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B F Scharschmidt

Publications and source records attributed to B F Scharschmidt.

88 records · Page 5Linked to original sources
PubMed1976

A new approach to quantitation of the various sources of bilrubin in man.

Studies of the "early labeling" of fecal bile pigment have been widely interpreted as indicating that 10 to 20 per cent of total bile pigment production in normal man is derived from the processes which give rise to the "early labeled" pigment peak (ELP). However, this conclusion is based on a very small number of studies with inherent experimental and analytic limitations. In the present study, a new experimental approach was employed. Plasma bilirubin turnover (BRT), total red blood cell volume (TRCV), and red cell survival were measured in 26 normal volunteers and 35 patients with various hepatic and/or hematologic disorders. The quantity of bilirubin derived from red blood cell degradation (BRRBC) was calculated from TRCV and the mean red cell life-span, and the difference between BRT and BRRBC, designated "excess bilirubin synthesis (EBS)," was considered to represent the quantity of bilirubin derived from the processes responsible for ELP. In normal volunteer subjects, EBS averaged 1.0 mg. per kilogram per day, and accounted for 25 per cent of daily bilirubin turnover. Hence, results derived by this approach exceeded the range estimated from analysis of "early labeled peak" data. Further analysis of the data in terms of a simple model of bilirubin sources was compatible with the hypothesis that EBS consists of an essentially constant component, averaging 0.8 mg. per kilogram per day, presumably derived principally from the liver, and a second component which varies with the erthropoietic rate. Hence, in normal man the liver may contribute the major fraction of EBS.

Acute Disease↗
PubMed1976

Abnormal hepatic transport of indocyanine green in Gilbert's syndrome.

The plasma fractional disappearance rate of indocyanine green (kICG, min-1) and the absolute hepatic ICG removal rate (VICG, mg per kg per min) were determined in 26 patients with Gilbert's syndrome (GS) and 19 normal control volunteers following intravenous administration of doses of 0.5, 2.0, 3.5, and 5.0 mg per kg of dye. The diagnosis of GS was based on studies of radiobilirubin kinetics in all cases and liver biopsy in 22 cases. The patients were further classified into 3 subgroups, based on patterns of sulfobromophthalein (BSP) kinetics, as follows: GS I (15 patients) had normal BSP metabolism; GS II (5 patients) had a defect in BSP metabolism beyond the stage of initial hepatic uptake; and GS III (6 patients) had a defect in the initial hepatic uptake of BSP (Gastroenterology 63:472-481, 1972). Both kICG and VICG were significantly reduced, compared to normal controls, in the GS III group with defective BSP uptake, but did not differ significantly from normal in the GS I and GS II groups. Michaelis-Menten analysis of the data indicated that VMAX for ICG uptake in the GS III group (1.2 +/- 0.6 mg per min per kg) was significantly reduced compared to the previously established normal value of 3.6 +/- 0.6 mg per min per kg; (P less than 0.01). For the total population of 26 patients with Gilbets' syndrome, there was a highly significant correlation (r= 0.77, P less than 0.01) between kICG and lambda21BSP, the fractional hepatic uptake rate for BSP. These studies confirm previous work indicating that patients with Gilbert's syndrome constitute a heterogeneous population with regard to defects in hepatic organic anion transport, some of the defects not being attributable to glucuronyl transferese deficiency. Future studies of Gilbert's syndrome must take into account the existence of these subgroups, since they may have different underlying pathogenetic mechanisms.

Adolescent↗
PubMed1975

Approaches to the management of fulminant hepatic failure.

This discussion has concerned the management of fulminant hepatic failure with stage III or IV encephalopathy occurring in a patient with previously normal liver function. Basic medical management must include special attention to the metabolic, neurologic, hemorrhagic, and infectious complications common to this syndrome as well as aggressive supportive care. Because the mortality rate remains high in spite of these measures, a variety of other approaches to therapy continue to be evaluated. These include corticosteroid administration, exchange transfusion, plasmapheresis, and the development of extracorporeal hepatic support systems.

Acidosis↗
PubMed1975

Hepatic organic anion uptake in the rat.

The hepatic uptake of bilirubin (BR), indocyanine green (ICG), and sulfobromophthalein (BSP) was studied in 350 anesthetized Sprague-Dawley rats by determining the initial plasma disappearance rate (V) of various doses of unlabeled ICG, or of tracer quantities of [3H]BR or [35S]BSP injected into the jugular vein simultaneously with varying amounts of unlabeled BR or BSP. Similar studies were also performed involving the simultaneous injection of potential inhibitors of hepatic uptake. The results indicate that: (a) hepatic uptake determined by direct tissue measurement could be accurately estimated from the plasma disappearance data; (b) saturation of hepatic uptake with increasing dose was readily demonstrated for each of these three organic anions, and in each instance a plot of V versus dose took the form of a rectangular hyperbola analyzable in terms of Michaelis-Menten kinetics; (c) for BR, the saturable uptake process showed a Vmax more than 100 times the normal net transfer rate from plasma to bile; (d) hepatic uptake of BR, BSP, and ICG showed relatively selective, mutually competitive inhibition; glycoholic acid did not inhibit hepatic uptake of any of these substances; and (e) "counter-transport" could be demonstrated for each of the three test substances. These data are compatible with the existence of a carrier-mediated transport process for hepatic uptake of each of these three organic anions and clarify the relationship of hepatic BR uptake to its overall transport from plasma to bile.

Animals↗
PubMed1975

Unconjugated hyperbilirubinemia. Physiologic evaluation and experimental approaches to therapy.

The plasma concentration of unconjugated bilirubin is determined by the rate at which newly synthesized bilirubin enters the plasma (bilirubin turnover) and the rate of irreversible bilirubin removal by the liver (hepatic bilirubin clearance). Measurement of each of these variables by kinetic studies with radiolabeled bilirubin permits a precise classification of cases of unconjugated hyperbilirubinemia into those due to increased bilirubin turnover (for example, hemolysis), those due to decreased bilirubin clearance (for example, Gilbert's syndrome), and those in which both mechanisms operate. The ability to quantitate hepatic bilirubin clearance makes it possible to detect gilbert's syndrome even in the presence of concomitant hemolysis. Of the hereditary disorders of bilirubin metabolism, Gilbert's syndrome is common but innocuous, whereas Crigler-Najjar syndrome is rare but devastating. An unusual case of Crigler-Najjar syndrome is described in which bilirubin encephalopathy developed at age 10. Various modalities used in an attempt to reduce her plasma bilirubin concentration by either increasing bilirubin clearance or reducing bilirubin turnover are described.

Adult↗
PubMed1974

Removing substances from blood by affinity chromatography. I. Removing bilirubin and other albumin-bound substances from plasma and blood with albumin-conjugated agarose beads.

Substances such as bilirubin that bind tightly to plasma proteins cannot readily be removed from blood. We describe here the use of affinity chromatography as a new approach to the removal of proteinbound metabolites and toxins from blood. Agarose beads were coupled via cyanogen bromide to human serum albumin so as to contain 30-50 mg of albumin/g wet wt. Such beads, when exposed to plasma from a patient with congenital nonhemolytic jaundice labeled with [(14)C]-bilirubin, bound more than 150 mug bilirubin/g of beads. The binding was saturable, concentration-dependent, relatively independent of flow rate, and reversible by elution with plasma, albumin, or 50% (vol/vol) ethanol. The beads could be repeatedly reused without loss of efficiency after ethanol elution and long storage in the cold. Salicylate, cortisol, and taurocholate, which bind weakly to albumin, were retarded by the beads but eluted with neutral buffer. Thyroxine, taurolithocholate, chenodeoxycholate, and digitoxin bound tightly but were eluted with 50% ethanol. Digoxin did not bind at all. When whole blood was passed over agarose-albumin beads, bilirubin was removed, calcium and magnesium fell slightly, but red cells, white cells, platelets, clotting factors, and a variety of electrolytes and proteins were substantially unchanged. Agarose-albumin beads may be useful for removing protein-bound substances from the blood of patients with liver failure, intoxication with protein-bound drugs, or specific metabolic deficits. Furthermore, it may be possible to make useful adsorbents by attaching other proteins to agarose or other polymer beads.

Bilirubin↗
PubMed1974

Removing substances from blood by affinity chromatography. II. Removing bilirubin from the blood of jaundiced rats by hemoperfusion over albumin-conjugated agarose beads.

In vitro studies indicate that bilirubin and other albumin-bound substances can be efficiently removed from plasma by filtration over albumin-conjugated agarose beads. The effectiveness of this technique in vivo was investigated in rats by using a closed extracorporeal hemoperfusion system. Five Gunn rats whose endogenous bilirubin pool had been labeled with [(3)H]bilirubin and five Sprague Dawley rats with surgically created biliary obstruction were chosen as models of unconjugated and conjugated hyperbilirubinemia. Indocyanine green was injected into rats and its removal also studied. In the Gunn rats, 98% of the bilirubin was removed from plasma during the initial pass over the column as determined isotopically and chemically. Plasma bilirubin levels fell more than 70% from 8.2+/-1.6 mg/100 ml (mean+/-SD) to 2.6+/-0.5 mg/100 ml during a 1-h hemoperfusion. An average of 1,061 mug of bilirubin was recovered from the columns, representing 22.5+/-4.2% of the total exchangeable bilirubin pool and 96+/-36.4% of the plasma pool. Results were similar in the rats with biliary obstruction and in those given indocyanine green. Normal Sprague Dawley rats experience minimal changes in formed blood elements, electrolytes, and proteins as the result of hemoperfusion. When the total volume of the column did not exceed 51% of the estimated blood volume of the animal, the survival rate was 100% in 20 studies, and the procedure was without observable ill effect. Extrapolation of both in vitro and in vivo data to man suggests that extracorporeal hemoperfusion over albumin-agarose columns may be a practical means of assisting hepatic excretory function.

Animals↗
PubMedDate not supplied

Normal fasting-state levels of serum cholyl-conjugated bile acids in Gilbert's syndrome: an aid to the diagnosis.

Fasting levels of cholic acid conjugates were determined by radioimmunoassay in the serum of 24 patients with extensively documented Gilbert's syndrome and in 98 healthy controls without unconjugated hyperbilirubinemia. The Gilbert's syndrome patients studied included all three subtypes, as determined from studies of the plasma disappearance kinetics of sulfobromophthalein and indocyanine green. Although patients with structural liver disease severe enough to produce hyperbilirubinemia almost invariably have elevated fasting serum levels of cholic acid conjugates, values were normal in each of the Gilbert's syndrome patients, including patients with metabolic abnormalities in sulfobromophthalein and indocyanine green transport. It is concluded that the measurement of fasting serum levels of cholic acid conjugates is a useful adjunct to the diagnosis of Gilbert's syndrome.

Cholic Acids↗
PubMedDate not supplied

Human liver transplantation: analysis of data on 540 patients from four centers.

The results of liver transplantation in a total of 540 patients from four centers in the United States and Western Europe have been collated. Twenty-five per cent of all transplants were performed for neoplastic disease. One- and 3-year survivals for this group were approximately 26 and 12% overall, and survival differed little for patients transplanted before and after January 1, 1980. Among the 44% of patients transplanted for endstage cirrhosis, 3-year survival was lowest for patients with alcoholic cirrhosis (20%). Three-year survival was greater for patients with nonalcoholic cirrhosis (29% overall), did not differ markedly among the various subtypes, and was greater for patients transplanted after January 1, 1980 (42%), as compared with before (22%). Patients with biliary atresia, sclerosing cholangitis, and metabolic and miscellaneous disorders constituted the remaining 30% of patients; 3-year survival varied from about 20 to 44% overall for the various subgroups, with a consistent trend toward improved survival among patients transplanted after January 1, 1980. The use of cyclosporin may not wholly explain this improved survival among more recently transplanted patients. Quality of life for transplant recipients surviving at least 3 months, as judged by a limited amount of data regarding time-in-hospital and functional status, appears to be good.

Female↗
PubMedDate not supplied

Gene therapy for liver disease.

With major advances in biomedical science over the last 2 decades, the possibility of treating human disease at a genetic level has become a tantalizing possibility. As a result, a growing number of investigators are focusing on the development of techniques to deliver therapeutic genes into cells. The liver has been a model organ in the development of this gene transfer technology. This review focuses on the attributes and limitations of the current gene delivery systems that have been explored in the context of liver disease and highlights the obstacles that must be addressed before hepatic gene therapy becomes a clinical reality.

Gene Transfer Techniques↗