Association between Vitamin D Deficiency and Anemia in Patients with End-Stage Renal Disease: A Cross-Sectional Study

PURPOSE

Despite new treatment strategies, anemia remains the most prevalent complication in patients with end-stage renal disease (ESRD). We investigated whether 25-hydroxyvitamin D [25(OH)D3] deficiency was associated with anemia in ESRD patients.

MATERIALS AND METHODS

We reviewed the medical records of 410 ESRD patients who had undergone renal transplantation (RTx) at Yonsei University Health System and who had 25(OH)D3 levels measured at the time of RTx. Patients were divided into two groups based on baseline 25(OH)D3 concentrations: group 1, 25(OH)D3 levels <10 ng/mL; and group 2, 25(OH)D3 levels ≥10 ng/mL.

RESULTS

Using multivariate regression models, 25(OH)D3, age, and erythrocyte-stimulating agent (ESA) dose were found to be significantly associated with hemoglobin (Hb) levels [25(OH)D3: β=0.263, p<0.001; age: β=0.122, p=0.010; ESA dose: β=-0.069, p=0.005]. In addition, logistic regression analysis revealed that patients in group 1 had a significantly higher risk for developing anemia (Hb level <10 g/dL) compared to group 2 patients, even after adjusting for potential risk factors for anemia (odds ratio=3.857; confidence interval=1.091-13.632; p=0.036).

CONCLUSION

25(OH)D3 deficiency was significantly associated with anemia in patients with ESRD. Randomized controlled trials are needed to determine whether vitamin D supplementation can improve anemia in these patients.

Hypoadiponectinemia and the presence of metabolic syndrome in patients with chronic kidney disease: results from the KNOW-CKD study

BACKGROUND

In patients with chronic kidney disease, metabolic syndrome has been demonstrated to be the culprit behind diverse complications. Adiponectin is known to have anti-atherogenic and cardio-protective effects. Meanwhile, the relationship between adiponectin and metabolic syndrome in patients with chronic kidney disease has not been clarified. The aim of this study was to elucidate the relationship between adiponectin level and metabolic syndrome in patients with chronic kidney disease.

METHODS

The KoreaN Cohort Study for Outcome in Patients with Chronic Kidney Disease is a cohort study that enrolled subjects with chronic kidney disease throughout South Korea. From February 2011 to July 2014, data were collected from 1332 patients with chronic kidney disease.

RESULTS

The mean age of the patients was 53.5 years and 803 patients (60.7%) were men. The median adiponectin level was 10.7 μg/mL and 585 (44.3%) patients had metabolic syndrome. In multiple linear regression analysis, log adiponectin was positively associated with high-density lipoprotein cholesterol levels (β = 0.006), whereas it was negatively associated with serum albumin (β = -0.284), triglyceride (log β = -0.288), high sensitivity C-reactive protein (log β = -0.058) levels and estimated glomerular filtration rate (β = -0.005). Multiple logistic regression analysis indicated that low adiponectin level was independently associated with a higher risk of metabolic syndrome (per 1 μg/mL increase; odds ratio = 0.953, 95% confidence interval = 0.898-0.970, P < 0.001) after adjustment for multiple confounding factors.

CONCLUSIONS

Hypoadiponectinemia is independently associated with the presence of metabolic syndrome in patients with chronic kidney disease.

Serum Ferritin Predicts Mortality Regardless of Inflammatory and Nutritional Status in Patients Starting Dialysis: A Prospective Cohort Study

Background: The impact of serum ferritin on prognosis in patients starting hemodialysis (HD) is not fully elucidated. Methods: A prospective cohort of 946 incident HD patients from 26 dialysis centers in Korea was selected for this study. Patients were divided into tertiles according to natural logarithm (Ln) ferritin concentrations. Results: During a median follow-up of 39 months, 88 (9.3%) patients died. Multivariate Cox proportional hazard analysis demonstrated that Ln ferritin was independently associated with an increase in cardiovascular mortality risk (hazard ratio (HR) 1.604, 95% CI 1.040-2.474, p = 0.033), infection-related mortality risk (HR 1.916, 95% CI 1.056-3.476, p = 0.032), and all-cause mortality risk (HR 1.547, 95% CI 1.156-2.069, p = 0.003). Conclusion: Serum ferritin levels at the time of HD commencement were a significant independent risk factor for mortality regardless of systemic inflammation and nutritional status. Therefore, elevated serum ferritin levels could be an effective indicator for prognosis.

Hyponatremia as a predictor of mortality in peritoneal dialysis patients

BACKGROUND AND AIM

Hyponatremia is common in patients with chronic kidney disease and is associated with increased mortality in hemodialysis patients. However, few studies have addressed this issue in peritoneal dialysis (PD) patients.

METHODS

This prospective observational study included a total of 441 incident patients who started PD between January 2000 and December 2005. Using time-averaged serum sodium (TA-Na) levels, we aimed to investigate whether hyponatremia can predict mortality in these patients.

RESULTS

Among the baseline parameters, serum sodium level was positively associated with serum albumin (β = 0.145; p = 0.003) and residual renal function (RRF) (β = 0.130; p = 0.018) and inversely associated with PD ultrafiltration (β = -0.114; p = 0.024) in a multivariable linear regression analysis. During a median follow-up of 34.8 months, 149 deaths were recorded. All-cause death occurred in 81 (55.9%) patients in the lowest tertile compared to 37 (25.0%) and 31 (20.9%) patients in the middle and highest tertiles, respectively. After adjusting for multiple potentially confounding covariates, increased TA-Na level was associated with a significantly decreased risk of all-cause (HR per 1 mEq/L increase, 0.79; 95% CI, 0.73-0.86; p<0.001) and infection-related (HR per 1 mEq/L increase, 0.77; 95% CI, 0.70-0.85; p<0.001) deaths.

CONCLUSIONS

This study showed that hyponatremia is an independent predictor of mortality in PD patients. Nevertheless, whether correcting hyponatremia improves patient survival is unknown. Future interventional studies should address this question more appropriately.

Optimal proteinuria target for renoprotection in patients with IgA nephropathy

Background

Proteinuria is a target for renoprotection in kidney diseases. However, optimal level of proteinuria reduction in IgA nephropathy (IgAN) is unknown.

Methods

We conducted a retrospective observational study in 500 patients with biopsy-proven IgAN. Time-averaged proteinuria (TA-P) was calculated as the mean of every 6 month period of measurements of spot urine protein-to-creatinine ratio. The study endpoints were a 50% decline in estimated glomerular filtration rate (eGFR), onset of end-stage renal disease (ESRD), and slope of eGFR.

Results

During a median follow-up duration of 65 (12–154) months, a 50% decline in eGFR occurred in 1 (0.8%) patient with TA-P of <0.3 g/g compared to 6 (2.7%) patients with TA-P of 0.3–0.99 g/g (hazard ratio, 2.82; P = 0.35). Risk of reaching a 50% decline in eGFR markedly increased in patients with TA-P of 1.0–2.99 g/g (P = 0.002) and those with TA-P≥3.0 g/g (P<0.001). ESRD did not occur in patients with TA-P<1.0 g/g compared to 26 (20.0%) and 8 (57.1%) patients with TA-P of 1.0–2.99 and ≥3.0 g/g, respectively. Kidney function of these two groups deteriorated faster than those with TA-P<1.0 g/g (P<0.001). However, patients with TA-P of 0.3–0.99 g/g had a greater decline of eGFR than patients with TA-P<0.3 g/g (−0.41±1.68 vs. −0.73±2.82 ml/min/1.73 m²/year, P = 0.03).

Conclusion

In this study, patients with TA-P<1.0 g/g show favorable outcomes. However, given the faster eGFR decline in patients with TA-P of 0.3–0.99 g/g than in patients with TA-P<0.3 g/g, the ultimate optimal goal of proteinuria reduction can be lowered in the management of IgAN.

Clinical features and outcomes of focal segmental glomerulosclerosis pathologic variants in Korean adult patients

BACKGROUND

Many studies have shown that clinical characteristics and outcomes differ depending on pathologic variants of focal segmental glomerulosclerosis (FSGS). However, these are not well defined in Asian populations.

METHODS

This retrospective study evaluated clinical features and outcomes of pathologic FSGS variants in 111 adult patients between January 2004 and December 2012. Primary outcome was the composite of doubling of baseline serum creatinine concentrations (D-SCr) or onset of end-stage renal disease (ESRD). Secondary outcome included complete (CR) or partial remission (PR).

RESULTS

There were 70 (63.1%), 20 (18.0%), 17 (15.3%), 3 (2.7%), and 1 (0.9%) patients with not-otherwise specified (NOS), tip, perihilar, cellular, and collapsing variants, respectively. At presentation, nephrotic-range proteinuria occurred more commonly in tip lesion than in other variants. The overall 5-year renal survival rate was 76.8%. During a median follow-up of 34.5 months, only 1 (5.0%) patient with a tip lesion reached the composite end point compared to 2 (11.8%) and 12 (17.1%) patients in perihilar and NOS variants, but this difference was not statistically significant in an adjusted Cox model. However, tip lesion was associated with a significantly increased probability of achieving CR (P = 0.044).

CONCLUSION

Similar to other populations, Korean adult patients with FSGS have distinct clinical features with the exception of a rare frequency of cellular and collapsing variants. Although pathologic variants were not associated with overall outcome, the tip variant exhibited favorable outcome in terms of achieving remission. Further studies are required to delineate long-term outcome and response to treatment of the pathologic variants.

Comparison of the Haas and the Oxford classifications for prediction of renal outcome in patients with IgA nephropathy

Pathologic features can provide valuable information for determining prognosis in IgA nephropathy (IgAN). However, it is uncertain whether the Oxford classification, a new classification of IgAN, can predict renal outcome better than previous ones. We conducted a retrospective cohort study in 500 patients with biopsy-proven IgAN between January 2002 and December 2010 to compare the ability of the Haas and the Oxford classifications to predict renal outcome. Primary outcome was a doubling of the baseline serum creatinine concentration (D-SCr). During a mean follow-up of 68 months, 52 (10.4%) and 35 (7.0%) developed D-SCr and end-stage renal disease, respectively. There were graded increases in the development of D-SCr in the higher Haas classes. In addition, the primary endpoint of D-SCr occurred more in patients with the Oxford M and T lesions than those without such lesions. In multivariate Cox regression analyses, the Haas class V (HR, 12.19; P=.002) and the Oxford T1 (hazard ratio [HR], 6.68; P<.001) and T2 (HR, 12.16; P<.001) lesions were independently associated with an increased risk of reaching D-SCr. Harrell's C index of each multivariate model with the Haas and the Oxford classification was 0.867 (P=.015) and 0.881 (P=.004), respectively. This was significantly higher than that of model with clinical factors only (C=0.819). However, there was no difference in C-statistics between the 2 models with the Haas and the Oxford classifications (P=.348). This study suggests that the Haas and the Oxford classifications are comparable in predicting progression of IgAN.

Effect of peritoneal dialysis modality on the 1-year rate of decline of residual renal function

PURPOSE

The effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort.

MATERIALS AND METHODS

We conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation.

RESULTS

The RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m² in CCPD patients and 3.63±3.67 mL/min/1.73 m² in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m² in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052).

CONCLUSION

Our results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities.

Urine output is associated with prognosis in patients with acute kidney injury requiring continuous renal replacement therapy

PURPOSE

Although some studies have found that early initiation of continuous renal replacement therapy (CRRT) is associated with better prognosis, no consensus exists on the best timing to start CRRT. We investigated whether the timing of CRRT initiation was relevant to overall mortality and explored which factors at the time of CRRT initiation were associated with better outcomes in critically ill patients with acute kidney injury (AKI).

MATERIALS AND METHODS

A total of 361 patients who received CRRT for AKI between 2009 and 2011 were collected and divided into 2 groups based on the median blood urea nitrogen (BUN) levels or 6-hour urine output immediately before CRRT was started. The impact of the timing of CRRT initiation stratified by BUN concentration or urine output on 28-day all-cause mortality was compared between groups.

RESULTS

When the timing of CRRT initiation was stratified by 6-hour urine output, 28-day all-cause mortality rates were significantly lower in the nonoliguric group compared with the oliguric group (P = .02). In contrast, clinical outcomes were not different between the low-BUN and the high-BUN groups (P = .30). Cox regression analysis revealed that 28-day all-cause mortality risk was significantly lower in the nonoliguric group stratified by 6-hour urine output, even after adjusting for age, sex, mean arterial pressure, Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores, and serum biomarkers (hazard ratio, 0.85; 95% confidence interval, 0.65-0.99; P = .04).

CONCLUSIONS

Urine output but not BUN concentration was significantly associated with a better prognosis in critically ill patients with AKI requiring CRRT.

Early experience using a left atrial appendage occlusion device in patients with atrial fibrillation

PURPOSE

Atrial fibrillation (AF) is one of the major risk factors for ischemic stroke, and 90% of thromboembolisms in these patients arise from the left atrial appendage (LAA). Recently, it has been documented that an LAA occlusion device (OD) is not inferior to warfarin therapy, and that it reduces mortality and risk of stroke in patients with AF.

MATERIALS AND METHODS

We implanted LAA-ODs in 5 Korean patients (all male, 59.8 ± 7.3 years old) with long-standing persistent AF or permanent AF via a percutaneous trans-septal approach.

RESULTS

1) The major reasons for LAA-OD implantation were high risk of recurrent stroke (80%), labile international neutralizing ratio with hemorrhage (60%), and 3/5 (60%) patients had a past history of failed cardioversion for rhythm control. 2) The mean LA size was 51.3 ± 5.0 mm and LAA size was 25.1 × 30.1 mm. We implanted the LAA-OD (28.8 ± 3.4 mm device) successfully in all 5 patients with no complications. 3) After eight weeks of anticoagulation, all patients switched from warfarin to anti-platelet agent after confirmation of successful LAA occlusion by trans-esophageal echocardiography.

CONCLUSION

We report on our early experience with LAA-OD deployment in patients with 1) persistent or permanent AF who cannot tolerate anticoagulation despite significant risk of ischemic stroke, or 2) recurrent stroke in patients who are unable to maintain sinus rhythm.

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.

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.

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.