Association between early-onset alcoholism and the dopamine D2 receptor gene.

We examined the allelic association between the dopamine D2 receptor (DRD2) gene and alcoholism in 100 biologically unrelated Japanese alcoholics and 93 unrelated controls. Genomic DNA was prepared from peripheral white blood cells using the phenol-chloroform method. A 310-bp region surrounding the TaqA site at the DRD2 locus was amplified by polymerase chain reaction (PCR), and the PCR product was incubated with TaqI. The A1 allele remained intact while the A2 allele was cut. The frequency of the A1/A1 genotype and the frequency of the A1 allele were higher in early-onset alcoholics than in controls, P < 0.05 and P < 0.01, respectively. Moreover, the frequency of the A1/A1 genotype and the frequency of the A1 allele were higher in early-onset alcoholics with family histories of alcohol dependence than in controls, P < 0.01 and P < 0.01, respectively. The results indicate that the DRD2 gene is associated with susceptibility to early-onset alcoholism, and that each additional A1 allele shifts onset of alcoholism to an earlier age.

Positive association between a DNA sequence variant in the serotonin 2A receptor gene and schizophrenia.

Sixty-two patients with schizophrenia and 96 normal controls were investigated for genetic association with restriction fragment length polymorphisms (RFLPs) in the serotonin receptor genes. A positive association between the serotonin 2A receptor gene (HTR2A) and schizophrenia was found, but not between schizophrenia and the serotonin 1A receptor gene. The positive association we report here would suggest that the DNA region with susceptibility to schizophrenia lies in the HTR2A on the long arm of chromosomes 13.

Lack of association between bipolar affective disorder and tyrosine hydroxylase DNA marker.

Sixty-eight patients with bipolar affective disorder and 88 controls were investigated for genetic association of tyrosine hydroxylase (TH) restriction fragment length polymorphisms (RFLPs). No significant association between bipolar affective disorder and TH was found. Thus the hypothesis that TH is involved in the pathogenesis of bipolar affective disorder was not supported.

P300 in first degree relatives of schizophrenics.

It has been reported that the amplitude of P300 is low in schizophrenic patients and high risk children. We recorded P300 components of the event-related potentials in first degree relatives of schizophrenic propositi who were considered to be over the age limit of the risk period for manifestation of schizophrenia and compared them with those of schizophrenic patients and controls. Both the first degree relatives and the schizophrenic patients showed lower P300 amplitude than the controls. There was no significant difference between the first degree relatives and schizophrenic patients in the P300 amplitude. These results would indicate that a low P300 amplitude is a trait marker for schizophrenia.

Failure to manipulate objects secondary to active touch disturbance.

A peculiar type of sensori-motor disturbance consequent to a lesion in the contralateral postcentral gyrus was reported. The symptom was characterized by motor clumsiness of the left hand without loss of strength and with preserved finger movements on visual imitation. Motor difficulty was most marked when the patient had to manipulate an object. The analysis of the patient's behavior and of his sensory deficits suggests that the basis of the clumsiness was a deficit in active touch perception.

Brain-to-blood efflux transport of estrone-3-sulfate at the blood-brain barrier in rats.

Efflux transport of estrogens such as estrone-3-sulfate (E1S), and estrone (E1) across the blood-brain barrier (BBB) was evaluated using the Brain Efflux Index (BEI) method. The apparent BBB efflux rate constant (Keff) of [3H]E1S, and [3H]E1 was 6.63 x 10(-2) +/- 0.77 x 10(-2) min(-1), and 6.91 x 10(-2) +/- 1.23 x 10(-2) min(-1), respectively. The efflux transport of [3H]E1S from brain across the BBB was a saturable process with Michaelis constant (Km) of 96.0 +/- 34.4 microM and 93.4 +/- 22.0 microM estimated by two different methods. By determining [3H]E1S metabolites using high performance liquid chromatography (HPLC) after intracerebral injection, significant amounts of [3H]E1S were found in the jugular venous plasma, providing direct evidence that most of [3H]E1S is transported from brain across the BBB in intact form. To compare the apparent efflux clearance across the BBB of E1S with that of E1, the brain distribution volume of E1S and E1 was estimated using the brain slice uptake method. The apparent efflux clearance of [3H]E1S was determined to be 74.9 +/- 3.8 microl/(min x g brain) due to the distribution volume of 1.13 +/- 0.06 ml/g brain. By contrast, the apparent efflux clearance of E1 was more than 227 +/- 3 microl/(min x g brain), since the distribution volume of [3H]E1 at 60 min was 3.28 +/- 0.13 ml/g. The E1S efflux transport process was inhibited by more than 40% by coadministration of bile acids (taurocholate, and cholate), and organic anions (sulfobromophthalein, and probenecid), whereas other organic anions did not affect the E1S efflux transport. The [3H]E1S efflux was significantly reduced by 48.6% after preadministration of 5 mM dehydroepiandrosterone sulfate. These results suggest that E1S is transported from brain to the circulating blood across the BBB via a carrier-mediated efflux transport system.

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.

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.

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.

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.

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.

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.

Fibrin deposition in disposable dialyzers before and after re-use.

We have estimated the degree of fibrin deposition as well as changes in dialyzer efficiency of Gambro Optima 13.5 mu dialyzers, re-used up to six times in six regular dialysis patients. After each dialysis the dialyzer was rinsed and left filled with formaldehyde. The patients were given I-125-fibrinogen before the study. The radioactivity from the dialyzer was continuously measured during each dialysis and rinsing procedure. Urea and creatinine clearances were determined 30 min after start of each dialysis. After the last re-use the dialyzer membranes were removed and divided into sections and the radioactivity of each section was measured. Twice as much fibrin deposition was found near the blood inlet of the dialyzer as near the outlet. A higher fibrin deposition was found after each re-use than after the initial dialysis. The clearances of urea and creatinine were scarcely influenced by the re-use. The half-life of fibrinogen in the patients was in the same range as in normal subjects.

The effect of hemodialysis on endogenous middle molecules in uremic patients.

Uremic plasma and dialysis fluid were separated by high speed gel filtration followed by gradient elution ion exchange chromatography into several UV-absorbing fractions containing middle molecules (MM) (7a, b, c, etc.), which were quantitated by integrating the peak areas of the chromatograms. Dialyzer clearance of MM was determined in vivo for two dialyzers, Gambro Optima and RP-6, but no difference could be found in spite of far better in vitro MM clearance of RP-6 than of Gambro Optima. Nor was there any difference in post-dialysis decrease in MM between the two dialyzers, or between them and two dialyzers with larger surface areas (Gambro Major and Dow HK-5). In 45 determinations of MM in blood obtained before and after dialysis, using different dialyzers, the mean decrease in MM was significantly larger than for creatinine, suggesting a much smaller distribution volume immediately available for exchange. Ultrafiltration without dialysis in 7 patients induced a significant decrease in plasma MM (7a, b, c, and g) in spite of stable osmolality, urea, creatinine, and sodium concentrations in plasma, suggesting that the reduction in body water affected the net production rate of these MM. In 5 studies, using RP-6 and a 75 l recirculating dialyzate, a rapid post-dialysis rebound was observed for MM in plasma, sometimes followed by a secondary decrease in plasma concentration. The volume of distribution of dialyzed MM, assessed from pre- and post-plasma concentrations and concentrations in the dialyzate, appeared to be much smaller than for urea and creatinine. In a stable dialysis population of 17 patients, significant negative correlations were found between pre-dialysis plasma concentrations of some MM (7a, 7b, 7f, 7g) and dialysis index or endogenous renal creatinine clearance. No such correlations were found for peaks 7c and 7d. The good correlation between 7b and dialysis index (r = 0.73) suggests that plasma determination of 7b may be used as a measure of the efficiency of MM removal.

Hypersequestration of 51Cr-labelled erythrocytes as a criterion for splenectomy in regular hemodialysis patients.

The splenic uptake of 51Cr-labelled autologous erythrocytes was studied by body surface counting in 20 hemodialysis patients. Evidence for splenic hypersequestration of erythrocytes was obtained in 7 patients. Splenectomy was performed in 6 of these and led to a reduction in transfusion requirements. One patient without evidence of splenic hypersequestration of red cells was also subjected to splenectomy but was not improved. The importance of following the splenic uptake of 51Cr for a sufficiently long time to detect a delayed uptake of 51Cr is pointed out.

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 effect of renal transplantation on middle molecules in plasma and urine.

The plasma level and urinary excretion of middle molecules were determined in 5 patients with chronic uremia undergoing renal transplantation. The results demonstrate that after successful transplantation, the uremic middle molecules disappear rapidly from plasma while being excreted in the urine. The reduction in plasma level of middle molecules after transplantation is more rapid than the reduction in creatinine concentration.

The influence of dialysis fluid composition on the blood pressure response during dialysis.

To elucidate the relative role of osmolar (sodium) and acetate shifts during dialysis, 6 patients with problems of overhydration underwent rapid ultrafiltration for 1 hr (mean weight reduction 2.0 kg), using the 1 m2 RP 6 dialyzer. Ultrafiltration was carried out at the beginning of each of 5 dialysis treatments at weekly intervals. Ultrafiltration was undertaken without dialysis (controls) and with simultaneous dialysis using acetate (40 mmoles/1) or bicarbonate (25 mmoles/1) in the dialysis fluid with dialyzate sodium concentration of 133 and 145 mmoles/1. The systolic blood pressure and mean arterial pressure which were stable with ultrafiltration only fell slightly when a high dialyzate sodium concentration was used and much further when the dialyzate sodium concentration was kept low. These changes were apparently related to the changes in plasma osmolality. Acetate had no effect on blood pressure at the higher sodium concentration, but a slight (insignificant) additive effect when used in the low-sodium dialyzate. Shifts in osmolality (sodium concentration) seem to be more important than the effect of acetate in inducing dialysis-associated hypotension.

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.