Complete hematologic remissions induced by 2-chlorodeoxyadenosine in children with newly diagnosed acute myeloid leukemia

The majority of children with acute myeloid leukemia (AML) who are treated exclusively with chemotherapy die of progressive disease. Improvement in outcome will likely require new active drugs capable of eradicating resistant blast cells early in the clinical course. We therefore assessed the cytoreductive potential of 2-chlorodeoxyadenosine (2-CdA), a halogenated purine analogue, in 22 consecutive children with newly diagnosed AML. The drug was administered as a single 120-hour continuous infusion (8.9 mg/m2 of body surface area per day) before the introduction of standard remission induction therapy. Six patients (27%) had complete hematologic remissions by a median of 21 days after treatment with the nucleoside (range, 14 to 33 days). Seven others had partial responses, yielding a total response rate of 59%. The drug also eliminated leukemic cells from cerebrospinal fluid in 4 of the 6 patients tested. Concentrations of 2-CdA in cerebrospinal fluid on day 5 after the initiation of treatment ranged from 12.4% to 38.0% (mean, 22.7%) of the steady-state plasma concentrations. Severe but reversible myelosuppression and thrombocytopenia developed in all patients. Analysis of factors that may have influenced the complete remission rate suggested a better outcome in patients with myeloblastic leukemia (M0-M2 subtypes in the revised French-American-British classification system). These results demonstrate clinically significant activity by 2-CdA against previously untreated AML in children, including leukemic blast cells in the central nervous system. Its use in combination chemotherapy may improve the outlook for patients with this often fatal hematologic cancer.

Ethnic differences in erythrocyte catechol-O-methyltransferase activity in black and white Americans

Catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catecholamine and catechol drugs such as levodopa and methyldopa. Human COMT activity is inherited as an autosomal co-dominant trait; approximately 25% of white individuals have low activity consistent with homozygosity for a low activity allele, about 50% have intermediate activity (i.e., heterozygous genotype) and 25% have high activity. COMT activity has not been characterized in African-Americans or other black populations. To investigate potential ethnic and gender differences in COMT, we measured erythrocyte COMT activity in 195 unrelated black and 202 unrelated white healthy individuals living in the Southeast United States. Overall, the black population had significantly higher COMT activity than the white population (median 15.7 vs. 11.4 U/ml of packed red blood cell volume; P < .001). Maximum likelihood estimation of COMT activity distribution identified significant ethnic differences, with high activity in 23% of whites and 55% of blacks, intermediate activity in 50% of whites and 38% of blacks and low activity in 27% of whites and 7% of blacks. No greater differences in COMT activity were observed in either ethnic group. We conclude that red blood cell COMT activity is significantly higher in black subjects than white subjects. Hardy-Weinberg estimates indicate that this ethnic difference is due to a higher frequency of high activity COMT alleles in blacks vs. whites (0.74 vs. 0.48).

A cell-specific nuclear receptor is essential for adrenal and gonadal development and sexual differentiation

Studies in adrenocortical cells have implicated the orphan nuclear receptor SF-1 in the gene regulation of the steroid hydroxylases. We used targeted disruption of the Ftz-F1 gene, which encodes SF-1, to examine its role in intact mice. Despite normal survival in utero, all Ftz-F1 null animals died by postnatal day 8; these animals lacked adrenal glands and gonads and were severely deficient in corticosterone, supporting adrenocortical insufficiency as the probable cause of death. Male and female Ftz-F1 null mice had female internal genitalia, despite complete gonadal agenesis. These studies establish that the Ftz-F1 gene is essential for sexual differentiation and formation of the primary steroidogenic tissues.

Roles of CCAAT/enhancer-binding protein and its binding site on repression and derepression of acetyl-CoA carboxylase gene

The gene for acetyl-CoA carboxylase, the rate-limiting enzyme in the biosynthesis of long-chain fatty acids, contains two distinct promoter regions, denoted PI and PII, which control the generation of different forms of mRNA. Multiple forms of acetyl-CoA carboxylase (ACC) mRNA with 5'-end heterogeneity are generated as a result of differential splicing of two primary transcripts formed under the control of these two promoters. PI is responsible for the generation of class I mRNAs of ACC, which are induced in a tissue-specific manner under lipogenic conditions. PII generates class II mRNAs of ACC, which are expressed constitutively. Possible mechanisms for the regulation of PI under normal physiological conditions and agents that activate the promoter have been investigated. PI contains a TATA and a CCAAT box. In addition to these sequences, this promoter contains a 28-CA repeat sequence 220 bases upstream from the transcription initiation site; the presence of this sequence leads to about 70% repression of the basal promoter activity. Repression by the 28-CA repeat sequence requires the GCAAT sequence in the CCAAT box. The negative effect of the 28-CA repeat sequence is relieved by a CCAAT/enhancer-binding protein (C/EBP), which binds to the GCAAT sequence. Insertion of the 28-CA repeat sequence into the thymidine kinase promoter results in repression that can also be relieved by the C/EBP gene product. However, the same sequence exerts no effect on ACC promoter II, which has no CCAAT box. During the differentiation of 30A5 preadipocytes into adipocytes, the expression of class I ACC mRNA and C/EBP mRNA is coordinately increased. Therefore, the presence of the CA repeat in the promoter may be responsible for the inactivity of PI, and C/EBP may be one of the factors that is responsible for the activation of PI under lipogenic conditions. Interaction of the CA repeat and the CCAAT box in the repression and derepression of the ACC gene provides a novel function for the CCAAT box and C/EBP in gene regulation.

Role of MB isoforms (isomers) in the early diagnosis of acute myocardial infarction

In addition to electrocardiogram (ECG), analysis of creatinine phosphokinase (CPK), lactate dehydrogenase (LDH) and their isoenzymes is commonly employed to diagnose acute myocardial infarction (AMI). The aim of this study was to observe the efficiency of isomers of CPK for early diagnosis of AMI. ECG, though useful in many ways, is not 100% sensitive. The drawback involved with CPK and LDH isoenzymes is the time lag factor in diagnosing AMI early enough for interventional therapy. Recently the subunits of these isoenzymes, namely MM and now the MB isomers are being tested for their effectiveness in the early diagnosis of AMI. In our experience MB isomers were found to be accurate markers in the early diagnosis of AMI. They were especially valuable in diagnosing myocardial infarction not detectable by ECG in cases such as non-Q AMI, cardiomyopathy, and bundle branch block among other such cases.

[Chemiluminescent immunoassay for anti-granulocyte antibody IgG]

In this paper is reported solid phase competitive chemiluminescent immunoassay (CLIA) for anti-granulocyte antibody (AGAb) IgG with N-(4-amiobytul)-N-ethylisoluminol (ABEI) labelled rabbit antibody IgG against granulocyte competing with the analyte and ABEI-CoCl2-H2O2 as the chemiluminescent system. The absolute limit of detection was 3.0 x 10(-14) mol ABEI/tube. One hundred and thirty one individuals were divided into three groups: leukocytopenic group (n = 58), control group (n = 41) and normal group (n = 32). Chemiluminescent index (CLI) was used as the diagnostic criterion for AGAb in serum. The results showed that the positive rate of the leukocytopenic group was significantly higher than that of the control group (P < 0.005), and the sensitivity, specificity and accuracy of the method were 43.1%, 90.2% and 62.6%, respectively.

Influence of alloferin on neuromuscular function in myasthenia patients undergoing thymectomy

Myasthenia gravis patients are hypersensitive to nondepolarizing relaxants, such as alcuronium, an intermediate-long nondepolarizing agent. This study observed the effects of alcuronium treatment in myasthenia gravis patients as compared with non-MG patients during operation. Ten MG patients (Ossermann class I-IV, scheduled for thymectomy) and 10 non-MG patients (ASA class I-II, scheduled for operation) were selected. An induction dose of alcuronium 0.2 mg/kg and thiopental 4-6 mg/kg was given, followed by intubation and ventilation with 50% nitrous oxide in oxygen and 0.5-1.5% ethrane. Neuromuscular transmission was monitored using an accelerograph and degrees of neuromuscular function at different depths were recorded. There were statistically significant differences between the two groups. The effect of alloferin in the MG group was quicker and deeper. This study also found a relation between MG class and the recovery of respiration: Respiratory recovery was quicker in classes I-II than in classes III-IV.

Characterization of the mouse FTZ-F1 gene, which encodes a key regulator of steroid hydroxylase gene expression

The cytochrome P450 steroid hydroxylases are coordinately regulated by steroidogenic factor 1 (SF-1), a protein expressed selectively in steroidogenic cells. Based on its expression in steroidogenic tissues and DNA-binding specificity, we isolated a putative SF-1 cDNA from an adrenocortical cDNA library. As evidence that this cDNA encodes SF-1, we now show that it is selectively expressed in steroidogenic cells, that an antiserum against its protein product specifically abolishes the SF-1-related gel-shift complex, and that its coexpression increases promoter activity of the 21-hydroxylase 5'-flanking region in transfection experiments. Sequence analyses of the SF-1 cDNA revealed that it is the mouse homolog of fushi tarazu factor I (FTZ-F1), a nuclear receptor that regulates the fushi tarazu homeobox gene in Drosophila. A second FTZ-F1 homolog, embryonal long terminal repeat-binding protein (ELP), was recently isolated from embryonal carcinoma cells. SF-1 and ELP cDNAs are virtually identical for 1017 base pairs, including putative DNA-binding domains, but diverge at their 5'- and 3'-ends. One genomic clone contained both SF-1- and ELP-specific sequences, confirming their origin from a single gene. Characterization of this gene defined shared exons encoding common regions and alternative promoters and 3'-exons leading to differences between the two FTZ-F1 transcripts. We used in situ hybridization with transcript-specific probes to study the ontogeny of SF-1 and ELP expression. ELP transcripts were not detected from embryonic day 8 to adult, consistent with its previous isolation from embryonal carcinoma cells and its postulated role in early embryonic development.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor-cell DNA content predicts outcome in children and adolescents with clinical group III embryonal rhabdomyosarcoma. The Intergroup Rhabdomyosarcoma Study Committee of the Children's Cancer Group and the Pediatric Oncology Group

PURPOSE

The prognostic value of tumor-cell DNA content (ploidy) was evaluated in children with unresectable, nonmetastic rhabdomyosarcoma of embryonal histology.

PATIENTS AND METHODS

Flow-cytometric techniques were used to estimate the ploidy of tumor specimens from 34 patients with embryonal rhabdomyosarcoma who were enrolled in the intergroup rhabdomyosarcoma study III (IRS III) from 1985 to 1991. Tumors were classified as diploid or hyperdiploid (DNA content, 1.1 to 1.8 times that of normal diploid cells). The influence of ploidy on clinical outcome was assessed by the Kaplan-Meier technique and Cox regression analysis with stepwise selection.

RESULTS

Twelve of the tumor specimens were diploid and 22 were hyperdiploid. The patient groups defined by diploid or hyperdiploid tumors had similar presenting characteristics (eg, age, tumor size, and anatomic site). Significantly more children with hyperdiploid tumors achieved a complete response than did children with diploid tumors (85% v 42%; P = .01). The probability of progression-free survival at 5 years (+/- SE) was 91% +/- 6% for the hyperdiploid group, compared with 17% +/- 11% for the diploid group (P < .001). Hyperdiploidy was also associated with a significantly higher overall survival rate at 5 years: 96% +/- 4% versus 50% +/- 14% (P = .004). Ploidy retained its prognostic significance after adjustment for tumor site in the Cox regression model.

CONCLUSION

Tumor-cell ploidy strongly correlates with outcome in children with nonmetastic, unresectable embryonal rhabdomyosarcoma. The two biologically distinct groups identified by this measure would benefit from further refinements in risk-directed therapy.

[Evaluation of pulmonary arterial pressure by pulsed Doppler echocardiography compared with cardiac catheterization]

Twenty-six patients undergoing right cardiac catheterization were examined by pulsed doppler echocardiography (PDE), spectrum analysis of the shape of flow velocity curve of the pulmonary arteria during systole was made. Pulmonary arterial pressure (PAP) was qualitatively and qualitatively evaluated by right ventricular systolic time interval (RSTI) derived from pulmonary doppler blood flow velocity pattern. The correlation between PAP and the values of RSTI was evaluated, multiple stepwise regression analysis was performed. The pulmonary flow pattern and the values of RSTI measured from right ventricular outflow tract (RVOT) and main pulmonary artery (MPA) were compared. The results showed that: 1. Qualitative evaluation of PAP: (1) the triangular configuration of the pulmonary flow pattern was the feature of the pulmonary ejection flow in pulmonary hypertension (PH). (2) AT < 100ms AT/ET < 0.30 and PEP/AT > 1.1 indicated PH (PAMP > or = 2.7 kPa, AT < 100 ms, sensitivity 92.3%, specificity 100%). 2. Quantitative evaluation of PAP: (1) simple regression analysis: AT, AT/PEP especially AT showed a good inverse correlation with PAP, which was improved when a logarithmic function was applied, but not improved by the square root of heart rate. The liner regression equation and the correlation coefficient were: log PASP = -6.3617 AT +2.825 (r = -0.7925, P < 0.001); log PADP = -0.4569 AT +74.182 (r = -0.8513, P < 0.001); log PAMP = -0.0073 AT +2.198 (r = -0.8635, P < 0.001). (2) multiple stepwise regression analysis: the stepwise analysis of six parameters (PEP, ET, AT, AT/ET, AT/PEP, square root of R-R) showed that AT, PEP were the best parameters correlated with PAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum interleukin-2 receptor levels in Hodgkin disease and other solid tumors of childhood

Serum levels of interleukin-2 receptor (IL2R) were determined in children with newly diagnosed Hodgkin disease (n = 68), Wilms tumor (n = 20), osteosarcoma (n = 18), rhabdomyosarcoma (n = 18), or Ewing sarcoma (n = 15). Measurements of soluble IL2R were positively correlated with disease stage in Hodgkin disease but not in other tumors. Very high levels of soluble IL2R (> or = 5000 U/ml) were significantly associated with a poorer treatment outcome in Hodgkin disease (p = 0.006) and retained significance in a multivariate analysis (p = 0.03). The addition of soluble IL2R measurements to existing prognostic models may improve risk assignment in children with Hodgkin disease.

Serum intercellular adhesion molecule-1 in childhood malignancy

Levels of soluble intercellular adhesion molecule-1 (ICAM-1) were measured in serum samples taken at diagnosis from pediatric patients with Hodgkin's disease (n = 69), acute lymphoblastic leukemia (n = 28), Wilms' tumor (n = 20), osteosarcoma (n = 17), rhabdomyosarcoma (n = 18), or Ewing's sarcoma (n = 15). Median levels of serum ICAM-1 were significantly higher in acute lymphoblastic leukemia and Hodgkin's disease than in controls and other malignancies. Levels were positively correlated with disease stage for patients with Hodgkin's disease, Ewing's sarcoma or Wilms' tumor, and with the frequency of relapse in Hodgkin's disease (P = .016). Serum levels were normal in all of 76 patients tested in remission. It remains to be determined whether increased serum ICAM-1 levels simply reflect a greater tumor burden or whether this molecule contributes directly to the progression of childhood malignancies.

Characterization of the mouse FTZ-F1 gene, which encodes a key regulator of steroid hydroxylase gene expression

The cytochrome P450 steroid hydroxylases are coordinately regulated by steroidogenic factor 1 (SF-1), a protein expressed selectively in steroidogenic cells. Based on its expression in steroidogenic tissues and DNA-binding specificity, we isolated a putative SF-1 cDNA from an adrenocortical cDNA library. As evidence that this cDNA encodes SF-1, we now show that it is selectively expressed in steroidogenic cells, that an antiserum against its protein product specifically abolishes the SF-1-related gel-shift complex, and that its coexpression increases promoter activity of the 21-hydroxylase 5'-flanking region in transfection experiments. Sequence analyses of the SF-1 cDNA revealed that it is the mouse homolog of fushi tarazu factor I (FTZ-F1), a nuclear receptor that regulates the fushi tarazu homeobox gene in Drosophila. A second FTZ-F1 homolog, embryonal long terminal repeat-binding protein (ELP), was recently isolated from embryonal carcinoma cells. SF-1 and ELP cDNAs are virtually identical for 1017 base pairs, including putative DNA-binding domains, but diverge at their 5'- and 3'-ends. One genomic clone contained both SF-1- and ELP-specific sequences, confirming their origin from a single gene. Characterization of this gene defined shared exons encoding common regions and alternative promoters and 3'-exons leading to differences between the two FTZ-F1 transcripts. We used in situ hybridization with transcript-specific probes to study the ontogeny of SF-1 and ELP expression. ELP transcripts were not detected from embryonic day 8 to adult, consistent with its previous isolation from embryonal carcinoma cells and its postulated role in early embryonic development.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin D deficiency suppresses cell-mediated immunity in vivo

Severe vitamin D deficiency has been produced in mice as evidenced by severe hypocalcemia and an absence of 25-hydroxyvitamin D in blood. Vitamin D deficiency was accompanied by a slight decrease in body weight and food consumption. Vitamin D-deficient and vitamin D-sufficient mice were sensitized with dinitrofluorobenzene (DNFB). Sensitivity to DNFB was determined by treatment of one ear with DNFB. The ratio of thickness of the treated ear to that of nontreated ear was used as an index of cell-mediated immune reaction. The incorporation of [3H]thymidine into the DNA of the ear was also used as an index of cell-mediated immunity as was the response of thymus lymphocytes to concanavalin A. Vitamin D deficiency markedly decreased the ear thickness ratio and the [3H]thymidine incorporation ratio in DNFB-sensitized mice. Similarly, the incorporation of [3H]thymidine into the DNA of concanavalin A-treated thymus lymphocytes from DNFB-sensitive mice was significantly reduced in vitamin D deficiency. These results show that in vivo vitamin D deficiency impairs cell-mediated immunity. The provision of a vitamin D-sufficient diet for 8 weeks corrected the impaired response of the immune system, while vitamin D administration for 3 weeks did not.

Study on initiation of human lung carcinogenesis

Cigarette smoking condensate and diethylnitrosamine can initiate human lung carcinogenesis as they are able to induce precancerous lesions of bronchioles and the transforming ability of human fetal lung (HFL) DNA. The induction of precancerous lesions in HFL and the acquirement of the transforming ability of HFL DNA by short-term exposure to carcinogens can be combined to yield an ideal model for the initiation of human lung carcinogenesis.

Production of a bifunctional hybrid molecule B72.3/metallothionein-1 by protein engineering

A hybrid anti-tumour B72.3 antibody/metallothionein protein B72.3MT-1 was produced by the construction of the expression vector mpSV2neo-EP1-B72.3MT-1. This vector contained the neo gene as a selection marker, the murine immunoglobulin promoter and enhancer, and the hybrid B72.3 heavy chain gene fragment with mouse metallothionein-1 cDNA gene ligated into its CH2 domain. The expression vector was transfected to the heavy chain loss mutant B72.3Mut(K) cell line. The hybrid protein B72.3MT-1 was purified from transfectant supernates using a Protein G column. We showed that the hybrid protein retained the binding reactivity for the TAG72 antigen as the original B72.3 antibody, and the metal-binding capacity of the native metallothionein molecule. Therefore, the bifunctional hybrid protein B72.3MT-1 may be very useful in cancer imaging when labelled with radionuclides such as 99mTc.

Recombinant bifunctional molecule FV/IFN-gamma possesses the anti-tumor FV as well as the gamma interferon activities

Recombinant DNA techniques were used to clone, construct and express the bifunctional molecule FV/IFN-gamma. The FV/IFN-gamma is a single-chain 42KD fusion protein expressed in E. coli under control of the strong T7 bacteriophage promoter in the expression vector pT7-7-FV-IFN-gamma. The fused gene fragment FV-IFN-gamma containing a single-chain anti-TAG72 FV gene fragment as well as the human recombinant cDNA fragment of IFN-gamma molecule. The renatured soluble form of FV/IFN-gamma was purified from E. coli inclusion bodies using HTPT chromatography. The yield of this fusion protein was estimated at 10mg/L. Our data showed that the FV/IFN-gamma molecule retained the TAG72 antigen-binding specificity and the IFN-gamma activity as measured in ELISA, Western blotting and up-regulation of CEA expression by IFN-gamma. Therefore, it may prove to be useful in targeting the biological effect of IFN-gamma to tumor cells and stimulating its immune destruction.

The tyrosine residue at position 97 in the VH CDR3 region of a mouse/human chimeric anti-colorectal carcinoma antibody contributes hydrogen bonding to the TAG72 antigen

One amino acid, tyrosine at position 96 and 97 in the VH CDR3 region of a mouse/human chimeric anti-TAG72 antibody cB72.3m4 was substituted by the phenylalanine residue and by a number of amino acids from different amino acid groups by the site-directed mutagenesis technique. The expression vector mpSV2neo-EP1-Vm11-16C1 containing mutant VH region fragments (Vm11-16) as well as the immunoglobulin enhances (E), promoter (P1) and the human genomic C1 region fragments, were transfected into a heavy-chain-loss mutant cell line B72.3Mut(K), respectively. Mutant chimeric cB72.3m11-16 antibodies were purified from the transfectant supernates and compared based upon their binding affinity for the TAG72 antigen relative to that of the original cB72.3m4 antibody. The data showed that a single amino acid substitution of tyrosine by phenylalanine and a number of amino acids including serine, asparagine, histidine and arginine at position 97 in the VH CDR3 region all resulted in approximate 18-fold lower binding affinity, whereas the substitution of tyrosine by phenylalanine at position 96 in the VH CDR3 region did not affect the binding affinity of the cB72.3m4 antibody. This suggests that the tyrosine residue at position 97 in the VH CDR3 region is in a contact position in the B72.3/TAG72 antibody/antigen interaction, and that the terminal hydroxyl group of the position 97 tyrosine side-chain contributes hydrogen bonding to the TAG72 antigen, whereas the position 96 tyrosine side-chain does not.

[A survey of T-2 toxin in wheat by an indirect enzyme-linked immunosorbent assay]

The survey of T-2 toxin in wheat randomly sampled in nine provinces was carried out, employing an indirect competitive enzyme-linked immunosorbent assay. Among 330 samples, 264 samples (80%) showed positive results. The mean concentrations was 53.3 ppb. and maximal concentration was 1122.0 ppb. It was also detected high concentration (84.5-1064.4) of T-2 toxin in human intoxication wheat samples in 1991. The investigation also showed that there existed close relationship between the level of T-2 toxin contamination and the epidemic of wheat scabby.