Economic analysis of CDC's culture- and smear-based tuberculosis instructions for Filipino immigrants.

SETTING: In 2007, the US Centers for Disease Control and Prevention (CDC) revised its tuberculosis (TB) technical instructions for panel physicians who administer mandatory medical examinations among US-bound immigrants. Many US-bound immigrants come from the Philippines, a high TB prevalence country. OBJECTIVE: To quantify economic and health impacts of smear- vs. culture-based TB screening. DESIGN: Decision tree modeling was used to compare three Filipino screening programs: 1) no screening, 2) smear-based screening, and 3) culture-based screening. The model incorporated pre-departure TB screening results from Filipino panel physicians and CDC databases with post-arrival follow-up outcomes. Costs (2013 $US) were examined from societal, immigrant, US Public Health Department and hospitalization perspectives. RESULTS: With no screening, an annual cohort of 35 722 Filipino immigrants would include an estimated 450 TB patients with 264 hospitalizations, at a societal cost of US$9.90 million. Culture-based vs. smear-based screening would result in fewer imported cases (80.9 vs. 310.5), hospitalizations (19.7 vs. 68.1), and treatment costs (US$1.57 million vs. US$4.28 million). Societal screening costs, including US follow-up, were greater for culture-based screening (US$5.98 million) than for smear-based screening (US$3.38 million). Culture-based screening requirements increased immigrant costs by 61% (US$1.7 million), but reduced costs for the US Public Health Department (22%, US$750 000) and of hospitalization (70%, US$1 020 000). CONCLUSION: Culture-based screening reduced imported TB and US costs among Filipino immigrants.

Biochemical and immunological properties of human terminal deoxynucleotidyl transferase purified from blasts of acute lymphoblastic and chronic myelogenous leukemia.

Terminal deoxynucleotidyl transferase was purified to homogeneity from the blasts of eight patients with leukemia and compared with purified transferase from normal human and calf thymus. In two cases phenylmethanesulfonylfluoride was added during purification to reduce proteolysis. Comparative kinetic analyses of the purified enzymes indicated no differences in catalytic properties. There was substantial variation in the molecular structure of terminal transferase on denaturing polyacrylamide gels: (a) a protein that migrated as a single polypeptide with M(r) = 62,000 was isolated from two patients with acute lymphoblastic leukemia and from MOLT-4 cells; (b) a protein that migrated as a single polypeptide with M(r) = 42,500 was isolated from two patients with acute lymphoblastic leukemia; (c) a protein that migrated as a single polypeptide with M(r) = 42,500 was isolated from two patients with chronic myelogenous leukemia in blast crisis; (d) a protein that migrated as two non-identical subunits of M(r) = 27,000 and 10,000, respectively, was isolated from two additional patients with chronic myelogenous leukemia in blast crisis. The subunit structure of d is characteristic of the homogeneous enzymes purified from human and calf thymus. Neutralizing and precipitating antibodies to terminal transferase from human lymphoblasts and calf thymus have been produced in rabbits and goats. Antisera directed against either human or calf antigens neutralize enzymatic activity and precipitate all forms of human terminal transferase. The multiple human forms give reactions of antigenic identity by immunodiffusion, but differ antigenically from the calf enzyme. The multiple forms of terminal transferase could represent physiological processing, artifactual degradation, or isozymes coded by several genes.

Overproduction of adenine deoxynucleosides and deoxynucletides in adenosine deaminase deficiency with severe combined immunodeficiency disease.

The deoxynucleotide, dATP, is elevated 50- to 1,000-fold above normal in erythrocytes, lymphocytes, and bone marrow from a child with adenosine deaminase deficiency and severe combined immunodeficiency disease. The child, when 17 mo of age, was also excreting approximately 30 mg of deoxyadenosine per day in urine (normal is less than 0.1 mg/day). Urinary excretion of uric acid was decreased. Elevated dATP levels in lymphocytes and bone marrow, and increased urinary excretion of deoxyadenosine, persisted despite hypertransfusion of the child with irradiated erythrocytes from a donor with normal adenosine deaminase. Overproduction of deoxynucleotides by increased salvage of adenosine appears to be the primary metabolic abnormality in patients with adenosine de aminase deficiency.

Biochemical and functional abnormalities in lymphocytes from an adenosine deaminase-deficient patient during enzyme replacement therapy.

Biochemical and immunological properties of lymphocytes were measured repetitively over a period of 40 mo during enzyme replacement by transfusion in a child with adenosine deaminase (ADA) deficiency and severe combined immunodeficiency disease. Catalytically defective ADA protein is present in the child's cells. ADA activity in his lymphocytes is 7 nmol/min per 10(8) cells with 51 ng of ADA protein/10(8) cells by radioimmunoassay. ADA activities in normal cord and adult lymphocytes average 193 and 92 nmol/min per 10(8) cells, respectively, with 429 and 223 ng of ADA protein/10(8) cells. Deoxy(d)ATP accumulates in the patient's erythrocytes and lymphocytes. Transfusion of irradiated packed erythrocytes partially corrects the metabolic defects. Frank metabolic relapse occurs if transfusions are discontinued for several months. The amounts of dATP in erythrocytes and lymphocytes averaged 13 and 2 times normal, respectively, during periods when transfusions were administered every 2-4 wk. Deoxyguanosine triphosphate and deoxycytidine triphosphate in lymphocytes were normal on 11 occasions, but deoxyribosylthymine triphosphate was ninefold increased. On 11 occasions dATP was measured in lymphocytes and erythrocytes isolated simultaneously. There was a positive, but statistically insignificant, correlation between amounts of dATP in the two types of cells (r = 0.25,P > 0.1). The absolute peripheral lymphocyte count was correlated with the activity of ADA in circulating erythrocytes and with the response of lymphocytes to phytohemagglutinin (r = 0.64, P < 0.01; r = 0.49, P < 0.05). Response of lymphocytes to stimulation by phytohemagglutinin in vitro and absolute peripheral lymphocyte counts were not significantly correlated with levels of dATP in the erythrocyte or lymphocyte during periods of intensive therapy. Although there was objective improvement during enzyme replacement, the child remained immunodeficient and biochemically abnormal.

Terminal deoxynucleotidyltransferase distribution in neoplastic and hematopoietic cells.

In the present study, terminal deoxynucleotidyltransferase was examined in the peripheral blood and (or) bone marrow of 115 children with a variety of neoplastic, hematologic, and other unrelated disorders. Terminal deoxynucleotidyltransferase activity was present at 4.08+/-0.74 U/108 cells in 23 morphologicall normal bone marrow samples from childhood controls. Terminal transferase was present at greater than 23 U/108 nucleated cells and at greater than31 U/108 blasts in the bone marrow of all children with acute lymphoblastic leukemia studied at initial diagnosis and at disease relapse. Terminal deoxynucleotidyltransferase was detectable at low levels, less than 7.5 U/108 cells, in all remission marrow smaples. Bone marrow terminal transferase activity was markedly elevated in all untreated acute lymphoblastic leukemia patients, whereas low levels which were difficult to interpret were present in the peripheral blood samples of two patients at diagnosis and six patients at relapse who had low absolute lymphoblast counts. Because of greater variation in the lymphoblast content of peripheral blood, bone marrow assays are more reliable in detecting disease activity. Marrow terminal deoxynucleotidyltransferase values obtained during the active phase of acute lymphoblastic leukemia were significantly greater than those found in other types of leukemia, bone marrow malignancies, and hematologic disorders. Terminal transferase determinations in blast cells of two patients with leukemic conversion of non-Hodgkin's lymphoma and in tumor cells from one patient with Burkitt's lymphoma were within the control range. These dat further define the usefulness of terminal deoxynucleotidyltrnasferase assay in the differentiation and classication of hematologic malignancies.

Induction of spleen cell growth and DNA polymerase activity by Corynebacterium parvum.

Corynebacterium parvum induces rapid proliferation of spleen cells with concomitant rapid increases in DNA synthesis as measured by [3H]thymidine uptake and increase in DNA polymerase activity. Cell number increased exponentially over 10 days. DNA polymerase activity increased 8-fold after C. parvum stimulation. The rapidity of response indicated a population response to the stimulus, and the data are consistent with a direct stimulation of spleen cell proliferation by C. parvum.

Adenosine deaminase and terminal deoxynucleotidyl transferase: biochemical markers in the management of chronic myelogenous leukemia.

Serial determinations of adenosine deaminase (ADA) activity in 69 patients with chronic myelogenous leukemia provided a biochemical marker of disease activity. Eighty-nine % of patients in the accelerated phase had an elevation of ADA activity. This elevation was not a direct reflection of an increased absolute blast count. Furthermore, five of seven patients studied serially from the stable phase into the accelerated phase had an increase in ADA activity before the absolute blast count increased. This is the first investigation which clearly demonstrates the potential value of measuring serial ADA activities in a large number of patients with chronic myelogenous leukemia.

Myeloblastic and lymphoblastic markers in acute undifferentiated leukemia and chronic myelogenous leukemia in blast crisis.

Blast cells were obtained from 17 patients with acute undifferentiated leukemia and 13 patients with chronic myelogenous leukemia in blast crisis. The blasts were tested with anti-i serum in cytotoxicity tests and with antisera to myeloblastic leukemia-associated antigens in immunofluorescence tests. The terminal deoxynucleotidyl transferase (TDT) content of the blasts was also measured. Lymphoblasts react strongly with anti-i, do not react with anti-myeloblast serum, and have high levels of TDT; myeloblasts react weakly with anti-i, do not react with anti-myeloblast serum, and have very low levels of TDT. Of the 17 patients with acute undifferentiated leukemia, there were six with blasts which reacted like lymphoblasts, six with blasts which reacted like myeloblasts, and five with blasts bearing different combinations of these lymphoblastic and myeloblastic markers. Eight of the 11 patients with lymphoblastic or mixed lymphoblastic-myeloblastic markers, but only one of the six with myeloblastic markers, achieved complete or partial remission in response to therapy. Thus, in acute undifferentiated leukemia, classification of blasts with these markers may be of prognostic value. Of the 13 patients with chronic myelogenous leukemia in blast crises, the markers were concordant (for myeloblasts) in only two cases. Three of the 13 patients had TDT-positive blasts, but the reactions of these cells with anti-i and with anti-myeloblast serum differed from those seen with lymphoblasts from patients with acute lymphoblastic leukemia. Although the cell involved in "lymphoid" blast crisis of chronic myelogenous leukemia is similar in many respects to that involved in acute lymphoblastic leukemia, these cells are not identical.

Serial observations on terminal deoxynucleotidyl transferase activity and lymphoblast surface markers in acute lymphoblastic leukemia.

Terminal deoxynucleotidyl transferase activity and cell surface markers were measured in peripheral lymphoid cells from 27 children with acute lymphoblastic leukemia in various phases of their disease. Lymphoblasts from untreated patients had smooth surface ultrastructure but heterogeneous surface receptors. Greater than 60% of lymphoblasts from 4 to 7 untreated patients formed rosettes with sheep red blood cells. Transferase activity was variable, ranging from 8 to 210 units/10(8) blasts, but it was consistently elevated at diagnosis and in relapse. Transferase levels did not correlate with the presence of lymphoblast surface receptors. During induction therapy transferase activity decreased rapidly, but it remained elevated in peripheral lymphoid cells even when blasts were not detectable in peripheral blood smears. Patients in remission had normal surface receptors and undetectable or minimally elevated levels of transferase. Terminal transferase activity may be a sensitive biochemical marker for a primitive cell population and may be important in the evaluation of therapeutic effectiveness in acute lymphoblastic leukemia.

Clinical utility of initial terminal deoxynucleotidyl transferase determinations in childhood acute leukemias.

Terminal deoxynucleotidyl transferase (TDT) activity was measured in bone marrow lymphoblasts obtained at diagnosis from 168 consecutive patients with childhood acute leukemia. Absolute concentrations of TDT were increased (greater than or equal to 20 units/10(8) blasts) in samples from 98 of 112 assessable patients with acute lymphocyte leukemia (ALL). The values ranged from less than 1 to 1502 units/10(8) blasts with a median of 90 units contrasted with less than 1 to 219 units (median, 2.6 units) in studies of children without leukemia. Results of an immunofluorescence assay were in good agreement with enzymatic detection of the polymerase. Among 115 patients with adequate marrow smears, 105 had TDT-positive blasts. By contrast, in most children with acute myelogenous leukemia, TDT activity was either undetectable or less than 10 units/10(8) blasts. Although the highest levels of TDT were found in blasts with the common ALL phenotype, quantitative determinations were not significantly related to the major immunological subtypes of ALL or to morphological features or periodic acid-Schiff reactivity of the lymphoblasts. The probability that a newly diagnosed case of leukemia would be ALL was 90% if TDT levels were greater than 20 units/10(8) blasts. We conclude that absolute concentrations of TDT, as determined in this study, are of little value in identifying subclasses of ALL. The immunofluorescence assay, which is much less expensive and easier to perform than the enzyme assay, should prove useful for confirming the diagnosis of ALL and for detecting extramedullary sites of leukemic infiltration.

State and Local Perspective on Implementation of the Centers for Disease Control and Prevention Dog Confinement Agreement.

The Centers for Disease Control and Prevention (CDC) works in conjunction with state, territorial, local and tribal agencies (STLTAs) to prevent the transmission of infectious agents. Issuance of confinement agreements using CDC Form 75.37 'Notice to Owners and Importers of Dogs' to importers of dogs that are not vaccinated or incompletely vaccinated against rabies is part of the agency's regulatory programme to prevent the entry of dogs infected with rabies. Although this is a regulatory programme that depends heavily on partnerships between CDC and STLTAs, CDC had never formally evaluated the acceptability of the confinement agreement process with these partners. Thus, a short survey of nine STLTAs was conducted to evaluate whether these partners have enough personnel and resources to implement the regulation and their general opinions of the confinement agreement process. The results illustrate that CDC partners are dissatisfied to some extent with the process, and there are multiple issues limiting their success in enforcing the regulation.

Regulation of terminal deoxynucleotidyl transferase gene expression in mice and men.

A nontemplate directed DNA polymerase, terminal deoxynucleotidyl transferase (terminal transferase) is expressed in a tissue-specific and development stage-specific manner. Its enzymatic properties and tissue localization have implicated the protein in development of normal immune function. Significant progress has been made in understanding the enzymology and important domains of this protein. More recently, studies have focused on regulation of the gene that codes for the protein in mice and humans. The murine gene has yielded to these studies more readily than the human gene. A murine basal promoter element has been identified along with several trans-acting protein factors that may regulate gene expression. In the human gene there is no evidence for a basal promoter element. Rather, the promoter exhibits tissue specific properties. The present article reviews recent developments in this field.

Terminal deoxynucleotidyl transferase (TdT) in RadLV-induced C57BL thymomas.

Newborn C57BL mice exposed to RadLV at birth were followed and periodically sampled for thymus and bone marrow TdT activity. Tumors detected at or before 100 days had mostly low TdT levels. Large thymic lymphocytic tumors detected after 100 days had elevated total TdT content per gland. Serial samples showed a changing TdT pattern with time. The mid period shifted from low levels to normal-to-high levels for both TdT content and total TdT per gland. No unusual bone marrow TdT activity change preceded the appearance of thymomas. TdT marks a unique precursor cell highly sensitive to RadLV associated with lymphomagenesis. RadLV induced both TdT+ and TdT- thymic lymphomas and both types were found to occur after lymphoma initiation by injection of RadLV into newborns.

Unusual immunofluorescence patterns for terminal deoxynucleotidyl transferase in blast crisis chronic myelogenous leukemia.

An unusual cytoplasmic distribution of terminal deoxynucleotidyl transferase (TdT) antigen in leukemic cells from two patients who had chronic myelogenous leukemia in blastic phase is described. In most leukemic cells that contain TdT, the intracellular location has been reported to be exclusively nuclear. The cells from these two patients demonstrated TdT staining in both the nucleus and the cytoplasm. The pattern is remarkably similar to that observed in thymocytes, in which bright cytoplasmic staining may also be seen. In the immunofluorescence procedures for detection of TdT in blasts from patients who have chronic myelogenous leukemia, significant cytoplasmic staining should not be mistaken for nonspecific absorption of immunoglobulins or specimen deterioration.

Evaluation of methods of detecting terminal deoxynucleotidyl transferase in human hematologic malignancies. Comparison of immunofluorescence and enzymatic assays.

Terminal transferase (TdT) activity and antigen have been measured in 267 specimens of human bone marrow and peripheral blood by using a biochemical assay for enzymatic activity and an immunofluorescence test for antigen. Oligo p(dA)50 and dGTP were used as reagents in the biochemical assay and either rabbit anti-calf TdT or rabbit anti-human TdT was used as the primary antibody for immunofluorescence. Because both false-positive and false-negative detection of TdT antigen occurs, the biochemical assay of TdT activity is considered the standard against which immunofluorescence assays must be measured. If specimens of cells contained TdT activity, then the immunofluorescence detected antigen in 91% of cases (rabbit anti-calf TdT) and 95% of cases (rabbit anti-human TdT). When no TdT activity was detected, the immunofluorescence test was positive in 7.8% of cases (rabbit anti-calf TdT) and 5.2% of cases (rabbit anti-human TdT). When air-dried slices were shipped by air mail to a distant location before being stained for immunofluorescence, TdT antigen was detected in only 33% of matched pair cases which contained TdT activity. From this study, the authors conclude that with current methodology, immunofluorescence tests for TdT antigen must be carried out on slides prepared in the testing laboratory and that such tests are reliable in more than 90% of cases. However, because a small percentage of results are false positives and false negatives, the authors suggest that if a patient's clinical response is not consistent with the immunofluorescence TdT result, an enzymatic assay for TdT activity be carried out.

Terminal deoxynucleotidyl transferase activity in thymocytes of kittens.

Activity of terminal deoxynucleotidyl transferase (TdT) was measured in the thymus of 8- to 14-week-old kittens. Microscopic evidence of involution or other morphologic changes were not observed in formalin-fixed hematoxylin and eosin-stained thymic tissue sections. Thymic tissue from young kittens (8 weeks old) had low TdT activity, as determined by enzymatic catalysis or immunoassay procedures. Markedly higher TdT activity was measured in thymic tissue of older kittens (13 to 14 weeks old). Feline TdT catalyzed the polymerization of deoxynucleotides at a higher rate in Mn2+ than in Mg2+. Results of protein immunoblotting experiments indicated that the major form of feline thymic TdT is a single, high molecular weight polypeptide in 13- to 14-week-old kittens. Detection of TdT activity in the feline thymus indicated that TdT may have the same diagnostic and therapeutic value in feline oncology as in human oncology.