Combining surgery with 125I brachytherapy for recurrent mediastinal dedifferentiated liposarcoma: A case report and review of literature

BACKGROUND

Dedifferentiated liposarcoma in the mediastinum is an extremely rare malignant neoplasm. A few previous case reports indicate that surgical resection is the major treatment, but frequent recurrence occurs locally. Due to its rarity, its clinical characteristics, optimal treatment and clinical outcomes remain unclear. Here, we report a case of multifocal recurrent dedifferentiated liposarcoma in the posterior mediastinum treated by combining surgery with ¹²⁵I brachytherapy, and summarize its clinical features, treatment and prognosis.

CASE SUMMARY

A 75-year-old man was admitted to our hospital with a history of gradual dysphagia for one year and aggravated dysphagia for 3 mo. Contrast-enhanced computed tomography (CT) revealed several large cystic-solid masses with lipomatous density, and calcification in the posterior-inferior mediastinum. The patient received a wide excision by video-assisted thoracoscopic surgery. Pathological analysis confirmed the tumors were dedifferentiated liposarcomas. The tumor locally relapsed 24 mo later, and another operation was performed by video-assisted thoracoscopic surgery. Fifteen months after the second surgery, the tumor recurred again, and the patient received CT-guided radioactive seeds ¹²⁵I implantation. After 8 mo, follow-up chest CT showed an enlarged tumor. Finally, his condition exacerbated with severe dysphagia and dyspnea, and he died of respiratory failure in July 2018.

CONCLUSION

We reviewed the literature, and suggest that surgical resection provides beneficial effects for dedifferentiated liposarcoma in the mediastinum, even in cases with local recurrence. ¹²⁵I brachytherapy may be beneficial for recurrent unresectable patients.

GABA and 5-HT Systems Are Involved in the Anxiolytic Effect of Gan-Mai-Da-Zao Decoction

The Gan-Mai-Da-Zao (GMDZ) decoction is one of the most famous Chinese medicine prescriptions to treat emotional diseases in China. Here we examined the anxiolytic-like effects of the GMDZ decoction in mice. The mice were orally administered with GMDZ decoction (1, 2, and 4 g/kg, respectively) for 7 days, diazepam (2 mg/kg, p.o.) and buspirone (5 mg/kg, p.o.) were used as positive controls. Then, elevated plus maze (EPM) test, light/dark box (LDB) test, and marble burying (MB) test, open field (OF) test and rota-rod test were performed. We found that GMDZ treatment (2 and 4 g/kg) significantly increased the percentage of open arm entries and time spent on the open arms in EPM as compared to the control. GMDZ treatment also significantly increased the time spent in the light box and the number of light box entries in LDB and reduced the number of marbles buried in MB. Similarly to those observed with diazepam and buspirone. In contrast, GMDZ did not affect the locomotor activity in the OF and motor coordination in the rota-rod test. Furthermore, the anxiolytic-like effects induced by GMDZ were inhibited by the γ-aminobutyric acid-A (GABA_A) receptor antagonist flumazenil and 5-hydroxytryptamine-1A (5-HT_1A) receptor antagonist WAY-100635. These results showed that GMDZ possesses anxiolytic-like effects in animal models, and its mechanism of action might be modulated by 5-HT_1A and GABA_A receptors.

[Long-term results of multicenter study based on childhood acute lymphoblastic leukemia 2005 protocol]

Objective: To evaluate the long-term efficacy and prognostic factors of childhood acute lymphoblastic leukemia (ALL) enrolled in Shanghai Children's Medical Center-Acute Lymphoblastic Leukemia-2005(SCMC-ALL-2005) multicenter study. Methods: Between May 2005 and December 2014, 1 497 newly diagnosed ALL patients were enrolled and treated in 5 hospitals of SCMC-ALL-2005 study group, using risk-stratified SCMC-ALL-2005 protocol. Risk group classification and treatment intensity were based on clinical features, genetic abnormalities, early response to treatment and levels of minimal residual disease (MRD). Kaplan-Meier method was used to generate overall survival (OS) and event-free survival(EFS) curves. Cox proportional hazards models were used for multivariate analyses. Results: The patients were followed up to December 31, 2016, the median follow-up time was 69 months (24-141 months). The 5-year and 10-year OS rates were (80.0±1.0)% and (76.0±2.0)%. The 5-year and 10-year EFS rates were (69.0±1.0)% and (66.0±2.0)%. The 5-year and 10-year relapse rates were (23.0±1.0)% and (25.0±2.0)%. The 5-year OS and EFS for low risk (LR), intermediate risk (IR) and high risk (HR) were (91.1±1.4)% and (83.3±1.8)%, (79.2±1.5)% and (68.9±1.7)%, (52.9±4.4)% and (30.0±3.8)%, respectively. MRD negative status (<0.01%) on day 55 was seen in 792 patients (82.8%) and positive MRD on day 55 was associated with poor prognosis (OR=1.9, 95%CI: 1.3-2.7, P=0.001). Twenty-four HR patients received allogeneic hematopoietic stem cell transplantation and 17(70.8%) of them were alive and in remission. A total of 164 severe adverse events occurred, 46 of them died, treatment-related mortality was 3.1%. Conclusions: In this large sample research, the overall outcome for multi-center SCMC-ALL-2005 study was favorable. This helps to promote the standardized treatment of childhood ALL to the whole country. MRD results on day 55 of induction therapy have important prognostic and therapeutic implications.

[Changes of insulin-like growth factor 1 axis in chronic kidney disease and its role in skeletal muscle atrophy]

Objective: To investigate the changes of insulin-like growth factor 1 (IGF-1) axis in chronic kidney disease (CKD) and its role in skeletal muscle atrophy. Methods: A total of 240 patients with CKD stage 1-5 (without dialysis treatment) were included between August 2016 and February 2017. Serum IGF-1 and IGF-1 binding protein-3 (IGFBP-3) were measured using chemiluminescence, and the influencing factors of serum IGF-1 and IGFBP-3 were analyzed. Besides, male Sprague-Dawley rats (200-250 g) were randomly assigned to the sham-operated control group (Control, n=15) and the 5/6 nephrectomy group (n=15) as CKD animal model. The expressions of local IGF-1 and IGF-1 receptor (IGF-1R) of skeletal muscles were evaluated at the level of transcription and protein by real-time PCR and Western blotting. Results: There was no significant correlation between changes of serum IGF-1 level and estimated glomerular filtration rate (eGFR) (r=-0.066, P=0.307). However, after multivariable adjustment, serum IGFBP-3 increased with decreasing of eGFR (r=-0.181, P=0.005) in adult CKD patients. In multivariate analysis, age, eGFR, serum cholesterol level and 24 h urinary protein quantification were independent factors of serum IGFBP-3 in patients with CKD (R²=0.243, P<0.001). Animal experiments showed that the expression of IGF-1 mRNA and protein decreased in skeletal muscles of CKD rats. Expressions of IGF-1R mRNA and protein were slightly reduced and phosphorylation of IGF-1R was severely impaired in skeletal muscles of CKD rats. Conclusions: IGF-1 levels seem to be independent of renal function, but IGFBP-3 levels increased with decreasing of eGFR, which may cause a low affinity of IGF-1 with IGF-1R in skeletal muscles. Low affinity of IGF-1 with IGF-1R, as well as the decreasing of IGF-1 synthesis could lead to disorders of IGF-1R phosphorylation, and thus cause atrophy of skeletal muscles.

Endostar combined with chemotherapy compared with chemotherapy alone in the treatment of nonsmall lung carcinoma: A meta-analysis based on Chinese patients

INTRODUCTION

Lung cancer is the leading cause of cancer-associated death world-wide. And the lung cancer is generally divided into small cell lung carcinoma and non-small cell lung cancer. For advanced NSCLC, the chemotherapy and target therapy were the important treatment modality. This meta-analysis was to evaluate the clinical efficacy and toxicity between endostar combined chemotherapy and chemotherapy alone in Chinese patients.

MATERIALS AND METHODS

We searched the PubMed, EMBASE, and CNKI databases to find the potential relevant articles reporting the endostar combined with chemotherapy regimen in the treatment of nonsmall cell lung cancer in Chinese patients. The tumor response and toxicity difference between the two groups were demonstrated by odds ratio (OR) and its 95% confidence interval (95% CI). All the data was pooled by Stata 11.0 (http://www.stata.com; Stata Corporation, College Station, TX) software.

RESULTS

We included 14 studies published in Chinese or English studies. The pooled results showed adding endostar in the chemotherapy regimen can significant increase the objective response rate (OR = 2.42, 95% CI = 1.87-3.12, P = 0.00) and disease control rate (OR = 2.22, 95% CI = 1.68-2.94, P = 0.00). For toxicities, the pooled data showed no statistical difference for grade III-IV granulocytopenia risk (OR = 1.04, 95% CI = 0.74-1.44, P = 0.83). Nausea and vomiting (OR = 0.93 95% CI: 0.51-1.52, P = 0.78) and grade III-IV alopecia (OR = 0.99, 95% CI: 0.76-1.29, P = 0.95). The funnel plot showed no statistical publications.

CONCLUSION

Combined treatment with endostar can improve the response rate for NSCLC patients without increasing the risk of developing severe adverse event.

[Study on effect of astragali radix polysaccharides in improving learning and memory functions in aged rats and its mechanism]

To observe the effect of Astragali Radix polysaccharides (APS) on the learning and memory functions of aged rats, in order to explore its mechanism for improving the learning and memory functions. Natural aging female SD rats were selected in the animal model and randomly divided into the control group, the APS low-dose group (50 mg x kg(-1)), the APS high-dose group (150 mg x kg(-1)) and the piracetam-treated group (560 mg x kg(-1)). They were orally administered with the corresponding drugs for consecutively 60 days. Besides, a young control group was set. The learning and memory functions of the rats were tested by the open-field test and the Morris water maze task. The Western-blot method was used to observe the levels of relevant neural plasticity protein N-methyl-D-aspartate receptor (NMDA receptor) in hippocampus, calcium/calmodulin dependent protein kinase II (CaMK II), protein kinase (PKA), the phosphorylation level of CAMP response element binding protein (CREB) and the protein expression of brain derived neurotrophic factor(BDNF). In this study, the authors found that the learning and memory functions and the hippocampus neural plasticity protein expression of the aged rat group were much lower than that of the young control group (P < 0.01). Compared with the aged rat group, the APS group showed the significant improvement in the impaired learning and memory functions of aged rats and the up-regulation in the hippocampus neural plasticity protein expression. The results showed that APS may improve the learning and memory functions of aged rats by increasing the expressions of relevant neural plasticity proteins.

Detection of marginal leakage of Class V restorations in vitro by micro-computed tomography

This in vitro study evaluated the efficacy of micro-computed tomography (CT) in marginal leakage detection of Class V restorations. Standardized Class V preparations with cervical margins in dentin and occlusal margins in enamel were made in 20 extracted human molars and restored with dental bonding agents and resin composite. All teeth were then immersed in 50% ammoniacal silver nitrate solution for 12 hours, followed by a developing solution for eight hours. Each restoration was scanned by micro-CT, the depth of marginal silver leakage in the central scanning section was measured, and the three-dimensional images of the silver leakage around each restoration were reconstructed. Afterward, all restorations were cut through the center and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by the micro-CT and the microscope were compared for equivalency. The silver leakage depth in cervical walls observed by micro-CT and microscope showed no significant difference; however, in certain cases the judgment of leakage depth in the occlusal wall in micro-CT image was affected by adjacent enamel structure, providing less leakage depth than was observed with the microscope (p<0.01). Micro-CT displayed the three-dimensional image of the leakage around the Class V restorations with clear borders only in the dentin region. It can be concluded that micro-CT can detect nondestructively the leakage around a resin composite restoration in two and three dimensions, with accuracy comparable to that of the conventional microscope method in the dentin region but with inferior accuracy in the enamel region.

[Feasibility of thoracoscopic pulmonary metastasectomy]

BACKGROUND & OBJECTIVE

With the developments in endoscopic surgery and the advances of radiological techniques, thoracoscopic pulmonary metastasectomy has been used more and more widely. This study was to evaluate the feasibility of thoracoscopic resection of pulmonary metastases.

METHODS

The clinical data of 17 patients who underwent thoracoscopic pulmonary metastasectomy were retrospectively analyzed.

RESULTS

All pulmonary metastases in the 17 patients were peripherally located and encountered during follow-up after treatment of primary disease. Metastases at other sites were excluded. Among the 17 cases of metastases, 10 were solitary metastasis, 4 were unilateral multiple metastases, 3 were bilateral metastases. All patients underwent thoracoscopic wedge resection. No major complications, operative mortality, and port site metastasis presented. Postoperative locoregional relapse occurred in 5 patients, in which 4 patients had multiple metastases, the rest 1 patient with soft tissue sarcoma underwent a second thoracoscopic resection of recurrent pulmonary lesion. The 1-, 3-, and 5-year survival rates were 77.3%, 53.1%, and 34.8%, respectively.

CONCLUSIONS

Thoracoscopic resection is feasible and effective for patients with a solitary pulmonary metastasis, especially when the lesion is smaller than 3 cm and peripherally located. Bilateral pulmonary metastases may also be resected by primary thoracoscopic operation.

[Predicting efficacy of neoadjuvant cheomotherapy on resectable stage IIIA non-small cell lung cancer by multi-gene expressions]

BACKGROUND & OBJECTIVE

Neoadjuvant chemotherapy for stage IIIA non-small cell lung cancer (NSCLC) remains controversial. The role of the expressions of P53, K-ras, HER2, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), CD44, and matrix metalloproteinase-9 (MMP-9) in predicting efficacy of neoadjuvant chemotherapy on stage IIIA NSCLC is still unclear although they have been found to be related to prognosis. This study was to determine the predictive effect of multi-gene expression on treatment outcome of neoadjuvant chemotherapy for resectable stage IIIA NSCLC.

METHODS

Expressions of p53, K-ras, HER2, VEGF, EGFR, CD44, MMP-9 in the patients enrolled in the prospective randomized controlled trial were detected by immunohistochemistry. The treatment efficacies of combination (neoadjuvant chemotherapy combined with surgery) group (36 patients) and surgery alone group (32 patients) were compared.

RESULTS

The high gene expression rate was 58.3% in combination group, and 40.6% in surgery alone group(P=0.145). In combination group, no significant difference of disease-free survival rate (P=0.903) and survival time (P=0.238) was found between patients with histopathologic regression and patients without histopathologic regression; high gene expression had no correlation with pathologic regression (P= 0.862); the mean disease-free survival time was significantly lower in high gene expression subgroup than in low gene expression subgroup [(14.1+/-9.8) months vs. (27.2+/-13.6) months, P=0.032]; the 2-year disease-free survival rate was 38.1% in high gene expression subgroup, and 46.7% in low gene expression subgroup (P=0.607).

CONCLUSIONS

Pathologic regression after neoadjuvant chemotherapy has no correlation with disease-free survival rate and survial time. The high gene expression maybe indicate high risk of postoperative metastasis; the necessity of postoperative chemotherapy needs further study.

[Treatment of non-small-cell lung cancer with paraplatin given by two different dosage calculation methods]

OBJECTIVE

To study the reasonable dosage for paraplatin according to different dosage calculations.

METHODS

A prospective, randomized, single-blinded study on 54 patients with advanced non-small-cell lung cancer (NSCLC) treated with paraplatin was conducted. Patients were divided to 2 groups. In group A, paraplatin dosage was calculated according to patients' body surface, and in group B, it was calculated according to the area under the curve (AUS). Hematological toxicity, response rate and survival rate in the two groups of patients were compared.

RESULTS

Neutropenia in group A and group B was seen in 77.8% and 37.0% (P < 0.05), and thrombocytopenia in 18.5% and 3.7% (P > 0.05) of patients, respectively. Hemoglobin decrease was seen in 48.2% of patients in both groups. The average quantity of paraplatin given in one cycle of treatment was 535.93 +/- 106.71 mg and 398.52 +/- 71.72 mg (P < 0.01) respectively. The average time interval between treatment cycles was 27.04 +/- 5.30 d and 22.85 +/- 2.80 d (P < 0.05). The response rate and survival rate of patients in group A and B were 22.2% versus 48.2% (P < 0.05), and 40.7% versus 44.4% (P > 0.05) respectively, but the median survival time was identical (12 months) in the two groups.

CONCLUSION

NSCLC patients given paraplatin with dosages calculated on the basis of AUC have higher response rate and less severe hematological toxicity than those given paraplatin with dosages on the basis of body surface. However, the median survival time and survival rate have no statistical differences between the two groups of patients.

[ARHI mRNA and protein expression in pancreatic cancers]

OBJECTIVE

To investigate ARHI mRNA and protein expression in pancreatic cancers.

METHODS

Fifty-seven paraffin-embedded resected cancer samples and patient-corresponding normal pancreatic tissues were determined by using immunohistochemistry staining and in situ hybridization method.

RESULTS

The positive rate of ARHI mRNA and protein expression in normal control pancreatic tissue was 84.2% and 82.5% respectively, and in cancer group was 52.6% both. The positive rate of mRNA and protein expression in cancer group was markedly decreased (P < 0.01). Yet the protein expression correlated with mRNA. Furthermore, positive staining of ARHI protein and mRNA can be observed in duodenal mucus epithelium, fibroblasts, smooth muscle myocytes, and wall of blood vessels. There was no correlation between positive rate and cancer differentiation, or clinical stages.

CONCLUSIONS

ARHI protein expression is down-regulated in pancreatic cancer, possibly plays a role as tumor suppress gene, ARHI protein expressed in multiple types of tissues including duodenal mucus epithelium, fibroblasts and so on.

Transplacental chemical exposure and risk of infant leukemia with MLL gene fusion

Infant acute leukemia (IAL) frequently involves breakage and recombination of the MLL gene with one of several potential partner genes. These gene fusions arise in utero and are similar to those found in leukemias secondary to chemotherapy with inhibitors of topoisomerase II (topo-II). This has led to the hypothesis that in utero exposures to chemicals may cause IAL via an effect on topo-II. We report a pilot case-control study of IAL across different countries and ethnic groups. Cases (n = 136) were population-based in most centers. Controls (n = 266) were selected from inpatients and outpatients at hospitals serving the same populations. MLL rearrangement status was derived by Southern blot analysis, and maternal exposure data were obtained by interviews using a structured questionnaire. Apart from the use of cigarettes and alcohol, very few mothers reported exposure to known topo-II inhibitors. Significant case-control differences were apparent for ingestion of several groups of drugs, including herbal medicines and drugs classified as "DNA-damaging," and for exposure to pesticides with the last two being largely attributable, respectively, to one nonsteroidal anti-inflammatory drug, dipyrone, and mosquitocidals (including Baygon). Elevated odds ratios were observed for MLL+ve (but not MLL-ve) leukemias (2.31 for DNA-damaging drugs, P = 0.03; 5.84 for dipyrone, P = 0.001; and 9.68 for mosquitocidals, P = 0.003). Although it is unclear at present whether these particular exposures operate via an effect on topo-II, the data suggest that specific chemical exposures of the fetus during pregnancy may cause MLL gene fusions. Given the widespread use of dipyrone, Baygon, and other carbamate-based insecticides in certain settings, confirmation of these apparent associations is urgently required.

EEN encodes for a member of a new family of proteins containing an Src homology 3 domain and is the third gene located on chromosome 19p13 that fuses to MLL in human leukemia

The MLL gene, the closest human homologue to the Drosophila trithorax gene, undergoes chromosomal translocation with a large number of different partner genes in both acute lymphoid and acute myeloid leukemias. We have identified a new partner gene, EEN, fused to MLL in a case of acute myeloid leukemia. The gene is located on chromosome 19p13, where two other MLL partner genes, ENL and ELL/MEN have also been identified. The deduced protein of 368 aa contains a central alpha-helical region and a C-terminal Src homology 3 (SH3) domain most similar to the C-terminal SH3 domain found in the Grb2/Sem-5/Drk family of genes. Sequence analysis of the fusion MLL/EEN transcript in our patient reveals that exon 6 of MLL is fused to the N-terminal end of EEN, a fusion that would create a chimeric protein that includes the major functional domain of EEN. EEN is expressed in a variety of tissue types and encodes a protein of approximately 46 kDa. The EEN protein is the human homologue of a member of a recently described murine SH3 domain-containing protein family. It is also highly related to a putative gene identified in Caenorhabditis elegans, and a number of similar sequences are present in the EST databases of several species.

MLL self fusion mediated by Alu repeat homologous recombination and prognosis of AML-M4/M5 subtypes

Fifty-six patients with de novo acute myeloid leukemia M4/M5 subtypes were studied for rearrangements of the mixed lineage leukemia gene, MLL (also called HRX, Htrx-1, or ALL-1). Ten patients (18%) showed rearrangements of the MLL gene, 9 in a major breakpoint cluster region within a centromeric 8.3-kb BamHI fragment, whereas rearrangement in one patient was the result of a direct tandem duplication of exons 2-6 of MLL. Analysis of sequences at the duplication junction revealed that the points of MLL fusion within introns 6 and 1 both lie within Alu elements. This suggests the involvement of Alu repeat mediated homologous recombination in MLL self fusion. For the 10 rearranged samples, cytogenetics analysis revealed a normal karyotype in 3, and 3 had abnormalities other than 11q23. Survival analysis of patients revealed no difference between those with rearrangement of MLL and those showing the germ-line configuration.

The influence of the extent of target organs on sensitivities of methods for screening rodent carcinogens

Two hundred and thirty-three rodent carcinogens from the Carcinogenic Potency Database (CPDB) were analyzed with CASE (Computer Automated Structure Evaluation), and a comparison of the extents of target organs with the sensitivities for long-term carcinogenic bioassays in rats and mice, Salmonella assay (Sty), electrophilic substructure alert analysis (ESAA) and CASE was made. The carcinogenicity of 233 chemicals was evaluated in both rat and mouse bioassays. The present study showed that the sensitivities of the five methods for screening carcinogens were related to the extents of target organs of carcinogens. Among the carcinogens that did not induce tumors (extent = 0) in rats, the sensitivities of Sty and ESAA were 46 and 53, respectively. Among the carcinogens which induced tumors at a single organ (extent = 1) in rats, the sensitivities were 57 and 64 respectively; and 71 and 80 at multiple organs (extent > 1) respectively. The sensitivities of CASE were 76, 82, and 89 respectively at these three different extents. Similar results were obtained with these carcinogens in mice. The results indicate that mutagenic or electrophilic carcinogens are more likely to induce tumors at multiple target organs; in contrast, most carcinogens which induced tumors at only a single target organ in one species are rarely mutagenic or electrophilic. The sensitivities of Sty and ESAA were lower than that of the CASE method in these carcinogens. CASE analyzed chemical structures of many carcinogens and non-carcinogens and then established a database of key fragments, and its parameters are not only based on mutagenicity or electrophilicity of chemicals, and this resulted in a more exact detection of the carcinogenicity of chemicals with the CASE method.

RT/PCR detection of SIL-TAL-1 fusion mRNA in Chinese T-cell acute lymphoblastic leukemia (T-ALL)

The TAL-1 gene is located on chromosome 1p32. In about 20% of T-cell acute lymphoblastic leukemias (T-ALL), this gene is disrupted in its 5' portion by a site-specific 100-kg deletion and is fused with the 5' part of the SIL gene, to form SIL-TAL-1 chimeric gene. In this study, we established a "nested" retrotranscriptase/polymerase chain reaction (RT/PCR) technique which allows detection of the SIL-TAL-1 transcriptional expression. A chimeric mRNA was observed in four of 17 T-ALL cases and has been shown to result from the fusion between the exon 1 of SIL and exon 3 of TAL. A sensitivity test showed that this RT/PCR procedure could detect one leukemic cell among 10(6) normal cells. A positive RT/PCR result was obtained in two cases during clinical remission, suggesting the presence of minimal residual disease (MRD). One patient developed clinical relapse 3 months after PCR positivity. Moreover, analysis of the Tald rearrangement by DNA-based PCR in four patients with SIL-TAL-1 fusion revealed the type A (Tald1) rearrangement in all cases. Sequence analysis demonstrated the presence of N region and non-random "P" nucleotide, as well as base deletions at the genomic SIL-TAL-1 joining site. These data indicate that detection of TAL-1 gene abnormality is important for diagnosis and monitoring of MRD in a subset of T-ALL.

Gamma and delta chain gene rearrangement of T cell receptor in acute lymphoblastic leukemia

The immunophenotype, rearrangements of T cell receptor (TCR) gamma and delta chain genes as well as the immunoglobulin heavy chain (IgH) gene were studied in 37 cases of morphologically defined acute lymphoblastic leukemia (ALL). According to the expression of differentiation antigens, 8 cases were classified as T-ALL, 26 B lineage ALL, 2 acute undifferentiated leukemia (AUL) and myeloid phenotype. An order of TCR gene rearrangements was observed in T-ALL, with the rearrangement of delta gene preceding that of gamma gene. Both genes were also found frequently rearranged and/or deleted in high proportions of the ALL of B cell lineage. However, the patterns of gene rearrangements were somewhat different between the T and B lineage ALLs. In contrast, the IgH gene rearrangements were observed only in the B lineage ALL. The immunogenotype analysis of ALL proved to be a useful marker of the clonality and provided us with important information on early human lymphoid differentiation. We conclude that the determination of TCR gamma gene V-J junctional sequence can be used as clonal marker for detecting the minimal residual disease during clinical remission.

Site-specific methylation inhibits transcriptional activity of platelet-derived growth factor A-chain promoter

Expression of the platelet-derived growth factor (PDGF) A-chain gene is temporally and spatially restricted in development and highly regulated in selected normal and tumor cell lines. Because DNA methylation appears to be important in regulating tissue specific gene expression, we tested the influence of in vitro methylation of the human PDGF A-chain promotor on its activity in vivo in transient transfection assays. We now report that PDGF A-chain promoter activity is strongly repressed by DNA methylation in a DNA sequence-specific manner and that the repression of promoter activity by methylation requires a methyl CpG-binding protein(s). We also report that incubation of HeLa cells with 5-azacytidine sharply increases levels of endogenous PDGF A-chain gene transcripts. These results indicate that the promoter activity of the PDGF A-chain gene is sharply and selectively reduced by in vitro DNA methylation and that DNA methylation in vivo also may reduce its function in selected cell lines.

[A computer system of automated evaluation of structure-activity relationship of chemical mutagens]

A computer automated structure evaluation (CASE) system has been established. The data base of the system consists of more than 2000 chemicals and hundreds of biophores and biophobes identified by CASE. All programs can be run in micro-computer. Thus, entry of a chemical unknown genetoxity will result in the generation of all the possible fragments. On the basis of the presence and/or absence of these descriptors, CASE can predict activity or lack of it. In addition, and independently of the above, CASE also performs spell out, please and comparison program of genetic toxicology. The CASE program can be used to predict the mutagenicity and carcinogenicity of the many untested chemicals in the ambient environment. The sensitivity and specificity of this system all exceeds 90% and therefore the system has a very good-prospect of being used for forecasting.

Cloning and sequence analysis of the Chlamydia trachomatis spc ribosomal protein gene cluster

We identified and sequenced a segment of Chlamydia trachomatis chromosomal DNA that shows homology to the Escherichia coli spc and distal region of the S10 ribosomal protein (r-protein) operons. Its sequence revealed a high degree of nucleotide and operon context conservation with the E. coli r-protein genes. The C. trachomatis spec operon contains the r-protein genes for L14, L24, L5, S8, L6, L18, S5, L15, and Sec Y along with the genes for r-proteins L16, L29, and S17 of the S10 operon. The two operons are separated by a 16-bp intragenic region which contains no transcription signals. However, a putative promoter for the transcription of the spc operon was found 162 nucleotides upstream of the CtrL14e start site; it revealed significant homology to the E. coli consensus promoter sequences. Interestingly, our results indicate the absence of any structure resembling an EcoS8 regulatory target site on C. trachomatis spc mRNA in spite of significant amino acid identity between E. coli and C. trachomatis r-proteins. Also, the intrinsic aminoglycoside resistance in C. trachomatis is unlikely to be mediated by CtrL6e since E. coli expressing CtrL6e remained susceptible to gentamicin (MIC less than 0.5 micrograms/ml).

The cervix-ripening effect of 15-methyl-prostaglandin F2 alpha methyl ester before vacuum aspiration for termination of early pregnancy in primigravidae

A double blind clinical trial on prostaglandin for cervix ripening prior to vacuum aspiration for termination of early pregnancy in primigravidae was carried out in 68 patients with 6-11 week's gestation. The patients were randomly treated with either 1.0 mg of 15-methyl-prostaglandin F2 alpha methyl ester vaginal suppository or a placebo suppository. A mean cervical dilation to 6.6 mm was achieved with minimal side effects in the prostaglandin group as against 4.3 mm in the placebo group. The 15-methyl-prostaglandin F2 alpha methyl ester suppository technique seems to be effective, safe and simple in ripening the cervix for termination of early pregnancy in primigravidae.

Use of all-trans retinoic acid in the treatment of acute promyelocytic leukemia

Twenty-four patients with acute promyelocytic leukemia (APL) were treated with all-trans retinoic acid (45 to 100 mg/m2/day). Of these, eight cases had been either nonresponsive or resistant to previous chemotherapy; the other 16 cases were previously untreated. All patients attained complete remission without developing bone marrow hypoplasia. Bone marrow suspension cultures were studied in 15 of the 24 patients. Fourteen of these patients had morphological maturation in response to the retinoic acid (1 mumol/L). Chloroacetate esterase and alpha-naphthyl acetate esterase staining as well as electronmicroscopic examination confirmed that retinoic acid-induced cells differentiated to granulocytes with increased functional maturation (as measured by nitroblue tetrazolium reduction, NBT). The single nonresponder to retinoic acid in vitro was resistant to treatment with retinoic acid but attained complete remission after addition of low-dose cytosine arabinoside (ara-C). During the course of therapy, none of the patients showed any abnormalities in the coagulation parameters we measured, suggesting an absence of any subclinical disseminated intravascular coagulation. The only side effects consisted of mild dryness of the lips and skin, with occasional headaches and digestive symptoms. Eight patients have relapsed after 2 to 5 months of complete remission. The others remain in complete remission at 1+ to 11+ months and are still being followed up. We conclude that all-trans retinoic acid is an effective inducer for attaining complete remission in APL.