Morphometric analysis of acetabular dysplasia in cerebral palsy

We carried out a morphometric analysis of acetabular dysplasia in patients with cerebral palsy requiring hip surgery using three-dimensional CT. We evaluated 54 hips in 27 patients. The contralateral normal hips of ten patients with unilateral Perthes’ disease were used as a control group. The acetabular defects were assessed qualitatively as anterior, posterior or global. Quantitative assessments were made using three-directional acetabular indices (anterosuperior, superolateral and posterosuperior) and measured by multiplanar reformation, from which we calculated the acetabular volume.

In the qualitative study, posterior defects were most common in the subluxation group whereas global defects predominated in the dislocation group. In the quantitative study, all acetabular indices in both the subluxation and dislocation groups were higher than those in the control group and the superolateral indices showed a tendency to elevation in the dislocation group. The acetabular volume was largest in the control group, smallest in the dislocation group, and intermediate between the two in the subluxation group.

Shear-dependent aggregation characteristics of red blood cells in a pressure-driven microfluidic channel

Though the aggregation of red blood cells (RBCs) is a major determinant of blood viscosity, there have not been any available techniques to measure the effect of RBC aggregation on blood viscosity over a range of shear rates. The microfluidic shearing technique with vibration has been applied to an aggregometer for measuring the dynamic aggregation characteristic of RBCs. In measuring backscattered light intensity I(t) and pressure p(t) over time, both aggregation and the stress-shear rate information can be determined simultaneously. The feasibility and accuracy of the new aggregation measurement technique has been demonstrated to correlate with blood viscosity for normal and heated blood. We found that RBC aggregability showed shear-dependent behavior, which can be correlated directly with shear-thinning blood viscosity. The present measurements of the dynamic aggregation characteristic over shear rate enable the interpretation of the shear-rate dependent blood viscosity, which is greatly affected by RBC aggregation.

Hereditary amyloidosis in early childhood associated with a novel insertion-deletion (indel) in the fibrinogen Aα chain gene

BACKGROUND

Systemic amyloidosis occurring in early childhood is extremely rare, and is usually of AA type complicating chronic inflammatory diseases. We report the molecular basis of amyloidosis in a Korean girl who presented at 7 years of age with asymptomatic proteinuria and developed amyloid hepatomegaly and end-stage renal failure within 2 years.

METHODS

Renal biopsy showed enlarged glomeruli virtually replaced by amyloid, but without interstitial or vascular involvement. The histologic appearance was identical to that seen in patients with hereditary fibrinogen Aalpha chain Glu526Val amyloidosis, and the amyloid deposits stained specifically with antibodies to fibrinogen. Mutations were sought in the genes of the amyloidogenic proteins, transthyretin, apolipoprotein AI, lysozyme and fibrinogen Aalpha chain genes by polymerase chain reaction (PCR) and sequencing.

RESULTS

A unique frameshift insertion-deletion (indel) mutation was identified in one allele of her fibrinogen Aalpha chain gene, which encodes a partly novel peptide and a premature stop signal, similar to the two previously reported amyloidogenic point deletions at codons 522 and 524 in this molecule. The mutation was absent in samples verified to be from her parents, indicating that it had occurred de novo.

CONCLUSION

This is the first description of hereditary fibrinogen Aalpha chain amyloidosis in an Asian individual, and the distinctive renal histology offered a strong clue to the diagnosis. The disease is potentially curable by combined hepatorenal transplantation.

Intradiscal electrothermal treatment for chronic lower back pain patients with internal disc disruption

Chronic lower back pain is one of the most common musculoskeletal problems; it is also the most expensive industrial injury. Not surprisingly, many treatments have been developed to combat this expensive and debilitating condition. One of these, intradiscal electrothermal treatment (IDET), was developed for patients with chronic discogenic lower back pain who failed to improve with any of the wide variety of non- surgical treatments. The present study sought to evaluate the efficacy of IDET for patients with chronic lower back pain. Twenty-five patients were enrolled in this prospective study; the patients received IDET between June 2001 and June 2003. MRI was used to confirm the diagnosis of internal disc disruption in all patients. The patients then underwent a pre-operative provocative test and discography. The follow-up duration was at least 1 year in all cases, and the visual analogue scale, recovery rate, and satisfaction of each patient were evaluated. The average age of the patients was 32 years (age range 18 to 49 years), and the patient group was 33% male and 67% female. Of the 25 patients, 5 underwent lumbar fusion surgery within 1 year of IDET. After IDET, 8 patients (32%) reported more pain than before, 14 patients (56%) reported less pain, and 3 patients (12%) experienced no change. Twelve patients (48%) were satisfied with IDET, 11 (44%) were dissatisfied, and 2 (8%) were undecided about the treatment. At least 1 year after IDET, nearly half the study patients were dissatisfied with their medical outcome. Consequently, 5 patients (20%) underwent fusion surgery at 1 year after IDET. Although other studies have shown good results with IDET for at least 2 years, this investigation suggests the IDET may be somewhat less effective. In order to firmly establish the efficacy of IDET for treating chronic discogenic lower back pain, additional studies with larger numbers of patients evaluated over longer time periods are recommended.

Effective local control of prostate cancer by intratumoral injection of (166)Ho-chitosan complex (DW-166HC) in rats

PURPOSE

The aim of this study was to evaluate the therapeutic effect and morphological alterations resulting from (166)Ho-chitosan complex (DW-166HC) in an animal model of prostate cancer.

METHODS

First, in a subcutaneous tumor model, 80 rats were randomly divided into four groups (n=20 in each group), and intratumoral injections of 0.05 ml (normal saline in group 1,( 165)Ho-chitosan complex solution in group 2, DW-166HC solution (10 mCi) in group 3, and DW-166HC solution (20 mCi) in group 4) were performed when the tumor measured approximately 1 cm along its long axis in each group. Further, in an orthotopic tumor model, 40 rats were similarly randomly divided into four groups (n=10 in each group), and intraprostatic injections of 0.05 ml [PBS in group 1,( 165)Ho-chitosan complex solution in group 2, DW-166HC solution (0.5 mCi) in group 3 and DW-166HC solution (1 mCi) in group 4] were performed at 1 week after implantation of the AIT cell line in the ventral prostate.

RESULTS

In the subcutaneous tumor model, mean tumor weights of groups 3 and 4 were significantly lower than those of groups 1 and 2 at 2 and 4 weeks post injection (p<0.05). At 2 and 4 weeks after injection in the orthotopic tumor model, the mean weights of the prostate, including tumor, in groups 3 and 4 were also significantly lower than those in groups 1 and 2 (p<0.05). No adverse injury was seen in adjacent organs at histopathologic examination.

CONCLUSION

Intratumoral injection of the beta-emitting radionuclide (166)Ho as a form of complex solution with chitosan appears to be a promising alternative therapeutic modality for the local control of prostate cancer.

Comparison of evidence-based therapeutic intervention between community- and hospital-based primary care clinics

The purpose of this study was to compare the proportion of therapeutic interventions that is supported by scientific evidence between hospital-based and community-based primary care clinics. The study setting is a primary care clinic in university-affiliated tertiary hospital and community-based primary care clinic in a region in Seoul. A retrospective review of patients' medical records was done according to the primary diagnosis and treatment for 890 patients in community-based clinic and 307 in hospital-based clinic. The evidence for the intervention was searched for in Medline (1966-2001) and other evidence-based databases. The evidence was then classified as one of the three categories (i) evidence from randomised controlled trials (RCTs); (ii) convincing non-experimental evidence; and (iii) interventions without substantial evidence. In the hospital-based clinics, out of 356 primary diagnosis and treatment pairs, 59.6% were supported by evidence from at least one RCTs, and 19.4% were supported by convincing non-experimental evidence. In the community-based clinics, 47.1% out of 893 pairs and 10.5% fell into each category. As a result, the proportion of interventions in community settings that were based on evidence meeting our criteria was significantly lower than that of the hospital-based settings. To facilitate evidence-based practice, supportive activity should be focused on the primary care settings based on community where medical practices are less evidence-based.

Muon-spin-rotation measurements of the penetration depth of the infinite-layer electron-doped Sr0.9La0.1CuO2 cuprate superconductor

Muon-spin-rotation (muSR) measurements of the in-plane penetration depth lambda(ab) have been performed in the infinite-layer electron-doped Sr0.9La0.1CuO2 high-T(c) superconductor (HTS). Absence of the magnetic rare-earth ions in this compound allowed us to measure for the first time the absolute value of lambda(ab)(0) in electron-doped HTSs using muSR. We found lambda(ab)(0)=116(2) nm. The zero-temperature depolarization rate sigma(0) proportional, variant 1/lambda(2)(ab)(0)=4.6(1) micros(-1) is more than 4 times higher than expected from the Uemura line. Therefore, this electron-doped HTS does not follow the Uemura relation found for hole-doped HTSs.

Ethanol modulates the expression of GABAB receptor mRNAs in the prenatal rat brain in an age and area dependent manner

Prenatal ethanol exposure has various deleterious effects on neuronal development. As GABA(B) receptor is known to play an important role during the development of the CNS, we now focused on its mRNA expression pattern in the rat brain during the late gestational days (GD) from 15.5 to GD 21.5. Ethanol's effect was also observed from GD 11.5 to GD 21.5. GABA(B1) receptor mRNA showed a high expression level in GD 15.5 and 19.5, while GABA(B2) receptor mRNA did in GD 15.5 and 21.5. The mRNAs levels depended on age and area during development. Ethanol exposure decreased GABA(B1) receptor from GD 11.5 to GD 19.5 with slight increases in GD 21.5. The decreasing effects were area dependent, with the highest effects in the forebrain including cortex, whereas slight effects were observed in the midbrain and hindbrain. The present results suggest an important role of GABA(B) receptor in the effects of ethanol on prenatal brain developmental processes.

Sequence variation in the gene encoding the major capsid protein of Korean fish iridoviruses

Ten iridoviruses were isolated from cultured fish from various regions in Korea; 7 from rock bream, 1 from red sea bream, 1 from sea bass, and 1 from rockfish. The full open-reading frame (ORF) encoding the major capsid protein (MCP) (1362 bp) from ten iridoviruses were sequenced and the nucleotide sequences were phylogenetically analyzed. Phylogenetic analysis revealed that the ten Korean isolates were classified into one cluster. However, their sequences were not identical and, based on the nucleotide sequence variation, they could be further divided into two subgroups. While nine Korean isolates were similar to the Japanese isolate red sea bream iridovirus (RSIV), one isolate was distinct from other iridovirus isolates. These results suggest that a diversity of iridoviruses exist in Korea and that a new variant strain has emerged.

Routine transradial access for conventional cerebral angiography: a single operator's experience of its feasibility and safety

The purpose of this study is to describe a single operator's experience with the feasibility and safety of transradial access in conventional cerebral angiography. 153 patients were enrolled consecutively. Among them, 20 patients were not suitable for transradial access. A Simmons catheter was used. Haemostasis was achieved using a compressive dressing of the wrist. We analysed the success rates of the arterial puncture and the successful catheterization rate for each supra-aortic vessel as well as all complications. The arterial access was successful in 96.3%. The supra-aortic vessels were catheterized with success rates of 99.2% (127/128) for the left subclavian artery and 100% for the other arteries. The mean procedure time was 19.3 min (range 10-55 min). Haemostasis was successfully achieved in every case. The most frequent complication was arm pain which occurred in 37 patients (28.9%). In conclusion, transradial selective cerebral angiography with a reversed-angle catheter is technically feasible and safe. It might be helpful in imaging follow-up of patients with arterial stenting or coil embolisation of the cerebral aneurysms. Modification of the catheter design is required to improve the selectivity of the supra-aortic branches.

Familiarity with, knowledge of, and attitudes toward epilepsy in residents of Seoul, South Korea

BACKGROUND AND PURPOSE

The aim of this study was to investigate the perceptions of epilepsy in Seoul, South Korea, a country where social stigma toward epilepsy is still pronounced.

METHODS

We randomly selected 1000 persons living in Seoul and performed telephone interviews regarding public awareness, knowledge, and attitudes toward epilepsy.

RESULTS

Among 1000 respondents, the 92% who had read or heard about epilepsy became the subjects of the study. Word of mouth was most often referenced as a source of knowledge (78%). Forty-seven percentage believed that epilepsy is inheritable, whereas 5% thought that epilepsy is a mental illness. Marriage of their children to an epileptic person, childbearing by women with epilepsy, and employing a person with epilepsy were opposed by more than 50% of respondents. The reasons for the negative attitudes were that epilepsy was hereditary and untreatable (P < 0.05, respectively).

CONCLUSIONS

Our study revealed that there still remains negative attitudes regarding the marriage, childbearing, and employment of persons with epilepsy, which may stem from misconceptions about the cause and treatability of epilepsy, possibly due in part to the influence of herbal medicine, and South Korea's ethnic homogeneity. Public health education either through media or school health education is urgently needed to improve knowledge about, and attitudes toward epilepsy.

The TB structural genomics consortium: a resource for Mycobacterium tuberculosis biology

The TB Structural Genomics Consortium is an organization devoted to encouraging, coordinating, and facilitating the determination and analysis of structures of proteins from Mycobacterium tuberculosis. The Consortium members hope to work together with other M. tuberculosis researchers to identify M. tuberculosis proteins for which structural information could provide important biological information, to analyze and interpret structures of M. tuberculosis proteins, and to work collaboratively to test ideas about M. tuberculosis protein function that are suggested by structure or related to structural information. This review describes the TB Structural Genomics Consortium and some of the proteins for which the Consortium is in the progress of determining three-dimensional structures.

Sludge thickening performance of mesh filtration process

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

Inhibition of proteoglycan and type II collagen synthesis of disc nucleus cells by nicotine

OBJECT

Systemic nicotine has been hypothesized to cause degeneration of the intervertebral disc which in turn decreases vascular supply to the disc through a cholinergic receptor-mediated process. Another possible mechanism may be through direct regulatory effects on disc cells. In this study, the authors tested the hypothesis that nicotine adversely affects nucleus pulposus cells by directly inhibiting proteoglycan synthesis and gene expression of type II collagen (Phase I study). They also assessed the hypothesis that nicotine inhibits the bone morphogenetic protein (BMP)-2-induced upregulation of extracellular matrix (Phase II study).

METHODS

Cells were isolated from nucleus pulposus obtained in rat lumbar discs and cultured on a monolayer. Media were treated with nicotine and/or recombinant human (rh)BMP-2 for 7 days. Sulfated glycosaminoglycan (SO4-GAG) in media was quantified using 1,9-dimethylmethylene blue (DMMB) assay. Gene assay of types I and II collagen, Sox9, and glyceraldehyde-3-phosphate dehydrogenase were quantified using reverse transcriptase-polymerase chain reaction (RT-PCR) and real time PCR. In the Phase I study, nicotine-treated (100 microg/ml) and non-treated cells were compared. The s-GAG production and messenger RNA (mRNA) of type II collagen and Sox9 decreased significantly in the nicotine-treated group. In the Phase II study, five groups were compared: 1) non-treatment; 2) rhBMP-2 only (100 ng/ml); and 3-5) with rhBMP-2 (100 ng/ml) and increasing doses of nicotine (1 [third group], 10, [fourth group], 100 [fifth group] microg/ml). The SO4-GAG production and mRNA of type II collagen and Sox9 decreased significantly in the groups treated with rhBMP-2 combined with 10 and 100 microg/ml of nicotine compared with the group treated with rhBMP-2.

CONCLUSIONS

The results of this study raise the possibility that nicotine may contribute to the process of disc degeneration by a direct effect on the nucleus pulposus cells, possibly by antagonizing the effect of BMP-2.

Multiple mechanisms for oxygen-induced regulation of the Clara cell secretory protein gene

The Clara cell secretory protein (CCSP) imparts a protective effect to the lung during oxidant injury. However, exposure to supplemental oxygen, a common therapeutic modality for lung disease, represses the expression of CCSP in the adult mouse lung. We investigated the mechanisms of hyperoxia-induced repression of the mouse CCSP promoter. Deletion experiments in vivo and in vitro indicated that the hyperoxia-responsive elements are localized to the proximal -166 bp of the CCSP promoter. Electrophoretic mobility shift and supershift analyses demonstrated increased binding of c-Jun at the activator protein-1 site, increased binding of CCAAT/enhancer binding protein (C/EBP) beta at the C/EBP sites, and decreased binding at the Nkx2.1 sites. Western analyses revealed that hyperoxia exposure induced an increase in the expression of the C/EBPbeta isoform liver-inhibiting protein (LIP) and an increase in cytoplasmic Nkx2.1. Cotransfection of LIP or c-Jun expression plasmids decreased the transcriptional activity of the proximal -166-bp CCSP promoter. These observations suggest that hyperoxia-induced repression of the CCSP gene is mediated, at least in part, at the level of transcription and that multiple mechanisms mediate this repression. Moreover, these novel observations may provide insights for generation of therapeutic interventions for the amelioration of oxidant-induced lung injury.

Dietary supplementation of (+)-catechin protects against UVB-induced skin damage by modulating antioxidant enzyme activities

PURPOSE

The aim of this study was to investigate the effects of dietary supplementation with (+)-catechin on cutaneous antioxidant enzymes and the skin damage caused by UVB irradiation.

METHODS

BALB/c mice were divided into three groups. Each group was fed a regular diet (RD) or a 2% catechin-supplemented diet for either 2 weeks (2CSD) or 4 weeks (4CSD) ad libitum prior to UVB irradiation. Skin was removed for the antioxidant enzyme assay, hematoxylin and eosin staining, and the TEM analysis before and at various time points after UVB (200 mJ/cm2) irradiation.

RESULTS

Before UVB irradiation, the superoxide dismutase (SOD) and catalase (CAT) activities of the 2CSD and the 4CSD groups were found to be lower than those of the RD group, whereas the glutathione peroxidase (GPx) activity of the 4CSD group was higher than those of the RD and the 2CSD groups (P<0.05). The SOD and CAT activities of the RD group decreased after UVB irradiation, while those of the 2CSD and the 4CSD groups increased immediately after irradiation and then decreased (P<0.05). Immediately after UVB irradiation, the GPx activities of the 4CSD and the 2CSD groups increased, but that of the RD group decreased. The GPx activity of all three groups showed a tendency to return to pre-UVB irradiation levels with time. Light microscopic findings of the RD group showed epidermal thinning and apoptotic cells at 24 h after UVB irradiation and mostly necrotic cells at 48 h, whereas only moderate thickening of the epidermis was observed in the 2CSD group at 48 h after irradiation. An electron microscopic examination produced similar findings. At 48 h after irradiation, nearly all epidermal cells seemed to be damaged in the RD group as compared to the 2CSD group.

CONCLUSION

These results demonstrate that dietary supplementation with (+)-catechin could protect epidermal cells against UVB-induced damage by modulating antioxidant enzyme activities.

Transcriptional regulation of CCSP by interferon-gamma in vitro and in vivo

Interferon gamma (IFN-gamma), a potent cytokine inducing a wide range of immunologic activities, is increased in the airway secondary to viral infection or during an inflammatory response. This increase in IFN-gamma concentration may alter the expression of specific airway epithelial cell genes that regulate adaptation of airway inflammatory responses. One protein induced by IFN-gamma is Clara cell secretory protein (CCSP), which may contribute to the attenuation of airway inflammation. This study was done to investigate the molecular mechanism by which IFN-gamma stimulates the expression of the CCSP gene in mouse transformed Clara cells and transgenic mice. Deletion mapping and linker-scanning mutations demonstrated that IFN-gamma-induced expression of CCSP was regulated, in part, at the level of transcription. In vitro and in vivo studies verified that the minimal IFN-gamma-responsive segment was localized to the proximal 166 bp of the 5'-flanking region. Additionally, IFN-gamma-induced expression of CCSP was mediated indirectly through an interferon regulatory factor-1-mediated increase in hepatocyte nuclear factor-3beta.

Cisplatin-induced apoptosis in auditory cells: role of death receptor and mitochondrial pathways

Cisplatin, a commonly used chemotherapeutic agent, has a major limitation due to its ototoxicity. Previous studies have shown that cisplatin induces apoptosis in auditory sensory cells, but the underlying mechanisms remain to be elucidated. In this study, cisplatin was found to induce apoptosis in a cochlear cell line, in a dose- and duration-dependent manner. Specific caspase assays revealed an early (6 h) but transient increase in caspase 8 activity, and a delayed (12 h) increase in caspase 9 activity. The enhanced caspase 8 activity was preceded by upregulation of p53 expression, and coincided with cleavage of Bid to its truncated form. This was followed temporally by activation and mitochondrial translocation of Bax, induction of mitochondrial permeability transition, release of cytochrome c into the cytosol, activation of caspase 9, and entry into the execution phase of apoptosis. Our results indicate the involvement of both the death receptor mechanisms as well as mitochondrial pathways in cisplatin-induced apoptosis of auditory cells in an in vitro model system.

Prognostic significance of the nadir prostate specific antigen level after hormone therapy for prostate cancer

PURPOSE

We determine whether the nadir prostate specific antigen (PSA) level after hormone therapy can be used to predict the progression to hormone refractory prostate cancer.

MATERIALS AND METHODS

We reviewed the progressive status and survival of 177 patients with stage C or D prostate cancer who had received hormone therapy at our institution. The overall survival rate, incidence of progression to hormone refractory prostate cancer and interval until progression were analyzed with reference to the nadir PSA level. Multiple regression analysis was used to analyze the predictive factors for progression to hormone refractory prostate cancer, and the relative efficacy of the nadir PSA level in predicting progression was evaluated by receiver operating characteristics analysis.

RESULTS

Median followup was 39 months (range 3 to 89) and 85.4% of patients (151) responded to treatment, of whom 77.5% (117) had progression to hormone refractory prostate cancer. Median time until nadir PSA levels were reached after hormone therapy was 8.1 months and median time until hormone refractory prostate cancer was 24.0 months. Nadir PSA levels were less than 0.2 ng./ml. in 31% of respondents, 0.2 to 1.0 ng./ml. in 23%, 1.1 to 10 ng./ml. in 42% and greater than 10 ng./ml. in 5%. These groups had similar clinicopathological characteristics. Nadir PSA levels correlated significantly with pretreatment PSA levels, Gleason scores and progression to hormone refractory prostate cancer (p = 0.01, p <0.01 and p <0.001, respectively), and inversely correlated with the interval to the establishment of hormone refractory prostate cancer (r = -0.465, p <0.05). By univariate analysis bone metastasis, nadir PSA, PSA at 6 months after treatment and pretreatment PSA were significantly associated with progression to hormone refractory prostate cancer. Only the nadir PSA was calculated to be an independent factor by multivariate analysis. Receiver operating characteristics analysis indicated that nadir PSA predicted progression to hormone refractory prostate cancer after 2 years with an accuracy of 86.2%. With the lower limit of the nadir PSA level set to 1.1 ng./ml., sensitivity was 80.3% and specificity was 83.8%, and these levels were deemed the most appropriate. Furthermore, nadir PSA after hormone therapy was an independent prognosticator for survival, as were initial levels of hemoglobin and alkaline phosphatase.

CONCLUSIONS

The nadir PSA level after hormone therapy may be the most accurate factor predicting the progression to hormone refractory prostate cancer and is an independent prognostic factor for survival. Furthermore, a lower limit for the nadir PSA level of 1.1 ng./ml. gives optimal sensitivity and specificity.

Suppression of clusterin expression enhanced cisplatin-induced cytotoxicity on renal cell carcinoma cells

OBJECTIVES

To evaluate whether antisense transfection targeted against clusterin enhances the chemosensitivity in renal cell carcinoma.

METHODS

Caki-1, a renal cell carcinoma cell line, and cisplatin were used as chemotherapeutic agents. Clusterin expression of Caki-1 cells after treatment with cisplatin was measured by Western blot analysis. After the construction of a clusterin suppression vector, clusterin expression was compared between Caki-1 cells transfected with the clusterin suppression vector (Caki-1/AS), Caki-1 cells transfected with control vector (Caki-1/VO), and parental Caki-1 cells. Tumor cell viability was measured with the MTT assay at 24 and 48 hours after cisplatin treatment.

RESULTS

The expression of clusterin increased gradually in Caki-1 cells, peaking at 24 hours, and was reduced to an almost undetectable level at 48 hours after cisplatin treatment. Clusterin expression was suppressed, and the percentage of viable tumor cells decreased significantly more in the Caki-1/AS than in the Caki-1/VO or parental Caki-1 cells at 24 hours after cisplatin treatment. The change in chemosensitivity of the Caki-1/AS cells lost its significance at 48 hours after cisplatin treatment.

CONCLUSIONS

Our results showed that clusterin expression increased transiently after treatment of cisplatin, and its suppression by antisense transfection enhanced the cisplatin-induced cytotoxicity of renal cell carcinoma cells. Clusterin suppression may be a useful modality in enhancing the effects of cytotoxic chemotherapy in renal cell carcinoma.

Prognostic significance of the nadir prostate specific antigen level after hormone therapy for prostate cancer

PURPOSE

We determine whether the nadir prostate specific antigen (PSA) level after hormone therapy can be used to predict the progression to hormone refractory prostate cancer.

MATERIALS AND METHODS

We reviewed the progressive status and survival of 177 patients with stage C or D prostate cancer who had received hormone therapy at our institution. The overall survival rate, incidence of progression to hormone refractory prostate cancer and interval until progression were analyzed with reference to the nadir PSA level. Multiple regression analysis was used to analyze the predictive factors for progression to hormone refractory prostate cancer, and the relative efficacy of the nadir PSA level in predicting progression was evaluated by receiver operating characteristics analysis.

RESULTS

Median followup was 39 months (range 3 to 89) and 85.4% of patients (151) responded to treatment, of whom 77.5% (117) had progression to hormone refractory prostate cancer. Median time until nadir PSA levels were reached after hormone therapy was 8.1 months and median time until hormone refractory prostate cancer was 24.0 months. Nadir PSA levels were less than 0.2 ng./ml. in 31% of respondents, 0.2 to 1.0 ng./ml. in 23%, 1.1 to 10 ng./ml. in 42% and greater than 10 ng./ml. in 5%. These groups had similar clinicopathological characteristics. Nadir PSA levels correlated significantly with pretreatment PSA levels, Gleason scores and progression to hormone refractory prostate cancer (p = 0.01, p <0.01 and p <0.001, respectively), and inversely correlated with the interval to the establishment of hormone refractory prostate cancer (r = -0.465, p <0.05). By univariate analysis bone metastasis, nadir PSA, PSA at 6 months after treatment and pretreatment PSA were significantly associated with progression to hormone refractory prostate cancer. Only the nadir PSA was calculated to be an independent factor by multivariate analysis. Receiver operating characteristics analysis indicated that nadir PSA predicted progression to hormone refractory prostate cancer after 2 years with an accuracy of 86.2%. With the lower limit of the nadir PSA level set to 1.1 ng./ml., sensitivity was 80.3% and specificity was 83.8%, and these levels were deemed the most appropriate. Furthermore, nadir PSA after hormone therapy was an independent prognosticator for survival, as were initial levels of hemoglobin and alkaline phosphatase.

CONCLUSIONS

The nadir PSA level after hormone therapy may be the most accurate factor predicting the progression to hormone refractory prostate cancer and is an independent prognostic factor for survival. Furthermore, a lower limit for the nadir PSA level of 1.1 ng./ml. gives optimal sensitivity and specificity.

Cisplatin induces apoptosis in LLC-PK1 cells via activation of mitochondrial pathways

Cisplatin, a commonly used chemotherapeutic agent, has a major limitation because of its nephrotoxicity. Recent studies have shown that cisplatin causes apoptotic cell death in renal tubule cells, but the underlying molecular mechanisms remain to be elucidated. In this study, cisplatin was found to induce apoptosis in a dose- and duration-dependent manner in cultured proximal tubule (LLC-PK1) cells, as evidenced by DNA laddering and TdT-mediated dUTP nick end-labeling assay. Pretreatment with the specific caspase 9 inhibitor LEHD-CHO completely prevented the apoptosis, whereas the caspase 8 inhibitor IETD-fmk had no effect. Furthermore, the activity of caspase 9 was upregulated about sixfold by cisplatin in a dose-dependent manner. These results implicated the caspase 9-dependent mitochondrial apoptotic pathways. Indeed, cisplatin triggered a duration-dependent translocation of cytochrome c from the mitochondria to the cytosol, by immunofluorescence and Western blots. Cisplatin treatment also resulted in the duration-dependent activation and mitochondrial translocation of the pro-apoptotic molecule Bax, by immunofluorescence. Finally, cisplatin induced a duration-dependent onset of the mitochondrial permeability transition. Our results indicate that cisplatin induces apoptosis in LLC-PK1 cells via activation of mitochondrial signaling pathways. The sequence of events may be summarized as follows: activation of Bax induces mitochondrial permeability transition, leading to release of cytochrome c, activation of caspase 9, and entry into the execution phase of apoptosis. Inhibition of this specific pathway may provide a strategy to minimize cisplatin-induced nephrotoxicity.

A recurred carotid siphon pseudoaneurysm after detachable coil embolization. Successfull endovascular management with detachable balloons

SUMMARY

Massive posterior epistaxis is one of the peculiar symptoms of pseudoaneurysms of the carotid siphon. We experienced a case of trauma- related pseudoaneurysm of the carotid siphon. The lesion was initially silent except for the mass effect. We initially treated the lesion with platinum detachable coil embolization of the pseudoaneurysm sac with preservation of the parent artery. However, the patient had delayed massive epistaxis with recurrence of the pseudoaneurysm. The patient was subsequently managed with endovascular occlusion of the affected internal carotid artery using detachable balloons. Complete internal carotid artery trapping is recommended as an initial treatment modality if the patient can tolerate to the occlusion test. Careful observation and follow-up of the patient is required if the lesion is inevitably managed with coil embolization of the pseudoaneurysm sac alone.

Combined effect of glutathione S-transferase M1 and T1 genotypes on bladder cancer risk

To evaluate the association between genetic polymorphism of GSTM1, GSTT1 and development of bladder cancer, a hospital-based case-control study was conducted in South Korea. The study population consisted of 232 histologically confirmed male bladder cancer cases and 165 male controls enrolled from urology departments with no previous history of cancer or systemic diseases in Seoul during 1997-1999. The GSTM1 null genotype was significantly associated with bladder cancer (OR: 1.6, 95% CI: 1.0-2.4), whereas the association observed for GSTT1 null genotype did not reach statistical significance (OR: 1.3, 95% CI: 0.9-2.0). There was a statistically significant multiple interaction between GSTM1 and GSTT1 genotype for risk of bladder cancer (P=0.04); the risk associated with the concurrent lack of both of the genes (OR: 2.2, 95% CI: 1.2-4.3) was greater than the product of risk in men with GSTM1 null/GSTT1 present (OR: 1.3, 95% CI: 0.7-2.5) or GSTM1 present/GSTT1 null (OR: 1.1, 95% CI: 0.6-2.2) genotype combinations.

A non-class I MHC intestinal epithelial surface glycoprotein, gp180, binds to CD8

The activation of CD8(+) T cells by normal intestinal epithelial cells in antigen-specific or allogeneic mixed cell culture systems has significant implications for the modulation of mucosal immune responses due to the fact that these T cells appear to have regulatory rather than cytolytic activity. A 180-kDa glycoprotein (gp180) has been identified and shown to be important in CD8(+) T cell activation by intestinal epithelial cells. In this study, we examine, in further detail, the role that the CD8 molecule plays in this interaction. It has been previously shown that monoclonal antibodies against gp180 inhibited the activation of CD8-associated p56(lck) in T cells. Although indirectly suggested by these data, there was no evidence that the activation of this protein tyrosine kinase was a direct result of gp180 interacting with the CD8 molecule. In this study, we document that soluble gp180 is able to bind to CD8-Fc fusion proteins and is absorbed by human CD8 alpha but not CD4 transfected murine T cells and that this interaction is dependent upon carbohydrate on the gp180 molecule. Furthermore, the sites used for binding by gp180 are distinct from those used by the conventional CD8 ligand, class I MHC. Thus, gp180 appears to be a novel CD8 ligand that plays an important role in the activation of CD8-associated kinases and of CD8(+) T cells.

Thrombospondin-1, vascular endothelial growth factor expression and their relationship with p53 status in prostate cancer and benign prostatic hyperplasia

OBJECTIVE

To evaluate the expression of thrombospondin-1 (TSP-1, a potent inhibitor of angiogenesis) and vascular endothelial growth factor (VEGF, an important angiogenic factor in solid tumours) in prostate cancer, and their relationship with p53 status.

PATIENTS AND METHODS

Using immunohistochemistry, the expression of VEGF, TSP-1 and p53 was assessed in 82 archival tissue specimens from 23 patients with benign prostatic hyperplasia (BPH), 22 with localized prostate cancer and 37 with metastatic prostate cancer. Seven of the last group had received androgen deprivation therapy. The relationship between the expression of VEGF, TSP-1 and p53 status was also evaluated with tumour grade and stage in patients with prostate cancer.

RESULTS

The seven patients receiving hormonal treatment were excluded from the analysis because androgen deprivation significantly increased TSP-1 and decreased VEGF expression (both P < 0.01). Immunohistochemical analysis showed significantly higher VEGF and significantly lower TSP-1 expression (both P < 0.01) in prostate cancer than in BPH tissues. There was also significantly higher VEGF and significantly lower TSP-1 expression (both P < 0.05) in tissues from metastatic than localized prostate cancer. There was no significant correlation between VEGF or TSP-1 expression and Gleason score, but a significant inverse correlation between TSP-1 and VEGF expression. There was a significant association between VEGF expression and p53 status (P < 0.05), but TSP-1 expression was not associated with p53 status.

CONCLUSIONS

Angiogenic factors, including VEGF and TSP-1, might be important in the development and progression of prostate cancer. These changes seem to be influenced by p53 status. Identifying the angiogenic factors involved in prostate cancer might lead to the development of diagnostic or therapeutic strategies based on anti-angiogenesis.

Recombinant Newcastle disease virus as a vaccine vector

A complete cDNA clone of the Newcastle disease virus (NDV) vaccine strain Hitchner B1 was constructed, and infectious recombinant virus expressing an influenza virus hemagglutinin was generated by reverse genetics. The rescued virus induces a strong humoral antibody response against influenza virus and provides complete protection against a lethal dose of influenza virus challenge in mice, demonstrating the potential of recombinant NDV as a vaccine vector.

Determination of propranolol concentration in small volume of rat plasma by HPLC with fluorometric detection

A simple, rapid and sensitive fluorescence high performance liquid chromatographic method was developed to determine propranolol concentration in the small volume of rat plasma without the solvent extraction step using pronethanol as the internal standard. The analysis was accomplished using a 5 microm CAPCELL PAK analytical cyano column at room temperature and a mobile phase consisted of 1% aqueous acetic acid containing 0.2% triethylamine and acetonitrile (65:35, v/v; pH 3.8). The flow-rate was kept at 0.5 mL/min and column effluent was monitored with a fluorescence detector at an excitation wavelength of 230 nm and an emission wavelength of 340 nm. Retention times for pronethalol and propranolol were 8.5 min and 10.5 min, respectively. Linear regressions for the standard curves were linear in the range 2-800 ng/mL, giving correlation coefficients above 0.998. The detection limit was 1.34 ng/mL. No analytical interference was observed from endogenous components in rat plasma. This simple and sensitive assay method was feasibly applied to the pharmacokinetic study of propranolol after intravenous administration of 2 mg/kg of propranolol to normal and carbon tetrachloride-induced liver cirrhotic rats.

Bile duct injuries leading to portal vein obliteration after transcatheter arterial chemoembolization in the liver: CT findings and initial observations

PURPOSE

To document the computed tomographic (CT) findings of transcatheter arterial chemoembolization (TACE)-induced, localized bile duct injuries leading to portal vein branch obliteration in the liver and to elucidate the clinical implications with retrospective review of the authors' experiences.

MATERIALS AND METHODS

Follow-up CT scans obtained in 11 patients with TACE-induced intrahepatic bile duct dilatation were reviewed retrospectively to evaluate serial changes in the adjacent portal vein branches and hepatic parenchyma. Clinical data, including time between TACE and CT and serum alkaline phosphatase levels, also were analyzed.

RESULTS

Of 11 patients with marked (n = 8) or mild (n = 3), lobar (n = 4) or segmental (n = 7) bile duct dilatation with or without bile collection in the tissue sheaths of the Glisson capsule or hepatic parenchyma, nine (82%) had bile duct changes at the first CT follow-up, within 1 month after TACE. Marked narrowing or obliteration of the adjacent intrahepatic portal vein branches in 10 (91%) patients resulted in progressive atrophy of the corresponding hepatic parenchyma in nine (82%) at variable times after TACE. The serum alkaline phosphatase level increased to more than 200 U/L in eight (89%) of nine patients 1 month after TACE.

CONCLUSION

TACE-induced intrahepatic bile duct injury resulting in obliteration of the adjacent portal vein branch seems to be one cause of hepatic parenchymal atrophic changes after TACE.

Solution structure of Pyrobaculum aerophilum DsrC, an archaeal homologue of the gamma subunit of dissimilatory sulfite reductase

The solution structure of DsrC, an archaeal homologue of the gamma subunit of dissimilatory sulfite reductase, has been determined by NMR spectroscopy. This 12.7-kDa protein from the hyperthermophilic archaeon Pyrobaculum aerophilum adopts a novel fold consisting of an orthogonal helical bundle with a beta hairpin along one side. A portion of the structure resembles the helix-turn-helix DNA-binding motif common in transcriptional regulator proteins. The protein contains two disulfide bonds but remains folded following reduction of the disulfides. DsrC proteins from organisms other than Pyrobaculum species do not contain these disulfide bonds. A conserved cysteine next to the C-terminus, which is not involved in the disulfide bonds, is located on a seven-residue C-terminal arm that is not part of the globular protein and is likely to dynamically sample more than one conformation.

Morphology and biology of parasite responsible for scuticociliatosis of cultured olive flounder Paralichthys olivaceus

Based on the arrangement and shape of the buccal structure, scuticociliates isolated from cultured olive flounder Paralichthys olivaceus belonged to the family Uronematidae and showed many characteristics of Uronema marinum. There was variation in the morphometry of clinical isolates taken from different organs of infected flounder. However, the isolates did not show any significant difference in morphometry under cultured conditions. The ciliates were easily maintained in in vitro medium to which antibiotic agents had been added and which had been enriched with the raw brain tissue of a healthy olive flounder. The ciliates propagated in a wide range of both temperature (6 to 30 degrees C) and salinity (10 to 35 ppt).

A case of del(13)(q22) with multiple major congenital anomalies, imperforate anus and penoscrotal transposition

"13q-"syndrome is known to have widely variable manifestations, including retinoblastoma, mental & growth retardation, malformation of brain & heart, anal atresia, and anomalies of the face and limbs. Here we report a case of del(13)(q22) with multiple major congenital anomalies for the first time in Korea. The patient was born at 36(+4) weeks of pregnancy by caesarian section. Birth weight was 1490g. On examination the following features were noted: - imperforate anus, ambiguous genitalia (bifid scrotum, penoscrotal transposition, hypospadia), syndactyly of toes, absence of thumbs, abnormal facies (dolichocephaly, telecanthus, large low set ears, saddle nose, high arched palate, micrognathia). Neurocranial ultrasonography showed atrophy of the corpus callosum and multiple calcifications. He died at 14 days. Post-mortem autopsy findings showed cholestasis and fatty metamorphosis of liver, abnormal lobulation (Rt:2, Lt:1) and lymphangiectasis of the lung, VSD, ASD, PDA of heart, and acute tubular necrosis of kidney. Cytogenetic studies was confirmed to 46,XY,del(13) (q22) by Giemsa banded chromosomes from peripheral blood lymphocytes.

Distortion product otoacoustic emissions in diabetics with normal hearing

In 18 diabetic patients with normal hearing, distortion product otoacoustic emissions (DPOAEs) were measured. DPOAEs' amplitude and latency were analysed and compared with the data obtained from non-diabetic controls. The mean amplitude and latency were lower in diabetics than in controls. These results suggested that diabetes mellitus may induce the functional alteration of outer hair cells even in the normal hearing group. Further studies should be performed to evaluate the predictability of DPOAEs in hearing loss of the diabetic patient.

Recurrent pyogenic cholangitis: comparison between MR cholangiography and direct cholangiography

PURPOSE

To compare the accuracy of magnetic resonance (MR) cholangiography with that of direct cholangiography for the evaluation of recurrent pyogenic cholangitis.

MATERIALS AND METHODS

Twenty-four patients with recurrent pyogenic cholangitis underwent MR cholangiography before surgery, and 18 of these 24 also underwent direct cholangiography. Two reviewers evaluated MR cholangiograms and direct cholangiograms and focused on identifying intrahepatic ductal dilatation, stricture, and calculi, as well as coexistent parenchymal abnormalities, on the basis of the classification of the internal lobes and segments of the liver. These observations were compared with surgical findings.

RESULTS

According to examination results in the surgical specimens, 24 patients had 46 segmental abnormalities. MR cholangiography depicted all 46 (100%) segments with ductal dilatation, 22 (96%) of 23 segments with focal ductal stricture, and 43 (98%) of 44 segments with ductal calculi. Eighteen patients who underwent direct cholangiography had 32 segmental abnormalities according to examination results in the surgical specimens. Direct cholangiography depicted 15 (47%) of 32 segments with ductal dilatation, eight (44%) of 18 segments with focal ductal stricture, and 14 (45%) of 31 segments with ductal calculi.

CONCLUSION

MR cholangiography is superior to direct cholangiography for accurate topographic evaluation of recurrent pyogenic cholangitis because it is able to depict all of the biliary tree, despite obstruction or stenosis.

Generation of protein lineages with new sequence spaces by functional salvage screen

A variety of different methods to generate diverse proteins, including random mutagenesis and recombination, are currently available and most of them accumulate the mutations on the target gene of a protein, whose sequence space remains unchanged. On the other hand, a pool of diverse genes, which is generated by random insertions, deletions and exchange of the homologous domains with different lengths in the target gene, would present the protein lineages resulting in new fitness landscapes. Here we report a method to generate a pool of protein variants with different sequence spaces by employing green fluorescent protein (GFP) as a model protein. This process, designated functional salvage screen (FSS), comprises the following procedures: a defective GFP template expressing no fluorescence is first constructed by genetically disrupting a predetermined region(s) of the protein and a library of GFP variants is generated from the defective template by incorporating the randomly fragmented genomic DNA from Escherichia coli into the defined region(s) of the target gene, followed by screening of the functionally salvaged, fluorescence-emitting GFPs. Two approaches, sequence-directed and PCR-coupled methods, were attempted to generate the library of GFP variants with new sequences derived from the genomic segments of E.coli. The functionally salvaged GFPs were selected and analyzed in terms of the sequence space and functional properties. The results demonstrate that the functional salvage process not only can be a simple and effective method to create protein lineages with new sequence spaces, but also can be useful in elucidating the involvement of a specific region(s) or domain(s) in the structure and function of protein.

Resistance to xenobiotic-induced autoimmunity maps to chromosome 1

Although evidence indicates that environmental factors play a major role in precipitating systemic autoimmunity in genetically susceptible individuals, little is known about the mechanisms involved. Certain heavy metals, such as mercury, are potent environmental immunostimulants that produce a number of immunopathologic sequelae, including lymphoproliferation, hypergammaglobulinemia, and overt systemic autoimmunity. Predisposition to such metal-induced immunopathology has been shown to be influenced by both MHC and non-MHC genes, as well as susceptibility to spontaneous lupus, in mice and other experimental animals. Among the various mouse strains examined to date, the DBA/2 appears to uniquely lack susceptibility to mercury-induced autoimmunity (HgIA), despite expressing a susceptible H-2 haplotype (H-2d). To define the genetic basis for this trait, two genome-wide scans were conducted using F2 intercrosses of the DBA/2 strain with either the SJL or NZB strains, both of which are highly susceptible to HgIA. A single major quantitative trait locus on chromosome 1, designated Hmr1, was shown to be common to both crosses and encompassed a region containing several lupus susceptibility loci. Hmr1 was linked to glomerular immune complex deposits and not autoantibody production, suggesting that DBA/2 resistance to HgIA may primarily involve the later stages of disease pathogenesis. Identification and characterization of susceptibility/resistance genes and mechanisms relevant to the immunopathogenesis of mercury-induced autoimmunity should provide important insights into the pathogenesis of autoimmunity and may reveal novel targets for intervention.

A conditional replication-competent adenoviral vector, Ad-OC-E1a, to cotarget prostate cancer and bone stroma in an experimental model of androgen-independent prostate cancer bone metastasis

Prostate cancer has a high propensity to metastasize to bone, which often resists hormone, radiation, and chemotherapies. Because of the reciprocal nature of the prostate cancer and bone stroma interaction, we designed a cotargeting strategy using a conditional replication-competent adenovirus to target the growth of tumor cells and their associated osteoblasts. The recombinant Ad-OC-E1a was constructed using a noncollagenous bone matrix protein osteocalcin (OC) promoter to drive the viral early E1a gene with restricted replication in cells that express OC transcriptional activity. Unlike Ad-PSE-E1a, Ad-OC-E1a was highly efficient in inhibiting the growth of PSA-producing (LNCaP, C4-2, and ARCaP) and nonproducing (PC-3 and DU145) human prostate cancer cell lines. This virus was also found to effectively inhibit the growth of human osteoblasts and human prostate stromal cells in vitro. Athymic mice bearing s.c. androgen receptor-negative and PSA-negative PC-3 xenografts responded to a single intratumoral administration of 2 x 10(9) plaque-forming unit(s) of Ad-OC-E1a. In SCID/bg mice, intraosseous growth of androgen receptor-positive and PSA-producing C4-2 xenografts responded markedly to i.v. administrations of a single dose of Ad-OC-E1a. One hundred percent of the treated mice responded to this systemic Ad-OC-E1a therapy with a decline of serum PSA to an undetectable level, and 80% of the mice with PSA rebound responded to the second dose of systemic Ad-OC-E1a. Forty percent of the mice were found to be cured by systemic Ad-OC-E1a without subsequent PSA rebound or tumor cells found in the skeleton. This cotargeting strategy shows a broader spectrum and appears to be more effective than systemic Ad-PSE-E1a in preclinical models of human prostate cancer skeletal metastasis.

DNA ligase I and proliferating cell nuclear antigen form a functional complex

DNA ligase I is responsible for joining Okazaki fragments during DNA replication. An additional proposed role for DNA ligase I is sealing nicks generated during excision repair. Previous studies have shown that there is a physical interaction between DNA ligase I and proliferating cell nuclear antigen (PCNA), another important component of DNA replication and repair. The results shown here indicate that human PCNA enhances the reaction rate of human DNA ligase I up to 5-fold. The stimulation is specific to DNA ligase I because T4 DNA ligase is not affected. Electrophoretic mobility shift assays indicate that PCNA improves the binding of DNA ligase I to the ligation site. Increasing the DNA ligase I concentration leads to a reduction in PCNA stimulation, consistent with PCNA-directed improvement of DNA ligase I binding to its DNA substrate. Two experiments show that PCNA is required to encircle duplex DNA to enhance DNA ligase I activity. Biotin-streptavidin conjugations at the ends of a linear substrate inhibit PCNA stimulation. PCNA cannot enhance ligation on a circular substrate without the addition of replication factor C, which is the protein responsible for loading PCNA onto duplex DNA. These results show that PCNA is responsible for the stable association of DNA ligase I to nicked duplex DNA.

The factors of child physical abuse in Korean immigrant families

OBJECTIVE

This study explores Korean immigrant mothers' attitudes toward child physical abuse based on an ecological perspective.

METHOD

One hundred and forty-four Korean immigrant mothers who came to the US after age 16 and have at least one child under 18 years old participated in this study. Data were collected using instruments translated in Korean that measure mothers' attitudes toward child physical abuse in four areas: degree of agreement with physical abuse, conflict tactics, belief in the use of physical punishment, and perceptions regarding physical abuse.

RESULTS

This study found that the following variables affect Korean immigrant mothers' attitudes toward child physical abuse at ecological levels of the environment: amount of time spent with children, experience of corporal punishment as a child, children's gender and age, family acculturation conflicts, mothers' age, and length of time in US at the micro level; involvement in their children's school and involvement in social organizations at the meso level; level of education and reported stress of immigrant life at the exo level; value of children in Korean culture, familiarity with Child Protective Services (CPS), perceived discrimination, and value of corporal punishment at the macro level.

CONCLUSIONS

This study suggests the importance of cultural sensitivity in social work practice when working with Korean immigrants. It also implies that intervention and prevention efforts of child abuse should be targeted at more than one level of the environment.

Effects of bicarbonate/lactate solution on peritoneal advanced glycosylation end-product accumulation

Advanced glycosylation end-products (AGEs) are associated with diabetic complications and peritoneal damage after long-term peritoneal dialysis (PD) with high glucose dialysis solutions. Glucose degradation products (GDPs) derived during heat sterilization of high glucose dialysis solutions are thought to accelerate AGE formation. A new technique of separating glucose from electrolytes has yielded markedly lower GDP levels and permitted the use of dialysis solutions containing the physiologic buffer bicarbonate. Formation of AGEs in vitro with this new solution is significantly lower compared with formation of AGEs with conventional solutions. The purpose of the present study was to investigate the effect of long-term intraperitoneal use of new, neutral dialysis solution (B/L) containing bicarbonate (25 mmol/L) and lactate (15 mmol/L) on peritoneal AGE accumulation and permeability. Normal male Sprague-Dawley rats were used. Twice daily for 12 weeks, 30 mL of new solution (B/L) or conventional solution [Lac (lactate 40 mmol/L)] was injected into the peritoneal cavity of the test rats. As a control, rats that were not injected were kept for 12 weeks in the same manner as the test rats. After 12 weeks, a 2-hour peritoneal equilibration test (PET) was performed in the test rats. After the PET, the parietal peritoneum and liver were obtained for evaluation of peritoneal morphology and for immunohistochemistry for AGE. Intensity of AGE staining was semi-quantitatively graded from 0 to 3. The omentum was also obtained and immediately frozen for analysis of pentosidine content by high-performance liquid chromatography. Compared with findings in the control group, hematoxylin and eosin staining of the parietal peritoneum and liver samples revealed partial denudation of mesothelial cells in the Lac group; denudation was not remarkable in the B/L group. The B/L solution showed significantly less AGE staining in the peritoneal cavity compared to conventional solution. However, B/L solution failed to lower pentosidine levels. Intraperitoneal volume and the ratio of dialysate glucose at 2 hours to dialysate glucose at instillation (D2/D0 glucose) were significantly lower and the ratio of dialysate urea to plasma urea at 2 hours (D2/P2 urea) was significantly higher in the Lac and B/L groups than in the control group. Intraperitoneal volume was significantly higher in the B/L group than in the Lac group; D2/D glucose and D2P2 urea did not differ between the two groups. In conclusion, peritoneal ultrafiltration decreased after long-term PD. The B/L solution showed a small but statistically significant protective effect against decreasing ultrafiltration as compared with Lac solution. The B/L solution attenuated peritoneal AGE accumulation compared with conventional solution, but did not affect peritoneal pentosidine levels. These findings indicate that biochemical kinetics of various AGE peptides are not unique, but multivalent.