Pathophysiology of peritoneal fluid eosinophilia in peritoneal dialysis patients

This study deals with the stress distribution in concrete deck slabs on composite steel beams used with integral abutment bridges. The applied loading is composed of one or more side-by-side HS20-44 trucks. The finite-element method is used to analyze two bridge structures with different numbers of beams, beam spacings, and supporting piles. The transverse and longitudinal slab stresses in the deck slab are investigated in the positive and negative bending regions near and away from the integral abutment. The slab stresses in the integral abutment bridges are compared with the corresponding stresses induced in the slab of equivalent jointed bridges. The results indicate that integral abutment bridges distribute the loads in the deck slab more uniformly than their jointed counterparts. The maximum stresses in the transverse direction of the slab can be 25–50% lower in the integral bridges than in their corresponding simply supported ones.     

Dihydropyridine type calcium channel blocker-induced turbid dialysate in patients undergoing peritoneal dialysis

Continuous awareness of systemic mycosis in immunocompromised patients is important. Early diagnosis is based on (direct) histologal examination and CT scan. Since treatment should start as early as possible, there is usually no time to await results of tissue cultures. Systemic treatment with amphotericin B and aggressive surgical débridement should be performed as soon as possible, while the place of hyperbaric oxygen and G-CSF remains to be established. In addition to routine preventive measures, prophylactic intranasal application of amphotericin B seems to be of value.     

Comparison of different measurements of lean body mass in normal individuals and in chronic peritoneal dialysis patients

To evaluate different methods of measuring lean body mass (LBM) in chronic peritoneal dialysis (CPD) patients, we first made comparisons in seven normal subjects. Seven methods (total body potassium [TBK] counting, bioelectrical impedance with calculations according to Segal and Deurenberg, near-infrared interactance with and without exercise level included as a variable, anthropometric measurements, and creatinine kinetics) were compared with the standard method of underwater weighing (UW) for measuring LBM. Significant correlations with LBM measured by UW (r > 0.938) were found with LBM measured by all other methods. Compared with UW, the best result in normals was found with TBK as it had high r values, small y-intercepts, and slopes of regression lines close to unity in both measurements of LBM and %LBM; in addition, fat-free mass index by TBK best approximated that by UW and TBK had the lowest mean prediction error with UW. In 11 patients on CPD, LBM was measured by all the above methods except UW. Significant correlations of all methods with LBM measured by TBK used as the reference standard were noted (all r > 0.76) in the CPD population. The LBM measured by creatinine kinetics correlated best (by kilograms or percentage of body weight [%BW]) with LBM from TBK compared with the other methods in which values tended to be higher. The fat-free mass index by creatinine output was nearest to the fat-free mass index by TBK. The root mean square prediction error was lowest between LBM by creatinine output and that by TBK. The findings support the concept of measuring creatinine outputs in CPD patients for estimates of LBM as an index of nutritional status as well as for creatinine clearances as an index of adequacy. Total body potassium and creatinine output measurements of LBM reflect the LBM at normal body fluid volumes ("dry weight") and may be better indices of nutrition in dialysis patients than the other techniques, which include excess fluid in the LBM.     

Peritoneal clearance and peritoneal transfer of oxalic acid, vitamin C, and vitamin B6 during continuous ambulatory peritoneal dialysis

The peritoneal clearance and peritoneal transfer of oxalic acid, vitamin C, and vitamin B6 in 32 patients during continuous ambulatory peritoneal dialysis (CAPD) using peritoneal dialysis solutions containing 1.5% or 2.5% glucose were examined. The plasma level of oxalic acid was significantly elevated in all patients, plasma vitamin C was in the normal range or in the upper margin of the normal range, and plasma vitamin B6 was in the normal range. The peritoneal clearance of oxalic acid was significantly lower, and the peritoneal clearance of vitamin B6 was the lowest in comparison to the peritoneal clearance of urea. With the exception of vitamin B6, the peritoneal clearance and peritoneal transfer of the examined parameters increased using the dialysis solution containing 2.5% glucose. We found direct relationships between the plasma levels of oxalic acid and creatinine as well as plasma vitamin C and between the peritoneal transfer of oxalic acid and the peritoneal transfer of vitamin C as well as vitamin B6. The significant hyperoxalemia of our patients was found to persist despite the relatively high peritoneal transfer of oxalic acid during CAPD. These results suggest that CAPD is not a method effective enough for permanent reduction of the plasma levels of oxalic acid.     

Pharmacokinetics of cefamandole in patients undergoing hemodialysis and peritoneal dialysis

The pharmacokinetics of cefamandole nafate, a new parenteral cephalosporin derivative, were evaluated in 11 patients with chronic renal failure (creatinine clearance less than 5 ml/min), including five patients during hemodialysis, four patients during routine peritoneal dialysis, and two patients during the interdialytic period. Peak serum levels of cefamandole were comparable to those observed in patients with normal renal function. Clearance of the drug during the interdialytic period and during hemodialysis and peritoneal dialysis was minimal, with a resultant significant prolongation of serum half-life. The nondialyzability of cefamandole is in contrast with reported studies of cephalothin, where significant reduction of the serum half-life was achieved during hemodialysis but not peritoneal dialysis. The concentration of cefamandole in the peritoneal dialysate after parenteral administration was observed to be bactericidal for many gram-negative pathogens and, with the exception of Streptococcus faecalis, most gram-positive organisms found in bacterial peritonitis in patients with severe renal failure. The present data suggest that if stable bactericidal serum levels of cefamandole are to be maintained during hemodialysis and peritoneal dialysis, a parenteral loading dose must be administered followed by one-half the loading dose every half-life.     

Calcium and magnesium deficiency-induced atrophy of muscle and calcium accumulation in the spinal cord

Four consecutive patients with mycosis fungoides received cyclic chemotherapy using cyclophosphamide, vincristine, and prednisone (COP). In one case, there was complete remission of disease for 15 months. In another, there was 50% regression of tumors with healing of the ulcerated surfaces. The third patient showed complete clearing of scaling and redness of the skin. In the fourth patient, the lesions progressed.     

Review of mathematical models of fluid flow,heat transfer,and mass transfer in electroslag remelting process

Abstract

The electroslag remelting (ESR) process has been used effectively to produce large ingots of high quality based on the controlled solidification and chemical refining that can be achieved. Despite the widespread application of industrial facilities, there are still issues that prevent an effective control of the process. This is particularly critical considering the large ingots produced industrially which makes the traditional trial and error approach prohibitively expensive. Thus, mathematical models of the process are a good alternative as a process control tool. To predict the relationship between operating parameters such as power input and type, fill ratio, depth of electrode immersion, and slag chemistry and the casting rate, microstructural features, and ingot chemical composition, it is then necessary to develop mathematical models based on differential equations describing the fluid flow, heat transfer, and mass transfer phenomena that take place during the process. In the present paper, mathematical models of the transport phenomena occurring during ESR are reviewed. Although the models have evolved to a point where several features of the process can be predicted and the dominant transport mechanisms have been elucidated, more effort is required before the models can be applied to define actual operating conditions.     

Pharmacokinetics of cefdinir and its transfer to dialysate in patients with chronic renal failure undergoing continuous ambulatory peritoneal dialysis

Cefdinir (CAS 91832-40-5) was administered orally as a 100-mg capsule (Cefzon) to a total of 12 patients with chronic renal failure undergoing continuous ambulatory peritoneal dialysis (CAPD) to investigate changes in the serum concentrations, excretion rate into the dialysate and serum-protein binding of cefdinir. Cmax values were 1.64-4.34 micrograms/ml, t1/2 values were 10.8-21.9 h., and AUC values were 31.1-73.1 micrograms.h/ml (0-30 h) in four patients given a single oral dose of 100 mg of cefdinir as a capsule. About 1 microgram/ml of cefdinir had still remained in the blood of all the patients 24 h after administration. The serum concentrations of cefdinir were dose-dependent in four patients of each group who were given an oral daily dose of 100 mg for 3 to 8 days and 200 mg (2 capsules) for 4 to 14 consecutive days. No marked change in laboratory test values or clinical symptoms before and after administration were observed in these dose regimes. Protein levels of 5.17-5.71 g/day were eliminated from the peritoneal dialysate and urine. Cefdinir inhibited 90 to 100% of the clinical isolates such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and other enteric bacteria causing catheter infection and peritonitis, and its antibacterial activity was stronger than that of amoxicillin (CAS 26787-78-0) or cefaclor (CAS 53944-73-3) against these clinical isolates.     

Dialysis adequacy and nutrition determine prognosis in continuous ambulatory peritoneal dialysis patients

Peritoneal membrane function was assessed in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) using parameters derived from urea kinetic modeling and the peritoneal equilibration test (PET). Their relationships with other nutritional markers and overall morbidity were determined. Data regarding the patients' nutritional status as determined by total body nitrogen (TBN) measurements, hospital admissions, and infectious complications within the last 12 months were reviewed. Total dialysate clearance (Kt/V) delivered was highly dependent on residual renal function (P < 0.0001). Kt/V derived from peritoneal clearance diminished with increasing age (P < 0.05). A higher delivered total Kt/V was associated with higher normalized protein catabolic rates (P < 0.002), which in turn were associated with improved TBN (P < 0.05). Hospital admissions decreased with improved normalized protein catabolic rates (P < 0.05), and higher serum albumin and total protein levels (P < 0.01 and P < 0.002, respectively). Infectious complications correlated positively with time on dialysis (P < 0.01), and correlated negatively with TBN measurements (P = 0.05). No correlations were found between infectious complications and serum albumin level or peritoneal protein loss. However, the total duration of hospitalization was shortened with higher serum albumin and total protein levels (P < 0.0001 and P < 0.002, respectively). Although Kt/V determinations did not correlate with clearances determined by the PET, the PET-determined creatinine transport rate correlated with TBN (P < 0.05) but not with infectious complications. In conclusion, nutritional parameters correlate with outcome on continuous ambulatory peritoneal dialysis. An integral relationship exists between nutritional status and dialysis delivery, which is best assessed by urea kinetic modeling.     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.     

Influence of extracellular fluid volume expansion on magnesium, calcium and phosphate handling along the rat nephron

Renal tubular handling of P, Ca, Mg and Na was studied in the rat both before and during mild hypertonic NaCl loading (ECVE), using micropuncture and clearance techniques and electron microprobe analysis. Micropuncture was performed at the late proximal and early distal tubule sites. ECVE significantly increased the urinary output of all four elements. In the case of Mg, the increase was relatively small and depended on slight but statistically unsignificant inhibition of reabsorption all along the entire length of the nephron. For Ca, it depended on the inhibition of proximal reabsorption, partially compensated by increased reabsorption along the loop. For P, it depended on proximal inhibition, no important net phosphate movement occurring in the loop during both periods. Ca reabsorption was highly correlated to that of sodium along the proximal tubule and Henel's loop, Ca and Mg reabsorption were closely related to the load delivered at the beginning of the structure. These observations are compatible with the view that tubular reabsorption of Ca and Mg is concentration rather than Tm limited, and that reabsorption of Ca, unlike that of Mg, is linked to the movements of sodium. Following ECVE, the difference between early distal and urinary deliveries increased significantly for Ca and P, but not for Mg. For phosphate, this difference accounted for by 45% of the delivery at the early distal tubule site, at variance with microinjection data obtained in the rat under similar salt loading conditions, which indicated that 17% only of the phosphate distal delivery were reabsorbed along the terminal segments. This discrepancy is discussed in terms of nephron functional heterogeneity.     

Biochemical analysis of peritoneal fluid in patients with and without bacterial infection

PURPOSE: The maximum preload torque of implant prosthetic retaining screws from four manufacturers and of two alloy types was measured to determine one index of interchangeability of intersystem components. MATERIALS AND METHODS: Implant prosthetic retaining screws from four manufacturers (3i Implant Innovations Inc, West Palm Beach, FL; Impla-Med Inc, Sunrise, FL; Nobelpharma USA Inc, Chicago, IL; and Implant Support Systems Inc, Irvine, CA) and of two metal types (gold and titanium) were investigated using an in vitro simulation model. Five screws of each type were tightened down against a gold cylinder using a Tohnichi BTG-6 torque gauge (Tohnichi American Corporation, Northbrook, IL) until fracture occurred. RESULTS: The 3i Implant Innovations gold and the Nobelpharma gold were not significantly different. The 3i Implant Innovations titanium and the Impla-Med gold were able to withstand less preload torque than the 3i Implant Innovations gold and the Nobelpharma gold. The Implant Support Systems titanium was able to withstand significantly more preload torque than all of the other screws. CONCLUSIONS: Interchanging implant prosthetic retaining screws could introduce new and unknown variables that may affect the long-term survival of implant fixtures and/or the implant prostheses.     

A comparative study of the outcome of renal transplantation in peritoneal dialysis and hemodialysis patients

Fifty-four cases of renal transplantation performed in peritoneal dialysis (PD) patients were compared with 48 cases in hemodialysis (HD) patients. Three immunosuppressive treatments were used: prednisolone, azathioprine and cyclosporine. Methylprednisolone was used to treat rejection, and polyclonal Atgem or monoclonal OKT3 antibodies were used if there was no response. There was no difference in sex, age, donor source, immunosuppressive regime, duration of dialysis before transplantation, or duration of follow-up between the two groups. Following transplantation, there was no significant difference in patient mortality and survival or graft survival between the groups. The incidences of infections were also similar in the two groups. PD is commonly used in developing countries as an alternative to hemodialysis for the treatment of chronic renal failure. This study has shown that renal transplantation can be successfully performed in patients treated by this method.     

Thermodynamic properties of aluminum, magnesium, and calcium in molten silicon

The thermodynamic properties of aluminum, magnesium, and calcium in molten silicon were investigated using a chemical equilibration technique at 1723 to 1848 K, 1698 to 1798 K, and 1723 to 1823 K, respectively. The activity coefficient of aluminum in molten silicon was determined by equilibrating molten silicon-aluminum alloys with solid Al₂O₃ and Al₆Si₂O₁₃, that of magnesium was determined by equilibrating molten silicon-magnesium alloys and MgO-SiO₂-Al₂O₃ melts doubly saturated with MgSiO₃ and SiO₂, and that of calcium was determined by equilibrating molten silicon-calcium alloys with SiO₂-saturated CaO-SiO₂ melts. The activity coefficients at infinite dilution relative to the pure liquid state were determined as follows:

Lithium effects on magnesium, calcium, and phosphate metabolism in rats

Rats were treated with lithium chloride for 8 weeks. At the last day of lithium administration, the animals were given radioactive calcium, magnesium, and phosphate. Electrolyte content and radioactivity were determined in serum, bone, muscle, liver and brain. Lithium led to an increase of inorganic phosphate in muscle and a decrease in serum. Uptake of radioactive phosphate was increased in muscle and liver but reduced in bone. The amount of magnesium in muscle and serum was increased in the lithium-treated rats, whereas the uptake of radioactive magnesium into bone was decreased. Uptake of radioactive calcium into bone was reduced, and radioactive calcium in serum was increased after lithium.     

Prevalence and risk factors for hepatitis C virus infection in continuous ambulatory peritoneal dialysis patients

BACKGROUND: Studies on hepatitis C virus antibodies (Anti-HCV) in CAPD patients are scarce and include a small number of patients. Nevertheless, risk factors related to Anti-HCV in these patients are still subject to controversy. Purpose of the study. To analyse the incidence and risk factors associated with the presence of Anti-HCV in CAPD patients. METHODS: We studied 255 patients from five different treatment centres of our region. The analysis was repeated after excluding 161 patients who had previously received haemodialysis treatment at least once. Anti-HCV testing was made by the 2nd-generation ELISA: As a supplementary test we used RIBA-4 in three centers and INNOLIA in the other two. Risk factors were analysed using logistic regression model for multivariate analysis. RESULTS: In the whole group, 29 patients (11.4%) were anti-HCV positive. Logistic regression analysis determined the following variables as independent risk factors: hepatitis previous to CAPD (P<0.001, odds ratio (OR):44.9), Anti HBc positivity (P=0.019, OR:9. 24), blood transfusions previous to CAPD (P=0.015, OR:1.05) and CAPD duration were excluded, the prevalence of HCV antibodies was 8.5% (8/94). In this group multivariate analysis showed that Anti-HCV positivity correlated with hepatitis previous to CAPD (P<0.0003, OR: 126) and Anti HBc positivity (P=0.002, OR:41.9). CONCLUSIONS: Our prevalence of hepatitis C virus (HCV) infection in CAPD patients was lower than other renal replacement therapy modalities, and correlated to events occurring mainly before starting CAPD treatment. This technique could be considered as low risk for HCV infection.