Motor learning in ideomotor apraxia

Using Luria's motor sequence test, we studied the learning ability of 34 right-handed patients with unilateral hemisphere lesions. Patients with ideomotor apraxia needed 4 to 6 trials in the test, while the remainder needed only 1 or 2. Ideomotor apraxics also required more time to complete the test. The lesions of patients who failed to master this test were not always found in the frontal lobes. These results suggest that the ability to learn motor sequences is impaired in apraxic patients and that the left hemisphere of the brain plays the major role in learning a new motor sequence. Patients with ideomotor apraxia are impaired not only when performing previously learned motor tasks but also when learning a new motor task.

Neuropsychological and neuropsychiatric findings in right hemisphere damaged patients

We evaluated 46 patients with right hemisphere strokes for unilateral spatial neglect (USN), anosognosia, hemiasomatognosia, extinction, constructional disturbance, motor impersistence and organic mental syndrome. High correlations were found among the incidences of USN, anosognosia, hemiasomatognosia, extinction, motor impersistence and constructional disturbance. USN, hemiasomatognosia, motor impersistence, constructional disturbance and anosognosia tended to occur with large lesions. Organic personality syndrome was frequent (33%) and was more often associated with USN, anosognosia, hemiasomatognosia, extinction, constructional disturbance and motor impersistence than other psychiatric symptoms.

Evaluation of impedance technique for fluid-volume monitoring during hemodialysis

Fluid-volume changes during hemodialysis were studied in 30 patients at four separate treatments in each patient. Readings of fluid-volume changes obtained by a fluid-balance monitor with non-invasive tetrapolar impedance technique were compared to changes in weight caused by the treatment. A correlation coefficient of r = 0.90 (p less than 0.001) was found. A survey of papers describing impedance measurements during hemodialysis or diuresis is also presented.

On drug artifacts in middle molecule analysis

In a retrospective study of 58 nondialyzed uremic patients, artifacts originating from furosemide, methyldopa, hydralazine, allopurinol and beta-blocking agents on determination of plasma middle molecules could not be substantiated. Furosemide administration did not have any influence on middle molecule determination in hemodialysis patients. The salicyclic acid administration in normal subjects resulted in increased urinary excretion of fraction 7c; the role of salicylic acid needs to be further investigated.

Assessment of hemolysis in regular hemodialysis patients by measuring carbon monoxide production rate

In 17 patients requiring regular hemodialysis, inter- and intradialytic hemoglobin catabolism measured as endogenous carbon monoxide production (VCO) were studied before (9 patients) and after (8 patients) the introduction of water treatment. Before the water treatment, VCo increased significantly from inter- to intradialytic periods whereas insignificant changes were noted after the water treatment. Thus water treatment leads to less destruction of erythrocytes in connection with hemodialysis. However, hemolysis associated with hemodialysis does not play a major role as a cause of anemia in these patients.

Serum lipids and lipoproteins in schizophrenic patients with normal renal function treated with hemodialysis

To study the effect of hemodialysis on serum lipids and lipoproteins, five patients with normal renal function who had undergone hemodialysis for schizophrenic symptoms for 10 weeks in a crossover study were investigated. Active or sham (no dialysate flow through the filter) dialysis was instituted randomly. Serum lipids were isolated by ultracentrifugation and precipitation before and after each period. High density lipoprotein (HDL) cholesterol levels were constantly low and correlated negatively with serum alkaline phosphatase concentrations (p less than 0.05). Serum and very low density lipoprotein (VLDL) triglycerides and VLDL cholesterol increased during active, and to a lesser extent during sham, dialysis. Dialysis of this intensity does not affect HDL. The low levels may be secondary to subclinical cholestasis from neuroleptic drug treatment. Some individuals may develop hypertriglyceridemia of unknown pathogenesis during hemodialysis. Both these lipoprotein abnormalities are risk factors for the development of atherosclerosis.

Hemodialysis in the treatment of chronic schizophrenic patients: a double-blind crossover study

In order to examine the reported beneficial effects of hemodialysis in chronic schizophrenic patients, a double-blind crossover study was carried out. Of the 47 patients considered for treatment, 10 diagnosed as chronic schizophrenics according to the Feighner and DSM-III criteria were accepted to the study. Seven of these patients completed the full program, four of whom belonged to a large family with a high incidence of schizophrenia. All patients were on antipsychotic medication throughout the study. Psychopathological evaluations were performed regularly in a blind fashion using the Comprehensive Psychopathological Rating Scale (CPRS) and the Nurse Observation Scale for Inpatient Evaluation (NOSIE-30). Samples of blood, urine, cerebrospinal fluid, and dialysate were obtained for examination. Three patients improved during active dialysis and two patients improved during sham treatment. Improvement in the five patients took place during the first treatment period. This study failed to demonstrate a therapeutic effect of hemodialysis superior to the sham procedures.

Levomepromazine elimination in patients during active and sham hemodialysis

The effect of active and sham dialysis on the plasma concentration of levomepromazine was studied in seven schizophrenic patients undergoing hemodialysis treatment in a double-blind crossover study. Samples of blood were collected before, after 2 h and 5 h of treatment, and once a week during the treatment program. The plasma concentrations decreased during both active and sham dialysis. The data indicate that there was no significant difference in the elimination of the drug between active and sham hemodialysis.

Clinical implications of uremic middle molecules in regular hemodialysis patients

Sixty-five regular hemodialysis patients, maintained on stable dialysis schedules for at least one month, were investigated to assess the relationship between uremic morbidity and the accumulation of individual middle molecule fractions (MM). Pre-dialysis plasma levels of MM were determined by the use of gel chromatography followed by ion exchange gradient elution chromatography. Thirty-three symptom-free patients were compared with 32 patients who exhibited uremic symptoms or complications (overhydration, the depletion syndrome, chronic or recurrent infection, isolated episodes of infection and pericarditis). The plasma concentrations of urea and creatinine were no higher in the symptomatic groups than in the controls. On the other hand, all the symptomatic groups showed higher levels of fraction 7 c in plasma than the controls. In addition, overhydration and chronic or recurrent infection were associated with high plasma levels of 7 f and 7 b respectively. Six patients with depletion syndrome, three of whom had progressive peripheral neuropathy, had significantly elevated plasma concentrations of MM including not only fraction 7 c but also fractions 7 b and 7 d. At the time of acute infections, plasma levels of 7 c were considerably higher than when the same patients were free from symptoms. Despite the association between uremic morbidity and the accumulation of MM, there is a great overlap between asymptomatic controls and "sick" uremic patients with regard to plasma levels of MM.

Accumulation and excretion of middle molecules

The accumulation and excretion of uremic middle molecules (MM) were assessed in 97 non-dialyzed azotemic patients with varying degrees of renal insufficiency. For comparison the excretion rates of MM were estimated in 12 normal subjects. By the use of combined gel filtration and ion exchange gradient elution chromatography the U-V absorbing fractions (7a, 7b, 7c, 7d, 7e, 7f and 7g) with middle molecular characteristics were isolated and quantified in uremic plasma. Accumulation of MM in sufficient quantities to be measured in the analytical system occurred only in patients with advanced renal failure with endogenous creatinine clearance below 11 ml/min. These MM fractions were either undetectable or present in trace quantities in the plasma of normal individuals. The excretion rates of certain MM (fractions 7c and 7f) were higher in uremic patients than in normal subjects, suggesting that the accumulation of these fractions occurred as a consequence not only of reduced urinary excretion but also of the enhanced production rate. The excretion rates of other fractions (7a, 7b and 7g) were of the same magnitude in uremic patients as in normal individuals. Renal clearances of the MM fractions were equal to or higher than endogenous creatinine clearance.

Uremic middle molecules in non-dialyzed azotemic patients: relation to symptoms and clinical biochemistries

Plasma concentrations of middle molecule (MM) fractions were quantitatively assessed by use of combined gel filtration and ion exchange chromatography in 82 non-dialyzed azotemic patients. "Sick" patients exhibiting uremic symptoms were compared with symptom-free azotemic patients with regard to plasma levels of individual MM fractions. The patients with edema, pericarditis and intercurrent infections had significantly higher plasma concentration of MM fraction 7c than symptom-free controls. The results confirm our earlier anecdotic observations that high plasma concentration of fraction 7c often associated with uremic symptoms. In the symptom-free group, the patients with polycystic kidney disease showed a significantly lower concentration of fraction 7b in plasma than those with pyelonephritis; the patients on protein restricted diet had higher plasma concentrations of fractions 7b and 7c than those on diets with daily protein intake of 60 g or more. Slight correlations between some biochemical parameters and MM fractions in plasma were found in the total patient material; the highest correlation between albumin and fractions 7c (r = -0.36), and 7d (r = 0.36), respectively. Statistical analysis of this survey has shown that the accumulation of MM fractions, especially fraction 7c, is associated with uremic "sickness", i.e. edema, pericarditis and intercurrent infection.

Fulminating anti-A autoimmune hemolysis with anuria in a renal transplant recipient: a therapeutic role of plasma exchange

In this communication we present a case of fulminating anti-A autoimmune hemolysis with anuria occurring during the postoperative course after a successful renal transplantation. The patient was treated with repeated plasma exchange in an effort to remove antibodies directed against the red cells and also to eliminate the products of hemolysis known to cause acute renal failure. Subsequently the hemolysis receded and the patient regained graft function. Repeated plasma exchange, in addition to immunosuppression, appeared to have contributed to the ultimate recovery of the patient.

Measurement of fibrinopeptide A in the evaluation of heparin activity and fibrin formation during hemodialysis

In order to monitor heparin activity during hemodialysis, were evaluated three commonly used methods; measurement of whole blood activated coagulation time (WBACT), whole blood thrombin time (WBTT) and heparin concentration in plasma, determined with a chromogenic substrate. Studies were performed on six regular dialysis patients during 4-hour dialysis sessions, employing three different heparin regimens; a single intravenous loading dose only, priming of the dialyzer with heparin followed by a heparin infusion and a pharmaco-kinetic model. Efficacy of heparinization was assessed by determination of fibrinopeptide A (FPA) which is a peptide split product of the fibrinogen molecule formed during thrombin-induced conversion to fibrin. There was a linear correlation (r = 0.95) between FPA-production in the dialyzer and the FPA content of the blood at the inlet to the dialyzer; the slope of the correlation line indicates that at least 65% of FPA formed in the dialyzer is disposed during passage through the patient. Considerably higher production of FPA was noted when the heparin concentration was below 0.5 IU/ml than at a higher level. This was a common finding at the end of a dialysis, regardless of regimen. No consumption of antithrombin (AT III) occurred during a dialysis with any of the heparin regimens. Good correlations were found between WBACT, WBTT and heparin concentration. Heparin activity during a dialysis may be monitored with any of these three methods with equal reliability. However, from a practical point of view, WBACT appears most attractive because of its simplicity. FPA generation, frequency of visible clots in the dialyzer and hemorrhagic manifestations were essentially the same for each of the heparin dose regimens. The simple administration of a single loading dose was as safe as the more complicated infusion technique.

The effects of three different heparin regimes on heparin concentrations in plasma and fibrin formation in dialyzers

Anticoagulation effects were studied during a 4-hr hemodialysis in 6 patients using 3 different heparin regimens: I. Intravenous loading dose only; II. priming of the dialyzer and continuous infusion of heparin for 2 hr; III. intravenous loading dose and continuous infusion of heparin based on anticoagulation kinetics. In all regimens the difference of fibrinopeptide A (delta FPA) between the blood inlet and outlet of the dialyzers increased at the end of the dialyses, indicating increased fibrin formation. There was a good correlation between delta FPA and the fibrin deposition on the membranes measured with I-125-fibrinogen. delta FPA increased when heparin concentration in plasma was less than 0.5 IU/ml. The anticoagulation kinetic regimen offered no advantage over the single loading dose regimen with regard to the formation and deposition of fibrin in the dialyzers.

Clinical trial of plasma exchange with a membrane filter in treatment of crescentic glomerulonephritis

Four patients with rapidly progressive crescentic glomerulonephritis were treated with repeated plasma exchanges, using a disposable plasma filter (PLASMAFLO), combined with immunosuppression and anticoagulation. A definite improvement of renal function was observed in two patients and complete recovery of the severe lung changes of Goodpasture's syndrome was seen in one of them. In another patient rapid progression of renal insufficiency was arrested. One patient with anuria at the start of treatment remained anuric. The filter was capable of removing as large a molecule as IgM, and the plasma concentrations of immunoglobulins and complement factors declined successively after each treatment. Plasma exchange with the filter technique is readily accessible and safe in hands of the hemodialysis staff. Easy availability and simplicity are important advantages over the centrifuge methods, considering that prompt commencement of the treatment is a key issue in success.