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Biomedical subjects

A Blumberg

Publications and source records attributed to A Blumberg.

At least 19 recordsLinked to original sources
PubMed2001

The influence of hypoalbuminemia on maximal flow rates and transmembrane pressure during plasmapheresis--an in vitro study.

BACKGROUND: Plasmapheresis has been used for the treatment of acute liver failure (ALF). In these patients, hypoalbuminemia is often observed. Since albumin improves the disaggregability of erythrocytes, hypoalbuminemia might deteriorate rheology and thus influence the overall performance of plasmapheresis. METHODS: Hypoalbuminemia was mimicked by using porcine blood because of its physiologically low albumin/globulin ratio (AGR). Filters (n = 16) were integrated in a closed extracorporeal in vitro system. In the control group (n = 8), native porcine blood (AGR 0.8) was used. In the study group (n = 8), we used porcine blood supplemented with human albumin to obtain the human AGR value of 1.2. Two different heparinization protocols were compared in each group (2.5 IU/ml: n = 4 with albumin and n = 4 without albumin versus 5 IU/ml: n = 4 with and n = 4 without albumin). RESULTS: In both heparinization protocols the higher AGR led to lower transmembrane pressure (TMP) levels compared to the lower AGR. The reduced TMPs enabled higher blood flow and filtration rates. CONCLUSION: Maintenance of a physiological AGR in ALF patients might improve the performance of plasmapheresis and--as opposed to raised heparinization--contribute to a safer application.

Animals↗
PubMed1999

[Febrile convulsions: assessment of current status].

Febrile seizures are the most frequent neurologic disorders during childhood. The pathogenesis is not clear even today. Viral infections of the upper airways, exanthema subitum, acute otitis media, infection of the urinary tract and febrile reactions after vaccination are the most frequent precipitating factors. Predictors in identifying children with very high risk of recurrence are young age at onset, family history of febrile seizures in a first-degree relative, a history of recurrent febrile seizures and a lower degree of fever at the onset of febrile seizures. A family history of epilepsy, neurodevelopmental abnormalities and a lower degree of fever at the onset of febrile convulsion are predictors of later epilepsy in children who have febrile seizures. The prognosis of febrile seizures is very good. In the acute situation, rectal diazepam should be given in the event of prolonged febrile seizures (> 3 minutes) only. Intermittent diazepam therapy and long-term antiepileptics are not recommended. The best prophylactic treatment is education and reassurance for parents and children.

Administration, Rectal↗
PubMed1999

Rapid and accurate assessment of glomerular filtration rate in patients with renal transplants using serum cystatin C.

BACKGROUND: Assessment of renal function in patients with renal transplants is of great importance. Various studies have reported cystatin C as an easily and rapidly assessable marker that can be used for accurate information on renal function impairment. To date, no study is available to define the role of cystatin C in patients with renal transplants. METHODS: Thirty steady-state patients (50% male/50% female) with status post-kidney transplantation were studied. To assess renal function, cystatin C, creatinine clearance, serum creatinine, beta2-microglobulin (beta2M), and [125I]iothalamate clearance were determined. Correlations and non-parametric ROC curves for accuracy, using a cut-off glomerular filtration rate (GFR) of 60 ml/min, were obtained for the different markers allowing for calculations of positive predictive values (PPV), positive likelihood ratios (PLR), specificity and sensitivity, respectively. Further, to evaluate the usefulness of these markers for monitoring, intraindividual coefficients of variation (CVs) for cystatin C and creatinine measurements were compared in 85 renal transplant patients. Measurements consisted of at least six pairs of results, which were obtained at different time points during routine follow-up. RESULTS: Cystatin C correlated best with GFR (r=0.83), whereas serum creatinine (r=0.67), creatinine clearance (r=0.57) and beta2M (r=0.58) all had lower correlation coefficients. The diagnostic accuracy of cystatin C was significantly better than serum creatinine (P=0.025), but did not differ significantly from creatinine clearance (P=0.76) and beta2M (P=0.43). At a cut-off of 1.64 mg/l, cystatin C has a PPV of 93%, PLR of 6.4, specificity 89% and sensitivity 70%, respectively. For beta2M, PPV 83%, PLR 1.7, specificity 67% and sensitivity 75% was seen at a cut-off of 3.57 mg/l. Accordingly, at a cut-off of 125 micromol/l for serum creatinine, a PPV 76%, PLR 1.4, specificity 44% and sensitivity 80% was revealed. Finally, at a cut-off of 66 ml/min/1.73 m2 for creatinine clearance, the following characteristics were found: PPV 94%, PLR 7.7, specificity 89% and sensitivity 85%. The intraindividual variation of creatinine was significantly lower than that of cystatin C (P<0.001). With increasing concentrations, their ratios of CV tended towards a value of 1, demonstrating identical variability at low GFR. CONCLUSION: Together, our data show that in patients with renal transplants, cystatin C, in terms of PPV and PLR, has a similar diagnostic value as creatinine clearance. However, it is superior to serum determinations of creatinine and beta2M. The intraindividual variation of cystatin C is greater than that of creatinine. This might be due to the better ability of cystatin C to reflect temporary changes especially in mildly impaired GFR, most critical for early detection of rejection and other function impairment. Thus, cystatin C allows for rapid and accurate assessment of renal function (GFR) in renal transplants and is clearly superior to the commonly used serum creatinine.

Adult↗
PubMed1998

Symmetric and asymmetric left ventricular hypertrophy in patients with end-stage renal failure on long-term hemodialysis.

BACKGROUND: Patients with end-stage renal disease on regular hemodialysis have an increased prevalence of left ventricular (LV) hypertrophy that is associated with morbidity and mortality. Asymmetric septal hypertrophy and impairment of LV outflow can occur in these patients and may contribute to adverse outcomes. More insight into the prevalence, extent, geometry, and promoting factors of LV hypertrophy is important. METHODS: An unselected group of 62 patients (31 women), aged 55 +/- 14 years, on maintenance hemodialysis was investigated by Doppler echocardiography. Eight patients with valvular heart disease were excluded from further analysis. We assessed prevalence of LV hypertrophy and asymmetric septal hypertrophy, as well as parameters of LV geometry and LV filling and outflow dynamics. RESULTS: Prevalence of LV hypertrophy was 65%. Patients were analyzed according to LV mass and geometry. Mean LV mass index was normal (105 +/- 17 g/m2) in Group 1 without LV hypertrophy (n = 19); it was markedly elevated in Group 2 (symmetric hypertrophy, n = 22) and Group 3 (asymmetric hypertrophy with systolic anterior movement of mitral valve, n = 7), and highest (191 +/- 54 g/m2) in Group 4 (asymmetric hypertrophy without systolic anterior movement of mitral valve, n = 6, p < 0.001). Age, body mass index, and duration of hypertension were associated with LV hypertrophy and asymmetric septal hypertrophy (p = 0.01). Group 3 with systolic anterior motion of mitral valve had the smallest end-diastolic LV diameters (p = 0.02); increased heart rates, and increased ejection velocities in the LV outflow tract (p = 0.03, and p = 0.005, respectively, vs. Groups 1, 2, and 4) which pointed to an impairment of LV outflow. CONCLUSIONS: Symmetric LV hypertrophy and asymmetric septal hypertrophy are frequent in patients on maintenance hemodialysis. Predictors for LV hypertrophy were age and body mass index, and, particularly for asymmetric septal hypertrophy, age and hypertension duration. Volume withdrawal during hemodialysis may lead to symptomatic hypotension due to dynamic obstruction in some patients with severe asymmetric septal hypertrophy.

Adult↗
PubMed1998

Surgical treatment of "steal syndrome" induced by arteriovenous grafts for hemodialysis.

OBJECTIVE: A rare but serious complication of angioaccess surgery for hemodialysis is the so called steal syndrome presenting as ischemia distal to an arteriovenous fistula. The main problem of various surgical techniques to correct steal is subsequent thrombosis of the fistula or persistence of distal ischemia. INTERVENTIONS: This paper describes an unknown technique for correction of ischemic steal consisting of ligation of the artery just distal to the take-off of the fistula and arterial bypass from the artery proximal to the take-off of the fistula to the artery distal to ligation. PATIENTS: Six patients with chronic renal insufficiency (3 male, 3 female) with patent upper arm cephalic fistulas presented with severe hand ischemia. RESULTS: Symptoms improved in all 6 patients immediately after operation. Successful hemodialysis could be maintained using the original fistula. CONCLUSIONS: The described technique is maybe the procedure of choice for the correction of fistula induced ischemic steal.

Adult↗
PubMed1997

Plasma potassium in patients with terminal renal failure during and after haemodialysis; relationship with dialytic potassium removal and total body potassium.

BACKGROUND: Chronic haemodialysis (HD) patients may present with severe predialysis hyperkalaemia which is improved by dialytic treatment. However, factors influencing the behaviour of postdialysis plasma potassium (plasma K) are not well known. METHODS: In this prospective study 14 patients (7 female, 7 male) on chronic HD were investigated during a standardized 4-h HD with a 2 m2 high-flux dialyser and up to 6 h postdialysis. Dialytic potassium removal was measured by dialysate collection. Total body potassium (TBK) was measured by whole-body counting of 40K. RESULTS: Plasma K declined from 5.65 to 3.62 mmol/l on HD. In spite of a total dialytic removal of 107 mmol of potassium plasma K rose to 5.01 mmol/16 h postdialysis. TBK, as adjusted for age, was 38.2 and 49.0 mmol/kg BW in female and male patients respectively, i.e. in the normal range. Of a total potassium removal of 107 mmol on HD only 42% originated from the extracellular space. Dialytic potassium removal was best correlated with removal of intracellular potassium but also with extracellular potassium content and with the product of plasma K x TBK. The 6-h postdialysis plasma K was correlated with the predialysis value but not with TBK or dialytic potassium removal. CONCLUSION: A rather high dialytic removal of potassium (which is correlated with plasma K x TBK) does not necessarily prevent a rapid postdialysis rebound of plasma K. Therefore patients with marked hyperkalaemia should be monitored closely postdialysis. TBK can be normal in haemodialysis patients who are well nourished.

Adult↗
PubMed1995

[Chronic hepatitis B infection and liver failure following kidney transplantation].

Chronic liver diseases, especially due to chronic hepatitis B virus infection, are among the leading causes of late mortality in renal transplant recipients. We report on 4 HBsAg-positive patients observed over a period of 8 years, who were free of symptomatic liver disease for 7-19 years after renal transplantation and died within a few days of acute hepatic failure. The cases presented document the prognostic relevance of chronic hepatitis B virus infection in renal transplant recipients and illustrate that an asymptomatic HBsAg carrier state can evolve within a very short time to fatal liver disease.

Adult↗
PubMed1995

Prevention of hepatitis C infection in haemodialysis units. A prospective study.

A prospective study was begun in our haemodialysis unit after four previously negative patients were found to be anti-HCV positive. A dedicated area and dedicated dialysis equipment (but not a separate room) were assigned to anti-HCV-positive patients and testing for HCV antibodies was performed every 3 months. A total of 131 patients were treated during the study period of 18 months. Of these, 50 patients were dialysed during the entire 18 months, and 21 were available to be tested six or more months after having left the centre. During the first 6 weeks after implementing the precautions two more anti-HCV-positive patients were detected. However, during the rest of the study period no further newly infected patients were found. It is concluded that the spread of HCV infection in a haemodialysis environment can be prevented by limited isolation procedures.

Acute Kidney Injury↗
PubMed1994

Influence of dialyser clearance measurement accuracy on haemodialysis prescription based on Kt/V.

Kt/V urea (u) has been used as a measure of adequacy of haemodialysis (HD). However, the accurate assessment of its components is difficult and subject to error in a clinical setting. This study was designed to evaluate different forms of dialyser clearance (K) measurements and their influence on Kt/V. Sixteen patients on high-flux HD were studied at blood flow (Qb) rates of 250 and 350 ml/min and at constant dialysate flow rates. K of urea was measured by the arteriovenous blood sampling technique (Kbu), corrected for access recirculation (Kbru) and compared with K as determined by dialysate collection (Kdu) using a new sampling device. At Qb 250 and 350 ml/min, Kbu as based on dialysate collection was significantly lower than Kbru and Kbu as based on arteriovenous blood sampling: at Qb 250, Kdu 169.0 +/- 13.3, Kbru 191.2 +/- 11.5, and Kbu 203.0 +/- 9.3 ml/min (P < 0.0005); at Qb 350, Kdu 196.5 +/- 17.3, Kbru 227.7 +/- 15.5, and Kbu 243.6 +/- 12.7 ml/min (P < 0.0005). At Qb 250 ml/min Kbu t/V (1.33 +/- 0.17) overestimated Kdu t/V (1.11 +/- 0.13) by 16:8%, at Qb 350 ml/min by 19.3% (1.58 +/- 0.19 versus 1.27 +/- 0.15). Dialyser clearances based on arteriovenous differences in blood overestimate true clearances (and therefore Kt/V) as measured by dialysate collection. This overestimation is more marked with higher blood flow rates.

Adult↗
PubMed1993

Dexamethasone therapy for bacterial meningitis in children. Swiss Meningitis Study Group.

Routine use of steroids as adjunctive treatment of bacterial meningitis remains controversial. We have carried out a prospective, placebo-controlled, double-blind study of dexamethasone in 115 children with acute bacterial meningitis in Switzerland. The patients were randomly assigned to receive either placebo (n = 55) or dexamethasone (n = 60) in addition to optimum antibiotic treatment (100 mg/kg daily ceftriaxone). Dexamethasone therapy (0.4 mg/kg) was started 10 min before the first dose of ceftriaxone and given every 12 h for 2 days. Baseline demographic, clinical, and laboratory features of the two groups were similar. After 24 h treatment meningeal inflammation as shown by cerebrospinal fluid (CSF) glucose concentration was significantly less with dexamethasone than with placebo (mean increase in glucose 63 [76] vs 40 [75]%, p = 0.008). However, other indices of inflammation showed similar changes in both groups. Addition of dexamethasone did not affect the rate at which CSF became sterile. Both groups showed prompt clinical responses and similar frequencies of complications (15 vs 12%). Monitoring for possible adverse effects of dexamethasone revealed no abnormalities. At follow-up examinations 3, 9, and 15 months after hospital discharge, 9 (16%) of 55 placebo recipients and 3 (5%) of 60 dexamethasone recipients had one or more neurological or audiological sequelae (p = 0.066); the relative risk of sequelae was 3.27 (95% CI 0.93-11.47). Our results and those of similarly designed studies lead us to believe that adjunctive dexamethasone therapy improves outcome from bacterial meningitis in infants and children. We recommend its use, preferably in the dose regimen used in this study.

Adolescent↗
PubMed1993

Immune-mediated type A gastritis and glomerulonephritis.

The first two cases reported in the literature of patients with immune-mediated type A gastritis with microcarcinoids (as part of a polyglandular syndrome type II in one) in combination with chronic glomerulonephritis are presented. Immune-mediated type A gastritis appears to be another immunologic disorder that can be associated with chronic glomerulonephritis.

Adult↗
PubMed1992

Effect of prolonged bicarbonate administration on plasma potassium in terminal renal failure.

In hemodialysis patients with hyperkalemia, i.v. sodium bicarbonate has recently been found to be ineffective in lowering plasma potassium within one hour. In the present study the effect of a prolonged bicarbonate infusion on plasma potassium was investigated. Twelve patients with terminal renal failure who were on hemodialysis were infused i.v. with 8.4% sodium bicarbonate (4 mmol/min) for one hour and with 1.4% (0.5 mmol/min) for five hours (total amount 390 mmol). Plasma bicarbonate rose from 17.5 at baseline to 28.4 and 29.6 mmol/liter, and blood pH from 7.32 to 7.46 and 7.48 at one and six hours, respectively. Plasma potassium did not change significantly after one and two hours (6.04 at baseline, 5.91 and 5.77 mmol/liter, respectively). Only at four and six hours did a moderate decline to 5.44 (P less than 0.05) and to 5.30 (P less than 0.01) occur, of which approximately half was calculated to be due to ECF volume expansion. However, no change or a very moderate decrease was observed in three patients even after six hours (+0.19, -0.32, -0.33 mmol/liter). Five patients with higher baseline plasma potassium (6.15 to 8.15 mmol/liter) behaved like seven with lower levels (5.25 to 5.87 mmol/liter). Tented T-waves in the ECG of seven patients disappeared after one hour only in one patient. Plasma aldosterone, norepinephrine and epinephrine were normal to elevated before and tended to fall during i.v. bicarbonate. Plasma dopamine and insulin were in the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Intracranial lipomas.

Intracranial lipomas are very rare tumors, mostly being localized in the midline and often asymptomatic. We report on three children with intracranial lipomas (one with extension to the cervical spinal cord) diagnosed by CT and/or MR. All three had different symptoms and neurological signs. We summarize the case reports in the literature since the CT-era.

Brain Neoplasms↗
PubMed1992

Aortic and mitral valve disease in patients with end stage renal failure on long-term haemodialysis.

OBJECTIVE: To identify valvar heart disease in patients with chronic uraemia by conventional and colour coded Doppler echocardiography. DESIGN: Case series of an unselected group of 62 patients with end stage renal failure. SETTING: Centre for haemodialysis in a referral hospital in Switzerland. PATIENTS: 62 patients on chronic haemodialysis. MAIN OUTCOME MEASURES: Frequency of structural and functional valve abnormalities and their relation to clinical findings. RESULTS: Structural changes were seen in 40 (64%) of 62 patients after 50 months (range 3-178 months) on haemodialysis. The mitral annulus and aortic cusps were thickened in 25 (40%) and in 34 (55%) patients respectively. Aortic stenosis was present in eight (mean (SD) age 60.5 (8.5) years), with a maximal instantaneous pressure gradient of 41 (14) mm Hg. Aortic regurgitation was seen in eight, mitral regurgitation in seven, and mitral stenosis in three patients. Patients with aortic stenosis had been on haemodialysis for significantly longer than the remaining patients (101 (43) v 46 (43) months, p = 0.01) and had significantly higher concentrations of serum alkaline phosphatase (176 (89) v 117 (47) IU/l, p less than 0.01) and of parathyroid hormone (54 (66) v 19 (29) ng/ml, p less than 0.02). CONCLUSIONS: Patients on long-term haemodialysis had an increased frequency of haemodynamically relevant changes in the aortic and mitral valves. The degenerative valve disease may be related in part to the duration of haemodialysis and to alterations in calcium metabolism as indicated by increased plasma concentrations of alkaline phosphatase and parathyroid hormone.

Alkaline Phosphatase↗
PubMed1992

Influence of long-term amelioration of anemia and blood pressure control on left ventricular hypertrophy in hemodialyzed patients.

The course of left ventricular hypertrophy was investigated in anemic hemodialysis patients treated with recombinant human erythropoietin (r-huEPO). 12 patients, aged 60.8 +/- 9.9 years (mean +/- SD) were treated for 18.8 +/- 2.7 months. Left ventricular size was estimated by echocardiography performed before treatment and at least 12 months after relieving anemia. Patients had signs of left ventricular and/or asymmetric septal hypertrophy when compared with a nonanemic and normotensive control group matched for sex and age. At baseline, hemoglobin (Hb) was 8.6 +/- 0.7 g/dl; interventricular septum thickness (IVST) was 1.75 +/- 0.34 cm, left ventricular posterior wall thickness (LVPWT) 1.32 +/- 0.19 cm, left ventricular muscle mass index (LVMI) 222.7 +/- 41 g/m2 and blood pressure (BP) 146.4 +/- 10/81.6 +/- 6 mm Hg. Hb rose to 11.4 +/- 1.2 g/dl (p less than 0.001); IVST and LVMI decreased to 1.42 +/- 0.35 cm (p less than 0.02) and 155.4 +/- 25.1 g/m2 (p less than 0.001); LVPWT and BP remained unchanged (1.30 +/- 0.26 cm and 146.8 +/- 16.9/81.2 +/- 7.8 mm Hg) at the end of the study. During the observation period, two groups of 5 and 7 patients differed from each other. The group of 5 patients had higher BP values (158.9 +/- 9.8/86.5 +/- 5.3 vs. 140.0 +/- 9.5/79.2 +/- 6.8 mm Hg, p less than 0.01), and the period with Hb values above 10 g/dl was shorter (14.5 +/- 2.4 vs. 17.8 +/- 2.4 months, p less than 0.05). These 5 patients failed to show a significant decrease in IVST and LVMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗