Diffuse intrahepatic biliary strictures in sarcoidosis resembling sclerosing cholangitis. Case report and review of the literature

We report a case of sarcoidosis with severe cholestasis and cholangiographic features of sclerosing cholangitis that responded dramatically to corticosteroid therapy. Although an association between sarcoidosis and primary sclerosing cholangitis has been suggested by previous reports, features suggestive of primary sclerosing cholangitis, including inflammatory bowel disease, hepatic histology and serum neutrophil cytoplasmic antibodies, were absent in this case. Cholangiography may be useful in the evaluation of patients with cholestatic sarcoid liver disease, and intrahepatic biliary strictures should be included in the spectrum of hepatic involvement by sarcoidosis. A trial of corticosteroid therapy may be of benefit in patients with bile ductal involvement by sarcoidosis.

Vanishing bile duct syndrome temporally associated with ibuprofen use

Nonsteroidal anti-inflammatory drugs are widely used, but the potential hepatotoxic side effects are not always appreciated. Herein, we report the first case, to our knowledge, of an atopic patient in whom severe cholestatic jaundice from bile ductopenia developed 3 wk after initiation of ibuprofen therapy. This drug-induced vanishing bile duct syndrome is probably an immunological (hypersensitivity) reaction. Vanishing bile duct syndrome as a consequence of ibuprofen use should be considered as a potential cause of chronic cholestasis when other more common etiologies have been excluded.

Plasma free fatty acid metabolism during storage of platelet concentrates for transfusion

New containers allow storage of platelet concentrates (PC) at 22 degrees C for up to 7 days, during which glycolytic and oxidative metabolism is vigorous. Recent evidence suggests that 85 percent of adenosine triphosphate regeneration is based on oxidative metabolism and that substrates other than glucose may be used. Because platelets can oxidize free fatty acids (FFA) as a possible source of energy during storage, the authors studied their availability, distribution, and turnover. Plasma FFA concentration was unchanged after 1 day of PC storage but significantly increased on Days 3, 5, and 7. Platelet-free plasma (PFP) stored under the same conditions as PC demonstrated a progressive increase in FFA, suggesting that some of the FFA accumulating in PC were derived from plasma rather than platelets. Indeed, during PC storage, plasma triglycerides decreased significantly, suggesting that they are a possible source of the increased levels of FFA found on Day 3 and thereafter. Thus, PC have a plasma FFA pool available continuously for oxidation during storage. Studies with radiolabeled palmitate suggested that FFA oxidation by platelets occurs during storage. The current findings show that plasma FFA could be a significant substrate for oxidative metabolism during storage of PC and that the oxidized FFA are replenished at least in part from plasma. These results may allow platelet storage to be improved, particularly in synthetic media.

Metabolism of 1-alkyl-2-acyl-GPC in human platelets in response to stimulation by thrombin

Washed human platelets were incubated with radioactive 1-[3H]alkyl-2-hydroxyglycero-3-phosphocholine (lyso-PAF) at 37 degrees C. [3H]lyso-PAF was converted by platelets into [3H]alkylacyl-GPC which was incorporated. Incorporation of radioactivity was time dependent and reached a maximum of 57 percent in one h. This formation and incorporation of [3H]alkylacyl-GPC was inhibited (50%) by extracellular calcium (1.3 mM). Labeled platelets were treated for 5 min with either thrombin (2.5 U/ml) or saline solution. While there was no change in the saline control, thrombin induced a reduction in the content of [3H]alkylacyl-GPC, accompanied by an increase in [3H]lyso-PAF presumably by stimulation of phospholipase A2. There was no apparent increase in radioactivity comigrating with PAF. This was probably due to the overwhelming dilution of the radioactive alkylacyl-GPC by the endogenous nonradioactive compound (ratio-1/3200). These studies suggest that human platelets can take up lyso-PAF and acylate it to alkylacyl-GPC which is susceptible to phospholipase A2 activity.

Acetyltransferase activity in human platelet microsomes and washed platelets

It has been demonstrated that human platelets form platelet-activating factor (PAF) when stimulated by thrombin, collagen and ionophore A-23187, but the mechanism of its formation has not been elucidated. In this study we demonstrated increased acetyltransferase activity (i.e., transfer of the acetyl moiety of [3H]acetyl-CoA to lyso-PAF (1-alkyl-sn-glycero-3-phosphocholine) to form PAF) occurring in human platelet microsomes made from platelets stimulated by thrombin or ionophore A-23187. This stimulation resulted in a 2-4-fold increase in acetyltransferase activity over unstimulated platelets. Acetyltransferase activity was also demonstrated by incubating [3H]acetate with whole platelets and stimulating with thrombin or ionophore A-23187. Radioactive PAF was detected when the platelets were stimulated. None was formed without stimulation. These findings indicate that acetyltransferase may play a role in the biosynthesis of PAF by human platelets.

Metabolism of platelet-activating factor by blood platelets and plasma

High performance liquid chromatography in combination with a radioactivity detector was used to study the metabolism of platelet-activating factor (1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) by washed platelets, platelet-free plasma and platelet-rich plasma obtained from rabbits and humans. Degradation of platelet-activating factor to its 2-lyso derivative was observed in rabbit and human plasma. This degradation of platelet-activating factor in plasma was completely inhibited by diisopropylfluorophosphate and was partially inhibited by ethylenediamine tetraacetic acid. Washed platelets metabolized platelet-activating factor not only to the 2-lyso compound but also, by reacylation of this lyso intermediate, to an analogue of platelet-activating factor probably containing a long-chain acyl group at the sn-2 position. These transformations occurred, but to a lesser extent, in platelet-rich plasma.

Human and rabbit platelets form platelet-activating factor in response to calcium ionophore

Homogenous preparations of human and rabbit platelets synthesized platelet-activating factor (PAF) when stimulated by calcium ionophore A23187. PAF was isolated by high performance liquid chromatography (HPLC) on a Lichrosorb Si60 column. PAF was well separated from other phospholipids especially sphingomyelin and lysolecithin. The retention times of PAF derived from human or rabbit platelets were identical to the commercially available semisynthetic PAF and radiolabeled PAF. The amount of PAF was determined by the extent to which it induced the aggregation of washed rabbit platelets.

Radioimmunologic identification of prostaglandins produced by serum-stimulated mouse embryo palate mesenchyme cells

High-performance liquid chromatography and radioimmunoassay were used to identify the prostaglandins synthesized by mouse embryo palate mesenchyme cells. Serum stimulated the release of several different metabolites of arachidonic acid including 6-ketoprostaglandin F1 alpha (the stable product of prostacyclin, prostaglandin I2), prostaglandin E2 and prostaglandin F2 alpha. Compared to control cells, the serum-stimulated cells produce elevated levels of prostaglandin E2 (36-fold), 6-ketoprostaglandin F1 alpha (15-fold) and prostaglandin F2 alpha (7-fold). The acetylenic analogue of arachidonic acid, 5,8,11,14-eicosatetraynoic acid prevented this accelerated synthesis.

Changes in thromboxane B2 and 6-keto-PGF1 alpha after direct electrical stimulation of the denervated rat gastrocnemius1,2

Radio-immunoassay was used to measure the amounts of Thromboxane B2 (TXB2) and 6-keto-PGF1 alpha produced in the gastrocnemius muscles of rats after denervation and direct electrical stimulation (2-4 mA intensity and 4 msec duration pulses given at 10 Hz continuously, 8 hours each day for 14 days). Compared to the normal control side, the normal-stimulated, the denervated control and the denervated-stimulated muscles, all indicated increases in the content (ng/g muscle) of TXB2 (120-155%, P less than 0.01) and 6-keto-PGF1 alpha (90-10 7%). This study suggests that electrical stimulation as well as denervation may lead to an elevation of these prostanoids.

The development of a radioimmunoassay for 12-L-hydroxyeicosatetraenoic acid

Antibodies directed toward 12-L-hydroxyeicosatetraenoic acid (12-L-HETE) were generated in rabbits by immunization with conjugates of 12-L-HETE and human serum albumin. The concentration of antibodies was determined by incubating immune plasma with 12-L-HETE that had been covalently linked to a solid support, washing the 12-L-HETE support, and measuring the quantity of bound antibodies by reaction with [125I]Protein A. The addition of 0.5 ng-10 ng of fluid-phase 12-L-HETE to the standard mixture of solid-phase 12-L-HETE and anti-12-L-HETE plasma inhibited by 21-80% the binding of antibodies and consequently of [125I]Protein A to the solid support. The 12-OH function positioned between two double bonds was the immunodominant determinant of this antigen-antibody reaction, but the carboxyl function also was recognized. This radioimmunoassay was used to detect and quantitate 12-L-HETE resolved by high pressure liquid chromatography.

Accumulation of cyclooxygenase products of arachidonic acid metabolism in gerbil brain during reperfusion after bilateral common carotid artery occlusion

Several of the cyclooxygenase products of arachidonic acid were measured in the cerebral hemispheres of gerbils subjected to transient interruption of the cerebral circulation. The levels of PGD2, PGF2 alpha, PGE2, TXB2, 13, 14-H2-15-keto-PGE2, and the stable nonenzymic product of prostacyclin, 6-keto-PGF1 alpha, were not altered at the end of a 5-min period of ischemia. However, the onset of reperfusion was accompanied by a rapid accumulation of these products. Levels were highest during the initial period of reperfusion, then decreased to approach control levels after 120 min. PGD2, PGF2 alpha, and PGE2 were the predominant metabolites detected. This postischemic accumulation of arachidonic acid metabolites could be blocked by prior administration of inhibitors of cyclooxygenase activity.

Analysis by high performance liquid chromatography of cyclooxygenase products of arachidonic acid metabolism in plasma of rabbits bearing the VX2 carcinoma

Cyclooxygenase products of arachidonic acid metabolism in the plasma of normal rabbits and animals bearing the VX2 carcinoma were separated by high performance liquid chromatography and the effluent fractions assayed by serologic methods. The products measured were 6-keto-PGF1 alpha, thromboxane B2, PGE2, PGF2 alpha, 13,14-dihydro-PGE2, 13,14-dihydro-15-keto-PGE2, 15-keto-PGE2, and 13,14-dihydro-15-keto-PGF2 alpha. In hypercalcemic, tumor-bearing rabbits, the plasma concentrations of 13,14-dihydro-15-keto-PGE2 and 13,14-dihydro-15-keto-PGF2 alpha were markedly elevated (in the range of 0.5 to 16 ng/ml). Previously unmeasured 6-keto-PGF1 alpha, thromboxane B2, 13,14-dihydro-PGE2 and 15-keto-PGE2 were not found in high concentrations in the plasma of tumor-bearing rabbits. These results add further support to our conclusion that the VX2 tumor produces hypercalcemia in the host by a mechanism which utilizes PGE2, rather than a subsequent metabolite of this prostaglandin, as the mediator between the neoplasm and bone.

Arachidonic acid metabolism by cells in culture: analyses of culture fluids for cyclooxygenase products by radioimmunoassay before and after separation by high pressure liquid chromatography

Biosynthesis of PGI2, measured as 6-keto-PGF1 alpha, thromboxane A2, measured as thromboxine B2, and prostaglandins E2, F2 alpha and D2 by lymphocytes (WEHI-5), endothelial cells, normal human lung cells (WI-38), normal human fibroblasts (D-550), rat adult Type II alveolar cells (L-2) and canine kidney cells (MDCK) was measured by radioimmunoassay of culture fluids before and after their separation by high pressure liquid chromatography. The metabolic profiles and the levels of each metabolite obtained by both procedures were comparable. The profile of arachidonic biosynthesis was unique to each cell. Endothelial cells synthesized primarily prostacyclin; the lymphocytes synthesized principally thromboxane. The dog kidney cells synthesized relatively large amounts of prostaglandin F2 alpha, I2 and E2, while the normal human lung cells produced predominantly prostaglandins E2, F2 alpha, and thromboxane. The rat adult alveolar cell (L-2) and the normal human fibroblasts (D-550) biosynthesized primarily prostaglandins E2 and F2 alpha.

Immunoassay of indomethacin: the use of [125I] protein A to detect specific serologic binding

The sera of rabbits that were injected with indomethacin covalently linked to human albumin bound increasing amounts of [14C] indomethacin during the course of immunization. The serum-binding components chromatographed with the gamma-globulin fraction and were precipitated with goat-anti-rabbit-gamma-globulin. When measured by radioimmunoassay with [14C] indomethacin under optimal conditions, 34 ng (95 pmoles) of unlabeled indomethacin inhibited [14C] indomethacin binding 50%. The antibodies reacted most effectively with indomethacin and the desmethylated analogue, 1-(p-chlorobenzoyl)-2-methyl-5-hydroxyindole-3-acetic acid, but not 2-methyl-5-methoxy-indole-3-acetic acid. An immunoassay based on the use of [125I] Protein A as tracer for IgG antibody was developed for quantitative determination of indomethacin at the picogram level. Indomethacin, immobilized by covalent linkaae to a solid support, bound the rabbit anti-indomethacin. Protein A, labeled with [125I], measured the levels of the bound IgG antibody. Fluid phase indomethacin competed with solid-phase indomethacin for the anti-indomethacin, which resulted in decreased anti-indomethacin and consequently decreased [125I] Protein A on the immobilized indomethacin-anti-indomethacin complex. The serologic specificity with the immobilized ligand immunoassay was the same as that found with the [14C] indomethacin radioimmunoassay, but the sensitivity for detection of indomethacin was increased over 300-fold.

The use of immobilized ligands and [125I]protein a for immunoassays of thromboxane B2, prostaglandin D2, 13,14-dihydro-prostaglandin E2, 5,6-dihydro-prostaglandin I2, 6-keto-prostaglandin F1 alpha, 15-hydroxy-9 alpha, 11 alpha(epoxymethano)prosta-5,13-dienoic acid and 15-hydroxy-11 alpha,9 alpha(epoxymethano)prosta-5,13-dienoic acid

Immunoassays were developed for quantitative determination of thromboxane B2, prostaglandin D2, 13,14-dihydro-prostaglandin E2, 5,6-dihydro-prostaglandin I2, 6-keto-prostaglandin F1 alpha, 15-hydroxy-9 alpha, 11 alpha (epoxymethano) prosta-5, 13-dienoic acid and 15-hydroxy-11 alpha, 9 alpha (epoxymethano) prosta-5,13-dienoic acid. Ligands immobilized by covalent linkage to a solid support, bound homologous rabbit antibodies. [125I] Protein A was used to measure the bound IgG antibody. Increments of homologous and heterologous fluid-phase ligand completed with solid-phase ligand for antibody and resulted in decreasing amounts of bound [125I]-Protein A. The serologic specificity for each immune system was determined. Immunoassays for thromboxane B2, 6-keto-prostaglandin F1 alpha, and 5,6-dihydro-prostaglandin I2 were used to identify their respective homologous ligands that were separated by normal phase and reversed phase high pressure liquid chromatography.

Provisional Abridged Life Tables for Urban and Rural Areas in Pakistan, Based on PGS 1968 and 1971

As is the case in many other countries, mortality has been undergoing substantial, though not precisely understood, changes in Pakistan. In the absence of a reliable and adequate system of vital registration in the country, the precise measurement of these changes is well nigh impossible. In Pakistan, an attempt to estimate levels of fertility and mortality on a sample basis was made through the Population Growth Estimation (PGE) project undertaken from 1962 through 1965 [5, 12]. Subsequently, another demographic survey, called the Population Growth Survey (PGS), was initiated and carried out from 1968 through 1971 [13]. In the PGE a dual system of data collection was utilized based on continuous (Longitudinal) registration and a periodic (Cross-Sectional) survey. In the PGS, data were collected through periodic surveys only. Data from the PGS have only recently been made available to researchers. The present set of life tables is based on the mortality statistics collected in 1968 and 1971 field operations of the PGS.