal abnormalities. Although this is a major problem, there are few data on the physiological variables affecting FDG urinary excretion that are critical to minimizing urinary FDG interference during PET imaging.

METHODS

The excretion of FDG in urine was determined during 90 min in four groups of rats (n = 24) under the following conditions: normal, hydrated, hydrochlorothiazide treated and phlorizin treated. FDG clearance rates were measured in both normal and phlorizin-treated animals and compared with the glomeruler filtration rate measured with 99mTc-diethylenetriamine pentaacetic acid. We measured FDG excretion in 10 patients who had no known renal disease and were undergoing PET scanning (divided into two groups: hydrated and dehydrated) to relate the animal data to humans.

RESULTS

The hydrated and phlorizin-treated animals had the highest excretion of FDG (39.68+/-5.00 % injected dose (%ID) and 45.64+/-9.77 %ID, respectively). Animals given the hydrochlorothiazide had the highest urinary volume, but the percentage excreted was comparable with the normal rats. Measurement of the clearance of FDG in animals before and after the administration of phlorizin determined the amount of FDG reabsorbed in the proximal tubules to be 56%+/-9.15%. The hydrated patients had a higher excretion of FDG than dehydrated patients (16.98+/-1.99 %ID versus 14.27+/-1.00 %ID, P < 0.021), and the volume of urine voided was significantly higher (P < 0.020).

CONCLUSION

Hydrochlorothiazide increases urine volume without enhancing FDG excretion. The hydration of patients before PET scanning may lead to more FDG reaching the bladder. Reduction of bladder activity by more frequent voiding facilitated by increased urine volume in hydrated patients may be offset by increased delivery of FDG to the bladder. A preferable means of increasing urinary volume without increasing delivery of FDG to the bladder may be the use of a diuretic.

Nutritional status of Korean peritoneal dialysis patients

OBJECTIVES

To assess the nutritional status of Korean peritoneal dialysis (PD) patients and to compare with data from Western literature, and to elucidate independent factors determining nutritional status and death.

DESIGN

Cross-sectional single-center study.

SETTING

Kidney Center, Soon Chun Hyang University Hospital.

MATERIALS

Ninety-eight CAPD patients were included. Of these, 54 patients were male, 32 patients were diabetic, mean age was 47.9+/-13.1 years, and mean duration of CAPD was 22.3+/-21.6 months. The patients were followed until death, transfer to hemodialysis (HD) or other units, transplantation, or until 3 years had elapsed after the first evaluation.

METHODS

Nutritional status was assessed by subjective global assessment (SGA), biochemical and anthropometric measurements, fat-free edema-free (FFEF) body mass by creatinine (Cr) kinetics, protein equivalent of total nitrogen appearance (PNA), and urea kinetic studies.

RESULTS

By SGA score, 53.1% of patients were classified as normal, 44.9% with mild-to-moderate malnutrition, and 2% with severe malnutrition. Patients with malnutrition were significantly older and had higher peritonitis rates, lower serum albumin (Alb), blood urea nitrogen (BUN), serum Cr, FFEF body mass, mid arm muscle circumference, and PNA (p < 0.05). On stepwise multiple regression analysis, the SGA score was negatively correlated with age and peritonitis rate (p < 0.01). At the end of the 3-year follow-up period, 11 patients were still on CAPD, 26 had died, 51 had transferred to HD and 5 to other units, 3 patients had been transplanted, and 2 patients were lost to follow-up. Patients who died during follow-up were older and had higher peritonitis rates and lower total serum protein, Alb, Cr, and FFEF body mass when compared to those who survived (p < 0.05). Independent predictors of death were age, peritonitis rate, and serum Alb (p < 0.01).

CONCLUSION

Malnutrition was as common in Korean PD patients as reported in the Western literature. Our data suggests that, to prevent malnutrition and early death, it is important to reduce the peritonitis rate, to improve protein intake, and to prescribe an adequate dose of peritoneal dialysis.

Leukotriene D4 inhibits Na+ uptake through cAMP and PLC pathways in primary cultured renal proximal tubular cells

Leukotriene D4 (LTD4) is one of the slow-reacting substances of anaphylaxis and is reported to have a diverse response including the mediation of glomerular nephritis. However, little is known about the functions of LTD4 and its mechanisms of action in primary cultured rabbit renal proximal tubular cells (PTCs). The purpose of this study is to investigate the effect of LTD4 on Na+ uptake and its related signal transduction pathways in PTCs. LTD4 (>10(-9) M) significantly inhibited the Na+ uptake after 15 min (in nmol/mg protein: controls 431.7+/-11.4 vs. LTD4 (10(-9) M) 355.0+/-23.6; p<0. 05); and its effect was blocked by MK-571 (10(-6) M), a leukotriene receptor antagonist, in PTCs. Preincubation with cilastatin, a renal dipeptidase inhibitor, and polyclonal antibody against renal dipeptidase potentiated the inhibitory effect of LTD4 on Na+ uptake. SQ 22536 (10(-6) M), an adenylate cyclase inhibitor, and the myristoylated protein kinase A inhibitor amide 14-22 (PKI; 10(-5) M) blocked the effect of LTD4 on Na+ uptake (in nmol/mg protein: LTD4 349.9+/-18.5 vs. SQ 22536+LTD4 476.5+/-22.0 and PKI+LTD4 440.3+/-19. 3; p<0.05), and LTD4 induced an increase in cyclic adenosine monophosphate (cAMP), suggesting the involvement of cAMP in the inhibition of Na+ uptake. In addition, U 73122 (10(-6) M) and neomycin (10(-4) M), phospholipase C (PLC) inhibitors, W-7 (10(-4) M), a calmodulin antagonist, and bisindolylmaleimide I, a protein kinase C (PKC) inhibitor, blocked the LTD4-induced inhibition of Na+ uptake, strongly suggesting involvement of the PLC-PKC signal pathways in the effect of LTD4. LTD4 significantly increased [Ca2]i by 49+/-7% as compared with baseline. TMB-8 (10(-5) M) and BAPTA/AM (10(-5) M), intracellular calcium mobilization blockers, completely blocked the LTD4-induced inhibition of Na+ uptake (in nmol/mg protein: LTD4 347.6+/-19.0 vs. TMB-8+LTD4 436.4+/-22.3 and BAPTA/AM+LTD4 419.9+/-14.3; p<0.05); however, EGTA (1 mM), a calcium chelator, partially blocked the LTD4-induced inhibition of Na+ uptake. In conclusion, LTD4-induced inhibition of Na+ uptake may be involved in both cAMP and PLC-PKC signal pathways in PTCs. In addition, Ca2+, which comes from the intracellular Ca2+ mobilization, is primarily responsible for the LTD4-induced inhibition of Na+ uptake.

Simultaneous reconstruction of the Achilles tendon and soft-tissue defect using only a latissimus dorsi muscle free flap

The combined loss of the Achilles tendon and the overlying soft tissue in the young ambulant patient with expectations of a normal life is a challenging problem. These patients need not only soft tissue but also dynamic and functional reconstruction. Four cases of major defects of the Achilles tendon and overlying soft tissue after trauma are presented. In each case, the tendon and the overlying soft tissues were reconstructed using only a latissimus dorsi muscle free flap and overlying split-thickness skin graft. In conventional methods, evolved in the reconstruction of the Achilles tendon and soft tissue, the size of the defect was a limit. However, this technique can be used to reconstruct an extensive defect, including distal calf muscle to the plantar metatarsal area. In one case, the flap was harvested in a myocutaneous unit, and the skin portion was deepithelialized for the coverage and enough padding on the bony exposure area in reverse position. The purpose of the present study was to reevaluate the potential of denervated muscle flap for a force-bearing conduit as an alternative reconstructive method of the Achilles tendon. The denervated latissimus dorsi muscle in this study eventually experienced the process of atrophy and fibrosis but maintained its original length. Although there remained some atrophic muscle fibers, a fibrosis of the muscle fibers formed a tendon-like fibrous band, and so the action of the posterior calf muscle could be transmitted through the tendon-like fibrotic change of the denervated latissimus dorsi muscle. The advantages of this technique are that (1) it is a single procedure, (2) it is adaptable to a wide range of defect sizes, (3) it allows faster wound healing supported by well-vascularized tissues, (4) it produces satisfactory function of the ankle joint and a padding effect, and (5) it produces good contour of the posterior calf to the sole and an acceptable donor-site morbidity.

Expression of ICAM-1 on conjunctival epithelium and ECP in tears and serum from children with allergic conjunctivitis

BACKGROUND

Conjunctival eosinophilia may be considered to be an indicator of conjunctival allergic disease. The absence of eosinophils on conjunctival scraping, however, cannot rule out the diagnosis of allergic conjunctivitis because eosinophil infiltration may be deeper in conjunctival tissue. Eosinophil cationic protein (ECP) is a toxic product secreted by activated eosinophil as a marker of eosinophil activation. Eosinophil cationic protein concentrations in body fluids correlate with the severity of some allergic diseases. ICAM-1 promotes adhesion of leukocytes to epithelium, endothelium, and upregulates inflammation. Expression of adhesion can be modified by many extracellular and intracellular variables such as proinflammatory cytokines, extracellular matrix proteins, and viral infection.

OBJECTIVE

We investigated whether local eosinophils are only activated in conjunctival epithelium or circulating activated eosinophils are involved in peripheral blood during allergic reaction of the eye. We also demonstrated the possible expression of ICAM-1 on epithelial cells from conjunctival scraping and compared them with soluble ICAM-1 values of serum and tears in children with allergic conjunctivitis and healthy children.

METHODS

Seventeen subjects were selected on the basis of clinical manifestations, history, skin prick test, and total serum IgE. A microcapillary tube was used to collect the tears from the inner canthus. Conjunctival epithelia were obtained by scraping the upper tarsal conjunctiva. The level of ECP was measured by the CAP system, soluble ICAM-1 was measured by ELISA, and ICAM-1 on conjunctival epithelial cells were expressed by the avidine-biotin peroxide complex procedure.

RESULTS

Serum IgE and the eosinophil count were increased in 10 out of 17 patients, positive skin prick tests were positive in 11 patients (Dermatophagoides pternyssinus; 9, Dermatophagoides farinae: 8), and eosinophilia in conjunctival epithelium was in 11 patients (4 patients: >3/HPF, 7 patients: 1-3/HPF). The ECP levels in tears were significantly increased in the patient group (12.0+/-8.0 versus 3.9+/-3.8 microg/mL, P = .01), but not in serum (52.5+/-43.1 versus 28.3+/-25.9 microg/mL). There is significant correlation between the eosinophil count in peripheral blood and on conjunctival epithelium (P = .007, r = .62; n = 25). The ICAM-1 expression score on conjunctival epithelial cells was significantly different between the patient group and controls (patient group: 1.77+/-1.25 versus control: 0.13+/-0.35 ng/mL, P = .002). There was a significant correlation between ICAM-1 expression on conjunctival epithelial cells and the ECP levels of tears (P = .01, r = .58; n = 25). Soluble ICAM-1 levels in serum and tears showed no significant difference between the patient group and controls, and also, there was no correlation between sICAM-1 levels in the serum and tears.

CONCLUSION

Eosinophil cationic protein in tears and ICAM-1 expression scores on conjunctival epithelium showed a significant difference between children with allergic conjunctivitis and the healthy controls, but circulating ECP and sICAM-1 in serum were not significantly different between the two groups. These results may suggest that ICAM-1 is locally upregulated in inflammation, mediating eosinophil activation and migration to conjunctival epithelium, but is not involved as inflammatory mediators in peripheral blood during allergic response in children with allergic conjunctivitis.

Analysis of induced sputum to examine the effects of inhaled corticosteroid on airway inflammation in children with asthma

BACKGROUND

Analysis of induced sputum can be performed safely in children with asthma and is useful for both cellular and biochemical markers of inflammation. Glucocorticosteroid inhalation has become the first line therapy for chronic asthma by suppressing airway inflammation, which produces the decrease of bronchial hyperreactivity and reduces the number of eosinophil in bronchial submucosa.

OBJECTIVE

To determine the characteristics of the inflammatory cells and their markers in sputum and to examine the pharmacokinetic effects of glucocorticoid within 3 hours after inhalation therapy on FEV1 and sputum inflammatory indices in children with clinically defined chronic asthma.

METHODS

Thirty subjects with asthma included 14 current symptomatic asthmatics and 14 normal controls inhaled 4.5% hypertonic saline for 10 minutes by nebulizer. The expectorated sputum were collected from all asthmatics before and 3 hours after corticosteroid inhalation for children with asthma and were reduced by dithiotreitol. Total cell counts and differentials were determined. ECP was measured by CAP system. Interleukin-5, GM-CSF and albumin were measured by double sandwich ELISA.

RESULTS

The mean eosinophil percentage and ECP in induced sputum of asthmatics were significantly higher than that of controls. The induced sputum samples obtained after glucocorticoid inhalation showed a significant reduction in mean eosinophil percentage, but FEV1, IL-5, GM-CSF, albumin, and ECP values were not significantly decreased.

CONCLUSION

The present results in induced sputum may be interpreted to reflect direct steroid action on airways and lack of effect on bone marrow effectors at 3 hours after glucocorticoid inhalation.

Interaction of fibroblasts on polycarbonate membrane surfaces with different micropore sizes and hydrophilicity

Surface topography appears to be an important but often neglected factor in implant performance. In this study, fibroblasts were cultured on a range of porous polycarbonate (PC) membranes with well defined surface topography (track-etched micropores, 0.2-8.0 microm in diameter) and wettability gradients. The wettability gradient on the PC membrane surfaces was produced by treating the surfaces with corona from a knife-type electrode whose power increased gradually along the sample length. The PC membrane surfaces were characterized by scanning electron microscopy (SEM) and the water contact angle measurement. Fibroblasts were cultured on the corona-treated PC membrane surfaces with different micropore sizes for 1 and 2 days. The cells attached on the membrane surfaces were examined by SEM and the cell density on the surfaces was estimated by counting the number of attached cells along the wettability gradient. It was observed that the cells were adhered and grew more on the hydrophilic positions of the membrane surfaces than the more hydrophobic ones, regardless of micropore size. It was also observed that cell adhesion and growth decreased gradually with increasing micropore size of the membrane surfaces. It seems that the cell adhesion and growth were progressively inhibited as the membrane surfaces had micropores with increasing size, probably due to surface discontinuities produced by tract-etched pores. On the membrane surfaces with smaller micropore sizes, the cells seemed to override these surface discontinuities.

Environmental factors and nutritional utilization patterns affect niche overlap indices between Aspergillus ochraceus and other spoilage fungi

The total number, and the type of C source utilized in common by an ochratoxin producing strain of Aspergillus ochraceus and six other spoilage fungi varied with the range used (95, Biolog GN plates, or 18 major C sources found in maize). The niche size and niche overlap index (NOI) were markedly influenced by water availability (water activity, aw) and temperature. With freely available water (0.995 aw) there was ecological similarity between A. ochraceus, A. alternata, A. candidus and A. flavus, all exploiting the same sources at both 18 and 30 degrees C. However, under water stress, A. ochraceus had a low NOI compared with A. niger, A. flavus and A. candidus, and Eurotium spp., suggesting that there was very little niche overlap in utilization of different C sources. The NOIs were not directly related to growth rates. Niche overlap between species was shown to be in a state of flux and significantly influenced by environmental factors. This may have important implications in understanding ecological interactions, and dominance by species in a community, and for pre-emptive exclusion of specific species.

Chitin synthase II inhibitory activity of ursolic acid, isolated from Crataegus pinnatifida

Two triterpenoid compounds, ursolic acid and uvaol, were isolated from Crataegus pinnatifida Bunge leaves. Ursolic acid inhibits chitin synthase II from S. cerevisiae with an IC50 value of 0.84 microgram/ml and the inhibition appears to be selective for chitin synthase II, whereas uvaol has no inhibitory activity up to 280 micrograms/ml. Oleanolic acid, alpha-hederin hydrate, and betulic acid inhibited the chitin synthase II activity under the same conditions with an IC50 of 5.6, 64.3, and 98.7 micrograms/ml, respectively.

Platelet and cell interactions on gold sputter-deposited polymeric surfaces

Surface treatment as gold sputter-deposited treatment onto various polymeric surfaces has been investigated to improve the cell-, tissue- and blood-compatibility. Surface treated samples were characterized by measurement of contact angle goniometer and electron spectroscopy for chemical analysis (ESCA). The contact angles on the gold-coated polymeric surfaces decreased from 95-65 degrees to around 50 degrees, i.e., increased hydrophilicity due to incorporation of gold thin layer. From the results of ESCA analysis of the modified polymeric surfaces, surface modification by the gold-sputter method was successfully performed. Morphology of the adhered platelets on the gold-coated polymeric surfaces showed lesser activating than control, and the number of adhered platelets surface modified samples decreased with decreasing water contact angle. Fibroblast cell adhesion and growth on the gold-coated polymeric surfaces were more active than those of control. It seems that surface wettability and surface chemistry of gold play important roles for platelet adhesion and cell adhesion, spreading and growth.

Perfusion impairments in infantile autism on technetium-99m ethyl cysteinate dimer brain single-photon emission tomography: comparison with findings on magnetic resonance imaging

The neuro-anatomical substrate of autism has been the subject of detailed investigation. Because previous studies have not demonstrated consistent and specific neuro-imaging findings in autism and most such studies have been performed in adults and school-aged children, we performed a retrospective review in young children in search of common functional and anatomical abnormalities with brain single-photon emission tomography (SPET) using technetium-99m ethyl cysteinate dimer (ECD) and correlative magnetic resonance imaging (MRI). The patient population was composed of 23 children aged 28-92 months (mean: 54 months) who met the diagnostic criteria of autism as defined in the DSM-IV and CARS. Brain SPET was performed after intravenous injection of 185-370 MBq of 99mTc-ECD using a brain-dedicated annular crystal gamma camera. MRI was performed in all patients, including T1, T2 axial and T1 sagittal sequences. SPET data were assessed visually. Twenty patients had abnormal SPET scans revealing focal areas of decreased perfusion. Decreased perfusion of the cerebellar hemisphere (20/23), thalami (19/23), basal ganglia (5/23) and posterior parietal (10/23) and temporal (7/23) areas were noted on brain SPET. By contrast all patients had normal MRI findings without evidence of abnormalities of the cerebellar vermis, cerebellar hemisphere, thalami, basal ganglia or parietotemporal cortex. In conclusion, extensive perfusion impairments involving the cerebellum, thalami and parietal cortex were found in this study. SPET may be more sensitive in reflecting the pathophysiology of autism than MRI. However, further studies are necessary to determine the significance of thalamic and parietal perfusion impairment in autism.

Sequential effects of high glucose on mesangial cell transforming growth factor-beta 1 and fibronectin synthesis

BACKGROUND

Transforming growth factor (TGF)-beta is recognized as the final common mediator of the principal lesions of diabetic nephropathy such as renal hypertrophy and mesangial expansion. To gain better understanding of the temporal relationships between high glucose (HG) and mesangial cell (MC) TGF-beta 1 synthesis and between TGF-beta 1 and extracellular matrix (ECM) synthesis, the present study examined early and sequential effects of HG on TGF-beta 1 and fibronectin (FN) mRNA expression and protein synthesis.

METHODS

Confluent primary rat MC was stimulated with 5.6 (control) or 30 (high) mM glucose after synchronizing the growth by incubation with serum-free media for 48 hours.

RESULTS

Mesangial cell TGF-beta 1 mRNA expression increased significantly in six hours and continued to increase until 48 hours in response to HG. The level of TGF-beta 1 mRNA was 1.5-fold higher than that of control glucose at six hours and 1.8-fold at 48 hours. TGF-beta activity in heat-activated conditioned media under HG increased 1.5- and 1.6-fold at 24 and 48 hours, respectively, compared to control glucose. FN mRNA increased significantly at 24 and 48 hours and 1.4-fold that of control glucose at both time points. FN protein also increased 1.5-fold that of control glucose at 48 hours. Anti-TGF-beta antibody completely abolished HG-induced FN synthesis.

CONCLUSIONS

The present finding demonstrate that HG stimulates TGF-beta 1 very early and prior to FN production and that HG-induced FN production is mediated by TGF-beta. This finding is consistent with the view that TGF-beta mediates increased ECM accumulation by MC under high glucose conditions.

Determination of 17 beta-estradiol and its metabolites in sewage effluent by solid-phase extraction and gas chromatography/mass spectrometry

The paper describes a simple and quantitative method for monitoring non-conjugated 17 beta-estradiol (E2) and its metabolites estrone (E1) and estriol (E3) as environmental contaminants in municipal sewage effluents. Estrogens were preconcentrated and cleaned up by solid-phase extraction using a reversed-phase C18 cartridge. They were derivatized with pentafluoropropionic acid anhydride, and the products were analyzed by gas chromatography/mass spectrometry. Recoveries from spiked distilled water and sewage were better than 87% at fortification levels of 100 and 20 ng/L. For a 1 L sewage sample and a concentration factor of 5000, detection limits were 5 ng/L for E1 and E2 and 10 ng/L for E3. In a brief survey of Canadian wastewater, these estrogens were detected in many raw sewage and effluent samples at concentrations ranging from 6 to 109 ng/L for E1, from < 5 to 15 ng/L for E2, and from < 10 to 250 ng/L for E3.

Interaction of Different Types of Cells on Polymer Surfaces with Wettability Gradient

Gradient surfaces whose properties are changed gradually along the sample length are of particular interest for basic studies of the interaction between biological species and surfaces since the effect of a selected property can be examined in a single experiment on one surface. We prepared a wettability gradient on low density polyethylene (PE) sheets by treating them in air with the corona from a knife-type electrode whose power increases gradually along the sample length. The PE surfaces oxidized gradually with the increasing corona power, and the wettability gradient was created on the surfaces as evidenced by the measurement of water contact angles, Fourier transform infrared spectroscopy in the attenuated total reflectance mode, and electron spectroscopy for chemical analysis. The wettability gradient surfaces prepared were used to investigate the interaction of different types of cells (Chinese hamster ovary, fibroblast, and endothelial cells) as well as serum proteins in terms of the surface hydrophilicity/hydrophobicity of polymeric materials. The cells adhered and grown on the gradient surface along the sample length were counted and observed by scanning electron microscopy. It was observed that the cells were adhered, spread, and grown more onto the positions with moderate hydrophilicity of the wettability gradient surface than onto the more hydrophobic or hydrophilic positions. The maximum adhesion and growth of the cells appeared at around water contact angles of 55 degrees, regardless of the cell types used. This result seems closely related to the serum protein adsorption on the surfaces; the serum proteins were also adsorbed more onto the positions with moderate hydrophilicity of the wettability gradient surface. Copyright 1998 Academic Press.

Platelet adhesion on the gradient surfaces grafted with phospholipid polymer

We have synthesized omega-methacryloyloxyalkyl phosphorylcholine (MAPC) polymers as new blood-compatible materials, with attention to the surface structure of the biomembrane and investigated their blood compatibility. The blood compatibility observed on the MAPC polymers is due to their strong affinity to phospholipids. When the blood comes in contact with the MAPC polymer, phospholipids in the plasma preferentially adsorb on the surface, compared with the plasma proteins or cells. The adsorbed phospholipids construct a biomembrane-like structure on the MAPC polymer surface. The MAPC polymers then have an excellent blood compatibility. In this study, we prepared a gradient poly(MAPC)-grafted polyethylene (PE) surface using a corona discharge treatment method to clarify the effect of the chemical structure of the MAPC unit on the blood compatibility of the MAPC polymers. The surface composition of MAPC and the hydrophilicity on the poly(MAPC)-grafted PE surface were determined by X-ray photoelectron spectroscopic (XPS) analysis and contact angle measurement with water, respectively. The phosphorus/carbon (P/C) ratio determined by the XPS analysis increased, but the water contact angle decreased with increasing corona irradiation energy. These results indicated that the surface density of the MAPC unit was increased. More than 2.5 cm from the starting point of the corona irradiation, the P/C ratio and water contact angle of the surface achieved a constant level. Thus, the surface was completely covered with the grafted poly(MAPC) chain. The effect of the methylene chain length of the MAPC unit on surface properties was also observed. The phospholipid polar group of the MAPC unit was effectively exposed on the surface as the chain length became longer. Moreover, the hydrophobicity of the surface was increased with the increase in the methylene chain length of the MAPC unit. The number of platelets adhering to the poly(MAPC)-grafted PE surface was reduced from the same point where the P/C ratio became constant.

Modeling the physiological responses of anuran R3 ganglion cells

Teeters and Arbib (Bio Cybernet 1991;64:197-207) presented a model of the anuran retina which qualitatively accounts for some of the characteristic response properties used to distinguish ganglion cell type in anurans. Teeters et al. (Vis Res 1993;33:2361-2379) tested the model's ability to reproduce data of Ewert and Hock (Exp Brain Res 1972;16:41-59) relating toad R2, R3 and R4 ganglion cell responses to moving worm, antiworm and square-shaped stimuli of various edge lengths for stimulus shape and size dependency. In this paper we provide an exhaustive analysis of the performance of the modeled R3 cells with respect to most of the known qualitative and quantitative physiological properties of natural R3 ganglion cells. We also introduce several relevant predictions of the model relating different responses of R3 cells under the effect of changes in different model components. In some cases the predictions have been tested in neurophysiological experiments.