Evaluating the Safety and effectivenesS in adult KorEaN patients treated with Tolvaptan for management of autosomal domInAnt poLycystic kidney disease (ESSENTIAL): short-term outcomes during the titration period

Background

Tolvaptan reduces height-adjusted total kidney volume (htTKV) and renal function decline in autosomal dominant polycystic kidney disease (ADPKD). This study was aimed at investigating the efficacy and safety of tolvaptan in Korean patients with ADPKD during the titration period.

Methods

This study is a multicenter, single-arm, open-label phase 4 study. We enrolled 108 patients with ADPKD (age, 19-50 years) with an estimated glomerular filtration rate (eGFR) of >30 mL/min/1.73 m2 and factors defined as indicative of rapid disease progression. After tolvaptan titration, we evaluated efficacy and side effects and assessed factors associated with the effects.

Results

After titration for 4 weeks, eGFR and htTKV decreased by 6.4 ± 7.9 mL/min/1.73 m2 and 16 ± 45 mL/m, respectively. No serious adverse drug reactions were observed during the titration period. The greatest eGFR decline was observed in the first week, with a starting tolvaptan dose of 45 mg. Multivariate linear regression for htTKV decline showed that the greater the change in urine osmolality (Uosm), the greater the decrease in htTKV (β, 0.436; p = 0.009) in the 1D group stratified by the Mayo Clinic image classification. Higher baseline eGFR was related to a higher htTKV reduction rate in the 1E group (β, -0.642; p = 0.009).

Conclusion

We observed short-term effects and safety during the tolvaptan titration period, with the greatest decrease in kidney function occurring during the first week. The decline of htTKV can be predicted as a short-term effect of tolvaptan by observing Uosm changes from baseline to end of titration in 1D and baseline eGFR in 1E groups.

New-onset Nephrotic Syndrome after Janssen COVID-19 Vaccination: a Case Report and Literature Review

Various coronavirus disease 2019 (COVID-19) vaccines are being developed, which show practical preventive effects. Here, we report a 51-year-old healthy man with nephrotic syndrome secondary to minimal change disease (MCD) after Ad26.COV.2 (Janssen) vaccination. He had no comorbid disease and received Ad26.COV.2 on April 13, 2021. Seven days after vaccination, he developed edema and foamy urine. Edema rapidly aggravated with decreased urine volume. He was admitted to the hospital 28 days after vaccination, and his body weight increased by 21 kg after vaccination. His serum creatinine level was 1.54 mg/dL, and 24-h urinary protein excretion was 8.6 g/day. Kidney biopsy revealed no abnormality in the glomeruli and interstitium of the cortex and medulla under the light microscope. Electron microscopy revealed diffuse effacement of the podocyte foot processes, thus, he was diagnosed with MCD. High-dose steroid therapy was applied, and his kidney function improved three days after steroid therapy. Three weeks after steroid use, his serum creatinine decreased to 0.95 mg/dL, and spot urine protein-to-creatine decreased to 0.2 g/g. This case highlights the risk of new-onset nephrotic syndrome secondary to MCD after vectored COVID-19 vaccination. Although the pathogenesis is uncertain, clinicians need to be careful about adverse renal effects of COVID-19 vaccines.

Mycophenolic Acid Trough Concentration and Dose Are Associated with Hematologic Abnormalities but Not Rejection in Kidney Transplant Recipients

BACKGROUND

Little is known regarding the safe fixed dose of mycophenolic acid (MPA) for preventing biopsy-proven acute rejection (BPAR) in kidney transplant recipients (KTRs). We investigated the correlation of MPA trough concentration (MPA C₀) and dose with renal transplant outcomes and adverse events.

METHODS

This study included 79 consecutive KTRs who received MPA with tacrolimus (TAC) and corticosteroids. The MPA C₀ of all the enrolled KTRs was measured, which was determined monthly by using particle-enhanced turbidimetric inhibition immunoassay for 12 months, and clinical data were collected at each time point. The clinical endpoints included BPAR, any cytopenia, and BK or cytomegalovirus infections.

RESULTS

No differences in MPA C₀ and dose were observed between KTRs with or without BPAR or viral infections under statistically comparable TAC concentrations. MPA C₀ was significantly higher in patients with leukopenia (P = 0.021) and anemia (P = 0.002) compared with those without cytopenia. The MPA dose was significantly higher in patients with thrombocytopenia (P = 0.002) compared with those without thrombocytopenia. MPA C₀ ≥ 3.5 μg/mL was an independent risk factor for leukopenia (adjusted odds ratio [AOR], 3.80; 95% confidence interval [CI], 1.24-11.64; P = 0.019) and anemia (AOR, 5.90; 95% CI, 1.27-27.51; P = 0.024). An MPA dose greater than the mean value of 1,188.8 mg/day was an independent risk factor for thrombocytopenia (AOR, 3.83; 95% CI, 1.15-12.78; P = 0.029). However, an MPA dose less than the mean value of 1,137.3 mg/day did not increase the risk of BPAR.

CONCLUSION

Either a higher MPA C₀ or dose is associated with an increased risk of cytopenia, but neither a lower MPA C₀ nor dose is associated with BPAR within the first year of transplantation. Hence, a reduced MPA dose with TAC and corticosteroids might be safe in terms of reducing hematologic abnormalities without causing rejection.

Superior Patient Survival for Continuous Ambulatory Peritoneal Dialysis Patients Treated with a Peritoneal Dialysis Fluid with Neutral pH and Low Glucose Degradation Product Concentration (Balance)

Background

In recent years, laboratory and clinical research has suggested the need for peritoneal dialysis fluids (PDFs) that are more biocompatible than the conventional PDFs commonly used today. Bioincompatibility of PDF has been attributed to low pH, lactate, glucose, glucose degradation products (GDPs), and osmolality. PDFs with neutral pH and low GDPs are now available commercially. In vitro and early clinical studies suggest that these solutions are indeed more biocompatible but, as of now, there is no evidence that their use improves patient outcome.

Methods

Using a dedicated database of over 2000 patients treated with PD in Korea, we were able to conduct a retrospective observational study comparing outcomes for incident continuous ambulatory PD patients treated with a standard, conventional, heat-sterilized PDF to the outcomes for patients treated with a novel, low GDP, neutral-pH PDF prepared in a dual-compartment, double-bag PD system (Balance; Fresenius Medical Care, St. Wendel, Germany). In an intention-to-treat analysis, patient and technique survival, peritonitis-free survival, and peritonitis rates were compared in 611 patients treated with Balance for up to 30 months and 551 patients with a standard PDF (stay·safe; Fresenius Medical Care) treated in the same era and with equivalent follow-up.

Results

The patients were well matched for most relevant characteristics except older age distribution for the patients treated with the standard PDF. Patients treated with Balance had significantly superior survival compared to those treated with the standard PDF (74% vs 62% at 28 months, p = 0.0032). In a multivariate Cox regression model including age, diabetes, and gender, the survival advantage persisted (relative risk of death for Balance 0.75, 95% confidence interval 0.56 – 0.99, p = 0.0465). Modality technique survival was similar in Kaplan–Meier analysis for both PDFs. No differences were detected in peritonitis-free survival or in peritonitis rates between the two solutions.

Conclusion

This study, for the first time, suggests that treatment with a novel biocompatible PDF with low GDP concentration and neutral pH confers a significant survival advantage. The exact mechanisms for such a survival advantage cannot be determined from this study. The usual criticisms of observational studies apply and the results reported here strongly warrant the undertaking of appropriately designed, randomized, controlled clinical trials.

The Effect of Mycophenolate Mofetil versus Cyclosporine as Combination Therapy with Low Dose Corticosteroids in High-risk Patients with Idiopathic Membranous Nephropathy: a Multicenter Randomized Trial

BACKGROUND

Appropriate immunosuppressive therapy for patients with idiopathic membranous nephropathy (MN) remains controversial. The effect of mycophenolate mofetil (MMF) versus cyclosporine (CsA) combined with low-dose corticosteroids was evaluated in patients with idiopathic MN in a multi-center randomized trial (www.ClinicalTrials.gov NCT01282073).

METHODS

A total of 39 biopsy-proven idiopathic MN patients with severe proteinuria were randomly assigned to receive MMF combined with low-dose corticosteroids (MMF group) versus CsA combined with low-dose corticosteroids (CsA group), respectively, and followed up for 48 weeks. Complete or partial remission rate of proteinuria and estimated glomerular filtration rate (eGFR) at 48 weeks were compared.

RESULTS

The level of proteinuria at baseline and at 48 weeks was 8.9 ± 5.9 and 2.1 ± 3.1 g/day, respectively, in the MMF group compared to 8.4 ± 3.5 and 3.2 ± 5.7 g/day, respectively, in the CsA group. In total, 76.1% of the MMF group and 66.7% of the CsA group achieved remission at 48 weeks (95% confidence interval, -0.18 to 0.38). There was no difference in eGFR between the two groups. Anti-phospholipase A2 receptor Ab levels at baseline decreased at 48 weeks in the complete or partial remission group (P = 0.001), but were unchanged in the no-response group. There were no significant differences between the two groups in changes in the Gastrointestinal Symptom Rating Scale and Gastrointestinal Quality of Life Index scores from baseline to 48 weeks.

CONCLUSION

In combination with low-dose corticosteroids, the effect of MMF may not be inferior to that of CsA in patients with idiopathic MN, with similar adverse effects including gastrointestinal symptoms. Trial registry at ClinicalTrials.gov (NCT01282073).

Risk of Stroke in Elderly Dialysis Patients

Despite the current knowledge about the risk of stroke and its related factors in general population, this issue in elderly patients receiving dialysis remains unresolved. Firstly, to compare the risk of stroke between hemodialysis (HD) and peritoneal dialysis (PD), data on 13,065 incident dialysis patients (aged ≥ 65 years; 10,675 in HD and 2,390 in PD) were retrieved from the Korean Health Insurance dataset. Secondly, to identify the risk factors of stroke amongst various clinical and laboratory parameters in HD, 980 elderly patients were retrospectively analyzed using an independent prospective cohort from 31 dialysis centers. For a mean duration of 1.8 years (maximum of 5 years), the risk of all cardiovascular diseases (ischemic heart disease and stroke) did not differ between HD and PD. However, when analyses were conducted separately by subtype, the risk of stroke, not ischemic heart disease, was significantly higher in HD patients than in PD patients. When the risk factors of stroke were probed after HD for a mean duration of 2.6 years (maximum of 7 years), the absolute dependence on social support, a previous history of cardiovascular disease, high levels of low-density lipoprotein cholesterol, and the use of a high number of anti-hypertensive drugs were identified as being significant. Based on the discrepancy of stroke risk between modalities and the HD-tailored risk factors of stroke, the monitoring and management of these factors may be a key strategy to reduce the risk of stroke in elderly patients receiving dialysis.

Increased Circulating T Lymphocytes Expressing HLA-DR in Kidney Transplant Recipients with Microcirculation Inflammation

We consecutively enrolled 82 kidney transplant recipients (KTRs) with stable renal function and 24 KTRs who underwent indication biopsy to compare the histological grading of renal allografts with the activity of circulating T lymphocyte subsets and monocytes determined by flow cytometry, which were obtained at 2 weeks after kidney transplantation (KT) and at the time of indication biopsy, respectively. The sum of the scores of glomerulitis (g) + peritubular capillaritis (ptc), inflammation (i) + tubulitis (t), interstitial fibrosis (ci) + tubular atrophy (ct), and fibrointimal thickening (cv) + arteriolar hyaline thickening (ah) was used to assign a histological grade to the renal allograft samples. The frequencies of CD4⁺HLA-DR⁺/CD4⁺ T cells and CD8⁺HLA-DR⁺/CD8⁺ T cells were significantly increased in KTRs with a microcirculation inflammation (MI) sum score ≥ 1 when compared with KTRs with an MI sum score = 0 as well as stable KTRs. In these 2 subsets, only CD4⁺HLA-DR⁺/CD4⁺ T cells were positively correlated with MI sum scores. Analysis using the receiver operating characteristic (ROC) curve showed that antibody-mediated rejection (AMR) could be predicted with a sensitivity of 80.0% and a specificity of 94.7%, using a cutoff value of 29.6% frequency of CD4⁺HLA-DR⁺/CD4⁺ T cells. MI was significantly associated with an increased frequency of activated T lymphocytes expressing human leukocyte antigen-antigen D related (HLA-DR). Further studies should focus on validating the utility of circulating CD4⁺HLA-DR⁺/CD4⁺ T cells as a noninvasive, immunologic monitoring tool for the prediction of AMR.

Comparison of Outcomes with Arteriovenous Fistula and Arteriovenous Graft for Vascular Access in Hemodialysis: A Prospective Cohort Study

BACKGROUND

Poor vessel quality and limited life expectancy in the elderly may make arteriovenous fistula (AVF) less ideal than arteriovenous graft (AVG) or catheter for vascular access (VA) in hemodialysis (HD).

METHODS

A total of 946 adult incident HD patients from clinical research center registry for end-stage renal disease prospective cohort in South Korea were analyzed for outcomes with AVF and AVG.

RESULTS

Overall, AVF was associated with better patient survival only in male (p < 0.001) and diabetic (p = 0.004) patients, although it was superior to AVG in access patency, regardless of diabetes mellitus status and gender. AVG (vs. AVF; hazard ratio (HR) 2.282; 95% CI 1.071-4.861; p = 0.032) was associated with poor patient survival. In elderly patients (≥65 years), AVF was associated with survival benefit only in male (p < 0.001) and diabetic (p = 0.04) patients, and with better access patency only in female (p = 0.05) and diabetic (p = 0.04) patients. AVG (vs. AVF; HR 3.158; 95% CI 1.080-9.238; p = 0.036) was associated with poor patient survival. In septuagenarian patients, AVF was associated only with survival benefit (p = 0.01) and there was no advantage in access patency (p = 0.12). However, AVF was superior to AVG in both access patency (p = 0.001) and patient survival (p = 0.03) even with propensity matching.

CONCLUSION

AVF is the more desirable VA and its survival benefits warrant its consideration in septuagenarian patients although a prolonged life expectancy is essential to realize the potential benefits of AVF.

Serum β2-Microglobulin Predicts Mortality in Peritoneal Dialysis Patients: A Prospective Cohort Study

BACKGROUND/AIMS

β2-Microglobulin (β2-M) is a surrogate marker of middle-molecule uremic toxins and is associated with mortality in chronic hemodialysis patients. However, the impact of serum β2-M levels on mortality in peritoneal dialysis (PD) patients is uncertain. The purpose of this study was to examine the association of serum β2-M levels with all-cause mortality in PD patients.

METHODS

A total of 771 PD patients were selected from the Clinical Research Center registry for end-stage renal disease cohort in Korea. Patients were categorized into 3 groups by tertiles of serum β2-M levels. The primary outcome was all-cause mortality.

RESULTS

The median value of serum β2-M was 23.6 mg/l (interquartile range 14.8-33.4 mg/l), and the median follow-up period was 39 months. The Kaplan-Meier analysis showed that the all-cause mortality rate was significantly different according to tertiles of serum β2-M in PD patients (p=0.03, log-rank). Multivariate Cox proportional analysis showed that the hazards ratio for all-cause mortality was 1.02 (95% CI 1.01-1.04, p=0.006) per 1 mg/l increase in β2-M after adjustment for multiple confounding factors that relate to malnutrition and inflammation marker. However, serum β2-M was not associated with all-cause mortality after adjustment for residual renal clearance.

CONCLUSIONS

These results are supportive of the potential role of the serum β2-M level as a predictor of mortality in PD patients.

Serum Gamma-Glutamyltransferase Levels Predict Mortality in Patients With Peritoneal Dialysis

Serum gamma-glutamyltransferase (GGT) level has been considered marker of oxidative stress as well as liver function. Serum GGT level has been reported to be associated with the mortality in hemodialysis patients. However, it is not well established whether serum GGT level is associated with all-cause mortality in peritoneal dialysis (PD) patients. The aim of this study was to determine the association between serum GGT levels and all-cause mortality in PD patients.PD patients were included from the Clinical Research Center registry for end-stage renal disease cohort, a multicenter prospective observational cohort study in Korea. Patients were categorized into 3 groups by tertile of serum GGT levels as follows: tertile 1, GGT < 16 IU/L; tertile 2, GGT = 16 to 27 IU/L; and tertile 3, GGT > 27 IU/L. Primary outcome was all-cause mortality.A total of 820 PD patients were included. The median follow-up period was 34 months. Kaplan-Meier analysis showed that the all-cause mortality rate was significantly different according to tertiles of GGT (P = 0.001, log-rank). The multivariate Cox regression analysis showed that higher tertiles significantly associated with higher risk for all-cause mortality (tertile 2: hazard ratio [HR] 2.08, 95% confidence interval [CI], 1.17-3.72, P = 0.013; tertile 3: HR 1.83, 95% CI, 1.04-3.22, P = 0.035) in using tertile 1 as the reference group after adjusting for clinical variables.Our study demonstrated that high serum GGT levels were an independent risk factor for all-cause mortality in PD patients. Our findings suggest that serum GGT levels might be a useful biomarker to predict all-cause mortality in PD patients.

Independent effects of systemic and peritoneal inflammation on peritoneal dialysis survival

Systemic inflammation, as evidenced by elevated inflammatory cytokines, is a feature of advanced renal failure and predicts worse survival. Dialysate IL-6 concentrations associate with variability in peritoneal small solute transport rate (PSTR), which has also been linked to patient survival. Here, we determined the link between systemic and intraperitoneal inflammation with regards to peritoneal membrane function and patient survival as part of the Global Fluid Study, a multinational, multicenter, prospective, combined incident and prevalent cohort study (n=959 patients) with up to 8 years of follow-up. Data collected included patient demographic characteristics, comorbidity, modality, dialysis prescription, and peritoneal membrane function. Dialysate and plasma cytokines were measured by electrochemiluminescence. A total of 426 survival endpoints occurred in 559 incident and 358 prevalent patients from 10 centers in Korea, Canada, and the United Kingdom. On patient entry to the study, systemic and intraperitoneal cytokine networks were dissociated, with evidence of local cytokine production within the peritoneum. After adjustment for multiple covariates, systemic inflammation was associated with age and comorbidity and independently predicted patient survival in both incident and prevalent cohorts. In contrast, intraperitoneal inflammation was the most important determinant of PSTR but did not affect survival. In prevalent patients, the relationship between local inflammation and membrane function persisted but did not account for an increased mortality associated with faster PSTR. These data suggest that systemic and local intraperitoneal inflammation reflect distinct processes and consequences in patients treated with peritoneal dialysis, so their prevention may require different therapeutic approaches; the significance of intraperitoneal inflammation requires further elucidation.

Near-infrared spectroscopy as a possible device for continuous monitoring of arterial carbon dioxide tension during cardiac surgery

Background: Insufflation of carbon dioxide (CO2) to the operative field has been used to prevent major organ injury attributed to air embolisms in cardiac surgery. However, it may be preferable to avoid hypercapnia induced by CO2 insufflation, owing to its potentially harmful effect. To investigate the effectiveness of near-infrared spectroscopy (NIRS) as a possible method for continuous monitoring of arterial CO2 tension during cardiac surgery, we evaluated the correlation between the change in arterial CO2 tension and the change in regional cerebral oxygen saturation (rScO2) obtained from NIRS in as controlled a condition as possible.

Methods: Thirty patients who underwent surgical correction for atrial or ventricular septal defects were enrolled in this study. Patients who had pulmonary hypertension or other intracardiac anomalies were excluded. Anesthetic and cardiopulmonary bypass (CPB) management were conducted according to our standard institutional practice. Data obtained from arterial blood gas analyses and corresponding regional cerebral oxygen saturation (rScO2) recorded from NIRS before and after the insufflations of CO2 during CPB were used for analysis.

Results: The change in arterial CO2 tension correlated with the change in rScO2 in the left hemisphere (r = 0.681, p <0.001, y = −1.393 + 0.547x) and right hemisphere (r = 0.690, p <0.001, y = −1.999 + 0.486x). To control the effects of other variables, including hematocrit and temperature, these relationship were not reduced (left hemisphere: r=0.678, p<0.001; right hemisphere: r=0.634, p<0.001).

Conclusions: Since the change in regional cerebral oxygen saturation was correlated with the change in arterial CO2 tension during mild hypothermic CPB, NIRS might be a possible non-invasive method for monitoring of arterial CO2 tension without incurring additional cost in this setting.

Prevalence of diabetic nephropathy in primary care type 2 diabetic patients with hypertension: data from the Korean Epidemiology Study on Hypertension III (KEY III study)

BACKGROUND

The prevalence of albuminuria is known to be higher in hypertensive compared to normotensive nondiabetic patients. In addition, systolic blood pressure (BP) is found to be an independent risk factor for albuminuria in type 2 diabetes mellitus (T2DM). Based on these findings, the prevalence of albuminuria is expected to be higher in T2DM with hypertension relative to T2DM without hypertension, but it has been largely unexplored.

METHODS

Prevalence rates of microalbuminuria, macroalbuminuria and renal insufficiency (RI) were investigated among 3738 hypertensive T2DM patients from 350 nationwide primary care clinics. Independent factors associated with albuminuria and RI were also characterized.

RESULTS

Clinical and laboratory data of 3712 patients were included in the analysis. BP was controlled in only 1164 patients (31.4%). There were 2595 normoalbuminuric patients (70.6%), and microalbuminuria and macroalbuminuria were present in 850 (23.1%) and 230 (6.3%), respectively. The prevalence of RI was 32.1% based on estimated glomerular filtration rate (eGFR) by Modification of Diet in Renal Disease formula. Systolic BP correlated significantly with the natural logarithmic values of urinary albumin-to-creatinine ratio (ACR) (R = 0.16, P < 0.0001). Multivariate logistic regression analysis revealed that male sex, the duration of diabetes, systolic BP, glycated hemoglobin and eGFR were significant independent factors associated with the presence of albuminuria, while advanced age, female sex, the duration of diabetes and urinary ACR were significant independent risk factors for RI.

CONCLUSIONS

A significant proportion of T2DM patients with hypertension had albuminuria and RI, and the duration of diabetes mellitus rather than the duration of hypertension was a significant independent factor associated with albuminuria and RI.

Improved gastrointestinal symptoms and quality of life after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant patients receiving tacrolimus

It is reported that a conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) relieves gastrointestinal (GI) symptom burden and improves health-related quality of life (HRQoL). However, it is unclear whether renal transplant recipients using tacrolimus receive the same benefit from the conversion. In this prospective, multi-center, open-label trial, patients were categorized into two groups by their GI symptom screening. Equimolar EC-MPS (n=175) was prescribed for patients with GI burdens; those with no complaints remained on MMF (n=83). Gastrointestinal Symptom Rating Scale (GSRS) and Gastrointestinal Quality of Life Index (GIQLI) were evaluated at baseline and after one month. Patients and physicians completed Overall Treatment Effect (OTE) at one month. EC-MPS-converted patients had worse GSRS and GIQLI scores at baseline than MMF-continued patients (all P<0.001). Significant improvements in GSRS and GIQLI scores were observed for EC-MPS-converted patients at one month, but MMF-continued patients showed worsened GSRS scores (all P<0.05). OTE scale indicated that EC-MPS patients improved in overall GI symptoms and HRQoL more than MMF patients did (P<0.001). In tacrolimus-treated renal transplant recipients with GI burdens, a conversion from MMF to EC-MPS improves GI-related symptoms and HRQoL.

Simultaneous detection of antibody binding and cytotoxicity in flow cytometry crossmatch for renal transplantation

BACKGROUND

The anti-HLA antibody can be detected using either a complement-dependent lymphocytotoxicity (CDC) assay or a flow cytometry crossmatch (FCXM) in renal transplantation. Discordant results are often obtained because the two methods detect different reaction phases between the donor lymphocytes and the recipient sera. This study was intended to confirm that antibody binding and cytotoxicity to the lymphocytes can be detected simultaneously in a single FCXM assay, cytotoxic FCXM.

METHODS

In the cytotoxic FCXM, the antibody binding to the lymphocytes was measured using anti-IgG-FITC, and the cytotoxicity using 7-aminoactinomycin D (7-AAD) after adding complement. For an evaluation of two test parameters, the cytotoxicity test moiety (dead-cell percentage) was compared with the anti-human globulin (AHG)-CDC, and the antibody-binding test moiety (sample/control fluorescence ratio) with the conventional FCXM in 77 positive and 30 negative crossmatches.

RESULTS

In the cytotoxic FCXM, both antibody binding and cytotoxicity could be assessed in a single anti-IgG-FITC/7-AAD plot. Regarding the correlation between the presence of HLA antibodies and the test result, the cytotoxicity parameter (r = 0.55) appeared to be more suitable than that of the AHG-CDC (r = 0.50) but the antibody-binding parameter (r = 0.83) was worse than that of the conventional FCXM (r = 0.93). The sensitivity of both parameters of the cytotoxic FCXM was not significantly different from each conventional counterpart (P = 0.33 and P = 0.22, respectively).

CONCLUSIONS

The simultaneous detection of Ab binding and cytotoxicity was possible by the cytotoxic FCXM with the test efficiencies similar to the conventional counterparts. If this new assay is improved through the further studies to optimize the critical assay variables, this may be used as an alternative to the conventional assays to acquire more information on the characteristics of the recipient's HLA alloantibodies.

Urinary Transforming Growth Factor-β–Induced Gene-h3 (βig-h3) as a Sensitive Predictor in Chronic Cyclosporine Nephrotoxicity

Transforming growth factor (TGF)-beta is involved in the pathogenesis of chronic cyclosporine nephrotoxicity (CyAN). Since the expression of TGF-beta induced gene h3 (betaig-h3) is up-regulated by TGF-beta, we evaluated the potential role of betaig-h3 as a sensitive urinary marker to monitor the progression/regression of chronic CyAN. Urinary betaig-h3 levels were determined using an enzyme-linked immunosorbent assay in nine patients with chronic CyAN and 13 patients with stable graft function. We scored the extent of tubulointerstitial fibrosis (TIF) and using immunoperoxidase labeling, determined betaig-h3 expression in renal tissues of patients with chronic CyAN. Urinary betaig-h3 excretion was higher in chronic CyAN compared to control subjects (173.4+/-26.0 vs 62.6+/-5.0 ng/mg creatinine, P<.01). In chronic CyAN, the degree of TIF correlated with increased urinary betaig-h3 levels (r=.785, P<.05). In kidneys with chronic CyAN, betaig-h3 labeling was more prominent at the basement membranes (BM) of the tubules where inflammatory cells had infiltrated the surrounding interstitium. Moreover, the BM of the atrophied tubules and their surrounding interstitium were strongly labeled. Urinary betaig-h3 levels decreased from 173.4+/-26.0 to 64.9+/-14.4 ng/mg creatinine at 1 month after discontinuation of CyA or reduction in CyA dosage (P<.01) despite unchanged serum creatinine levels. Urinary betaig-h3 levels increased in patients with chronic CyAN and decreased after discontinuation or reduction of CyA dosage. Our results suggested that urinary betaig-h3 levels could be used as a sensitive urinary marker to monitor the progression or regression of chronic CyAN.

Polymorphisms in TGF-beta1 gene and the risk of lung cancer

BACKGROUND

Transforming growth factor-beta1 (TGF-beta1) functions as a suppressor of tumor initiation by inhibiting cellular proliferation or by promoting cellular differentiation or apoptosis in the early phase of cancer development. Variations in the DNA sequence in the TGF-beta1 gene may lead to altered TGF-beta1 production and/or activity, and so this can modulate an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of the TGF-beta1 -509C > T and 869T > C (L10P) polymorphisms and their haplotypes with the risk of lung cancer in a Korean population.

METHODS

The TGF-beta1 genotypes were determined in 432 lung cancer patients and in 432 healthy control subjects who were frequency-matched for age and gender. The TGF-beta1 haplotypes were predicted using a Bayesian algorithm in the Phase program.

RESULTS

Individuals with at least one -509T allele were at a significantly decreased risk of adenocarcinoma (AC) and small cell carcinoma (SM), as compared with carriers with the -509CC genotype [adjusted odds ratio (OR), 0.63; 95% confidence interval (CI), 0.42-0.96; P = 0.04; and adjusted OR, 0.45; 95% CI, 0.27-0.76; P = 0.002; respectively]. For the 869T > C polymorphism, the combined TC + CC genotype was associated with a significantly decreased risk of SM compared with the TT genotype (adjusted OR, 0.52; 95% CI, 0.31-0.88; P = 0.01). Consistent with the results of the genotyping analyses, the -509T/869C haplotype was associated with a significantly decreased risk of AC and SM as compared with the -509C/869T haplotype (adjusted OR, 0.75; 95% CI, 0.57-0.98; P = 0.04; and adjusted OR, 0.67; 95% CI, 0.47-0.96; P = 0.02; respectively).

CONCLUSION

The TGF-beta1 -509C > T and 869T > C polymorphisms and their haplotypes may contribute to genetic susceptibility to AC and SM of the lung.

Superior patient survival for continuous ambulatory peritoneal dialysis patients treated with a peritoneal dialysis fluid with neutral pH and low glucose degradation product concentration (Balance)

BACKGROUND

In recent years, laboratory and clinical research has suggested the need for peritoneal dialysis fluids (PDFs) that are more biocompatible than the conventional PDFs commonly used today. Bioincompatibility of PDF has been attributed to low pH, lactate, glucose, glucose degradation products (GDPs), and osmolality. PDFs with neutral pH and low GDPs are now available commercially. In vitro and early clinical studies suggest that these solutions are indeed more biocompatible but, as of now, there is no evidence that their use improves patient outcome.

METHODS

Using a dedicated database of over 2000 patients treated with PD in Korea, we were able to conduct a retrospective observational study comparing outcomes for incident continuous ambulatory PD patients treated with a standard, conventional, heat-sterilized PDF to the outcomes for patients treated with a novel, low GDP, neutral-pH PDF prepared in a dual-compartment, double-bag PD system (Balance; Fresenius Medical Care, St. Wendel, Germany). In an intention-to-treat analysis, patient and technique survival, peritonitis-free survival, and peritonitis rates were compared in 611 patients treated with Balance for up to 30 months and 551 patients with a standard PDF (stay . safe; Fresenius Medical Care) treated in the same era and with equivalent follow-up.

RESULTS

The patients were well matched for most relevant characteristics except older age distribution for the patients treated with the standard PDF. Patients treated with Balance had significantly superior survival compared to those treated with the standard PDF (74% vs 62% at 28 months, p = 0.0032). In a multivariate Cox regression model including age, diabetes, and gender, the survival advantage persisted (relative risk of death for Balance 0.75, 95% confidence interval 0.56 - 0.99, p = 0.0465). Modality technique survival was similarin Kaplan-Meieranalysis for both PDFs. No differences were detected in peritonitis-free survival or in peritonitis rates between the two solutions.

CONCLUSION

This study, for the first time, suggests that treatment with a novel biocompatible PDF with low GDP concentration and neutral pH confers a significant survival advantage. The exact mechanisms for such a survival advantage cannot be determined from this study. The usual criticisms of observational studies apply and the results reported here strongly warrant the undertaking of appropriately designed, randomized, controlled clinical trials.

Increased microvascular blood content is an early event in colon carcinogenesis

BACKGROUND

Increased premalignant epithelial microvascular blood content is a common theme in neoplastic transformation; however, demonstration of this phenomenon in colon carcinogenesis has been stymied by methodological limitations. Our group has recently developed a novel optics technology, four dimensional elastic light scattering fingerprinting (4D-ELF), which allows examination of the colonic mucosal architecture with unprecedented accuracy. In this study, we utilised 4D-ELF to probe the preneoplastic colonic microvasculature.

METHODS

Colonic mucosal blood content was assessed by 4D-ELF at serial preneoplastic time points from azoxymethane (AOM) treated Fisher 344 rats and age matched control animals. We also examined the pretumorigenic intestinal mucosa of the MIN mouse, and compared with wild-type mice. Finally, in a pilot study, we examined superficial blood content from the endoscopically normal mid transverse colon in 37 patients undergoing screening colonoscopy.

RESULTS

In the AOM treated rat model, augmentation of superficial mucosal and total mucosal/superficial submucosal blood supply preceded the appearance of aberrant crypt foci (ACF) and temporally and spatially correlated with future ACF occurrence. These findings were replicated in MIN mice. The 4D-ELF based results were corroborated with immunoblot analysis for haemoglobin on mucosal scrapings from AOM treated rats. Moreover, 4D-ELF analysis of normal human colonic mucosa indicated that there was a threefold increase in superficial blood in patients who harboured advanced adenomas.

CONCLUSION

We report, for the first time, that blood content is increased in the colonic microvasculature at the earliest stages of colon carcinogenesis. These findings may provide novel insights into early biological events in colorectal carcinogenesis and have potential applicability for screening.

Effect in a rat model of heparinized peritoneal dialysis catheters on bacterial colonization and the healing of the exit site

We performed a prospective, double-blind, randomized study to evaluate whether stable surface heparinization of silicone peritoneal dialysis (PD) catheters prevents bacterial colonization or biofilm formation and improves healing of the exit site. Heparinized catheters were implanted in 20 Sprague-Dawley rats (group H) and non heparinized catheters in another 20 (group C). The PD catheters, constructed of silicon tubing with two polyester cuffs, were patterned after the standard Tenckhoff catheter. A covalent multipoint method of attachment onto polymeric surfaces was used for stable, permanent chemical immobilization of heparin on the PD catheter. Dialysis exchanges (25-mL instillation volume) were performed twice daily for 4 weeks through the permanent catheter. Prophylactic antibiotics were not used. The exit sites were evaluated at 2-week intervals. The extent of biofilm coverage on the intraperitoneal portion of the catheter (obtained at the end of the experiment) was assessed, and sonicated fluid from the catheter tip was cultured for evaluating bacterial colonization of the catheter. Exit-site scores in group H were lower than in group C (p = 0.052) at the end of week 4. Bacterial colonization tended to be less common in group H [2 of 12 catheters (17%)] than in group C [8 of 15 catheters (53%); p = 0.058], but the extent of biofilm, the peritonitis rate, and the inflammation score of tissue adjacent to the cuff were not different between the groups. Those data suggest that heparinized PD catheters can be a practical approach to the prevention of bacterial colonization and can improve healing of the exit site.

Effects of peritoneal rest on peritoneal transport and peritoneal membrane thickening in continuous ambulatory peritoneal dialysis rats

OBJECTIVE

To evaluate the effects of peritoneal rest on peritoneal transport and morphology in a rat model of peritoneal dialysis.

DESIGN

Twenty-four rats (Sprague-Dawley, male, 250-300 g) were divided into three groups: group 1 (control, n = 6) without dialysis, group 2 (n = 9) sacrificed immediately after 3 weeks of dialysis, and group 3 (n = 9) sacrificed after 4 weeks of peritoneal rest after 3 weeks of dialysis. Both dialysis groups were dialyzed twice daily with an intraperitoneal instillation volume of 25 mL of 3.86% dextrose solution for 3 weeks. Peritonitis was induced by supplementing the dialysis fluid with lipopolysaccharide (5 microg/mL) on days 8, 10, and 12 in both dialysis groups. Peritoneal equilibration tests were performed on each animal at baseline. The equilibration tests were repeated at the 4th and the 8th week of dialysis. Morphometric analyses of the peritoneal membrane were carried out in tissue specimens obtained at the time of sacrifice.

RESULTS

The D/D0 ratio for glucose at two hours in groups 2 and 3 at the beginning of week 4 was significantly lower than at baseline, indicating an increase in peritoneal permeability to glucose after 3 weeks of dialysis. D/D0 in group 3 at the beginning of week 8, after 4 weeks of peritoneal rest, was significantly higher than at week 4. The drain volume in groups 2 and 3 at week 4 was significantly lower than at baseline; however, the drain volume in group 3 at week 8 was significantly higher than at week 4. The thickness of the parietal peritoneal membrane in group 3 was significantly greater than in group 1 and less than in group 2 (group 1, 11.4+/-7.6 microm; group 2, 37.5+/-18.4 microm; group 3, 21.4+/-12.1 microm).

CONCLUSIONS

Peritoneal rest improves ultrafiltration in rats by decreasing the hyperpermeability of glucose and also reduces the degree of peritoneal thickening. These data suggest that dialysis-induced changes in peritoneal transport and morphology are reversible under the conditions of peritoneal rest in this experimental model.

Molecular cloning and analysis of transcription initiation in the Anagrapha falcifera multiple nucleocapsid polyhedrosis virus polyhedrin gene

Using Autographa californica multiple nucleocapsid polyhedrosis virus (AcMNPV) polyhedrin to probe the Southern blots of Anagrapha falcifera multiple nucleocapsid polyedrosis virus (AfMNPV), we identified the location of the AfMNPV polyhedrin gene within the 7.2 kb EcoRI fragment. The 7.2 kb EcoRI fragment of AfMNPV was cloned and the nucleotide sequences of the polyhedrin coding region and its flanking regions were determined. Nucleotide sequence analysis indicated the presence of an open reading frame (ORF) of 735 nucleotides (nt) which could encode 245 amino acids with a predicted molecular mass of 29 kDa. The nucleotide sequences within the coding region of the AfMNPV polyhedrin shared 80% similarity with the polyhedrin gene from AcMNPV but were most closely related to Bombyx mori NPV with 92% sequence identity. The size of the AfMNPV polyhedrin mRNA, determined by the Northern blot analysis, was estimated to be 1200 nt. The consensus promoter sequence (ATAAG) for the baculovirus very late gene was also observed. Two degenerate poly(A) tailing signals were found immediately downstream of the translational stop codon. The transcription initiation site, mapped by primer extension analysis, was found to be at T located 24 nt upstream from the A of the translation initiation codon. This site is located 26 nt downstream from the second A of the consensus TAAG, the transcription initiation site of most other NPVs.

Bone marrow immunoscintigraphy (BMIS): a new and important tool for the assessment of marrow fibrosis in renal osteodystrophy?

One of the classic histologic forms of renal osteodystrophy is osteitis fibrosa, and its distinguishing characteristic is bone marrow (BM) fibrosis, caused by the activation of marrow parenchymal cells. A bone biopsy must be performed in order to establish the diagnosis of renal osteodystrophy. The clinical use of bone biopsy is restricted, however, due to the invasiveness of the procedure. In recent studies, bone scans have provided information useful for the differential diagnosis between osteomalacia and osteitis fibrosa. However, bone scans can not provide information on the bone marrow status. Bone marrow immunoscintigraphy (BMIS) using Tc-99m anti-granulocyte antibody (AGA), a highly sensitive test for the detection of bone marrow abnormalities which is also a noninvasive method, has rarely been reported in chronic renal failure (CRF). BMIS can provide information in patients with myelofibrosis. The purpose of this study was to evaluate the usefulness of BMIS in CRF patients with special regards to biochemical parameters. Nineteen CRF patients (13 men, 6 women; mean age: 48 +/- 11 years) in whom bone scintigraphy using Tc-99m MDP (methylene diphosphonate) showed the so-called superscan pattern were included in the study. Their primary renal diseases were chronic glomerulonephritis (n = 14), diabetes (n = 4), and polycystic kidney disease (n = 1). Modes of therapies were continuous ambulatory peritoneal dialysis (CAPD) (n = 13; mean duration: 9.5 months), HD (n = 5; mean duration: 7.8 months), and conservative treatment (n = 1). BMIS using Tc-99m labeled anti-granulocyte monoclonal mouse antibody BW250/183 was performed, and the results were compared with the biochemical parameters of the patients. According to the presence of BM expansion, which may represent marrow fibrosis, the 19 patients were divided into two groups: Group I (n = 7) with BM expansion and Group II (n = 12) with normal marrow distribution. The biochemical parameters and bone markers of Group I were compared with those of Group II. There was no significant difference in biochemical parameters (blood hemoglobin, serum ferritin, erythropoietin, BUN, creatinine) between the two groups. There were no significants difference in serum calcium, phosphorus, tartate-resistant acid phosphatase (TRAP), and intact parathyroid hormone (iPTH) between the two groups. Serum alkaline phosphatase (ALP) and osteocalcin were significantly (P < 0.05) higher in Group I than in Group II. These results suggest that patients with bone marrow expansion in BMIS have increased levels of ALP and osteocalcin, indicating an increased osteoblastic activity. BMIS may be useful for the detection of bone marrow expansion due to marrow fibrosis in renal osteodystrophy, and for the evaluation of the extent of bone marrow fibrosis.

The absence of toxicity in intraperitoneal iron dextran administration: a functional and histological analysis

OBJECTIVE

To determine the influence of iron dextran intraperitoneal administration on the function and histology of the peritoneum in rats undergoing chronic peritoneal dialysis.

DESIGN

Prospective, randomized experimental study.

MATERIALS

Fifty-four Sprague-Dawley rats were divided into five groups: 3 study groups--high dose group (H), n = 12; intermediate dose (M), n = 12; and low dose group (L), n = 12--a dialysis control group (D), n = 12; and a tissue control (C), n = 7.

INTERVENTIONS

The study groups were given Dianeal containing iron dextran in a concentration of 0.5, 0.25, and 0.125 mg/L (groups H, M, and L respectively). Group D was given standard Dianeal. Group C was never dialyzed.

MAIN OUTCOME MEASURES

A 2-hour peritoneal equilibrium test (PET) was performed on the eighth day, at 3 months, and at 6 months. After the final PET, the animals were sacrificed and the peritoneal membrane was evaluated by gross inspection and light microscopy (silver, prussian blue, and trichrome staining).

RESULTS

Peritoneal transport of small solutes followed the same pattern in all groups, increasing over time. The peritonitis index was similar in the groups. No iron deposits or morphologic differences were seen in the gross inspection of the peritoneal cavity. No peritoneal iron deposition was detected in the histological analysis with prussian blue staining. No differences were noted in the light microscopic analysis of the mesothelial cell layer (silver staining), nor did the morphometric analysis of the submesothelial space show any differences in thickness between the groups.

CONCLUSION

These findings suggest the absence of toxic effects of iron dextran on the peritoneal cavity of rats in the concentrations studied. Further studies should be performed to evaluate the effectiveness of these dosages delivered intraperitoneally to maintain iron homeostasis.

The effect of antibiotic prophylaxis on the healing of exit sites of peritoneal dialysis catheters in rats

OBJECTIVE

To evaluate the influence of intraperitoneal (i.p.) antibiotic (AB) prophylaxis on the quality of healing and infection rates of exit sites in peritoneal dialysis catheters.

STUDY DESIGN

Twenty-one Sprague-Dawley rats were dialyzed 3 times per day for 6 weeks. Dianeal solution containing AB was used for all the rats during the first 5 days. The animals were randomized on the sixth day into three groups: group A (AB-free after randomization), group B (AB for 3 weeks), and group C (AB during 6 weeks). Scores were given to each exit site according to the observation. Mean scores from each group were compared in an attempt to find significant differences between the groups. Dialysate and exit-site drainage samples were taken weekly for microbiology.

RESULTS

Eight episodes of peritonitis were diagnosed, six in group A and two in group B. The most common bacteria causing peritonitis were gram-negative rods. The mean scores were not significantly different between groups C and B throughout the study, even after the discontinuation of the prophylaxis. Group A, when compared to the other two groups, had significantly higher scores after the second week and throughout the rest of the study.

CONCLUSION

Intraperitoneal antibiotic prophylaxis for 3 weeks after catheter implantation is an effective way to prevent early colonization of exit sites, providing a better healing quality and lower incidence of catheter-related infection. Although the extension of the prophylaxis for 6 weeks seems to be beneficial, it was not statistically proven in this study.

CAPD, an acceptable form of therapy in elderly ESRD patients: a comparative study

Rapid growth in the number of dialysis patients over the age of 65 is occurring coincidentally with the overall aging of the general population. Elderly patients are often poor and physically incapacitated, needing family or social support. These patients may also be susceptible to malnutrition and have multiple complicating medical disorders in addition to end-stage renal disease (ESRD). Thus the selection of an appropriate dialysis modality is particularly critical in elderly patients. Continuous ambulatory peritoneal dialysis (CAPD) offers many advantages to elderly patients, including hemodynamic stability, steady-state chemistries, and no need to create a vascular access. However, little data are available in the literature documenting the use of CAPD in this setting. Therefore, to evaluate the efficacy of CAPD in elderly patients, we retrospectively reviewed the clinical outcomes of 23 patients 65 years of age or older at the start of CAPD (elderly group). Then for each of these patients, 23 comparison subjects younger than 65 were chosen from CAPD patients at our hospital (control group). The control group was matched for sex, CAPD duration, cause of ESRD, and initial connection device. In the elderly group, 23 patients (12 male, 11 female) with a mean age of 70 +/- 4 years (range 65-86 years) were treated with CAPD for 15 +/- 17 months. In the control group, 23 patients (12 male, 11 female) with a mean age of 41 +/- 11 (range 18-57) were treated with CAPD for 16 +/- 17 months. Diabetic nephropathy was the cause of ESRD in 35% of patients. The negative CAPD selection of patients was higher in the elderly group (61% vs 17%, p = 0.0025) as well as in the group that needed a helper (61% vs 17%, p = 0.0025). The exit-site infection and peritonitis rates were not statistically different between the two groups (0.43 vs 0.91 episodes/patient-year and 1.46 vs 2.03 episodes/patient-year). The dialysate leakage and bleeding rates were comparable (13% vs 22% and 9% vs 9%). One-year catheter survival was similar in the elderly and younger patients (87.5% vs 84.0%). Although the negative CAPD selection of patients was higher in the elderly group, outcomes were similar to those seen in younger patients. Therefore, CAPD is an acceptable form of therapy for the elderly ESRD patients, particularly if a helper can participate.

Ultrasound-guided cannulation of the femoral vein for acute haemodialysis access

BACKGROUND

Central venous access is a mandatory part of patient management in many clinical settings and is usually achieved with a blind, external landmark-guided technique. The purpose of this study is to evaluate whether an ultrasound technique can improve on the external landmark method.

METHODS

We prospectively evaluated an ultrasound-guided method in 28 patients undergoing femoral vein cannulation for acute haemodialysis access and compared the results with 38 patients in whom an external landmark-guided technique was used. External landmark-guided technique was done by manual localization of the femoral artery in the femoral triangle inferior to the inguinal ligament with needle insertion medial to the artery. Ultrasound-guided cannulation was performed in the same location with the aid of an ultrasound device (Site-Rite, Dymax Corp., USA) with a 7.5 MHz transducer covered by a sterile sheath.

RESULTS

Cannulation of the femoral vein was achieved in all patients (100%) using ultrasound and in 34 patients (89.5%) using the landmark-guided technique. The vein was entered on the first attempt in 92.9% of patients using ultrasound and in 55.3% using the landmark technique (P < 0.05). Average access time (skin to vein) was similar but total procedure time was 45.1 +/- 18.8 s by the ultrasound approach and 79.4 +/- 61.7 s by the landmark approach (P < 0.05). Using ultrasound, puncture of the femoral artery occurred in 7.1% of patients, and haematoma in 0%. Using external landmark technique, puncture of the femoral artery occurred in 15.8% of patients, and haematoma in 2.6%.

CONCLUSIONS

Ultrasound-guided cannulation of the femoral vein reduces the time required for the procedure, reduces the number of passes needed to puncture the vein, and minimizes complications such as arterial puncture or haematoma.

Mitochondrial DNA sequence analysis of four Alzheimer's and Parkinson's disease patients

The mitochondrial DNA (mtDNA) sequence was determined on 3 patients with Alzheimer's disease (AD) exhibiting AD plus Parkinson's disease (PD) neuropathologic changes and one patient with PD. Patient mtDNA sequences were compared to the standard Cambridge sequence to identify base changes. In the first AD+PD patient, 2 of the 15 nucleotide substitutions may contribute to the neuropathology, a nucleotide pair (np) 4336 transition in the tRNA(Gln) gene found 7.4 times more frequently in patients than in controls, and a unique np 721 transition in the 12S rRNA gene which was not found in 70 other patients or 905 controls. In the second AD+PD patient, 27 nucleotide substitutions were detected, including an np 3397 transition in the ND1 gene which converts a conserved methionine to a valine. In the third AD+PD patient, 2 polymorphic base substitutions frequently found at increased frequency in Leber's hereditary optic neuropathy patients were observed, an np 4216 transition in ND1 and an np 13708 transition in the ND5 gene. For the PD patient, 2 novel variants were observed among 25 base substitutions, an np 1709 substitution in the 16S rRNA gene and an np 15851 missense mutation in the cytb gene. Further studies will be required to demonstrate a causal role for these base substitutions in neurodegenerative disease.

Detection of 17p loss in gastric carcinoma using polymerase chain reaction

BACKGROUND

The loss of heterozygosity (LOH) of 17p has been previously studied with conventional Southern blot-restriction fragment length polymorphism analysis, but the relatively low informativity was an obstacle to extensive analysis. To overcome this problem and to investigate the significance of 17p LOH in gastric carcinoma, we employed polymerase chain reaction and subsequent silver staining of DNA.

EXPERIMENTAL DESIGN

LOH of p53 gene and D17S5 locus on 17p was analyzed using polymerase reaction; the relationships between 17p LOH and conventional clinicopathologic parameters were evaluated.

RESULTS

The LOH of p53 gene and D17S5 was found in 36.5% (23 out of 63) and 63.3% (38 out of 60) informative cases, respectively. There was no significant correlation between LOH of these two loci, whereas the frequency of the D17S5 locus was significantly higher (p < 0.01), which suggested that there may be another putative tumor suppressor gene between the two loci or distal to D17S5. The LOH of p53 gene and D17S5 locus was not significantly associated with abnormal p53 expression, depth of invasion, histologic type of the tumor (Lauren's classification), or the status of lymph node metastasis.

CONCLUSIONS

The polymerase chain reaction and silver staining of DNA seemed to be a simple and excellent method for the evaluation of chromosomal allelic loss. The 17p LOH was frequently found in gastric carcinoma, but specific association with conventional clinicopathologic parameters was not found.

Induction of natural chimerism after retransplantation of the liver in rats

Immunological aspects after orthotopic rat liver retransplantation (re-OLT) were examined in association with cell migration and mixed chimerism. At day 2 after the first orthotopic liver transplantation (day 0) in the combination of DA (MHC haplotype, RT1a) donor into PVG (RT1c) recipient, the grafted DA liver was removed and a new PVG liver was implanted into the same PVG recipient (re-OLT). In the PVG recipient at various times after the re-OLT, DA-derived antigen and cells were detected using a DA-specific anti-class I mAb R3/13 in conjunction with ELISA, immunoblotting, and immunohistochemistry. The level of soluble class I antigen, which had risen to 270 ng/ml after the first OLT, substantially decreased within 24 hr after re-OLT. Using immunoblotting, DA class I antigen was detected in the PVG recipient's lymphoid organs at day 3 after DA liver grafting and persisted for up to 21 days after the DA liver was replaced by a new PVG liver. Immunohistochemistry on sections of spleen from re-OLT rats showed that the level of migratory cells expressing DA class I correlated with the findings obtained by immunoblotting. While the DA-derived antigen and cells were detected in the re-OLT recipient, the DA-specific inhibition of mixed lymphocyte reaction was observed in re-OLT serum. Our results suggest that the implanted DA liver graft was the source of DA soluble class I antigen, but DA-derived antigen and cells detected in the re-OLT recipient organs could persist for a relatively long time under immunosuppression after the implanted DA liver was removed by re-OLT.

HRAS protooncogene polymorphism and breast cancer

The potential association of polymorphism in the HRAS protooncogene variable repeat region with susceptibility to cancer has become a controversial topic. A number of studies have produced results that appear inconsistent. We report here a multidisciplinary study with a combined molecular and epidemiological approach, addressing the specific question of the association of rare HRAS alleles and breast cancer. Extensive questionnaire data and peripheral blood for DNA extraction were obtained from 160 cases of incident breast cancer and from two control groups totaling 405 unaffected women from five outpatient clinics in North Carolina between April 1990 and June 1991. Controls were frequency matched to cases on age and race. Our results, adjusted for race and age, showed a positive overall association between the presence of rare HRAS alleles and breast cancer. This relationship was somewhat stronger in control group 2 (odds ratio = 3.0; P < 0.01) than in control group 1 (odds ratio = 2.0; P < 0.05). The relationship was 3-6 times stronger in blacks than in whites. In the case series, rare HRAS alleles were associated with hormone receptor negative tumors. This association was stronger in blacks and younger women. There was no confounding or effect modification by any other breast cancer risk factors. We conclude that rare HRAS alleles are associated with breast cancer and that this association may be stronger in black women than in white women. Rare HRAS alleles may also be related to more aggressive tumors, particularly in blacks and younger women. HRAS alleles have the potential to become a valuable screening biomarker for women at increased risk for breast cancer.

Immunogenetic and nutritional profile in insulin-using youth-onset diabetics in Korea

There are few reports on the genetic, immunological and nutritional characteristics of insulin-using youth-onset diabetes mellitus, insulin-dependent diabetes mellitus (IDDM) and malnutrition-related diabetes mellitus (MRDM) in Korea. Among 1266 hospitalized Korean diabetics, 29 (2.3%) were IDDM and 84 (6.6%) were MRDM. A diabetes history of first-relatives (28.6%) was more frequently found in the MRDM group than in the IDDM (14.8) and non-insulin-dependent diabetes mellitus (NIDDM) (19.0%) groups. HLA-DR4 was more common among IDDM (54.2%) and MRDM (52.4%) patients than controls (26.3%), and HLA-DR3 was more common among only IDDM patients (29.2%) than controls (10.9%). Conventional islet-cell antibodies were detected in 8 of 15 IDDM patients tested (53.3%) and in 11 of 22 MRDM patients (50.0%). MRDM patients had higher serum basal (1.02 +/- 0.51 ng/ml) and peak (1.44 +/- 0.76 ng/ml) C-peptide concentrations than IDDM patients, but lower concentrations than NIDDM patients. Before the onset of diabetes, the calorie intake of 21 MRDM patients assessed was 63.1% of the daily requirement and the intake of carbohydrate, protein and fat was 71.7%, 55.9% and 39.8%, respectively. In summary, our data suggest that IDDM in Korea is associated with HLA-DR3 or HLA-DR4, indicating a risk for IDDM in Western societies; furthermore, MRDM has a history of undernutrition at the preonset period and is also associated with HLA-DR4. It might be also concluded that MRDM in Korea is another expression of IDDM caused by the shortage of some nutrients for the structural and/or functional maintenance of pancreatic beta-cells.

Carbamylation of hemoglobin in vivo with chronic sublethal dietary cyanide: implications for hemoglobin S

Carbamylation of the hemoglobin in sickle cell anemia has been demonstrated to improve the status of this hemoglobinopathy. Using an animal model of West African human patterns of chronic sublethal dietary cyanide ingestion, 12 miniature swine consuming either 0, 0.4, 0.7, or 1.2 mg of cyanide/kg body weight/day were studied for 24 weeks to determine if this dietary regime could produce irreversible carbamylated hemoglobin. Throughout the study, the hematological status of all animals remained similar; however, the levels of carbamylated hemoglobin as measured by nanomoles of valine hydantoin varied proportionally to dietary sublethal cyanide intakes, indicating that these natural dietary levels could effect an important and presumably permanent modification of the hemoglobin's beta chain. Serum thiocyanate levels were also positively correlated with cyanide ingestion loads (r = 0.83, P less than 0.01). The implications of these findings in swine are important for the millions of humans with hemoglobin S who regularly consume similar levels of dietary cyanide and for our assessments of the biochemical and medical status of hemoglobin S under natural conditions.

Influence of dietary cyanide on immunoglobulin and thiocyanate levels in the serum of Liberian adults

Serum thiocyanate, antibody titers to thiocyanates, and serum immunoglobulins (IgM, IgG, IgA) were measured in 73 Liberian adults normally consuming diets of low, moderate, high, or no (control) cassava-derived cyanide (CN(-)). When control and low groups (n = 40; daily intake less than 0.60 mg CN(-) per kg body weight) were contrasted with moderate and high groups (n = 33; daily intake greater than or equal to 0.60 mg CN(-) per kg body weight), the authors observed that (1) one-time serum thiocyanate measurements were not sensitive to long-term cyanide intake; however, (2) antibody titers to thiocyanates were positively correlated with cassava-based cyanide intakes (r = .22, P = 0.05); and (3) serum IgM, IgG, and IgA levels were elevated in individuals regularly consuming moderate and high levels of dietary cyanide. Possible responsible mechanisms and health implications are discussed.