Therapeutic potential of BMSC-conditioned medium in an in vitro model of renal fibrosis using the RPTEC/TERT1 cell line

We investigated the therapeutic potential of bone marrow-derived mesenchymal stem cell-conditioned medium (BMSC-CM) on immortalized renal proximal tubule epithelial cells (RPTEC/ TERT1) in a fibrotic environment. To replicate the increased stiffness characteristic of kidneys in chronic kidney disease, we utilized polyacrylamide gel platforms. A stiff matrix was shown to increase α-smooth muscle actin (α-SMA) levels, indicating fibrogenic activation in RPTEC/TERT1 cells. Interestingly, treatment with BMSC-CM resulted in significant reductions in the levels of fibrotic markers (α-SMA and vimentin) and increases in the levels of the epithelial marker E-cadherin and aquaporin 7, particularly under stiff conditions. Furthermore, BMSC-CM modified microRNA (miRNA) expression and reduced oxidative stress levels in these cells. Our findings suggest that BMSC-CM can modulate cellular morphology, miRNA expression, and oxidative stress in RPTEC/TERT1 cells, highlighting its therapeutic potential in fibrotic kidney disease. [BMB Reports 2024; 57(2): 116-121].

Kidney Transplantation Using Expanded-Criteria Deceased Donors: A Comparison With Ideal Deceased Donors and Non-Expanded-Criteria Deceased Donors

PURPOSE

The use of expanded-criteria deceased-donor (ECD) kidneys must be evaluated within the objective perspective of critical organ shortage and graft function and survival. In this study, we aimed to compare the clinical outcomes of ECD reliance with concurrent use of ideal-criteria deceased donors (IDDs) and non-ECDs in adult renal transplantation.

METHODS

Between February 2000 and December 2015, we analyzed 405 deceased-donor renal transplants, specifically 129 grafts (31.9%) from ECDs, 233 grafts (57.5%) from non-ECDs, and 43 grafts (10.6%) from IDDs. ECDs were classified according to the United Network for Organ Sharing guidelines, while an IDD was defined as a younger person (10-39 years of age) with no medical risk factors who died from a traumatic head injury. Donor and recipient risk factors were separately analyzed and correlated with recipient graft function, and survival was evaluated.

RESULTS

ECDs were older (56.8 ± 6.3 years); showed increased incidence of hypertension, diabetes, and cerebrovascular brain death; and had a higher pre-retrieval serum creatinine level than the other groups. ECD kidney recipients were also older (50.6 ± 9.8 years), had a shorter waiting time (P = .031), and demonstrated a low frequency of re-transplantation (P = .028). Long-term renal function followed longitudinally was lower in ECD kidney recipients until five years after transplantation, while the glomerular filtration rate (GFR) level at 7 and 10 years did not differ significantly among the groups (P = .074 and .262, respectively). There were no significant differences in terms of graft survival (P = .394) or patient survival (P = .737) among the groups.

CONCLUSIONS

Although the long-term renal function followed longitudinally was lower in ECD kidney recipients, the use of renal grafts from ECDs is an acceptable method to resolve the disparity of critical organ shortage. However, the classification of the high-risk group should be updated with consideration given to differences in regional characteristics.

Genetic parameters of carcass and meat quality traits in different muscles (longissimus dorsi and semimembranosus) of Hanwoo (Korean cattle)

We estimated heritability () and genetic and phenotypic correlations for carcass and meat quality traits of longissimus dorsi (LD) and semimembranosus (SM) muscles in 30-mo-old Hanwoo steers. Variance and covariance components were estimated using REML procedures under univariate and bivariate models. The mean carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS) were 428.20 ± 46.30 kg, 87.38 ± 8.54 cm2, 13.00 ± 5.14 mm, and 5.21 ± 1.56, respectively. The mean CIE reflectance of meat lightness (L*), redness (a*), and yellowness (b*) were 40.01 ± 2.73, 22.37 ± 2.18, and 10.35 ± 1.46, respectively, in LD muscles and 36.33 ± 2.44, 22.91 ± 2.43, and 10.25 ± 1.65, respectively, in SM muscles. The mean Warner-Bratzler shear force (WBSF), intramuscular fat content (IMF), water-holding capacity (WHC), and protein and ash content in LD and SM muscles were 3.84 ± 0.96 and 6.52 ± 1.21 kg, 15.91 ± 4.39 and 5.10 ± 1.94%, 62.07 ± 3.38 and 71.61 ± 2.06%, 20.01 ± 1.39 and 21.34 ± 0.89%, and 0.80 ± 0.10 and 0.93 ± 0.07, respectively. The estimates of CWT, EMA, BFT, and MS were 0.51 ± 0.13, 0.45 ± 0.13, 0.29 ± 0.09, and 0.22 ± 0.08, respectively. The estimates were moderate for meat quality traits and were 0.37 ± 0.12, 0.40 ± 0.12, 0.33 ± 0.10, 0.33 ± 0.10, 0.30 ± 0.11, and 0.24 ± 0.09 for L*, WBSF, IMF, WHC, and protein and ash content, respectively, in LD muscle; estimates from SM muscle were comparatively low (0.08 ± 0.06 to 0.25 ± 0.09). Estimates of for a* and b* were also low (0.08 ± 0.06 to 0.13 ± 0.07). Carcass weight had a moderate, positive genetic correlation with EMA (0.60 ± 0.13) and a weak correlation with MS and BFT. The genetic correlations among the 3 colorimeter variants were strong and positive within and between muscles. Intramuscular fat content had moderate to strong and negative genetic correlations with WBSF (-0.49 ± 0.18), WHC (-0.99 ± 0.01), and protein (-0.93 ± 0.04) and ash content (-0.98 ± 0.06) in LD muscle, whereas the associations were less pronounced in SM muscle. In general, CWT and EMA had low genetic and phenotypic correlations with meat quality traits, which suggests that the traits are independent and have distinct genetic contributions in each muscle. Conversely, with few exceptions, meat quality traits had genetic and phenotypic correlations with MS and BFT. In conclusion, the estimated genetic parameters for carcass and meat quality traits could be used for genetic evaluation and breeding programs in Korean Hanwoo cattle populations.

Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice

Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and antisperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h(-1)) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation.

MacroH2A1 downregulation enhances the stem-like properties of bladder cancer cells by transactivation of Lin28B

The histone variant, macroH2A1, has an important role in embryonic stem cell differentiation and tumor progression in various types of tumors. However, the regulatory roles of macroH2A1 on bladder cancer progression have not been fully elucidated. Here, we show that macroH2A1 knockdown promotes stem-like properties of bladder cancer cells. The knockdown of macroH2A1 in bladder cancer cells increased tumorigenicity, radioresistance, degeneration of reactive oxygen species, increased sphere formation capability and an increase in the proportion of side populations. We found that macroH2A1 is required for the suppression of Lin28B identified as a novel downstream target of macroH2A1 in bladder cancer. Loss of macroH2A1 expression significantly correlated with the elevated levels of Lin28B expression and subsequently inhibited the mature let-7 microRNA expression. Furthermore, the stable overexpression of Lin28B enhances the several phenotypes, including tumorigenicity and sphere-forming ability, which are induced by macroH2A1 depletion. Importantly, Lin28B expression was regulated by macroH2A1-mediated reciprocal binding of p300 and EZH2/SUV39H1. Our results suggest that Lin28B/let-7 pathway is tightly regulated by macroH2A1 and its cofactors, and have a pivotal role in the bladder tumor progression and the regulation of stem-like characteristics of bladder cancer cells.

The early protective effect of glutamine pretreatment and ischemia preconditioning in renal ischemia-reperfusion injury of rat

BACKGROUND

Heat shock proteins (HSP) play an important role in protecting cells against stress.

METHODS

Using a rat model, we tested the hypothesis that pretreatment with glutamine (Gln) and ischemia preconditioning (IPC) increase the expression of HSP resulting in attenuation of renal ischemia/reperfusion (I/R) injury. Sprague-Dawley rats were randomized into 4 groups [group I, Gln injection (+), IPC (+); group II, Gln injection (+), IPC (-); group III, saline injection (+), IPC (+); group IV, saline injection (+), IPC (-)]. Renal HSP70 expression was determined by Western blotting and kidney function was assessed by blood urea nitrogen and serum creatinine. Renal cross-sections were microscopically examined for tubular necrosis, exfoliation of tubular epithelial cells, cast formation, and monocyte infiltration.

RESULTS

Gln pretreatment increased intrarenal HSP expression (P = .031). In group I, tubulointerstitial abnormalities were clearly slighter compared with the other groups (P < .001).

CONCLUSION

Our experiments suggest that (1) a single dose of Gln could induce HSP expression and (2) IPC could relieve renal I/R injury. In addition, IPC combined with Gln pretreatment had a synergic protective effect against renal I/R injury.

Insulin Phosphorylates Tyrosine Residue 464 of Tub and Translocates Tubby into the Nucleus in HIRcB Cells

BACKGROUND

The tubby protein has a motif that might be relevant for its action in the insulin signaling pathway. Previous studies have indicated that tubby undergoes phosphorylation on tyrosine residues in response to several stimuli and is known to localize in the nucleus as well as in the plasma membrane. However, the relationship between phosphorylation and nuclear translocation is not well understood. Here, we report that insulin directly phosphorylates tubby, which translocates into the nucleus.

METHODS

The effects of insulin on Tubby were performed with Western blot. The immunoprecipitation and confocal microscopy were performed to prove phosphorylation and nuclear translocation.

RESULTS

Mutation study reveals that tyrosine residue 464 of tubby gene (Tub) is a phosphorylation site activated by insulin. In addition, major portions of tubby protein in the plasma membrane are translocated into the nucleus after insulin treatment. Tyrosine kinase inhibitor pretreatment blocked insulin-induced tubby translocation, suggesting that phosphorylation is important for nuclear translocation. Moreover, mutant tyrosine residue 464 did not translocate into the nucleus in respond to insulin. These findings demonstrate that insulin phosphorylates tyrosine residue 464 of Tub, and this event is important for insulin-induced tubby nuclear translocation.

CONCLUSION

Insulin phosphorylates tyrosine residue 464 of Tub and translocates tubby into the nuclei of HIRcB cells.

Contrast-enhanced magnetic resonance angiography in the early period after kidney transplantation

Our objective was to evaluate the usefulness of three-dimensional (3-D) contrast-enhanced (CE) magnetic resonance angiography (MRA) to assess renal parenchyma, arterial inflow stenosis, and peritransplant fluid collections in the early period after kidney transplantation (KT). Between January 2010 and April 2011, we examined a consecutive series of 144 renal transplants using 3-D CE MRA at 14 days after KT. MRA showed parenchyma infarctions (n = 17, 11.8%), arterial inflow stenoses (n = 23, 16%), lymphoceles (n = 14, 9.7%), and hematomas (n = 6, 4.2%). The degree of renal transplant artery inflow stenosis was graded qualitatively based on diameter criterion; <50% = mild, 50% to 70% = moderate, and >70% = severe in 10 (6.9%), 5 (3.5%), and 8 (5.6%) subjects, respectively. The study recipients were divided into 3 groups according to the degree of renal artery inflow stenosis (group I: normal; group II: mild and moderate, <70%; group III: severe, >70%). Among group III patients who underwent digital subtraction angiography, 5 had percutaneous transluminal angioplasty or stenting performed after 1 month. Their mean resume creatinine levels at 1, 6, and 12 months after transplantation were not significantly different from those in the other groups (P = .391, .447, .110). The prevalence of graft loss (n = 2) was high in group III (P = .012), although the frequency of acute rejection episodes was not different among the groups (P = .890). The incidences of renal parenchyma infarction, peritransplant fluid collection and arterial inflow stenosis were unexpectedly high in the early period after KT. Thus, 3-D CE MRA provided a rapid global assessment of the renal parenchyma, transplant arterial system, and peritransplant fluid collection that can be helpful to detect or exclude many causes of renal transplant dysfunction.

Ginsenoside-Rp1 inhibits platelet activation and thrombus formation via impaired glycoprotein VI signalling pathway, tyrosine phosphorylation and MAPK activation

BACKGROUND AND PURPOSE

Ginsenosides are the main constituents for the pharmacological effects of Panax ginseng. Such effects of ginsenosides including cardioprotective and anti-platelet activities have shown stability and bioavailability limitations. However, information on the anti-platelet activity of ginsenoside-Rp1 (G-Rp1), a stable derivative of ginsenoside-Rg3, is scarce. We examined the ability of G-Rp1 to modulate agonist-induced platelet activation.

EXPERIMENTAL APPROACH

G-Rp1 in vitro and ex vivo effects on agonist-induced platelet-aggregation, granule-secretion, [Ca(2+) ](i) mobilization, integrin-α(IIb) β(3) activation were examined. Vasodilator-stimulated phosphoprotein (VASP) and MAPK expressions and levels of tyrosine phosphorylation of the glycoprotein VI (GPVI) signalling pathway components were also studied. G-Rp1 effects on arteriovenous shunt thrombus formation in rats or tail bleeding time and ex vivo coagulation time in mice were determined. KEY RESULT: G-Rp1 markedly inhibited platelet aggregation induced by collagen, thrombin or ADP. While G-Rp1 elevated cAMP levels, it dose-dependently suppressed collagen-induced ATP-release, thromboxane secretion, p-selectin expression, [Ca(2+) ](i) mobilization and α(IIb) β(3) activation and attenuated p38(MAPK) and ERK2 activation. Furthermore, G-Rp1 inhibited tyrosine phosphorylation of multiple components (Fyn, Lyn, Syk, LAT, PI3K and PLCγ2) of the GPVI signalling pathway. G-Rp1 inhibited in vivo thrombus formation and ex vivo platelet aggregation and ATP secretion without affecting tail bleeding time and coagulation time, respectively.

CONCLUSION AND IMPLICATIONS

G-Rp1 inhibits collagen-induced platelet activation and thrombus formation through modulation of early GPVI signalling events, and this effect involves VASP stimulation, and ERK2 and p38(-MAPK) inhibition. These data suggest that G-Rp1 may have therapeutic potential for the treatment of cardiovascular diseases involving aberrant platelet activation.

Does donor kidney to recipient body weight ratio influence long-term outcomes of living-donor kidney transplantation?

This study evaluated the effect of the donor kidney to recipient body weight (Kw/Rw) ratio on long-term graft function and survival. We investigated retrospectively whether there was any association between Kw/Rw ratio and long-term graft survival and function after a follow-up of >10 years. We studied a consecutive series of 123 adult-to-adult living kidney transplants. According to the Kw/Rw ratio, patients were divided into 3 groups: "low" (Kw/Rw <2.85; n = 29), "medium" (2.85 ≤ Kw/Rw < 4.04; n = 63), and "high" (≥4.04; n = 31). Among the 3 groups, the mean serum creatinine levels at 1 and 6 months as well as 1 year after transplantation were significantly lower among patients with a high Kw/Rw ratio than in those with a medium or low ratio, but serum creatinine levels at 3 and 5 years did not differ significantly (P = .394 and 0.620, respectively). Graft survival rates at 5 and 10 years after transplantation were significantly lower in the "low" group. We observed a significant association between Kw/Rw ratio and graft survival (P = .018). The Kw/Rw ratio is an important factor for long-term graft survival and early graft function. However, it did not significantly affect subsequent renal function.

Hypoxia induces Wee1 expression and attenuates hydrogen peroxide-induced endothelial damage in MS1 cells

In an oxygen-depleted environment, endothelial cells initiate an adaptive pattern of synthesis, which may enable them to survive hypoxic crises. Using high-resolution two-dimensional gel electrophoresis in conjunction with mass spectroscopy, we obtained a 24 differential display of proteins in the pancreatic endothelial cell line, MS-1, at four time points following induction of hypoxia. The induction of Wee1 under hypoxia was confirmed both at the mRNA and protein levels. The phosphorylation of cell division cycle 2, which is downstream of Wee1, was also increased after hypoxic exposure. In addition, pre-exposure to hypoxia attenuated a decrease in hydrogen peroxide-induced cell number. The induction of bax (a pro-apoptotic protein) and reduction of bcl (an anti-apoptotic protein) after hypoxia stimulus were also attenuated by hypoxic pre-exposure. Moreover, hydrogen peroxide-induced morphologic damage did not appear in the wild-type Wee1-expressing cells. Taken together, our results suggest that Wee1 may have important role in hypoxia- induced pathophysiological situations in endothelial cells.

Pesticide poisonings in South Korea: findings from the National Hospital Discharge Survey 2004-2006

OBJECTIVES

Pesticide poisoning stands as a major public health issue worldwide. The objective of this study was to examine the epidemiologic characteristics of pesticide-related hospitalizations in South Korea.

METHODS

Data from the Korea National Hospital Discharge Survey were analyzed to describe the epidemiologic characteristics of pesticide poisoning among hospitalized patients from 2004 through 2006. Pesticide-related hospitalizations were identified using the International Classification of Diseases, Tenth Revision codes. National estimates of pesticide-related hospitalizations were calculated using sampling weights for number of hospitalizations.

RESULTS

A total of 25,982 pesticide-related hospitalizations were estimated during the years 2004-2006, yielding an average annual pesticide-related hospitalization rate of 17.8 per 100,000 population in South Korea. Age-specific rates for pesticide-related hospitalization increased with age, with the highest rate noted among those aged 70 or above. The majority of pesticide-related hospitalization was cases of intentional poisoning in rural areas. Seasonal variation in the rate was observed, with summer being the highest among both men and women.

CONCLUSIONS

Pesticide-related hospitalization is prevalent and demonstrates demographic and seasonal and regional variations. More effective strategies to reduce pesticide-related hospitalizations are required in South Korea.

Biodegradation of estrogen conjugates by bacteria isolated from river sediments

The objective of this study was to investigate the ability of E. coli in river sediments to degrade estrogen conjugates. Biodegradation experiments on glucuronide estrogens (E1-GLU, E2-GLU and E3-GLU) using E. coli, non-E. coli bacteria as well as sediment crude extracts were carried out in batch mode. A pure identified E. coli strain (KCTC 2571) was used for comparison of enzyme activity. The results showed that the degradation rate of estrogen conjugates by KCTC 2571 and E. coli isolated from sediments followed a similar trend. Fecal bacteria showed a high ability to deconjugate glucuronided estrogens. Approximately 50% of glucuronide moieties were cleaved within 4 h of contact time in experiments using pure E. coli. The degradation rate was slower in experiments using crude extracts of sediments, and conjugated estrogens were not completely degraded even after 12 h of reaction. These results provide a clear understanding of the fate and behavior of estrogen by bacteria in the environment.

Role of arachidonic acid-derived metabolites in the control of pulmonary arterial pressure and hypoxic pulmonary vasoconstriction in rats

BACKGROUND

The roles of arachidonic acid (AA) metabolites in hypoxia-induced pulmonary vasoconstriction (HPV), a critical physiological mechanism that prevents ventilation/perfusion mismatch, are still incompletely understood.

METHODS

Pulmonary arterial pressure was measured in ventilated/perfused rat lungs. Isometric tones of rat intralobar pulmonary arteries were also measured, using a myograph.

RESULTS

Hypoxia (Po₂, 3%)-induced pulmonary arterial pressure increases (ΔPAP(hypox)) were stable with blood-mixed perfusate, but decayed spontaneously. ΔPAP(hypox) was inhibited by 29%, 16%, and 28% by the thromboxane A₂ (TXA₂) antagonist SQ-29548, the 5-lipoxygenase inhibitor, MK886, and the leukotriene D₄ antagonist, LY-171883, respectively. The prostacyclin synthase inhibitor tranylcypromine augmented ΔPAP(hypox) by 5%, whereas inhibition of cytochrome P450 did not affect ΔPAP(hypox). Consistently, the TXA₂ analogue U46619 increased ΔPAP(hypox) whereas prostacyclin abolished ΔPAP(hypox). However, leukotriene D₄ had no direct effect on ΔPAP(hypox). In the isolated pulmonary arteries, pretreatment with U46619 was essential to demonstrate hypoxia-induced contraction.

CONCLUSIONS

The above results suggest that TXA₂ and cysteinyl leukotrienes, other than leukotriene D₄, are endogenous factors that facilitate HPV in rats. The indispensable role of TXA₂-induced pretone in the HPV of isolated pulmonary arteries indicates that the signal from thromboxane receptors might be a critical component of oxygen sensation mechanisms.

The efficacy of repeated radiofrequency medial branch neurotomy for lumbar facet syndrome

OBJECTIVE

Radiofrequency (RF) medial branch neurotomy is an effective management of lumbar facet syndrome. However, pain may recur after period of time. When pain recurs, it can be repeated, but the successful outcome and duration of relief from repeated procedures are not clearly known. The objective of this study was to determine the success rate and duration of pain relief from repeated radiofrequency medial branch neurotomy for lumbar facet syndrome.

METHODS

A retrospective review of medical records was done on 60 consecutive patients, from March of 2006 to February of 2009, who had an initial successful RF neurotomy but subsequently underwent repeated procedures due to recurrence of pain. All procedures were done in carefully selected patients after at least two responsive medial branch nerve blocks. C-arm fluoroscopic guide, impedance, sensory and motor threshold monitoring tools were used for the precise placement of electrodes. Responses of repeated procedures were compared with initial radiofrequency neurotomy for success rates and duration of pain relief.

RESULTS

There were 48 females and 12 males. Mean age was 52.4 years (range, 26-83). RF medial branch neurotomy was done on one side in 38 and both sides in 22 patients, each covering at least three segments. Average visual analog scale at last procedure was 6.8. Twelve patients had previous lumbar operations, including 4 patients with instrumentations. Fifty-five patients had two procedures and five patients had three procedures. Mean duration of successful pain relief (> 50% of previous pain for at least 3 months period) after initial radiofrequency neurotomy was 10.9 months (range, 3-28) in 51 (85%) patients. From repeated procedures, successful pain relief was seen in 50 (91%) patients with average duration of 10.2 months (range, 3-24). Five patients had third procedure, which was successful in 4 (80%) patients with mean duration of 9.8 months (range, 5-16). This was not statistically different from initial results. There were no permanent neurological complications from the procedures.

CONCLUSION

Results of this study indicate that the frequency of success and durations of relief from repeated RF medial branch neurotomy for lumbar facet syndrome are similar to initial results that provided relatively prolonged period of pain relief without major side effects. Each procedure seems to provide successful pain relief for about 10 months in more than 85% of carefully selected patients when properly done.

Pseudomonas stutzeri YPL-1 Genetic Transformation and Antifungal Mechanism against Fusarium solani, an Agent of Plant Root Rot

An actively antagonistic bacterium that could be used as a biocontrol agent against Fusarium solani, which causes root rots with considerable losses in many important crops, was isolated from a ginseng rhizosphere and identified as a strain of Pseudomonas stutzeri. In several biochemical tests with culture filtrates of P. stutzeri YPL-1 and in mutational analyses of antifungal activities of reinforced or defective mutants, we found that the anti-F. solani mechanism of the bacterium may involve a lytic enzyme rather than a toxic substance or antibiotic. P. stutzeri YPL-1 produced extracellular chitinase and laminarinase when grown on different polymers such as chitin, laminarin, or F. solani mycelium. These lytic extracellular enzymes markedly inhibited mycelial growth rather than spore germination and also caused lysis of F. solani mycelia and germ tubes. Scanning electron microscopy revealed degradation of the F. solani mycelium. Abnormal hyphal swelling and retreating were caused by the lysing agents from P. stutzeri YPL-1, and a penetration hole was formed on the hyphae in the region of interaction with the bacterium; the walls of this region were rapidly lysed, causing leakage of protoplasm. Genetically bred P. stutzeri YPL-1 was obtained by transformation of the bacterium with a broad-host-range vector, pKT230. Also, the best conditions for the transformation were investigated.

CPAP of 10 cmH2O during cardiopulmonary bypass followed by an alveolar recruitment manoeuvre does not improve post-bypass oxygenation compared to a recruitment manoeuvre alone in children

This randomised controlled study assessed whether continuous positive airway pressure (CPAP) of 10 cmH2O during cardiopulmonary bypass improves post-bypass oxygenation in children compared with no CPAP during bypass. We studied children with a ventricular septal defect. CPAP of 10 cmH2O was applied during bypass in the CPAP group (n=24), whereas the lungs were left deflated in the control group (n=20). In both groups, an alveolar recruitment maneuver was performed by applying positive pressure of 30 to 40 cmH2O for five seconds before weaning from bypass. Postoperative ventilation had the peak inflation pressure set to produce an expired tidal volume of 8 ml/kg with positive end expiratory pressure of 5 cmH2O. Arterial blood gas and haemodynamic measurements were performed at skin incision, five minutes after weaning from bypass, five minutes after chest closure and four hours after arrival in the intensive care unit. In four children CPAP was discontinued because it adversely affected the operating field. There was no difference in demographic characteristics, haemodynamic data, bypass time and operation time. No difference was observed between the groups with respect to pH, PaO2, P(A-a) DO2, PaCO2, and ETCO2 at each time. Variability in the data was greater than expected, leading to a decrease in the expected power of the study. CPAP at 10 cmH2O during bypass was not found to improve the post-bypass oxygenation as compared with leaving the lung deflated during bypass in children undergoing ventricular septal defect repair who had an alveolar recruitment maneuver at the end of bypass.

Practical anatomic landmarks for determining the insertion depth of central venous catheter in paediatric patients

BACKGROUND

Various methods have been recommended to decide a proper insertion depth of central venous catheter (CVC). The carina is recommended as a useful target level for the CVC tip position. We evaluated the sternal head of a right clavicle and the nipples as anatomic landmarks for determining the optimal depth of CVC in paediatric patients.

METHODS

Ninety children, <5 yr, undergoing catheterization through the right internal jugular vein were enrolled. The insertion depth was determined as follows. The insertion point was designated as 'Point I'. The sternal head of the right clavicle was called 'Point A' and the midpoint of the perpendicular line drawn from Point A to the line connecting both nipples was called 'Point B'. The insertion depth of CVC was determined by adding the two distances (from I to A and from A to B) and subtracting 0.5 cm from this. A chest radiography was taken and the distance of the CVC tip from the carina level was measured by the Picture Archiving and Communicating System.

RESULTS

The mean distance of the CVC tip from the carina level was 0.1 (1.0) (P=0.293) cm above the carina (95% CI 0.1 cm below the carina-0.3 cm above the carina). There was no specific relationship between the distance of the CVC tip from the carina level and the patients' age, height, and weight.

CONCLUSIONS

The CVC tip could be placed near the carina by using the external landmarks without any formulae, images, and devices in children in our study.

Toxicity of artificial runoff fostered with dry deposition particulates from industrial, commercial, and highway area in Gwangju, Korea

The adverse effects of rainwater and artificial urban runoff (an imitation of urban runoff during rainfall event) were investigated using a battery of bioassays employing three test species. Urban dusts were collected at three representative sites; commercial, industrial and highway areas. The water quality parameters of rainwater and artificial runoff revealed low hardness (23.4 approximately 34.2 mg*L(-1) as CaCO(3)) and alkalinity (7.0 approximately 34.2 mg*L(-1) as CaCO(3)). High toxicities were observed in the bioassays for the artificial runoffs. The average toxic units for D. magna, S. capricornutum, and O. latipes were 1.26(+/-0.84), 1.34(+/-1.10) and 2.05(+/-1.08), respectively. Of these species, O. latipes revealed significantly higher toxicity compared to D. magna and S. capricornutum (p < 0.05). Embryo lesions were observed with 6.25% treatments, and these significantly increased at 12.5% treatments (p < 0.05). The EC(50) values for each artificial runoff were 22.5, 22.6 and 25.4% for commercial, industrial and highway areas, respectively. With 12.5% treatment, significant delays in hatching times were observed (p < 0.05); all embryos tested did not hatched at 100% treatment. Similarly, a significant decrease in hatching success was observed at every sampling point from 25% treatment (p < 0.05). The adverse effects of artificial runoff on the three test species suggests that urban surface runoff can cause significant impairment in aquatic ecosystems.

Primary Adrenal Lymphoma Presenting with Cauda Equina Syndrome

Primary adrenal lymphoma (PAL) is an extremely rare extranodal lymphoma. Moreover, cauda equina syndrome (CES) as a first sign of a primary adrenal lymphoma is very exceptional. Here, we report a 35-year-old man was admitted because of primary adrenal lymphoma presenting with CES. He was treated with chemotherapy including rituximab, cyclophosphamide, vincristine, adriamycin, and prednisolone (R-CHOP). At present 30 months after chemotherapy of R-CHOP, the patient is considered free of tumor. The good results obtained for our case could be due to the relative early detection by CES and the use of combination of monoclonal antibody (R-CHOP).

GlideScope video laryngoscope: a randomized clinical trial in 203 paediatric patients

BACKGROUND

The GlideScope intubating device has been reported to provide a comparable or superior laryngoscopic view compared with direct laryngoscopy in adults. This study compared the use of the GlideScope with direct laryngoscopy for the laryngoscopic view and intubation time in children.

METHODS

The laryngoscopic view in 203 children was scored using both the Macintosh laryngoscope and the GlideScope using Cormack and Lehane (C&L) grades. After scoring each laryngoscopic view with and without BURP, the patients were randomly allocated to two groups. The trachea was intubated using direct laryngoscopy (Group DL, n=100) or the GlideScope (Group GS, n=103). We compared C&L grades for the two views in the same patient, and also the time to intubate for each group.

RESULTS

The GlideScope improved the view without BURP in the patients with C&L grade 2 (16/26, P<0.01) and with C&L grades 3 and 4 (7/11, P<0.05). The view with BURP was also improved by the GlideScope in C&L grade 2 (4/9, P<0.05) and with C&L grades 3 and 4 (4/5, P=0.059). The mean time for tracheal intubation was 36.0 (17.9) s in the GS group and 23.8 (13.9) s in the DL group (P<0.001).

CONCLUSIONS

In children, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy but required a longer time for intubation.

Alternative method for predicting optimal insertion depth of the laryngeal tube in children

BACKGROUND

Little information is available about the accuracy of the teeth mark on the laryngeal tube (LT) as a guide to correct placement in children. The aim of this crossover study was to evaluate three methods for optimal insertion depth of the size (#) 2 tube in children weighing 12-25 kg.

METHOD

In 24 children, the LT #2 was consecutively inserted by three different methods: (A) until the thick teeth mark on the tube was aligned with the upper incisors, (B) until resistance was felt, and (C) by inserting to a depth, previously measured, of the curved distance between the cricoid cartilage and the upper incisor. In each case, the depth of insertion, the degree of effective ventilation, the presence of leakage, and the fibreoptic view were assessed.

RESULTS

Insertion based on the teeth mark led to a shorter insertion depth and a greater incidence of inadequate ventilation compared with the other two methods. There was no difference in the adequacy of ventilation between methods B and C. The vocal cords were more easily identified with methods B (62.5%) and C (75%) than with method A (12.5%).

CONCLUSIONS

Insertion of the LT #2 aligned with the teeth mark can result in a shallow insertion depth and inadequate ventilation. The measured distance from the cricoid cartilage to the upper incisor offers alternative guidance for correct LT insertion.

Spinal cord infarction after decompressive laminectomy for spontaneous spinal epidural hematoma--case report

A 68-year-old woman presented to the emergency department for evaluation of bilateral leg weakness. On admission, she had paraparesis with incomplete sensory deficit. Magnetic resonance (MR) imaging of the thoracolumbar spine revealed spontaneous spinal epidural hematoma (SSEH) compressing the spinal cord. The patient was taken to the operating room for urgent surgical decompression and evacuation of the SSEH. After the surgery, she woke up with complete paraplegia. Postoperative MR imaging showed the spinal cord was edematous, with minimal remnant hematoma. MR imaging after 1 month clearly showed anterior spinal artery thrombosis. No significant neurological improvement occurred during the 3-month follow up. Surgeons should consider the possibility of this devastating complication before aggressive and early surgical intervention in a patient with SSEH causing cord compression and neurological deficit.

Long term results from percutaneous radiofrequency neurotomy on posterior primary ramus in patients with chronic low back pain

PURPOSE

We report on our experience of percutaneous radiofrequency neurotomy (PRN) on the posterior primary ramus (PPR) with at least two years follow-up.

METHODS

228 patients underwent PRN on the PPR for refractory low back pain. 128 patients met the inclusion criteria of facetal originated pain (group II), while 100 patients did not (group I). Radiofrequency (RF) procedures were applied in the usual manner. Pain relief was assessed at 1 week, 1 month, 6 months and 2 years using visual analog scale (VAS).

FINDINGS

Positive responders were 56% at 1 week, 46% at 1 month, 18% at 6 months, and 13% at 2 years after PRN in group I, and 78.9% at 1 week, 75.4% at 1 month, 62.5% at 6 months, and 54.7% at 2 years in group II. Prominent local tenderness, percussion tenderness, pain on getting up, extension and transitional movement, radiating pain on buttock and/or posterior thigh, and good immediate response were found to be significantly related to good outcome.

CONCLUSION

PRN on the PPR has long-term beneficial effects. Long-term good results can be achieved after proper selection of patients with facet joint related low back pain.

Clinical efficacy of radiofrequency cervical zygapophyseal neurotomy in patients with chronic cervicogenic headache

The purpose of the present study was to assess the clinical efficacy of radiofrequency (RF) cervical zygapophyseal joint neurotomy in patients with cervicogenic headache. A total of thirty consecutive patients suffering from chronic cervicogenic headaches for longer than 6 months and showing a pain relief by greater than 50% from diagnostic/prognostic blocks were included in the study. These patients were treated with RF neurotomy of the cervical zygapophyseal joints and were subsequently assessed at 1 week, 1 month, 6 months, and at 12 months following the treatment. The results of this study showed that RF neurotomy of the cervical zygapophyseal joints significantly reduced the headache severity in 22 patients (73.3%) at 12 months after the treatment. In conclusion, RF cervical zygapophyseal joint neurotomy has shown to provide substantial pain relief in patients with chronic cervicogenic headache when carefully selected.

A new and simple transection knife for study of neurodegeneration and neuroregeneration in animal model

BACKGROUND

The purpose of this study was to design and make a simple, inexpensive brain knife that could produce consistent results following transection in animal model.

MATERIALS AND METHODS

After testing various materials including commercially available products, microelectrode recording needles as used in deep brain stimulation (DBS) surgery were selected as ideal candidates. They were modified to serve as type of wire-knife for the purposes of study. For this study, the major pathway for dopaminergic neuron from substantia nigra to striatum was selected for transection. A total of 40 Sprague-Dawley rats were assigned to 8 groups; normal, 1-4, 6, 8, and 10 weeks post-transection. Degree of cell death was determined and surviving neurons were counted by means of fluorescent microscopic examination, immunohistochemistry involving tyrosine hydroxylase (TH)-immunoreactive staining, and mapping to verify complete transection.

RESULTS

Compared to control, percentage of remaining neurons in each group was 61.3, 36.8, 29.9, 5.1, 5.9, 7.0%, respectively. Completeness of lesion was correlated with the absence of TH-immunoreactivity in the striatum.

CONCLUSION

Our model seems to provide complete cell death in early period after transection with consistent results. Thus, this type of brain knife can be very handy, without any extra cost, in any research model involving transection of fiber bundle for studies on neurodegeneration and neuroregeneration.

Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters

Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.

Depth of a central venous catheter tip: length of insertion guideline for pediatric patients

BACKGROUND

In pediatric patients, several studies have been undertaken to establish central venous catheter (CVC) tip optimal depth. Assessments of catheter tip position using chest radiographs may be misleading, whereas transesophageal echocardiography (TEE) has been shown to accurately monitor catheter tip placement at the superior vena cava-right atrial (SVC-RA) junction. The aim of this study was to issue a guideline for ideal catheter insertion depth, from the right internal jugular vein (IJV) using TEE to confirm the position of the catheter tip at the SVC-RA junction.

METHODS

Over a 6-month period, we studied 60 right internal jugular vein catheterizations in infants and children undergoing surgery for congenital heart disease. Positions of CVC tips were confirmed to be at the SVC-RA junction by TEE. Distance from the skin puncture site to the SVC-RA junction, height, weight, and age were recorded.

RESULTS

Distances measured were found to be highly correlated with patient height. The following guideline allows the CVC tip to be positioned above the RA in 97.5% of patients with an accuracy of 95%: optimal depth of insertion (cm) = 1.7 + (0.07 x height) in patients whose height is between 40 and 140 cm.

CONCLUSION

The model proposed for the insertion of the CVC tip in pediatric patients could be used to prevent inadvertent catheter tip placement into the atrium.

Dissimilatory Fe(III) reduction by an electrochemically active lactic acid bacterium phylogenetically related to Enterococcus gallinarum isolated from submerged soil

AIMS

The isolation and identification of a glucose-oxidizing Fe(III)-reducing bacteria (FRB) with electrochemical activity from an anoxic environment, and characterization of the role of Fe(III) in its metabolism.

METHODS AND RESULTS

A Gram-positive (Firmicutes), nonmotile, coccoid and facultative anaerobic FRB was isolated based on its ability to reduce Fe(III). Using the Vitek Gram-positive identification card kit and 16S rRNA gene sequence analysis, the isolate was identified as Enterococcus gallinarum, designated strain MG25. On glucose this isolate produced lactate plus small amounts of acetate, formate and CO2 and its growth rates were similar in the presence and absence of Fe(O)OH. These results suggest that MG25 can couple glucose oxidation to Fe(III) reduction, but without conservation of energy to support growth. Cyclic voltammetry showed that strain MG25 was electrochemically active.

CONCLUSIONS

An electrochemically active and FRB, E. gallinarum MG25, was isolated from submerged soil. Fe(III) is used in the bacterial metabolism as an electron sink.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report concerning the electrochemical activity of glucose-oxidizing FRB, E. gallinarum. This organism and others like it could be used as new biocatalysts to improve the performance of a mediator-less microbial fuel cell.

Usefulness of the carina as a radiographic landmark for central venous catheter placement in paediatric patients † †Presented, in part, at the 2005 Annual Meeting of European Society of Anaesthesiologists, Vienna, Austria

BACKGROUND

Several reports have proposed radiographic landmarks for the proper positioning of central venous catheters (CVC). The carina is one of the proposed landmarks in adults. Here, we evaluate the possibility of using the carina as a radiographic landmark for the identification of proper positioning of the CVC tip in paediatric patients.

METHODS

We studied 57 right internal jugular vein catheterizations in infants and children undergoing surgery for the treatment of congenital heart disease. After placing the CVC tip at the junction of the superior vena cava and the right atrium (SVC-RA junction) via intraoperative transoesophageal echocardiography, and by taking postoperative anterior-posterior chest radiographs, we measured the longitudinal distance from the carina to the SVC-RA junction, using the Picture Archiving and Communicating System.

RESULTS

The average distance between the carina and the SVC-RA junction was 1.5 cm (95% CI 1.3-1.8 cm). No catheter tip was above the carina. Although there was no particular relationship between this distance and the patient's age, height, or weight, the distance between the carina and the SVC-RA junction tended to be more variable in younger and smaller children.

CONCLUSIONS

The carina can be used as a radiographic landmark for the proper CVC tip placement in paediatric patients. If the tip of the CVC is not distal to the carina the chances are minute that it is in the right atrium.

New immobilization method for immunoaffinity biosensors by using thiolated proteins

A new immobilization method for immunoaffinity (IA) biosensors that ensures the high surface density and the stability of the IA layer was developed. For the immobilization of biomolecules, the molecular recognition protein was first thiolated by covalent conjugation of mercaptopropionic acid, and then the thiolated protein was attached on the gold surface of the transducer. In this work, horseradish peroxidase (HRP) and its antibody were used as a model antigen-antibody, and the following properties of the IA layer prepared by thiolated protein were estimated: (i) biological integrity of HRP after the immobilization process by using activity assay, (ii) charge transfer resistance by immobilization, (iii) mass loading by the surface plasmon resonance (SPR) biosensor, (iv) number of binding sites, and (v) feasibility test for the measurement of capacitive change by the antigen-antibody interaction. Based on these parameters, the immobilization method by using thiolated protein was determined to be feasible for application to IA biosensors.

Bioleaching of cadmium and nickel from synthetic sediments by Acidithiobacillus ferrooxidans

The microbial leaching process was evaluated for the treatment of synthetic sediments contaminated with cadmium and nickel sulfides. A series of batch leaching experiments was conducted to compare metal solubilization in sediment inoculated with Acidithiobacillus ferrooxidans -inoculated sediments to that in sterile control sediment. The rate and extent of metal solubilization were significantly higher in A. ferrooxidans -inoculated reactors than in acidified sterile reactors. The efficiency of cadmium (Cd) solubilization (80) in the bioleaching process was higher than that of nickel (Ni) solubilization (60). The performance of leaching reactors containing only culture supernatants was comparable to that of A. ferrooxidans -inoculated reactors, indicating that indirect non-contact leaching by the products of microbial metabolism is the predominant mechanism for metal solubilization rather than direct microbial sulfide oxidation. Moreover, the similar (60-75%) extents of Cd(2+) leaching with A. ferrooxidans , cell-free filtrate, and Fe(3+) suggest that abiotic oxidation of CdS by Fe(3+) controls the overall leaching rate, and the role of A. ferrooxidans is most likely not to oxidize CdS mineral directly but to regenerate Fe(3+) as an oxidant.

Correlation of bispectral index with end-tidal sevoflurane concentration and age in infants and children

BACKGROUND

The bispectral index (BIS) has been evaluated as a tool for measuring depth of anaesthesia, but the use of BIS in a paediatric population is still controversial. This study was designed to evaluate the correlation of BIS with end-tidal sevoflurane concentration and age in infants and children.

METHODS

Eighty-one patients undergoing elective urology surgery were allocated into three age groups; 6 months to 2 yr (n=28), 3-7 yr (n=33), and 8-12 yr (n=20). Sevoflurane was administered to achieve steady-state end-tidal sevoflurane concentrations (ET(sevo)) of 2.0, 3.0, and 4.0%; these were achieved consecutively either from the lowest or from the highest concentration. The BIS (version XP) was monitored continuously.

RESULTS

In all three groups, BIS decreased significantly when ET(sevo) increased from 2.0 to 3.0% but there was a paradoxical increase in BIS values when ET(sevo) increased from 3.0 to 4.0%. The non-linear regression analysis showed a significant correlation between BIS and age at each ET(sevo). The younger patients showed the higher BIS values.

CONCLUSIONS

In children aged 6 months to 12 yr, the BIS increased paradoxically as ET(sevo) increased from 3.0 to 4.0%. BIS values showed a wide variation in the same ET(sevo) and the age itself was considered to be a factor affecting the BIS values.

Transfusion for a patient of cis-AB blood type undergoing a redo cardiac operation

cis-AB, a rare ABO genotype, is the result of a mutated gene resulting in dual specific hybrid enzymes. A single-point mutation reverses the specificity of human blood group B synthesizing galactosyltransferase. This may lead to misclassification in ABO grouping and adverse transfusion reactions. Recently, the authors experienced a case of a patient with cis-AB blood type undergoing pulmonary valve replacement and tricuspid valvuloplasty. We transfused the patient with Rh+ A packed red blood cell, fresh frozen plasma and platelet concentrates without any clinically significant transfusion reactions.

Early and late reversal of rocuronium with pyridostigmine during sevoflurane anaesthesia in children

This study investigated the effect of pyridostigmine administered at different levels of recovery of neuromuscular function after rocuronium during sevoflurane anaesthesia in children. Fifty-one patients aged 3 to 10 years, ASA physical status 1 or 2 were randomized to 4 groups: a spontaneous recovery group; or, reversal with pyridostigmine 0.25 mg/kg with glycopyrrolate 0.01 mg/kg at one of three times: 5 minutes after rocuronium administration; at 1% twitch height (T1) recovery; or at a 25% twitch height (T25) recovery. Anaesthesia was induced with thiopentone (5-7 mg/kg) and maintained with 2-3% sevoflurane and 50% nitrous oxide. Atropine (0.015 mg/kg) and, after calibrating the TOF-Watch, rocuronium (0.6 mg/kg) were then administered. Maximal block occurred 1.1+/-0.5 min (mean, SD) after rocuronium administration. In the spontaneous recovery group, the clinical duration (recovery to T25) was 40.1+/-8.8 min and the recovery index (time between T25 and T75) 19.9+/-9.8 min. Recovery to TOF >0.9 from the time of rocuronium administration was reduced by approximately 30% in the pyridostigmine groups compared to the spontaneous recovery group. There was no significant difference among the three pyridostigmine groups. When pyridostigmine was given at T1 or T25, the time from pyridostigmine administration to TOF >0.9 was shorter than for the group receiving pyridostigmine 5 minutes after rocuronium.

Comparison of Central Venous Catheterization Sites in Infants

This study aimed to compare the rates of success and complications between different sites of central venous catheterization in infants. A total of 272 infants were randomized to four groups: right subclavian group (G-RSCV), right internal jugular group (G-RIJV), left subclavian group (G-LSCV) and left internal jugular vein group (G-LIJV). In 77.2% of the patients, we successfully introduced a catheter at the first attempt. The rate of successful catheter placement was highest in the RIJV (RIJV 89.7%, LIJV 79.4%, RSCV 66.2% and LSCV 55.9%). With regard to complications, the rate of arterial puncture, guide wire advancement failure and malpositioning of the catheter were all significantly more frequent during SCV catheterization (SCV versus IJV: 10.1% versus 2.1%, 12.4% versus 0% and 13.4% versus 0.6%, respectively). Our results imply that IJV, especially RIJV, should be the first choice for central venous catheterization in infants.

Ion channels of Fasciola hepatica incorporated into planar lipid bilayers

Ion channels are important target sites of anthelmintics, but little is known about those in Fasciola hepatica. In this work, we applied a planar lipid bilayer technique to characterize the properties of single ion channels in F. hepatica. Under a 200/40 mM KCl gradient, a large conductance channel of 251 pS was observed in 18% of the membranes studied. The channel was selective to K(+) over Cl(-) with a permeability ratio of K(+) to Cl(-) (PK/PCl) of 4.9. Open state probability (Po) of the channel was less than 0.5 and dependent on voltage (-60 to approximately +40 mV) and Ca(2+) (approximately 100 microM). The other two types of single channels observed in 11 and 5% of membranes, respectively, were a K(+)-permeable channel of 80 pS (PK/PCl=4.6) and a Cl(-)-permeable channel of 64 pS (PK/PCl=0.058). Open state probability of both channels showed little voltage dependence. The results indicate that distinct single channels of 60 to approximately 251 pS are present in relative abundance and, in addition, that the planar lipid bilayer technique can be a useful tool for the study of single ion channels in F. hepatica.

The effect of bloodless pump prime on cerebral oxygenation in paediatric patients

BACKGROUND

In paediatric patients, crystalloid prime for cardiopulmonary bypass (CPB) causes further haemodilution in comparison with blood-containing prime. Thus it may affect the cerebral oxygen supply/demand balance. The purpose of the study was to compare the effect of bloodless pump prime with that of blood-containing prime on cerebral oxygenation in children.

METHODS

Thirty-six paediatric patients scheduled for elective repair of atrial or ventricular septal defect were enrolled. In Group C (n = 18), the CPB circuit was primed only with crystalloid. In Group B (n = 18), red blood cells were added to achieve a haematocrit (Hct) of 20% during CPB. The regional cerebral oxygen saturation (rSO(2)) value measured by near-infrared spectroscopy was compared between the two groups.

RESULTS

In both groups, rSO(2) decreased below baseline at the start of CPB and during rewarming (P < 0.001, for both groups during each period). At the start of CPB, haemodilution was greater in Group C than in Group B (Hct 16.1 +/- 0.7% vs. 20.7 +/- 0.5%; P < 0.01), and there was a greater reduction in rSO(2) in Group C (49.0 +/- 5.4% vs. 59.2 +/- 7.0%; P < 0.01). During rewarming, rSO(2) was significantly lower in Group C than in Group B (57.8 +/- 5.3% vs. 62.8 +/- 6.2%; P < 0.01).

CONCLUSIONS

In paediatric patients, the haemodilution associated with crystalloid priming causes a greater reduction in rSO(2) than with blood-containing prime at the starting period of CPB and the rewarming period.

Confinement and processing effects on glass transition temperature and physical aging in ultrathin polymer films: novel fluorescence measurements

Fluorescence intensity measurements of chromophore-doped or -labeled polymers have been used for the first time to determine the effects of decreasing film thickness on glass transition temperature, T(g), the relative strength of the glass transition, and the relative rate of physical aging below T(g) in supported, ultrathin polymer films. The temperature dependence of fluorescence intensity measured in the glassy state of thin and ultrathin films of pyrene-doped polystyrene (PS), poly(isobutyl methacrylate) (PiBMA), and poly(2-vinylpyridine) (P2VP) differs from that in the rubbery state with a transition at T(g). Positive deviations from bulk T(g) are observed in ultrathin PiBMA and P2VP films on silica substrates while substantial negative deviations from bulk T(g) are observed in ultrathin PS films on silica substrates. The relative difference in the temperature dependences of fluorescence intensity in the rubbery and glassy states is usually reduced with decreasing film thickness, indicating that the strength of the glass transition is reduced in thinner films. The temperature dependence of fluorescence intensity also provides useful information on effects of processing history as well as on the degree of polymer-substrate interaction. In addition, when used as a polymer label, a mobility-sensitive rotor chromophore is demonstrated to be useful in measuring relative rates of physical aging in films as thin as 10 nm.

Lack of bioequivalence of two oxytetracycline formulations in the rabbit

Oxytetracycline (OTC) has been used for over 40 years in veterinary medical field. Various forms of oxytetracycline preparations have been marketed, but little information is available on the bioequivalence of OTC preparations. This study was conducted to evaluate the bioequivalence of two OTC powder preparations available in Korea. Fourteen rabbits were randomly allocated into two groups. During the first period, a dose (200 mg/kg) of reference product was orally administered to the rabbits in Group A and test product to those in Group B. After 7-day washout period the reference and test products were given in group B and A, respectively. Blood samples were drawn at 17 points during 48 hours after administration and plasma OTC concentrations were measured by using HPLC. The solution concentrations of OTC dissolved from two products were not significantly different in the dissolution test. The mean area under the curve (AUC0- infinity ) and peak plasma concentration (C(max)) values for test and reference OTCs were 7.22 +/- 3.90 and 11.04 +/- 7.37 microg h/ml, 1.11 +/- 0.65 and 1.85 +/- 1.15 microg/ml, respectively. The relative bioavailability and C(max) of test product to those of reference product was 65.4% and 60.0%, respectively. The ranges of AUC and C(max) of test drug compared to those of reference drug under 90% confidence limits were 27 104% and 28 91.5%, respectively. The results of statistical analysis indicate that the two pivotal pharmacokinetic parameters, AUC and C(max) of test product are not within the 20% of those of the reference, suggesting that the test OTC is not bioequivalent to the reference OTC.

Evaluation of skin surface hydration in Korean psoriasis patients: a possible factor influencing psoriasis

Psoriasis is recognized as a chronic, relapsing disorder of the skin, and its clinical course is influenced by various environmental factors. However, only a few articles have addressed the effect of low epidermal hydration status as an exacerbating factor of psoriasis. Our study was performed to investigate the relationship between subjective assessment and quantified data regarding dryness parameters in psoriasis patients. Seventy psoriasis patients were enrolled in our study. Subjective assessments were undertaken by evaluating the extent of involvement, erythema, scale and infiltration of individual lesions. Functional status of stratum corneum was evaluated by measuring electrical capacitance and conductance of the lesional and uninvolved skin of psoriatic patients. In addition, measurement of trans-epidermal water loss was performed. The results showed poor hydration status and barrier function in involved psoriatic epidermis compared with the uninvolved skin. Subjective assessment showed fairly good correlation with the quantified values. In conclusion, the degree of dryness in psoriatic skin lesions--which we presume to be one of the aggravating factors of psoriasis--seemed to be related to disease severity.

Interface, volume, and thermal attenuation of hot-electron spins in Ni80Fe20 and Co

The relative importance of interface, volume, and thermal scattering in spin-dependent hot-electron transmission of magnetic trilayers is quantified. While interfaces produce significant attenuation (factor 2.2 per interface), the spin asymmetry is dominated by volume scattering. Extracted thermal attenuation lengths (130 A at 300 K for Ni80Fe20) show that thermal spin-wave scattering is stronger than hitherto assumed. This suggests that spontaneous spin-wave emission, rather than the details of the spin-dependent band structure, may cause the strong filtering of minority hot-electron spins.