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Biomedical subjects

R L Stahl

Publications and source records attributed to R L Stahl.

18 recordsLinked to original sources
PubMed1991

Malignant angioendotheliomatosis presenting as disseminated intravascular coagulopathy.

Disseminated intravascular coagulopathy (DIC) occurred in a patient with hemolytic anemia and anasarca. Skin and muscle biopsy showed intravascular lymphomatosis (malignant angioendotheliomatosis). Combination chemotherapy resulted in resolution of the DIC and anasarca. After an unmaintained 8-month clinical remission, the patient had central nervous system relapse and died. Malignant angioendotheliomatosis is a rare disorder that should be considered among the occult causes of DIC.

Aged↗
PubMed1991

Lymphomatous polyneuropathy. Biopsy of clinically involved nerve and successful treatment.

We present a patient with large-cell lymphoma in remission who, over several weeks, developed widespread multifocal polyneuropathy. There was involvement of all four limbs, most severely the left upper extremity that had become useless. Biopsy of the left saphenous nerve within an area of sensory loss showed lymphoma in the endoneurium. There was no other evidence of recurrent lymphoma despite extensive investigation, including bone marrow, lumbar puncture, magnetic resonance imaging of the spine, and computed tomography of the abdomen and pelvis. Intensive systemic chemotherapy was accompanied by nearly complete recovery. Biopsy of a symptomatic nerve is preferable to routine sural nerve biopsy in this condition because of its patchy distribution. Treatment with systematic chemotherapy can be effective.

Adult↗
PubMed1991

Therapy of the Kasabach-Merritt syndrome with cryoprecipitate plus intra-arterial thrombin and aminocaproic acid.

A patient with the Kasabach-Merritt syndrome with disseminated intravascular coagulopathy and congestive heart failure due to a giant hepatic cavernous hemangioma achieved thrombosis of his tumor with a combination of cryoprecipitate plus intra-arterial thrombin and epsilon aminocaproic acid. This was documented by an absence of Indium 111-labelled platelet sequestration, marked decrease in thrombin:antithrombin complex generation, and normalization of platelet count and fibrinogen. Interventional angiography with aminocaproic acid and thrombin is advocated in patients whose tumors are amenable to such an approach so as to avoid a systemic antifibrinolytic state.

Aged↗
PubMed1990

A hypercoagulable state follows orthotopic liver transplantation.

Orthotopic liver transplantation may be associated during the postoperative period with hepatic artery thrombosis, a catastrophic occurrence generally necessitating emergency retransplantation. To assess the contribution of the coagulation mechanism to this complication, the levels of procoagulant and anticoagulant proteins were followed in 41 liver transplant patients during the first 10 postoperative days. The mean activities of all procoagulant factors reach normal values on day 1 except for factors V and VII, which achieve normal activity by day 3. Supernormal levels of factor VIII activity and antigen are noted (peak values on day 5 of 334% +/- 113% and 481% +/- 260%, respectively). The anticoagulant proteins show delayed recovery, with deficient antithrombin III levels seen in 81% of patients on day 3 and 57% on day 5. Similarly, proteins C and S are subnormal in 24% and 21%, respectively on day 3, and 20% and 10%, respectively, on day 5. During this period, elevated levels of thrombin/antithrombin complexes are encountered, reflecting in vivo activation of the coagulation mechanism. Activated thrombin is, therefore, being generated at a time when a decrease in the major regulatory anticoagulant proteins exists. These data suggest an imbalance between the hemostatic and thrombotic mechanisms and indicate a sustained prothrombotic state that may contribute to the risk for hepatic artery thrombosis. Using a regimen of low-dose heparin and fresh frozen plasma infusion, no thromboses have been seen in 65 consecutive liver transplants.

Blood Coagulation Disorders↗
PubMed1990

Surgical options, hematologic evaluation, and pathologic changes in Budd-Chiari syndrome.

This article presents a scheme of management for Budd-Chiari syndrome based on experience with 33 patients. Therapy in acute Budd-Chiari syndrome is dictated by the liver biopsy, with hepatocyte necrosis indicating the need for placement of a decompressive shunt. The type of shunt was determined by intrahepatic vena cava obstruction; a higher morbidity rate was associated with the mesoatrial shunt in 11 patients than with a portacaval shunt in 10 patients. Successful shunt placement allowed stabilization of the liver biopsy and maintenance of good hepatocyte function [galactose elimination capacity (preoperative: 349 +/- 40 mg/minute; 20 months: 344 +/- 60 mg/minute)]. Severe fibrosis and reduced galactose elimination capacity (264 +/- 43 mg/minute) indicated advanced disease--chronic Budd-Chiari syndrome--and were indications for liver transplant. Hematologic evaluation documented a myeloproliferative disorder in 8 of the last 13 patients evaluated; perioperative and late anticoagulation and/or chemotherapy reduced recurrent thrombosis. We conclude that the Budd-Chiari syndrome requires different therapies depending on the stage of disease. If no hepatocyte injury is present on biopsy, therapy may not be needed. Acute, reversible injury can be managed by placement of a decompressive shunt. Irreversible damage requires transplantation. Selection of the right therapy requires a complete evaluation.

Budd-Chiari Syndrome↗
PubMed1985

A reappraisal of leukocyte dehydroascorbate reductase.

Dehydroascorbate reductase (glutathione:dehydroascorbate oxidoreductase, EC 1.8.5.1) activity was determined in human leukocyte homogenates using a direct spectrophotometric assay. Despite previous studies, using a less sensitive coupled assay, which reported that this enzyme was present in leukocytes, we found that neither neutrophil nor chronic lymphocytic leukemia lymphocyte extracts had detectable activity. Furthermore, when the product was quantitated by HPLC, protein-dependent generation could not be demonstrated. Mixing experiments with a partially purified enzyme preparation from spinach leaves provided no evidence for the presence of an inhibitor in neutrophil homogenates. These findings suggest that in human leukocytes, dehydroascorbate reduction does not occur enzymatically.

Chromatography, High Pressure Liquid↗
PubMed1985

Vasculitic leg ulcers in chronic myelogenous leukemia.

Recurrent bilateral leg ulcers developed in two patients receiving hydroxyurea therapy during the chronic phase of chronic myelogenous leukemia. The ulcers were extremely painful and were associated with extensive edema and vasculitic papules. A small-vessel vasculitis with degeneration of collagen and ulceration was seen on biopsy. The ulcers did not respond to treatment with steroids or low-dose cyclophosphamide but gradually healed with local measures. The possible pathogenesis of ulcers in chronic myelogenous leukemia is discussed.

Aged↗
PubMed1985

Chronic lymphocytic leukemia.

Chronic lymphocytic leukemia is a neoplasm characterized by the accumulation of monoclonal lymphocytes in blood, bone marrow, and other tissues. Staging of the disease is based on lymphoid mass and the presence of anemia or thrombocytopenia, with prognosis also related to the pattern of bone-marrow involvement, chromosomal abnormalities, and surface membrane phenotype. Transformation to a diffuse large-cell lymphoma or to prolymphocytic leukemia may occur as a terminal event. A number of biochemical and surface membrane abnormalities that may suggest approaches for future clinical investigations have been described.

Aged↗
PubMed1985

Relationship of dehydroascorbic acid transport to cell lineage in lymphocytes from normal subjects and patients with chronic lymphocytic leukemia.

Dehydroascorbic acid is the principal form for the cellular uptake by blood cells of vitamin C. Since previous studies from this laboratory had shown a higher content of ascorbic acid and dehydroascorbic acid (DHA) in chronic lymphocytic leukemia (CLL) lymphocytes when compared to their normal counterparts, DHA uptake was characterized using these cells. The affinities of CLL and normal lymphocytes for DHA uptake were similar, as demonstrated by the Km values of 3.7 and 3.5 mM, respectively. Differences were found in other kinetic constants of DHA uptake. The Vmax for normal lymphocytes, 634 mumol/liter cell H2O/min, was approximately twice that of CLL cells, 392 mumol/liter cell H2O/min. In addition, the initial velocity and the maximal DHA uptake by normal lymphocytes were greater than that of CLL lymphocytes. These differences were not simply a reflection of lymphocyte subsets since CLL B-cells demonstrated lower uptake rates than did normal B-cells whereas CLL T-cells were similar to their normal counterparts. The alterations appear to be specific for the leukemic B-cell since they were not shared by neoplastic cells from two patients with T-cell CLL. When analyzed in light of the 3-fold greater cellular DHA and ascorbic acid content in B-cell CLL as compared to normal lymphocytes, these kinetic parameters support the occurrence of a concentration-dependent transport system for DHA. We conclude that the DHA uptake properties of CLL lymphocytes of B-cell origin serves to distinguish this lineage from T-cell CLL or normal lymphocytes.

Ascorbic Acid↗
PubMed1984

Unrecognized pulmonary embolism presenting as disseminated intravascular coagulation.

Six patients are described in whom disseminated intravascular coagulation of uncertain cause was found to be due to occult pulmonary embolism. The peripheral blood smear showed thrombocytopenia in all patients and schistocytes in four. Coagulation studies revealed increased levels of fibrinogen/fibrin degradation products (six of six patients), positive results for fibrin monomer (five patients), prolonged thrombin times (four patients), hypofibrinogenemia (three patients), prolonged prothrombin times (two patients), and decreased plasma coagulation factors (two patients). Pulmonary embolism was confirmed by lung scanning or pulmonary angiography. Institution of full-dose heparin therapy was associated with hemostatic and clinical improvement in all patients. The association of disseminated intravascular coagulation with occult pulmonary embolism merits recognition since full-dose heparinization is required for successful therapy.

Adenoma↗
PubMed1984

Chronic lymphocytic leukemia lymphocytes: membrane anomalies and H2O2 vulnerability.

This paper reviews selected biochemical and functional studies characterizing B lymphocytes from patients with chronic lymphocytic leukemia. When compared to B lymphocytes from the circulation of normal subjects, a number of differences are noted. Functionally, the CLL B lymphocyte is impaired in mitogen response, cap formation following attachment of multivalent ligands, and the density of surface immunoglobulins. It also differs from normal in the content of the ectoenzyme 5' nucleotidase, which is often decreased, and the concentration of ascorbic and dehydroascorbic acid, which are markedly elevated in these cells. The level of tocopherol is decreased. CLL and normal B lymphocytes are more vulnerable than T lymphocytes to the toxic effect of H2O2. This sensitivity is Ca2+ dependent and inhibited by nanomolar concentrations of nonsteroidal antiinflammatory agents. These studies identify the human B lymphocyte as a cell that should be a suitable target for selective killing by H2O2.

B-Lymphocytes↗
PubMed1983

A spectrophotometric assay for dehydroascorbate reductase.

A simple spectrophotometric assay for dehydroascorbate reductase based on the change in absorbance associated with the formation of ascorbic acid is described. Using a partially purified preparation from spinach leaves, the reaction was found to be linear with time and enzyme concentration. The reaction rate determined by this assay correlated well with that obtained by a high-performance liquid chromatography method. Possible advantages over currently available assays as well as potential applications are discussed.

Ascorbic Acid↗
PubMed1976

In vitro study of hemolysis induced by flow-regulated and pressure-dependent flow pumps.

In vitro experiments showed that a pressure-dependent flow pump which "obeys Starling's law" (with flexible tube stretched on vertical rotor) was less hemolytic than a classical flow-regulated pump (with pump inset occluded between a rotor and a stator). The degree of hemolysis obtained with fresh human blood was higher with blood from chronic respiratory patients than with blood from normal donors. Also, the hemolysis was less with fresh heparinized blood than with stored ACD blood, and less with normal blood than with diluted blood. Comparing hemodialysis pumps with ECC pumps showed that hemolysis tripled with the pressure-dependent flow types and was 30 times higher with the classical pumps.

Blood Flow Velocity↗