A continuous hematocrit (HCT) monitor, Crit-Line, was introduced to examine the change in patients' blood volume (BV) due to albumin loss during double filtration plasmapheresis (DFPP) treatments. Nine patients with autoimmune diseases or ABO incompatible renal transplantation received 15 DFPP treatments under Crit-Line monitoring. In these patients, plasma albumin concentration (C(P)) changed from 3.7 +/- 0.6 g/dl to 3.5 +/- 0.5 g/dl and HCT from 28.7% +/- 3.3% to 31.3% +/- 4.3% (change ratio [CR] of BV = -8.1%) during treatment with albumin concentrations (C(S)) of 9.5 +/- 1.0 g/dl and 500 ml volumes (V(S)) of supplementation fluid. Although the apparent CR value of C(P) was -5.3%, on average, the CR of albumin in the patients' plasma (M(P)) was -16.1%, which means a corrected CR value of C(P) by the HCT value to eliminate the influence of the patient's blood volume contraction during treatment. Albumin loss usually occurred in DFPP treatments. The decrease in BV was induced by an oncotic pressure drop due to albumin loss, and often resulted in a blood pressure drop. The amount of albumin loss during DFPP treatments strongly depends on sieving coefficients of the plasma separator (SC(PS)) and the plasma fractionator (SC(PF)), the filtration fraction of the plasma fractionator (FF(PF)), pretreatment C(P) value, and C(S) and V(S) values of the supplementation fluid. To determine the optimum C(S) and V(S) values for each patient, the authors introduced a variable blood volume model for albumin transport in DFPP. In this model, changes in C(P), HCT, and BV values could be estimated during treatment. For example, a patient with an HCT of 31.2%, body weight of 61.1 kg, and pretreatment C(P) of 4.4 g/dl received a DFPP treatment using a plasma separator, OP-05 (SC(PS) of 0.99), and a plasma fractionator, Evaflux 2A (SC(PF) of 0.40), under FF(PF) of 0.8 with a V(S) of 500 ml. A value for C(S) of about 10 g/dl is required for the patient to maintain a normal C(P) level during treatment by an estimation from the model. As a result of the treatment with a C(S) of 10 g/dl, the patient had no adverse reactions, such as a blood pressure decrease, during treatment under these conditions.

Blood Volume↗

PubMedDate not supplied

Solute removal characteristics of continuous recirculating peritoneal dialysis in experimental and clinical studies.

Continuous recirculating peritoneal dialysis (CRPD) was introduced to enhance solute removal efficiency in conventional peritoneal dialysis (PD) therapies such as continuous ambulatory peritoneal dialysis (CAPD). In CRPD, a portion of the dwell dialysate in the patient's peritoneal cavity is drained through a double-lumen catheter and purified by an extracorporeal dialyzer. In this study, solute removal characteristics and safety of CRPD are examined in ex vivo and clinical studies. Recirculation dialysis experiments using nine dogs (13.6 +/- 2.5 kg of body weight) were carried out for 240 min in the ex vivo study, whereas another seven dogs (12.1 +/- 2.8 kg) received conventional peritoneal dialysis (CPD) (120 min dwelling x 2) and six additional dogs (11.9 +/- 2.7 kg) received a Tidal PD (20 min dwelling x 12; 50% of tidal volume ratio) as controls. The ex vivo study revealed that CRPD has a higher efficiency for solute removal than CPD and is equivalent to Tidal PD. In the BUN reduction rate, the 19.4 +/- 5.5% in 240 min CRPD (n = 9) was significantly higher (p < 0.05) than the 3.5 +/- 3.6% in 240 min CPD (n = 7) and equivalent to the 17.3 +/- 4.7% in 240 min Tidal PD (n = 6). Continuous recirculating peritoneal dialysis maintained a low UN level in the peritoneal cavity due to dialysis with an extracorporeal dialyzer. This tendency was also seen in creatinine removal. In the clinical study, CRPD (n = 10) and CPD (n = 5) treatments were used in three renal failure patients. Higher solute removal efficiency was shown in CRPD than in CPD treatments, and the urea peritoneal clearance was 14.1 +/- 4.4 ml/min in CRPD (n = 10), significantly higher (p < 0.05) than the 7.3 +/- 2.1 ml/min in CPD (n = 5). No fibrin formation occurred during CRPD treatments.

Adult↗

PubMedDate not supplied

Can cytokines be removed by hemofiltration or hemoadsorption?

To study the removability of pro-inflammatory cytokines by hemofiltration (HF), we performed experimental HF with various high-flux membranes (HFM) using a closed circuit system filled with monocyte-free human plasma, which contained TNFalpha, IL-1beta, and IL-6. Plasma and filtrate samples were taken before and 1, 2, 3, and 4 hours after the initiation of HF, and each cytokine was determined by enzyme-linked immunosorbent assay. IL-1beta was well removed through filtration during experimental HF using HFM (PAN>CTA>PMMA>PS). TNFalpha and IL-6 were only minimally filtered out by HF using HFM. TNFalpha was removed to some extent by using PS, and IL-6 was partially removed by using PMMA during experimental HF through other mechanisms, such as adsorption, than the filtration. IL-1beta and IL-6 were effectively removed by HA using charcoal adsorbent column, especially during the first 2 hours, while TNFalpha was only partly removed.

Adsorption↗

PubMedDate not supplied

Effects of internal filtration on the solute removal efficiency of a dialyzer.

To improve solute removal efficiency, several types of dialyzers with enhanced internal filtration were introduced for clinical application. In these dialyzers, enhanced internal filtration increased convective transport of the solute, in addition to diffusive transport. In this study, the effects of internal filtration on solute removal efficiency were examined by both analytic and experimental studies. Internal filtration is affected by blood (Q(B)) and dialysate (Q(D)) flow rates; the patient's hematocrit and plasma level of total protein; and the effective length (L(eff)), inner diameter (D), and density ratio (DR) of the hollow fibers. An analytic model was introduced for the estimation of the changes in mass and momentum along the dialyzer. It clarified the effects of these parameters on maximum internal filtration flow rate (Q(IF)) and clearance (K) of urea (60 daltons), vitamin B(12) (1,355), and myoglobin (17,000). As a result of the analytic study, Q(IF) was increased, resulting in a smaller D, a longer L(eff), and a larger DR value. Several types of dialyzers with the same cellulose triacetate membrane, produced by Toyobo Co, Ltd., Ohtsu, Japan, and Nissho Corporation, Kusatsu, Japan, were used for the experimental study. An in vitro evaluation using myoglobin solution showed the same trends as found in the analytic study. For example, a dialyzer with 150 microm of D has a 72.0 ml/min myoglobin K value, much higher than that of 53.7 ml/min for a dialyzer with 200 microm of D under constant Q(B) (300 ml/min) and DR (50%) values. Development of a dialyzer with enhanced internal filtration, however, should take the patient's safety into account, and hemolysis and endotoxin invasion from the dialysate to the patient should be avoided.

Filtration↗

PubMedDate not supplied

A rare case of desquamative esophagitis occurring during radiotherapy for esophageal carcinoma.

With the recent progress and increase in availability of fiberendoscopy, acute esophagitis is now much more frequently detected than before. Desquamative esophagitis is a rare form of esophagitis classified as acute esophagitis, but it has come to be reported more frequently in recent years. However, since desquamation seemed to have occurred in relation with the administration of radiotherapy in the present case, this brings to two the total number of cases with radiological involvement, the other case reported by Itai being the first in the world. This is the second report of desquamative esophagitis occurring during radiotherapy for esophageal carcinoma.

Aged↗

PubMedDate not supplied

Dynamic MRI with slow injection of contrast material for the diagnosis of pituitary adenoma.

Magnetic resonance (MR) imaging of pituitary adenoma is usually carried out in dynamic studies with bolus contrast material injections, with the result that few strong images are obtained. Dynamic studies using a slowly injected contrast material were carried out in 14 cases of pituitary adenomas. The examinations were performed with a 1.5 Tesla superconducting MR imaging system using the spin-echo technique. Gd-DTPA (0.1 mmol/kg) was slowly injected (within 90 sec) by hand, providing seven to nine dynamic images during 350 sec from the start of injection. The average time to reach the maximum signal intensity was 170.6 sec in adenoma and 156.2 sec in normal gland tissue. The maximum contrast signal intensity ratio of adenoma to normal gland was 0.527 in the fifth image. The contrast of adenoma to normal gland tissue was calculated by the following formula: ASII (adenoma signal intensity index) = (adenoma signal intensity-tissue signal intensity)/tissue signal intensity. The most remarkable contrast between adenoma and normal tissue was obtained from the fourth to eighth images. In other words, we could obtain the strongest contrast at 144.8 sec to 299.6 sec from the start of contrast injection. Our results with slow injection suggest that stronger images can be obtained a longer period after contrast injection.

Adenoma↗