Cerebral embolism after mechanical thrombolysis of a clotted hemodialysis access.

Clinically significant embolic complications after thrombolysis of clotted hemodialysis grafts are uncommon. Most of the concern has focused on the risks associated with pulmonary emboli. We report a case of a hemodialysis patient who developed a cerebral embolism after percutaneous graft thrombolysis who was found to have a patent foramen ovale and intermittent right-to-left shunt.

Role of physician assistants in dialysis units and nephrology.

We surveyed physician assistants who work in nephrology to report their experience level, primary employer, salary, job responsibilities, and job satisfaction. Additional data were obtained from the Nephrology Manpower Study. The 67 responding physician assistants of 97 surveyed have 10.8 +/- 6.5 years (mean +/- standard deviation) total experience (6.2 +/- 5.0 years in nephrology). Typically, nephrologists (56.1%) or hospitals (30.3%) employ them. The majority (74%) earn $49,999 to $75,000; 79.1% work in outpatient units, 52.4% in inpatient units, 52.4% in hospitals, 43.3% in outpatient offices, and 23.9% in transplant units. In outpatient units, they manage 111 +/- 111 patients, mostly in free-standing (71.1%), for-profit (69.7%), corporately owned (87.3%) units in urban (80%) or suburban (18%) areas. Most (>85%) manage all dialysis- and nondialysis-related problems, including health maintenance; 84.3% are contacted first by staff, and 78% see patients more often than physicians. Of nephrologists who responded to the Manpower Study, 8.9% work with physician assistants and 20.7% work with nurse practitioners. Nephrologists in academic practice or private nephrology groups are more likely to use physician assistants (P < 0.05) and nurse practitioners (P < 0.005) than those in solo practice or multispecialty groups. Nephrologists with physician assistants (33.8 +/- 19.5 v 41.7 +/- 16.8 h/wk) or nurse practitioners (35.8 +/- 18.1 v 42.7 +/- 16.9 h/wk) tended to spend less time in direct patient care than those without physician extenders (P < 0.001). Nephrologists with renal fellows, however, spent the least time of all in direct patient care (30.0 +/- 15.9 v 47.3 +/- 14.9 h/wk; P < 0.001). Physician assistants can perform nearly all the medical tasks in dialysis units. They may offer one approach to providing effective and complete care for patients if nephrology manpower becomes limited.

Phosphorus removal with a variable chloride, CO2 acidified dialysate using an unmodified single pass system.

A method of providing dialysate was developed that used CO2 gas, rather than acetic acid, as an acidifying agent, allowing for the delivery of a variable chloride concentration. The system can be used on a standard, unmodified dialysis machine. The aim of the study was to test the technical feasibility of the dialysate delivery system and to determine whether use of the dialysate, which is free of acetate and can increase serum chloride concentrations above those normally achieved during the early phases of dialysis, could influence mass phosphorus removal. Using a crossover design, the effects of a standard acetate containing dialysate were compared with the acetate free, variable chloride dialysate on serum phosphorus kinetics and mass phosphorus removal in six hemodialysis patients. Although, as predicted, the serum chloride levels were higher during the initial phases of dialysis and serum bicarbonate concentrations were equivalent at the end of treatment, it was not possible to measure any differences in serum phosphorus levels during any of the time points during or immediately after dialysis, nor was any difference in mass phosphorus removal observed. Despite the presence of considerable animal evidence that acetate metabolism causes the intracellular shift of phosphorus, our study did not show any benefit, in terms of mass phosphorus removal, of an acetate free dialysate solution.

Altered expression of HLA antigens and CD16 Fc receptors on leukocytes of alcoholic subjects and uremic patients.

The possible influences of ethanol and its metabolic product acetate on the surface expression of HLA class I and class II antigens and CD16 Fc receptors were examined. Fluorescent-labeled monoclonal antibodies and flow cytometry were used to measure these antigens on leukocytes from reference controls, subjects admitted for alcohol detoxification, uremic patients undergoing hemodialysis using Cu-prophan dialyzers and fluids containing 4 to 37 mM acetate, and uremic patients that were not hemodialyzed. In comparison to the controls, the mean intensity of staining for class I antigens was not changed significantly on lymphocytes or monocytes from alcoholics but was depressed on cells from eight of 12 uremic patients. Interferon-gamma above 5 units/ml was detected in less than 15% of plasma samples from controls, uremic patients or alcoholics on admission but was detected in four of eight samples from alcoholics at discharge (2-4 days after admission). The intensity of staining for class II antigens was depressed by more than 50% on lymphocytes from alcoholics and uremic patients. The expression of HLA class I and class II antigens was depressed whether uremic patients were hemodialyzed or not. The percentage of lymphocytes expressing CD16 was depressed in three of seven alcoholics and five of seven hemodialyzed patients. In contrast, the percentage of monocytes expressing CD16 was increased in six of seven hemodialyzed patients and three of five uremic patients not undergoing hemodialysis suggesting activation of monocytes in these patients. Plasma levels of beta 2-microglobulin were elevated by 61% in alcoholics, 50-fold in hemodialyzed patients, and 26-fold in nonhemodialyzed uremic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo pretreatment with human chorionic gonadotropin fails to reverse the dysfunction of isolated Leydig cells from chronically uremic rats.

In order to further investigate the previously reported hypogonadal state of chronically uremic rats, we examined the effects of in vivo pretreatment with human chorionic gonadotropin (hCG) on in vivo and in vitro Leydig cell function, comparing paired intact rats with rats made chronically uremic by 5/6 nephrectomy. The in vitro testosterone (T) secretory responses to varying concentrations of hCG or dibutyryl cAMP and the number of gonadotropin receptors were determined following hemicastration. The rats were then treated with hCG for 3 days and the remaining testes were removed and studied as before. Compared with intact rats, the uremic rats had higher serum concentrations of urea nitrogen (P less than 0.001); serum T concentrations were lower in uremic rats before (P less than 0.001), but not after (P greater than 0.6) treatment. Treatment produced increases in serum T only in uremic rats (P less than 0.001). Serum LH was lower in uremic rats before treatment (P less than 0.001) and was reduced (P less than 0.001) to similar levels (P greater than 0.8) in both groups after treatment. Baseline in vitro T secretion was lower (P less than 0.001) from Leydig cells of uremic than intact rats both before and after treatment. Analysis of variance of dose-response curves showed pre- and post-treatment T secretory responses to hCG or dibutyryl cAMP in vitro to be less from Leydig cells of uremic rats (P less than 0.01). Before treatment, Leydig cell gonadotropin receptor number was lower in uremic than intact rats (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of immune status of hemodialyzed adults: association with prior transfusions.

Peripheral blood leukocytes of 29 hemodialyzed adults, 19 transfused and 10 nontransfused, were studied using immunofluorescent staining with monoclonal antibodies and in vitro measurement of natural killer (NK) cell activity. When compared with control subjects, the absolute number of leukocytes in transfused hemodialyzed patients was significantly reduced (P less than 0.01), as were the absolute numbers of OKT11+ cells (P less than 0.01), and OKT4+ cells (P less than 0.0001). The percent representation of OKT11+ and OKT4+ cells was also significantly lower among transfused hemodialyzed patients (P less than 0.01 and 0.001, respectively), and this loss of OKT4+ cells resulted in a decrease in the ratio of OKT4+/OKT8+ cells (P less than 0.01). The absolute number of Leu-7+ cells was also decreased in the transfused group (P less than 0.05). A decrease in in vitro NK cell activity was present in both transfused and nontransfused hemodialyzed subjects. Whether these differences in peripheral blood lymphocytes were induced by the erythrocyte transfusions could not be determined; however, if they reflect changes in central lymphoid tissues, then these results may help explain the prolonged survival of renal allografts in transfused individuals.

Renal transplantation in a patient with multiple myeloma and light chain nephropathy.

A case of multiple myeloma in a 41-year-old white man that resulted in chronic renal failure is discussed. During the period of hemodialysis treatment, remission of the patient's myeloma was induced by chemotherapy. Thereafter a transplanted cadaver kidney functioned well for 3.5 years despite episodes of sepsis, administration of nephrotoxic chemotherapeutic agents, and recurrence of the myeloma with intermittent excretion of Bence Jones protein in the urine. The results of this fully documented case, as well as two other cases we have previously reported, support the strategy of offering cadaver renal transplantation to carefully selected individuals who require long-term dialysis and whose myeloma is in remission after chemotherapy.

Recurrent renal vein thrombosis consequent to membranous glomerulonephritis.

The diagnosis by inferior vena cavography of right renal vein thrombosis with extension into the vena cava was made in a 33 year old man with idiopathic membranous glomerulonephritis and multiple pulmonary emboli. After one year of continuous anticoagulant drug therapy with heparin and coumadin, venography showed absence of clots in the vena cava and therapy was discontinued. Proteinuria in excess of 4 g/24 hr continued. Six months later pulmonary emboli recurred and venography again demonstrated large clots in the vena cava and right renal vein. The potential for recurrence of renal vein thrombosis and pulmopnary embolism in the presence of active renal diseases is thus demonstrated.

Field trial of compact travel dialysis system.

To increase mobility for home hemodialysis patients, a portable, light weight hemodialysis system has been bench and field tested. The combination of a 21 L dialysate reservoir and small, high speed blood and dialysate pumps has permitted the entire system to be contained in a twenty two pound, 22 X 13 X 6 inch aluminum suitcase. Initial evaluation in hospitalized patients has shown the system to be safe and efficient. Acceptable clearances of creatinine and urea are maintained throughout a five hour dialysis by changing the bath at 120 and 210 minutes. Successful application of the system in travel by 3 patients, who perfomed a total of 12 dialyses in their hotel rooms while on vacation, indicates the broad potential of the new system.