Uptake of L-triiodothyronine into human cultured lymphocytes

The cellular uptake of [125I]L-triiodothyronine and its analogues was investigated in IM-9 human cultured lymphocytes. Uptake of L-triiodothyronine was one half maximal within 15 min of incubation and maximal within 45 min. The efflux of the hormone followed first order kinetics having a one half time of 15 min. Treating the cells with either the mitochondrial inhibitors antimycin-A and potassium cyanide, or lowering the incubation temperature to 12 degrees C, markedly reduced uptake. The uptake of [125I]L-triiodothyronine was saturable having an affinity constant (Kd) of 110 nM. When thyroid hormone analogues were studied D-triiodothyronine and triiodothyroacetic acid (analogues known to bind avidly to nuclear receptors) competed only weakly with [125I]L-triiodothyronine for uptake. These findings indicated the importance of the intact L-alanine side chain of the thyroid hormone molecule for its uptake into lymphocytes. Other studies, with cultured rat hepatocytes, demonstrated a similar saturable uptake system for [125I]L-triiodothyronine. These studies suggest, therefore, that the uptake of thyroid hormones and their analogues into cells may be an important step in the biological actions of these hormones.

Doxorubicin cardiotoxicity in children

To characterize the long-term effects of doxorubicin hydrochloride (Adriamycin) on left ventricular function, a total of 588 echocardiograms were obtained prospectively in 46 children who were treated for malignancy. We found shortening fraction of the left ventricle to be more useful than systolic time intervals for detecting cardiotoxic effects. Abnormal cardiac function occurred in 43% of patients but only 4% developed congestive heart failure which was irreversible. There appeared to be strong individual variation in response to the effects of doxorubicin on the heart unrelated to treatment regimen, age of onset of treatment, or total cumulative dose. If the SF remained normal it was possible to give a dose greater than 550 mg/m2. If cardiac dysfunction occurred following cessation of doxorubicin, it did so within five months in 95% of patients. Discontinuing doxorubicin therapy in patients with SF LEss than 20% who did not have clinical signs of congestive heart failure resulted in improved shortening fraction and administration of digoxin did not further improve the SF. Sequential echographic evaluation of cardiac function at frequent intervals has proven to be useful during and following treatment with doxorubicin.

Bile secretory apparatus: evidence for a vesicular transport mechanism for proteins in the rat, using horseradish peroxidase and [125I]insulin

The morphologic mechanisms involved in the uptake, transport, and secretion of proteins into bile were studied in rat liver in vivo. When both horseradish peroxidase (HRP) and insulin were injected into the portal veins of anesthetized rats, these proteins were subsequently detected in bile. Utilizing the technique of combined cytochemistry and quantitative autoradiography, both HRP and [125I]insulin were coincidentally localized within endocytic vesicles within the interior of hepatocytes at various time points after simultaneous intraportal injection. The data suggest that both proteins followed two pathways involving endocytic vesicles of approximately 1000 A in diameter. In the first pathway these protein-containing vesicles were transported through the hepatocyte and subsequently fused with the bile canalicular membrane, resulting in secretion of contained proteins into the biliary space. The second pathway also involved endocytosis into 1000 A vesicles, but these vesicles were transported to the Golgi region and its associated system of lysosomes and endoplasmic reticulum (GERL). Whether the proteins in these vesicles were later secreted into bile was unclear. Measurement of HRP and [125I]insulin or its metabolites, in bile, provided direct evidence that exogenously administered proteins (or their fragments) gain entrance into the biliary space. Studies in which metabolites of [125I]insulin, [125I]monoiodotyrosine (MIT), and 125I, were injected intraportally, demonstrated that less than 10% of [125I]MIT and less than 1.5% of Na125I were retained in perfusion-fixed and processed liver tissue. This study suggests that proteins in blood plasma are taken up by hepatocytes and secreted into bile via a vesicular transport mechanism.

Binding of cholecystokinin to high affinity receptors on isolated rat pancreatic acini

The binding of cholecystokinin (CCK) to its receptors on isolated rat pancreatic acini was investigated employing high specific activity, radioiodinated CCK (125I-BH-CCK), prepared by the conjugation of 125I-Bolton-Hunter reagent (125I-BH) to CCK. Binding was specific, time-dependent, reversible, and linearly related to the acinar protein concentration. After incubation for 30 min at 37 degrees C, the 125I-BH-CCK both in the incubation medium and bound to acini remained intact, as judged by gel filtration and trichloroacetic acid precipitation studies. Scatchard analysis was compatible with two classes of binding sites on acini: a very high affinity site (Kd, 64 pM) and a lower affinity site (Kd, 21 nM). 125I-BH-CCK binding to acini was competitively inhibited by CCK and four of its analogues in proportion to their biological potencies but not by unrelated hormones. Stimulation of amylase secretion by CCK and inhibition of 125I-BH-CCK binding by the same analogues carried out under identical conditions revealed a correlation (r = 0.99) between binding potency and amylase secretion. Stimulation of amylase secretion by CCK closely paralleled the occupancy of the high affinity CCK binding sites. It is concluded that the high affinity CCK binding sites most likely are the receptors mediating the stimulation of amylase secretion by CCK.

Autoradiographic evidence for hepatic lobular concentration gradient of bile acid derivative

Using an iodinated bile-acid analog with hepatic uptake and transport characteristics similar to conventional bile acids, the hepatic lobular gradient concept of Goresky was studied utilizing autoradiography. 125I-labeled cholylglycylhistamine (125I-CGH) was infused into the portal veins of male Sprague-Dawley rats and the livers were fixed for light microscopic autoradiography at 1 and 5 min after infusion. In two animals, sequential samples of bile were collected to assess the transport characteristics of 125I-CGH. By 1 min, virtually all (98%) of the injected 125I-CGH was taken up and retained by hepatocytes after perfusion fixation. Less than 15% of the label was lost during subsequent tissue processing. 125I-CGH appeared in bile within minutes, reaching maximum levels at 7 min. Quantitative autoradiography demonstrated that the first six to nine periportal hepatocytes were, by far, the most active (P less than 0.0005) in sequestering the bile-acid analog than were the remaining cells in the lobule. This study, therefore, provides the first autoradiographic evidence of a hepatic lobular concentration gradient for the uptake of a bile-acid analog.

Clinical and occult testicular leukemia in long-term survivors of acute lymphoblastic leukemia

Twenty-nine of 60 boys with acute lymphoblastic leukemia survived for more than 30 months and were potential candidates for discontinuation of therapy. Six patients developed overt clinical testicular leukemia: one at 34 months from diagnosis while receiving therapy and five at three to 17 months after therapy was stopped. Elective wedge biopsy of the testes has become part of the evaluation prior to discontinuation of therapy since 1977. Six of 18 boys had microscopic evidence of leukemic infiltration of the testes: four with diffuse involvement and two with focal clusters of leukemic cells. Testicular biopsy is recommended at the time of discontinuation of therapy and perhaps early in the course of the disease, although a negative biopsy does not exclude some focal lesions. The eventual outcome of those with occult testicular leukemia remains to be determined.

Photoacoustic Measurements on Semiconducting Powder Samples

Photoacoustic measurements of several semiconducting powder samples have been performed, and the measured band-gap energies obtained are found to be in good agreement with published values. The advantages of the photoacoustic technique are briefly discussed.

Evaluation of 24-hour infusion of high-dose methotrexate--pharmacokinetics and toxicity

High-dose methotrexate was administered by constant infusion over 24 h to children with various malignancies. Citrovorum factor was given at the completion of methotrexate infusion and continued for 72 h. Serum concentration of 10(-4) M could be sustained for 24 h with doses of methotrexate over 100 mg/kg. This infusion regimen was well tolerated and only mild neutropenia and mouth sores were seen in most patients. Severe toxicity was seen in one patient and was related to prolonged retention of methotrexate in the circulation. Careful monitoring of serum drug level is mandatory in the use of any high-dose methotrexate regimen.

Leukemic infiltration of the testis during long-term remission

Of 33 boys with acute lymphocytic leukemia treated at the Cincinnati Children's Hospital during 1971--1974, 14 remained in clinical and bone marrow remission for periods longer than 2.5 yr. Of these 14 patients, 8 then developed testicular leukemia. In 7 of these 8 patients, testicular infiltration was the first or only evidence of relapse. In 2 of the patients the gonads were not grossly abnormal, and testicular relapse was discovered as a result of routine wedge biopsy before therapy was to have been stopped. This experience has led to our policy of routine testicular biopsy in boys with acute lymphocytic leukemia who have had continuous remission for 3 yr and who are otherwise candidates for discontinuance of maintenance therapy.

Severe infiltration of the kidneys with ultrasonic abnormalities in acute lymphoblastic leukemia

A 3-year-old boy with acute lymphoblastic leukemia had enlarged kidneys with impairment of renal function and hypertension as the presenting features of relapse. Ultrasound demonstrated multiple nodular areas of echolucency within enlarged kidneys that reverted to normal when the patient was in remission but then recurred during relapse. This noninvasive procedure may be useful in patients with acute lymphoblastic leukemia to determine the incidence and prognostic significance of renal involvement at the time of diagnosis, and to follow the course of those who have demonstrable changes.

Entry of insulin into human cultured lymphocytes: electron microscope autoradiographic analysis

Electron microscope autoradiographs were prepared of IM-9 human cultured lymphocytes incubated with iodine-125-labeled insulin. With the use of [125I]insulin and Ilford L-4 emulsion, the technique had a resolution half-distance of approximately 0.085 micrometer. Autoradiographs revealed a time-dependent entry of insulin into the cell interior that was maximal after 30 minutes of incubation. At this time point nearly 40 percent of the [125I]insulin was in the interior of the cell at a distance 1 micrometer or greater from the plasma membrane. Grain distribution and volume density analyses revealed that the intracellular insulin was concentrated in the endoplasmic reticulum and nuclear membrane.

Acute respiratory illness in children with acute lymphoblastic leukemia

Ten of 70 children (14%) with acute lymphoblastic leukemia developed severe interstitial pneumonitis within three weeks after induction of central nervous system prophylactic therapy. The clinical picture was characterized by fever, cough, progressive dyspnea, and hypoxemia with complete resolution in one to three weeks, except in one patient who died during the acute illness from respiratory failure. P. carinii organisms were found in the lung tissue of only one patient. The etiology of the pneumonitis in the other nine children was probably viral, acquired or activated during a period of lymphopenia and immunosuppression. The morbidity and potential mortality from the pneumonitis warrants early recognition by open lung biopsy and intensive supportive therapy.

Cellular uptake and nuclear binding of insulin in human cultured lymphocytes: evidence for potential intracellular sites of insulin action

Human cultured lymphocytes (IM-9) were used to demonstrate that insulin can enter the intact cell and bind to the nucleus. When these lymphocytes were incubated with 125I-labeled insulin, specific cellular uptake reached a maximum within 2 min and remained at a plateau for 90 min or longer. Partially purified nuclei from such cells contained approximately 15-20% of the total cellular radioactivity. Nuclei freed of all other cellular fractions (by washing the partially purified nucleic with Triton X-100) bound approximately 7% of the total cellular radioactivity. In contrast to the rapid uptake of labeled insulin into the intact cell, specific binding to the nucleus was half-maximal after 5 min of incubation and maximal after 90 min. Both the cellular uptake and subsequent nuclear binding of labeled insulin were progressively inhibited by increasing concentrations of unlabeled hormone. Independent evidence for the nuclear binding of insulin was obtained by preparing autoradiographs of lymphocytes incubated for various times with labeled insulin. Such preparations strongly suggest that insulin binds to the plasma membrane, enters the cytosol, and then binds to the nucleus.

Echocardiographic evaluation of adriamycin cardiotoxicity in children

Thirty children with malignant solid tumors receiving adriamycin had serial evaluation of left ventricular (LV) function by echocardiography. The echocardiographic studies showed a progressive decrease in myocardial contractility as evidenced by changes in several parameters of LV function with increasing cumulative doses of the drug. Using the patients as their own controls, serial echocardiography appears to be a reliable method for detecting early alteration of cardiac function in the asymptomatic patient. This technique may prove useful to prevent cardiomyopathy secondary to adriamycin and to prolong therapy beyond the currently established limits.

Rhmod, a second kindred (Craig)

Three Rhmod siblings were found to have identical Rh: w1, w2, -3, -4, w5 (see article) phenotypes. All had stomatocytic hemolytic anemia. On quantitative hemagglutination studies, as well as on hand tests, all Rh antigens were not equally depressed. Rh17 (Hr0, 'not D') and Rh29 (RH, 'total Rh') were both normal. Rh5 (hr", e) was only slightly depressed. Rh25 (LW) had 50% of the expression expected in normal Rh:-1 cells. Rh1 (Rh0, D), Rh13 (RhA), Rh14 (RhB), Rh15 (RhC), and Rh16 (RhD), were severely depressed. Rh2 (rh', C) was depressed, while Rh7 (rhi, Ce) was absent. Both Rh19 (hrS) and Rh31 (hrB) were depressed. Rh12 (rhG, G) was distinctly depressed, scoring considerably less than rGrG red cells. The unrelated parents, the child of the proposita, and some siblings of each parent showed lessened depression of Rh antigens without displaying the consistent pattern that might be expected from a presumed single suppressor gene. Absence of a consistent pattern may have resulted from differing Rh genotypes, but a frequently observed depression involved Rh14, Rh15, and Rh16 (RhB, RhC, and RhD) without an effect on either Rh1 (RH3 or D) or Rh13 (RhA).

Surface markers and prognostic factors in acute lymphoblastic leukemia

We investigated the surface markers on lymphoblasts from 37 patients with acute lymphoblastic leukemia. Spontaneous rosette formation with sheep erythrocytes (E rosettes) identified T cells and the presence of surface immunoglobulin identified B cells. Eight patients had T-marker lymphoblasts; 28 had no markers (null lymphoblasts), and one patient had B-marker lymphoblasts. The eight patients with T-marker acute lymphoblastic leukemia had massive leukemic infiltration, frequently a mediastinal mass, and a poor prognosis. The T-marker lymphoblasts had a weak or negative periodic acid-Schiff reaction and a very low antigenic stimulation to allogeneic lymphocytes. The association of T-marker lymphoblasts and some of the conventional poor-risk factors appears to be reliable in predicting a poor prognosis.

Synthesis of inducible tyrosine aminotransferase in a cell-free extract from cultured hepatoma cells

A cell-free extract from cultured rat hepatoma cells is described that incorporates amino acids into chains of tyrosine aminotransferase that are identical, by several criteria, with tyrosine aminotransferase from rat liver. Extracts from steroid-induced cells are 6-to 10-times more active for tyrosine aminotransferase synthesis than extracts from uninduced cells, although the total incorporation rates are identical.