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D K Cho

Publications and source records attributed to D K Cho.

50 records · Page 3Linked to original sources
PubMed2001

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.

Animals↗
PubMed2000

Measurement of the W-->taunu production cross section in pp collisions at square root s=1.8 TeV.

We report on a measurement of sigma(pp-->W+X)B(W-->taunu) in pp collisions at sqrt[s]=1.8 TeV at the Fermilab Tevatron. The measurement is based on an integrated luminosity (lum) of 18 pb-1 of data collected with the D0 detector during 1994-1995. We find that sigma(pp-->W+X)B(W-->taunu)=2.22+/-0.09 (stat)+/-0. 10 (syst)+/-0.10 (lum) nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, gWtau/gWe, be unity. We find gWtau/gWe=0.980+/-0.031, in agreement with lepton universality.

Journal Article↗
PubMed2000

Probing Balitsky-Fadin-Kuraev-Lipatov dynamics in the dijet cross section at large rapidity intervals in pp collisions at sqrt[s]=1800 and 630 GeV.

Inclusive dijet production at large pseudorapidity intervals (Deltaeta) between the two jets has been suggested as a regime for observing Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. We have measured the dijet cross section for large Deltaeta in pp collisions at sqrt[s]=1800 and 630 GeV using the D0 detector. The partonic cross section increases strongly with the size of Deltaeta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alphaBFKL(20 GeV)=1.65+/-0.07.

Journal Article↗
PubMed1999

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.

Animals↗
PubMed1998

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.

Biomarkers↗
PubMed1997

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.

Acute Kidney Injury↗
PubMed1997

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.

Adult↗
PubMed1993

Effects of rehmanniae radix water extract on renal function and renin secretion rate in unanesthetized rabbits.

This study was undertaken to explore the effects of different preparations of Rehmanniae Radix on renal function and renin secretion rate. Steamed Rehmanniae showed a decrease in urine volume, renal hemodynamics, and urinary excretion of electrolytes confined to the infused kidney, and was followed by an increase in urinary excretion of electrolytes from both kidneys. Dried Rehmanniae showed a decrease in urine volume, glomerular filtration rate, and urinary excretion of electrolytes, while raw Rehmanniae showed only an increase in urinary excretion of electrolytes. Steamed Rehmanniae and dried Rehmanniae decreased renin secretion rate, but raw Rehmanniae tended to increase renin secretion. These results suggest that the Rehmanniae Radix preparations have different effects on renal function and renin secretion rate.

Animals↗
PubMed1988

Urinary calculi in renal transplant recipients.

UNLABELLED: Urinary calculi are an uncommon complication in renal transplant recipients. During a 15-year period, in 544 cases of kidney transplantation with a functioning allograft for more than 3 months, and a long-term follow-up, we have observed 9 cases (1.7%) of urinary calculi. Calculi occurred in 6 male and 3 female patients, 6 patients were recipients of living related and 3 of cadaveric kidneys. Calculi were diagnosed as early as 3 months and as late as 3.5 years after transplantation, but most were detected within the first year. The location of the calculi was the bladder in 4 cases, the transplant in 3, and indeterminant in 2. Crystallographic analysis of retrieved stones revealed calcium oxalate and/or phosphate in 4 cases, triple phosphate in 2, and uric acid in 1. All patients had one or more stone-predisposing factors, such as obstructive uropathy and recurrent urinary tract infection (4 cases), hyperoxaluria (3), or hypercalciuria (2). During long-term follow-up (mean 60 months), only one patient lost the renal graft, 14.5 years after transplantation, primarily from causes unrelated to urinary calculi. One instance of stone recurrence was noted. IN CONCLUSION: (1) urinary calculi after renal transplantation are relatively uncommon; (2) predisposing factors and crystallographic composition of the calculi are identical in type, but not frequency, to those of nontransplant patients; and (3) with proper medical and surgical management, post-transplant urolithiasis does not appear to affect graft prognosis.

Adult↗
PubMedDate not supplied

Ketorolac tromethamine absorption, distribution, metabolism, excretion, and pharmacokinetics in animals and humans.

Ketorolac tromethamine (KT), a potent non-narcotic analgesic, with cyclooxygenase inhibitory activity, was administered (14C-labeled and unlabeled) intravenously (iv), orally (po), and intramuscularly (im) in solution to humans, cynomolgus monkeys, rabbits, rats, and mice. KT was absorbed rapidly (Tmax less than 1.0 hr) and efficiently (greater than 87%) following po and im doses in all species. The plasma half-life of ketorolac (K) ranged from 1.1 hr (rabbits) to 6.0 hr (humans). The protein binding of K ranged from 72.0% (mouse) to 99.2% (humans). Linear pharmacokinetics of K was observed in the mouse after single oral doses of KT ranging from 0.25 to 16 mg/kg. Radioactivity was excreted predominantly into urine, ranging from 78.9% (mouse) to 102% (monkey) following iv doses. The dose was excreted into urine primarily as K conjugates, K, and p-hydroxy-K in humans. The monkey was similar to humans with respect to kinetics, but did not form the p-hydroxy metabolite. The rabbit was unusual in that it exhibited substantial presystemic metabolism (50%). The rat excreted a much higher percentage of radioactivity into the feces and formed an additional unidentified metabolite. The most comparable species with respect to humans metabolically was the mouse. The metabolism and excretion of K was similar following iv, po, and im doses within each species studied.

Administration, Oral↗