The association between bronchopulmonary dysplasia grade and risks of adverse neurodevelopmental outcomes among preterm infants born at less than 30 weeks of gestation

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a multifactorial disease with neurodevelopmental implications. This study aims to quantify the risks of adverse neurodevelopmental outcomes for each BPD grade among preterm infants born at less than 30 weeks' gestation.

METHODS

We retrospectively studied infants who received care in our institution until at least 36 weeks postmenstrual age and had a formal neurodevelopmental assessment in our infant follow-up clinic using the Bayley Scales for Infant and Toddler Development (BSID). We assessed the association between BPD grade and adverse neurodevelopmental outcomes using descriptive statistics and regression models.

RESULTS

Two hundred and fifty infants, including 89 (35.6%), 87 (34.8%), 65 (20.6%), and 9 (3.6%) with No BPD, Grade 1, Grade 2, and Grade 3 BPD, were included in the study. Small for gestational age, late pulmonary hypertension, dexamethasone administration, and adverse neurodevelopmental outcomes were more common as BPD grade increased. In a logistic regression analysis, Grades 2 and 3, but not Grade 1, BPD were associated with increased odds of a composite adverse neurodevelopmental outcome by 2.7 and 7.2 folds, respectively. A BSID domain-specific analysis showed that higher grades were associated with lower scores in the cognitive, gross motor, and fine motor domains.

CONCLUSIONS

Grades 2 and 3 BPD, but not Grade 1, correlate with risks of adverse neurodevelopmental outcomes at a grade-dependent manner in our single-center cohort retrospective study. Further validation using a multi-center large cohort is warranted.

[A case report of death from toxic encephalopathy caused by emamectin·chlorfenapyr]

Emamectin·chlorfenapyr is insecticide compounded by emamectin benzoate and chlorfenapyr. There is no special antidote after poisoning, and the mortality rate of patients is very high. We admitted a case of toxic encephalopathy caused by oral administration of emamectin·chlorfenapyr. The clinical manifestations of patient were gastrointestinal symptoms, profuse sweating, high fever, changes in consciousness. After admitted to the hospital, despite active comprehensive treatment, the patient died of ineffective rescue eventually.

[Application of transbronchial cryobiopsy in the diagnosis of postoperative complications after lung transplantation: a report of 6 cases]

Objective: To investigate the efficacy and safety of transbronchial cryobiopsy (TBCB) after lung transplantation. Methods: The clinical characteristics, TBCB procedure, diagnosis and treatment, and outcomes of lung transplant recipients of 6 patients (all male, aged 33-67 years) with TBCB in China-Japan Friendship Hospital from May to November 2021 were retrospectively analyzed. Results: Among the 6 patients diagnosed by TBCB, there were 2 cases of organizing pneumonia, 1 acute cellular rejection, 1 antibody-mediated rejection, and 1 bronchiolitis obliterans, and 1 diffuse alveolar damage. After the clinical diagnosis was confirmed, the condition improved after adjustment of the treatments followed. There were no serious complications related to the TBCB procedure. Conclusion: TBCB is valuable and relatively safe in the diagnosis of complications after lung transplantation, but the indications need to be strictly controlled.

Machine learning for prediction of bronchopulmonary dysplasia-free survival among very preterm infants

Background

Bronchopulmonary dysplasia (BPD) is one of the most common and serious sequelae of prematurity. Prompt diagnosis using prediction tools is crucial for early intervention and prevention of further adverse effects. This study aims to develop a BPD-free survival prediction tool based on the concept of the developmental origin of BPD with machine learning.

Methods

Datasets comprising perinatal factors and early postnatal respiratory support were used for initial model development, followed by combining the two models into a final ensemble model using logistic regression. Simulation of clinical scenarios was performed.

Results

Data from 689 infants were included in the study. We randomly selected data from 80% of infants for model development and used the remaining 20% for validation. The performance of the final model was assessed by receiver operating characteristics which showed 0.921 (95% CI: 0.899–0.943) and 0.899 (95% CI: 0.848–0.949) for the training and the validation datasets, respectively. Simulation data suggests that extubating to CPAP is superior to NIPPV in BPD-free survival. Additionally, successful extubation may be defined as no reintubation for 9 days following initial extubation.

Conclusions

Machine learning-based BPD prediction based on perinatal features and respiratory data may have clinical applicability to promote early targeted intervention in high-risk infants.

Percutaneous CT-Guided Microwave Ablation Combined with Vertebral Augmentation for Treatment of Painful Spinal Metastases

BACKGROUND AND PURPOSE

Percutaneous thermal ablation followed by vertebral augmentation is an emerging minimally invasive therapeutic alternative for the management of spinal metastases. This study aimed to retrospectively evaluate the effectiveness and safety of microwave ablation combined with vertebral augmentation for the treatment of painful vertebral metastases.

MATERIALS AND METHODS

Overall, 91 patients with 140 metastatic vertebrae who experienced refractory moderate-to-severe pain were treated with CT-guided microwave ablation and vertebral augmentation. Procedural effectiveness was determined using the visual analog scale, daily morphine consumption, and the Oswestry Disability Index preprocedurally and during follow-up. Local tumor control was assessed at follow-up imaging.

RESULTS

The procedure was technically successful in all patients. The median visual analog scale score and mean morphine dose were 6 (range, 4-10) and 77.8 (SD, 31.5) mg (range, 15-143 mg), preprocedurally; 5 (range 3-8) and 34.5 (SD, 23.8) mg (range, 0-88 mg) at 3 days; 4 (range, 2-7) and 28.7 (SD, 16.4) mg (range, 0-73 mg) at 1 week; 3 (range, 1-6) and 24.6 (SD, 13.2) mg (range, 0-70 mg) at 1 month; 3 (range, 1-6) and 21.70 (SD, 10.0) mg (range, 0-42 mg) at 3 months; and 3 (range, 1-8) and 21.0 (SD, 9.9) mg (range, 0-46 mg) at 6 months postprocedurally (all P < .05). A decrease in the Oswestry Disability Index score was also observed (P < .01). Local control was achieved in 94.8% of the treated metastatic vertebrae during the 6-month follow-up period. Asymptomatic cement leakage occurred in 42 (30%) treated vertebrae. A grade 3 neural injury was observed in 1 patient (1.1%). The patient's neurologic function returned to normal following treatment with mannitol, glucocorticoids, and radiation therapy.

CONCLUSIONS

This study demonstrates that percutaneous CT-guided microwave ablation combined with vertebral augmentation is a safe and effective minimally invasive intervention for the treatment of painful spinal metastases.

Transcriptome and metabolome analyses of the immune response to light stress in the hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀)

Light intensity is an important environmental factor that affects fish growth and health through multiple physiological activities and metabolism and eventually impacts aquaculture harvest. There is a need to evaluate the fish stress response to light intensities, which will benefit aquaculture. Here, hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) was treated with three light intensities for evaluation of the light stress response, including high light intensity (1 250 lx), low light intensity (10 lx) and moderate light intensity (250 lx). Transcriptome analysis showed that a total of 71 318 unigene sequences were obtained with an N50 of 2 589 bp. Compared to the control group (250 lx), 1 697 differentially expressed genes (DEGs), a considerable quantity, were detected in the 1 250 lx group. Among those genes, 548 were upregulated, and the remaining 149 genes showed decreased expression. Comparatively small numbers of DEGs were detected in the 10 lx group; 54 out of 103 genes exhibited upregulated expression, and 49 genes showed downregulation. For further KEGG analysis, 82 DEGs were enriched in nine common signalling pathways in immunity, of which 73 DEGs were significantly inhibited in the 1 250 lx group. In contrast, only 11 DEGs were enriched in three immunity pathways, with nine DEGs showing a significant increase in the 10 lx group. The metabolome analysis revealed 59 and 44 differential metabolites (DMs) from the 1 250 lx and 10 lx groups, respectively. Of note, those DMs from the 1 250 lx-treated group were tendentiously involved in amino acid metabolism and lipid metabolism pathways, while the purine metabolism, amino acid metabolism and lipid metabolism pathways were mostly found in the 10 lx treatment group. In summary, our data indicated that high light intensity significantly inhibited the immune response in hybrid grouper, while low light intensity presented low stimulation of immune activity. In addition, both high and low light intensity could inhibit protein synthesis and amino acid metabolism. Taken together, hybrid grouper exhibited a much milder stress response to low light intensity than to high light intensity.

Association between Skeletal Muscle Strength and Dysphagia among Chinese Community-Dwelling Elderly Adults

OBJECTIVES

Swallowing disorder is a health burden for the elderly in China. This study aimed to investigate the prevalence of dysphagia and to test the association between skeletal muscle strength and swallowing problems among community-dwelling older adults.

DESIGN

A cross-sectional study.

SETTING

Community-dwelling Chinese elderly in China.

PARTICIPANTS

3361 adults aged 65 years or above were involved, among which 1740 (51.8%) were female, with average age of 72.64 (Standard deviation, SD=6.10) years old.

MEASUREMENTS

Handgrip strength (HGS) was used to evaluate skeletal muscle strength. Dysphagia assessment was performed using the Eating Assessment Tool-10 (EAT-10) and the 30mL water swallow test (WST). Binary logistic regression was used to evaluate the relationship between skeletal muscle strength and dysphagia, and covariates as age, gender, material status, etc. were adjusted.

RESULTS

The prevalence of dysphagia were 5.5% and 12.9%, screened by EAT-10 and 30mL WST respectively. Participants with dysphagia showed lower HGS (21.73 ± 9.20 vs. 25.66 ± 11.32, p<0.001, by EAT-10; 20.26 ± 9.88 vs. 26.22 ± 11.28, p<0.001, by WST). The adjusted model suggested that muscle strength is a protective factor for swallowing disorders (adjusted OR=0.974, 95%CI: 0.950-0.999, by EAT-10; adjusted OR=0.952, 95%CI: 0.933-0.972, by WST). Subgroup analyses of WST found the effects were significant among participants aged in 70-74 years group and ≥75 years group, rather than those aged under 70.

CONCLUSION

Dysphagia was significantly associated with skeletal muscle strength among the community-dwelling elderly population. Effective interventions should be taken to manage the decline of muscle strength for the older adults, especially early prevention before 70 years old.

Citrobacter rodentium Induces Tissue-Resident Memory CD4+ T Cells

Tissue-resident memory T cells (TRM cells) are a novel population of tissue-restricted antigen-specific T cells. TRM cells are induced by pathogens and promote host defense against secondary infections. Although TRM cells cannot be detected in circulation, they are the major memory CD4+ and CD8+ T-cell population in tissues in mice and humans. Murine models of CD8+ TRM cells have shown that CD8+ TRM cells maintain tissue residency via CD69 and though tumor growth factor β-dependent induction of CD103. In contrast to CD8+ TRM cells, there are few models of CD4+ TRM cells. Thus, much less is known about the factors regulating the induction, maintenance, and host defense functions of CD4+ TRM cells. Citrobacter rodentium is known to induce IL-17+ and IL-22+ CD4+ T cells (Th17 and Th22 cells, respectively). Moreover, data from IL-22 reporter mice show that most IL-22+ cells in the colon 3 months after C. rodentium infection are CD4+ T cells. This collectively suggests that C. rodentium may induce CD4+ TRM cells. Here, we demonstrate that C. rodentium induces a population of IL-17A+ CD4+ T cells that are tissue restricted and antigen specific, thus meeting the criteria of CD4+ TRM cells. These cells expand and are a major source of IL-22 during secondary C. rodentium infection, even before the T-cell phase of the host response in primary infection. Finally, using FTY 720, which depletes circulating naive and effector T cells but not tissue-restricted T cells, we show that these CD4+ TRM cells can promote host defense.

Wild-type phosphatase and tensin homolog deleted on chromosome 10 improved the sensitivity of cells to rapamycin through regulating phosphorylation of Akt in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most frequently diagnosed cancers in China, but the etiology and mode of carcinogenesis of this disease remain poorly understood. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), as a negative regulator of Akt/mTOR pathway, frequently mutates or is inactive in many cancers. Although mTOR has been thought a promising cancer therapeutic target, the sensitivity of tumor cells to rapamycin was still to be revaluated. In this study, we measured the effects of rapamycin on cell proliferation and phosphorylation of Akt in ESCC cells with varying degrees of differentiation. And then, the relationship between PTEN status and the sensitivity of cells to rapamycin was investigated in EC9706 cells with or without wild-type PTEN in vitro and in vivo. The results demonstrated ESCC cells with poor differentiation were insensitive to rapamycin of high concentration and rapamycin obviously promoted the phosphorylation of Akt in these cells, but it had no obvious effects on p-Akt in cells with well differentiation. Also, we showed that wild-type PTEN improved the sensitivity of poor differentiation cells to rapamycin through inhibiting phosphorylation of Akt in vitro and in vivo. This study explored the possible molecular mechanism of some ESCC cells insensitive to rapamycin and provided a measure for treating ESCC patients with PTEN inactivation using mTOR inhibitors.

In vivo Toll-like receptor 5 (TLR5) imaging with radiolabeled anti-TLR5 monoclonal antibody in rapamycin-treated mouse allogeneic skin transplantation model

BACKGROUND

In organ transplantation, increasing evidence, both in experimental and human studies, indicates that Toll-like receptor (TLR) activation is involved in the innate immune recognition of allograft. TLR5, the only protein recognition receptor of TLRs, is indicated potentially to be the immune regulation target. This study was designed to determine whether TLR5 could be a biomarker for in vivo allograft visualization, after immunosuppressant rapamycin treatment, using radiolabeled sodium iodide ((131) I)-anti-TLR5 monoclonal antibody (mAb).

METHODS

BALB/c mice were transplanted with C57BL/6 skin, with/without rapamycin treatment (the rapamycin-treated group and the phosphate buffered saline [PBS]-rejection group, respectively). In vivo dynamic whole-body phosphor-autoradiography and ex vivo biodistribution studies were conducted after (131) I-anti-TLR5 mAb injection.

RESULTS

Dynamic phosphor-autoradiography imaging showed clear graft localization from 12 h onward. At 72 h after injection, graft uptake quantified from images was higher for the rapamycin-treated group (26,448 ± 904 digital light units [DLU]/mm(2) ), compared with the PBS-treated allo-rejection group (9176 ± 576 DLU/mm(2) ). Treatment with anti-TLR5 mAb inhibited graft uptake. Organ biodistribution study reflected the same tendency, and (131) I-anti-TLR5 mAb uptake reached a maximum of 12.05 ± 1.86 %ID/g (percent injected dose per gram) at 1 h, and graft-to-native skin ratio reached 8.10 ± 0.10 %ID/g at 72 h after injection in rapamycin-treated grafts.

CONCLUSION

Radiolabeled anti-TLR5 mAb showed higher uptake in allo-treated grafts compared with allo-rejection grafts, which was proved by non-invasive dynamic phosphor-autoradiography imaging, and invasive ex vivo biodistribution. Radiolabeled anti-TLR5 mAb is a new tracer for non-invasive in vivo imaging of TLR5 in rapamycin-treated allograft.

Abstract P3-02-04: QM-FISH analysis of the genes involved in the G1/S checkpoint signaling pathway in triple-negative breast cancer

OBJECTIVES: To analyze copy number alterations(CNAs) of the genes involved in the G1/S checkpoint signaling pathway of triple-negative breast cancer (TNBC) and non- triple-negative breast cancer(non-TNBC) and in order to find specific CNAs associated with overall survive for TNBC.In all,to provide an effective target for future treatment.

METHODS: We selected the samples randomly form Tianjin Cancer Hospital between August, 2006 and August, 2007,which contained one hundred TNBC cases and one hundred non-TNBC cases. Quantitative mμlti-gene fluorescence in situ hybridization (QM-FISH) was used to study CNAs of the genes involved in the G1/S checkpoint signaling pathway, including CCND1,c-Myc,p21, CHEK2, p16, Rb1, Mdm2and p53.

RESULTS: The amplification rates of c-Myc and the deletion rates of p53 in TNBC tended to be higher than those in non-TNBC, whereas the amplification rates of CCND1 and Mdm2 in non-TNBC tended to be higher than those in TNBC. In Kaplan-Meier analysis, the amplification of CCND1 (P = 0.02) and c-Myc (P = 0.02) as well as the deletion of p53 (P = 0.01) predicted worse survival in the TNBC group. While in the non-TNBC group, the amplification of CCND1 (P = 0.01) and Mdm2 (P = 0.04) as well as the deletion of p53 (P = 0.049) were associated with worse survival. The amplification of c-Myc and the deletion of p53 in TNBC were associated with higher mortality risk (HR,2.87;95%CI,1.14-7.21[P = 0.03]; HR, 3.34;95%CI, 1.22-9.09 [P = 0.02]), whereas the mortality risk tended to be higher in the patients with amplification of CCND1 (HR, 4.35;95%CI,1.23-15.39 [P = 0.02])in non-TNBC.

CONCLUSIONS: The amplification rates of c-Myc and deletion rates of p53 in TNBC tended to be higher than those in non-TNBC, whereas the amplification rate of CCND1 and Mdm2 tended to be higher in non-TNBC. c-Myc and p53 were independent prognostic factors for TNBC, while CCND1 was the independent prognostic factors for non-TNBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-02-04.

Abstract P1-08-05: The prognostic significance of Ki-67 expression before and after neoadjuvant anthracycline-taxane-based chemotherapy in different biological breast cancer phenotypes

Purpose

This study was conducted to analyze the Ki-67 expression before and after neoadjuvant chemotherapy and clinical pathology characteristics of different biological breast cancer phenotypes at our center. A correlation study was performed between Ki-67 index change and the prognosis of different biological breast cancer phenotypes and prognosis in Northern China.

Methods

A regression analysis was performed on 213 patients with invasive breast carcinoma accepted NAC admitted to Tianjin Medical University Cancer Institute and Hospital of Breast Surgery from January 2007 to April 2008. These patients were subtyped by hormone receptor status and HER2 status.The Ki67 index (percentage of Ki67-positive cancer nuclei) were determined immunohistochemically. The prognostic value of the Ki-67 index for different biological breast cancer phenotypes disease-free survival (DFS) and overall survival (OS) was investigated by use of Kaplan–Meier curves and multivariable Cox regression.

Results

The overall pathologic CR (pCR) rate, defined as no invasive residuals in breast and axilla, was 17.8%. The highest pCR rate of 32.1% was observed in patients with HR-/HER2+ tumors, which is 11.4%, 20.0% and 26.2% in HR+/HER2- HR+/HER2-,HR+/HER2+and HR-/HER2- tumor respectively(P = 0.024).The Ki-67 expression of pre-NAC and post-NAC have prognostic significance in HER2- breast cancer, which have not significance different in HER2+ breast cancer:The best Ki-67 idex cut point of pre-NAC and post-NAC to predict long-term survival was respectively 20% and 10% in HR+/HER2- breast cancer. Moreover, patients with a higher Ki-67 index (&gt; cut-off point) showed significantly lower 5year-DFS/OS rates compared with those whose Ki-67 index were below cut-off point. In addition, Ki-67 index of post-NAC were independent prognostic factors for 5 year disease-free survival of patients with HR+/HER2- breast cancer. Ki-67 change between pre- and post-NAC as an independent prognostic factor independently predict prognosis in the patients who have not achieved pCR, while the best cut-off point was 18%.

Conclusion

The Ki-67 index of pre- and post-NAC could predict the prognosis in the patients with HER2- breast cancer. Moreover, the Ki-67 change between pre- and post-NAC was an independent prognostic factor in the patients who have not achieved pCR.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-05.

DISTINCT ROLES FOR DISCOIDIN DOMAIN RECEPTOR 1 (DDR1) EXPRESSED ON BONE MARROW DERIVED CELLS AND VESSEL WALL CELLS DURINGATHEROGENESIS

We have recently described a critical role for the discoidin domain receptor 1 (DDR1) collagen receptor tyrosine kinase in the regulation of fibrosis and inflammation during atherosclerotic plaque development. DDR1 isexpressed on both SMCs and macrophages; however the role of DDR1 expressed in these distinct cells during atherogenesis remains unresolved. In the current study, female Ldlr^-/- mice that were either Ddr1^+/+ or Ddr1^-/-were lethally irradiated and reconstituted with bone marrow from male Ddr1^+/+ or Ddr1^-/- donors yielding three groups of chimeric mice: Ddr1^+/+^?^+/+ (control); Ddr1^+/+^?^-/-^ (vessel wall deletion); and Ddr1^-/-^?^+/+ (bone marrow deletion). Chimeric mice were placed on an atherogenic diet for 12 weeks and hadsimilar body weights, total leukocyte counts, levels of Sry chimerism, and fasting plasma triglycerides at sacrifice, although total cholesterol was increased by 42% in Ddr1^+/+^?^-/- mice. Deletion of DDR1 inbone marrow derived cells (Ddr1^-/-^?^+/+) resulted in a 66% reduction in atherosclerotic lesion area in thedescending aorta compared to Ddr1^+/+^?^+/+ mice. Aortic sinus plaquesfrom Ddr1^-/-^?^+/+ mice were 36% smaller than Ddr1^+/+^?^+/+ plaques but the proportion of plaque area occupied by cells and matrix was similar between groups. By contrast, deletion of DDR1 in vessel wall cells (Ddr1^+/+^?^-/-) resulted in a 57% increase in atherosclerosis in the descending aorta. Furthermore, aortic sinus plaques from Ddr1^+/+ ^?^-/- mice had markedly increased fibrillar collagen and elastin accumulation compared to Ddr1^+/+^?^+/+ plaques resulting in a 156% increase in lesion area and reduced SMC and macrophage content. In conclusion, while DDR1 on bone marrow derived cells is required for plaque development, DDR1 expressed on vessel wall cells negatively regulates plaque matrix accumulation and results in the formation of larger lesions with altered cellular composition. Our data suggest a dual role for DDR1 in the regulationof atherogenesis and plaque matrix content.

Synthesis and thrombolytic activity of new thienopyrimidinone derivatives

It has been observed that ticlopidine and clopidogrel show, apart from their delayed antiplatelet properties, an immediate and transient thrombolytic action related to the ability of these thienopyridines to stimulate the secretory function of vascular endothelium. With the objective to construct new molecules with identical thrombolytic potency but at a higher level, we carried out different structural modifications in the thienopyridine chemical molecule to conclude that the presence of a second N atom in the pyridine cycle (yielding pyrimidine moiety) and the presence of an additional cycle fused to the thienyl ring would lead to enhanced thrombolytic effects. Here we report the six-step synthesis of a series of new benzothienopyrimidinone derivatives characterized by this searched for potent thrombolytic activity. The pharmacological assay used anaesthetised Wistar rats with extracorporal circulation in which arterial blood superfused thrombi adhering to a strip of collagen. Weight of thrombi was continuously monitored. Six compounds of the series were much more potent thrombolytic agents than their thienopyridine references: the effective thrombolytic dose that produced 30% of maximum thrombolysis (ED30) was at a range of 8 to 170 microg kg(-1) as compared with ED30 values of 16000 to 20000 microg kg(-1) for clopidogrel and ticlopidine respectively. Especially with the most active compound, this difference in the threshold thrombolytic dose, giving an intensity of action higher by three orders of magnitude, was accompanied by a lengthening of the response. Apart from that these compounds have shown to be synthetic thrombolytics, they certainly deserve further studying.

In vivo blockade of macrophage migration inhibitory factor prevents skin graft destruction after indirect allorecognition

BACKGROUND

The effector mechanisms that ultimately destroy transplanted tissues are poorly understood. In particular, it is not clear how CD4+ T cells primed to donor-derived determinants expressed on recipient MHC molecules (the indirect pathway) can mediate graft destruction in the absence of cognate recognition of peptide: MHC on the graft cells themselves. Macrophage migration inhibitory factor (MIF) inhibits macrophage movement and is a proinflammatory and regulatory cytokine known to be essential for development of delayed-type hypersensitivity reactions.

METHODS

To test whether MIF participates in graft destruction following indirect recognition, we studied rejection of MHC-II-deficient skin grafts placed on allogeneic SCID recipients adoptively transferred with naïve CD4+ T cells, and the recipients were treated with neutralizing anti-MIF monoclonal antibody or isotype control IgG. In this model graft rejection can only occur indirectly as the graft cells lack MHC II for recognition by the recipient CD4+ T cells.

RESULTS

We found that in vivo blockade of MIF inhibited indirect CD4+ cell-mediated skin graft destruction, and markedly reduced detectable macrophages within the grafts. The neutralizing anti-MIF antibody significantly inhibited alloreactive DTH but did not prevent T cell priming or interferon-gamma release by primed T cells.

CONCLUSIONS

The results strongly implicate MIF as an active participant in skin graft destruction after indirect recognition and suggest that this effect is mediated through an inhibition of macrophage migration and/or function.

[Influence of HLA class I molecules expression on tumor cell resistance to NK lysis and the IFN-gamma regulatory effect]

OBJECTIVE

To investigate the relation between the NK lysis and HLA molecules expressed on the target cells as well as the regulatory effect of IFN-gamma.

METHODS

The level of HLA-ABC molecules on seven human tumor cell lines were detected through the indirect immune fluorescence stain. NK lysis changes were observed after the blocking of HLA molecules on the target cells with the anti-HLA monoclonal antibodies or treating target cells with IFN-gamma.

RESULTS

1. Most of the tumor cell lines showed a complete or partial loss of HLA-ABC molecules, 2. After the HLA molecules had been marked on the target cells with the anti-HLA-ABC antibodies, the tumor cell susceptibility to the lysis of NK cells attack increased significantly and 3. After having being treated with IFN-gamma 500 U/ml for more than 48 hours, the HLA-ABC molecule levels on K562, M21 and PG cells went up. At the same time, their susceptibility to NK lysis was reduced. However, the resistance to Karpas, HL60 and HT29 NK lysis demonstrated a noticeable increase. The IFN-gamma promoted the apoptosis of HL60 and HT29 cells.

CONCLUSION

The NK cells are capable of recognizing the HLA molecules on the target cells and show no lysis in providing a negative signal with the KIRs, an effect which the anti-HLA monoclonal antibodies are able to eliminate. IFN-gamma can be applied to make up for the loss of HLA molecules on some of the tumor cells, it can also facilitate some of the tumor cells' apoptosis.

Oriental noodles

Oriental noodles have been consumed for thousands of years and remain an important part in the diet of many Asians. There is a wide variety of noodles in Asia with many local variations as result of differences in culture, climate, region and a host of other factors. In this article noodle classification, formulation, processing and evaluation are reviewed, with emphasis on eight major types. Wheat quality requirements, basic flour specifications, ingredient functions, and production variables are identified for different noodles. In the evaluation of flour for noodle making, three key quality attributes are considered: processability, noodle color and texture. Noodle process behavior is particularly important in the modern industrial production. Each noodle type has its own unique color and texture characteristics. Flour color, protein content, ash content, yellow pigment and polyphenol oxidase activity are important factors responsible for noodle color. Starch characteristics, protein content and quality play major roles in governing the texture of cooked noodles. However, the relative importance of starch and proteins varies considerably with noodle type. Starch pasting quality is the primary trait determining the eating quality of Japanese and Korean noodles that are characterized by soft and elastic texture, while protein quantity and strength are very important to Chinese-type noodles that require firm bite and chewy texture. Other factors such as ingredients added in the noodle formula and processing variables used during noodle preparation also affect the cooked noodle texture as well.

[A study of Wilson's disease gene encoded products and gene mutations]

OBJECTIVE

To investigate the pathogenesis of Wilson's disease(WD).

METHODS

Hepatocytes were isolated from WD patients' bioptic hepatic samples and cultured in vitro; WD proteins, the gene putative encoded products, were detected by SDS-PAGE in conjunction with Western blotting in liver samples of three patients and two controls. Their genomic DNAs were analyzed by means of direct DNA sequencing of WD gene (ATP7B) on exon 8.

RESULTS

The WD proteins lanes from two WD patients were found to be much weaker than that from the control, from which one WD patient was proven as heterozygote of 778 position CGG-->CTG(Arg778Leu) and 770 position CTC-->CTG change of ATP7B.

CONCLUSION

WD is highly heterogeneous in clinical manifestations and inheritance pattern. Abnormally expressed putative WD proteins in WD patients might be the results of ATP7B mutations, and the study of ATP7B products would help to probe into the pathogenesis of WD.

[A study of gene products encoded by Wilson disease gene]

OBJECTIVE

To investigate the pathogenesis of Wilson disease (WD) by detecting its gene products encoded by WD gene (ATP7B).

METHODS

Patients diagnosed as WD were analyzed by SDS-PAGE in conjunction with Western blot. Two antibodies were used, which are specially against the sixth copper binding domain (Anti-CuBD) and ATP binding domain (Anti-ABD) of WD protein.

RESULTS

The WD proteins were not expressed in two patients when using anti-CuBD, and poorly expressed when using anti-ABD.

CONCLUSIONS

WD is highly heterogeneous in clinical manifestations and inheritance pattern. Two WD patients might simultaneously have exon 5 mutations and exon 8 mutations. The study of WD gene products would probe into the pathogenesis of WD.

The discoidin domain receptor tyrosine kinase DDR1 in arterial wound repair

Collagens act as important signaling molecules regulating vascular smooth muscle cell responses during arterial wound repair. Discoidin domain receptors (DDRs) are a novel class of receptor tyrosine kinases that bind to several collagens and stimulate matrix metalloproteinase (MMP) production, but little is known about their expression and function in the vasculature. We posited a critical role for the DDRs controlling smooth muscle cell migration and proliferation and thus repair following arterial injury. Smooth muscle cells were isolated from the aortas of mice with a targeted deletion of the DDR1 gene (DDR1-null) and studied in culture using models that mimic critical steps in neointimal thickening. Our studies suggest that DDR1 plays an important role in regulating attachment to collagen, chemotaxis, proliferation, and MMP production in smooth muscle cells. Following mechanical injury to the carotid arteries, cross-sectional area of the neointima was significantly lower in DDR1-null mice than in wild-type mice. There was also a significant decrease in collagen deposition in the injured arteries of the DDR1-null mice. Our results support the hypothesis that DDR1 plays an important role as a collagen receptor, mediating intimal thickening after vascular injury.

[Using fluorescence PCR analysis for early diagnosis and carriers detection of Chinese Wilson's disease]

OBJECTIVE

To diagnose the pre-symptomatic cases of Chinese Wilson's disease(WD) and detect the potential carriers by using fluorescence PCR technique.

METHODS

Screening the high frequency spot Arg778Leu of WD gene mutation in 66 Chinese WD patients, 55 healthy family members and 30 controls, and selecting 3 random samples (2 from WD patients, 1 from controls) for DNA sequencing to testify the accuracy of fluorescence PCR.

RESULTS

Among 66 Chinese WD cases, 5 were found homozygous for mutation of Arg778Leu and 21 were compound heterozygous; the gene mutation rate was totally 39.4%. Out of 55 healthy family members, 12 were found heterozygous, and it was confirmed that 11 of these 12 individuals were WD gene carriers but not pre-symptomatic patients. The results of direct DNA sequencing consisted with those results detected by fluorescence PCR.

CONCLUSION

The Arg778Leu mutation in exon 8 is the high frequency spot of Chinese Wilson's disease gene. Fluorescence PCR analysis is a rapid, accurate gene diagnostic method and demonstrates a high detecting rate.

[ABO genotyping by PCR-direct sequencing method]

OBJECTIVE

To analyze the sequence difference between human A, B, and O alleles and establish the method of ABO genotyping by PCR direct sequencing.

METHODS

PCR-direct sequencing technique was used to analyze two regions of cDNA from A transferase gene, 233-433 and 660-788.

RESULTS

Two nucleotide substitutions at 258th and 297th were found in 233-433 region, and a nucleotide substitution at 700th was found in 660-788 region. At 258th, the nucleotide was guanine in A and B alleles, and adenine in O allele. At 297th, the nucleotide was adenine in A allele, and guanine in B allele. As this position, O allele was subdivided into two types, O(A) and O(G). At 700th, the nucleotide was guanine in A and O alleles, and adenine in B allele. Therefore, 8 genotypes, AA, AO(A), AB, BB, BO(G), O(A) O(A), O(G) O(G) and O(A) O(G), could be clearly determined by only analyzing the 233-433 region. The other two genotypes, AO(G) and BO(A), could be further distinguished by analyzing the 660-788 region.

CONCLUSION

The technique of PCR-direct sequencing provides an effective and new method for ABO genotyping further.

Thrombolysis by thienopyridines and their congeners

We propose that anti-platelet thienopyridines, such as ticlopidine or clopidogrel, are thrombolytic owing to endothelial release of prostacyclin (PGI2) and tissue plasminogen activator (t-PA). In this study we used anaesthetised Wistar rats with extracorporal circulation in which arterial blood superfused thrombi which adhered to a strip of collagen. Weight of thrombi was continuously monitored. When administered intravenously, clopidogrel or its R enantiomer deprived of anti-platelet action, both at doses of 3 mg x kg(-1), produced lost in weight of thrombi by 14.1 +/- 1.3% or 16.0 +/- 1.4% (n = 9), and at doses 10 mg x kg(-1) by 28.3 +/- 2.3% or 30.4 +/- 1.9% (n = 8), respectively. Maximum of thrombolysis occurred 30-45 min following the drug administration. Ticlopidine at a dose of 30 mg x kg(-1) reduced weight of thrombi by 33.7 +/- 1.7% (n = 32). Thrombolytic action of ticlopidine was accompanied by a rise in 6!keto-PGF1alpha blood levels from 0.42 +/- 0.10 to 1.58 +/- 0.29 ng x ml(-1) and t-PA antigen plasma levels from 4.70 +/- 1.00 to 12.90 +/- 1.15 ng x ml(-1) (n = 7). Five out of eleven tested thienopyridine congeners with pyrimidine or pyrimidinone instead of pyridine rings had thrombolytic potencies similar to that of clopidogrel (ED30s at a range of 6.2-11.4 mg x kg(-1)). A substantial increase in thrombolytic potency (ED30s at a range of 0.3-2.1 mg x kg(-1)) was observed for congeners in which thienyl ring was condensed with an additional cyclopentyl, cyclohexyl or cycloheptyl structures or in which thienopyridine complex was replaced for a pyridopyrimidine one. We claim that thienopyridines, independently of their delayed anti-platelet action, do produce immediate thrombolysis in vivo. This new activity emulates capacity of their native, non-metabolised molecules to release prostacyclin and tissue plasminogen activator. We have also shown that structural changes in molecules of thienopyridines may intensify their thrombolytic potency.

The analgesic action of semen coicis on severe functional dysmenorrhea--a sequential trial observation

The analgesic effect of Semen Coicis was observed with the sequential trial in 26 cases of severe functional dysmenorrhea. The results showed that the markedly effective rate was 90%, which was much better than that of the control group treated by indomethacin plus subcutaneous injection of atropine (P < or = 0.01).

A role for hyaluronan in macrophage accumulation and collagen deposition after bleomycin-induced lung injury

Elevated concentrations of hyaluronan (HA) are associated with the accumulation of macrophages in the lung after injury. We have investigated the role of HA in the inflammatory and fibrotic responses to lung injury using the intratracheal instillation of bleomycin in rats as a model. After bleomycin-induced lung injury, both HA content in bronchoalveolar lavage (BAL) and staining for HA in macrophages accumulating in injured areas of the lung were maximal at 4 d. Increased HA in BAL correlated with increased locomotion of isolated alveolar macrophages. HA-binding peptide was able to specifically block macrophage motility in vitro. Importantly, systemic administration of HA-binding peptide to rats before injury not only decreased alveolar macrophage motility and accumulation in the lung, but also reduced lung collagen alpha (I) messenger RNA and hydroxyproline contents. We propose a model in which HA plays a critical role in the inflammatory response and fibrotic consequences of acute lung injury.

Type VIII collagen stimulates smooth muscle cell migration and matrix metalloproteinase synthesis after arterial injury

Type VIII collagen is a matrix protein expressed in a number of tissues undergoing active remodeling, including injured arteries during neointimal formation and in human atherosclerotic plaques; however, very little is known about its function. We have investigated whether the type VIII collagen stimulates smooth muscle cell (SMC) migration and invasion by binding to integrin receptors and up-regulating matrix metalloproteinase (MMP) production. SMCs attached to plates coated with type VIII collagen in a dose-dependent manner, with maximal attachment occurring with coating solutions containing 25 microgram/ml collagen. Type VIII collagen at 100 microgram/ml stimulated an 83-fold increase in the migration of SMCs in a chemotaxis chamber. Antibodies against beta1 integrin receptors prevented attachment and migration of SMCs. Antibodies against alpha1 or alpha2 integrins reduced attachment of SMCs to type VIII collagen by 29% and 77%, respectively. We found that SMCs grown from the rat neointima, but not medial SMCs, increased their production of MMP-2 and -9 on adherence to type VIII collagen. This suggests that there is an important difference in phenotype between intimal and medial SMCs and that intimal SMCs have distinct matrix-dependent signaling mechanisms. Our findings suggest that type VIII collagen deposited in vascular lesions functions to promote SMC attachment and chemotaxis, and signals through integrin receptors to stimulate MMP synthesis, all of which are important mechanisms used in cell migration and invasion.

[The application of minisatellite MS31A MVR-PCR digital coding technique in forensic science]

Using isotope incorporate amplification technique of special 31A, 31A-A, 31A-G primers and alpha-32PdCTP, the minisatellite MS31A (located at D7S21 loci) was studied. A rapid, simple, and accurate MVR-PCR technique was successfully established. The technique can be applied in individual identification minutes amples, such as blood stains, semen stains contaminated by vaginal fluid, hair and bones. The sensitivity analysis revealed that this technique could detect 1 ng genoma DNA. It is also discribed about the application of the method in 40 criminal cases of rape and murder.

Evidence that NMDA receptors mediate the responses of putative RVLM presympathetic neurons to vagal afferent stimulation in rats

Experiments were performed in 25 urethane-anaesthetized male Sprague-Dawley rats. Forty-six RVLM neurons were identified as putative presympathetic neurons according to their arterial baroreceptor reflex related properties, i.e. they were inhibited by stimulation of the aortic nerve; silenced by elevation of blood pressure and had a cardiac cycle related rhythm of spontaneous discharge. Responses of these neurons to tripled square wave stimulation of vagal afferents was tested by means of peristimulus time histograms. In addition to a long-lasting inhibition (I2), some neurons had one (P0) or two excitatory peaks (P1 and P2), and there was a short-lasting inhibition (I1) between P1 and P2. After microinjection of CPP (0.1 microl, 50 mM) into the NTS, the inhibitory responses were blocked, but the excitatory peaks were not affected; in the CVLM, CPP microinjection of the same dose had a similar effect on the responses elicited by vagal afferent stimulation in 15 of the 24 neurons tested. No detectable effects were observed in 9 neurons. However, intravenously administered ketamine attenuated or abolished these responses, either inhibitory or excitatory, in a dose dependent way. These results suggest: (1) an NMDA mechanism is involved in both the inhibitory and the excitatory responses. For the inhibitory responses, the involvement is both in the NTS and in the CVLM; for the excitatory responses, it is probably in the RVLM. (2) There may be a direct excitatory amino acid (EAA) pathway from the NTS to the RVLM.

The effect of high dose endotoxin on CYP3A2 expression in the rat

PURPOSE

The purpose of our research was two-fold: 1) to further characterize the downregulation of CYP3A2 mRNA, protein, and activity during an acute phase response (APR); 2) most importantly, to relate the time-dependent activation of nuclear proteins to putative DNA binding sequences within the CYP3A2 5'-flanking region, with the loss in CYP3A2 expression.

METHODS

Rats were injected (2.0 mg/animal, i.p.) with LPS and sacrificed at 1, 2, 4, 6, 8, 24, 48, and 72 hours. Hepatic nuclear protein was isolated and analyzed for binding activity to AP-1, NFkappaB, and NF-IL6 consensus sequences. Hepatic CYP3A2 mRNA levels were determined by solution hybridization and CYP3A2 protein, CYP3A2 activity, and total P450 were measured in hepatic microsomes.

RESULTS

Computer analysis of the 5'-flanking region of CYP3A2 revealed the presence of 5 NF-IL6 and 4 AP-1 putative DNA binding sites. The strongest increase in AP-1 binding activity occurred between 6 and 24 hr, and the alteration in binding complexes to an NF-IL6 oligonucleotide occurred between 4 and 24 hr. Maximum loss in CYP3A2 mRNA occurred at 8 hr post-LPS injection and remained lowered at the 24 hr timepoint. CYP3A2 protein was significantly decreased at 24, 48, and 72 hours post-LPS treatment with corresponding decreases in CYP3A2 activity and total P450.

CONCLUSIONS

The changes in NF-IL6 and AP-1 binding after LPS treatment, which appears to correlate with the changes in CYP3A2 mRNA, combined with the presence of putative NF-IL6 and AP-1 sites located in the CYP3A25'-flanking region, may indicate a potential role for NF-IL6 and AP-1 in CYP3A2 downregulation during an APR.

The characterization of a human RHAMM cDNA: conservation of the hyaluronan-binding domains

A full-length human RHAMM cDNA clone was isolated by a combination of screening a human breast cDNA expression library with the murine RHAMM 2 cDNA as well as 5' RACE and RT-PCR using messenger RNA from human breast cell line (MCF-10A). The full-length cDNA contained 725 aa that encoded an 84 kDa protein. Although the coding region of the human RHAMM cDNA resembles the murine RHAMM v4, it has additional unique N-terminal (489 bp) and C-terminal (33 bp) regions. Also, only 1 of 5 repeat sequences encoded in the murine cDNA are present in human cDNA. The overall homology between the overlapping region of human and mouse RHAMM v4 cDNA clone is 85%, but the HA binding motif (B[X7]B), shown to be critical for the signaling capability of this receptor, is 100% conserved.

Pyrido[2,3-d]pyrimidin-4(3H)-one derivatives and 1,2,3,4-tetrahydro- pyrido[2,3-d]pyrimidine derivatives: synthesis and in vitro study of their activity against platelet aggregation

Some new derivatives of pyrido[2,3-d]pyrimidin-4(3H)-one A and 1,2,3,4-tetrahydro-pyrido[2,3-d]pyrimidines B were prepared. The study of their in vitro antiaggregating activity showed that the compounds A possessed an inhibitory potency when aggregation was induced with ADP. Their reduction to derivatives of 1,2,3,4-tetrahydro-pyrido[2,3-d]pyrimidine B led to a new series of molecules possessing a greater antiaggregating power. When compared to that of acetylsalicylic acid under the same conditions, this activity was weaker with collagen, the same with arachidonic acid-induced aggregation, but greater when aggregation was induced by ADP. However, they inhibited serotonin release only slightly. Compared to ginkgolide they remained weaker with PAF-induced aggregation.

Structure of a frequently rearranged rRNA-encoding chromosome in Giardia lamblia

It has been shown previously that the rRNA encoding chromosomes in Giardia lamblia undergo frequent rearrangements with an estimated rate of approximately 1% per cell per division (Le Blancq et al., 1992, Nucleic Acids Res., 17, 4539-4545). Following these observations, we searched for highly recombinogenic regions in one of the frequently rearranged rRNA encoding chromosomes, that is chromosome 1, a small, 1.1 Mb chromosome. Chromosome 1 undergoes frequent rearrangements that result in size variation of 5-20%. We analyzed the structure of chromosome 1 in clonal lineages from the WB strain. The two ends of chromosome 1 comprise telomere repeat [TAGGG] arrays joined to a truncated rRNA gene and a sequence referred to as '4e', respectively. Comparison of the structure of four polymorphic versions of chromosome 1, resulting from independent rearrangement events in four cloned lines, located a single polymorphic region to the variable rDNA-telomere domain. Chromosome 1 is organized into two domains: a core region spanning approximately 850 kb that does not exhibit size heterogeneity among different chromosome 1 and a variable region that spans 185-450 kb and includes the telomeric rRNA genes, referred to as the variable rDNA-telomere domain. The core region contains a conserved region, spanning approximately 550 kb adjacent to the telomeric 4e sequence, which is only present in the 4e containing chromosomes and a 300 kb region of repetitive sequences that are also components of other chromosomes as well. Changes in the number of rDNA repeats accounted for some, but not all, of the size variation. Since there are four chromosomes that share the core region of chromosome 1, we suggest that the genome is tetraploid for this chromosome.

Induction of arsenite tolerance and thermotolerance by arsenite occur by different mechanisms

Both V79 and As/R28A cells (an arsenite-resistant Chinese hamster V79 cell variant) show increased resistance to toxic concentrations of arsenite after pretreatment with a nontoxic concentration. The induced tolerance can be completely inhibited by actinomycin D or cycloheximide. Pretreatment with a nontoxic heat shock (45 degrees C, 10 min) resulted in a clear increased thermotolerance in both cell lines but failed to induce arsenite tolerance in either cell line. Pretreatment with arsenite induced a thermotolerance in V79 cells but not in As/R28A cells. These results are consistent with a model whereby the signal for induction of arsenite tolerance involves binding of arsenite to a protein effector which is amplified in the As/R28A line, thereby preventing action of arsenite in the regulation of heat shock factor which induces the heat shock response.

[CT scan in 52 cases of retinoblastoma]

The results of CT scan in 52 patients (61 eyes) with retinoblastoma (Rb) managed and confirmed by clinical and pathological examination are reported. The features and value of imaging of CT scan are described and discussed. In this series, 96.72% of cases revealed Rb and 90.16% of the cases with Rb tumor showed evidence of calcification on CT scan. The contrast enhancement of the tumor was slight. 19.67% of the cases with Rb tumor showed retrobulbar extension and invaded intracranium (including 3 cases of intracranical tumor extension and one case of trilateral Rb). We think it is important to perform CT scan in suspected cases of Rb, and in patients with Rb invading the orbit or intracranium as well as in bilateral Rb. Some problems in the diagnosis and differential diagnosis are briefly discussed.

Thieno[2,3-d]pyrimidin-4(3H)-one derivatives and 1,2-dihydrogenated homologues: synthesis, enhanced in vitro antiaggregant activity for reduced compounds

Some derivatives of thieno[2,3-d]pyrimidin-4(3 H)-one A and their 1,2-dihydrogenated homologues B were synthesized. The study of their in vitro antiaggregating activity showed that the first compounds exhibited significant inhibiting power when aggregation was induced with ADP. Their reduction to derivatives of 1,2-dihydrothieno[2,3-d]pyrimidin-4(3 H)-one led to a new series of molecules possessing a large antiaggregant activity. When compared to that of acetylsalicylic acid under the same conditions, this activity was the same with collagen or arachidonic acid-induced aggregation, but greater when aggregation was induced by ADP. Serotonin release was also inhibited.

Synthesis and in vitro study of platelet antiaggregant activity of some 4-quinazolinone derivatives

Some new 4-quinazolinones were prepared. Their antiplatelet activity was evaluated in vitro with respect to aggregation induced by ADP, collagen, arachidonic acid and the platelet serotonin release reaction. Most molecules showed an inhibiting power similar to that of acetylsalicylic acid under the same conditions, and even greater when aggregation was induced by ADP. Reduction of the 4-quinazolinone derivatives to their 1,2,3,4-tetrahydroquinazoline homologues produced an increase in platelet inhibitory action except when ADP is the inductor.

Action of some salicylate derivatives on in vitro platelet aggregation. Inhibitory and inhibition antagonistic effects

Twenty salicylate derivatives were tested for their antagonistic activity on the inhibitory effect of aspirin on platelet aggregation. The blocking effect was not limited to the salicylate but also characterised some of its substituted compounds. The substituant influence did not seem to be related to electronic or size parameters. This antagonistic activity of these derivatives decreased as concentrations increased, owing to the emergence of their own inhibitory activity: several salicylate derivatives showed dual inhibitory and inhibition antagonistic activity, with both properties present at the same concentration. A mechanism involving dissociated activities on the two enzymatic sites of cyclooxygenase is proposed.

In vitro neuronal differentiation of Drosophila embryo cells

Early gastrula-stage Drosophila embryo cells will differentiate in vitro to form several cell types, including neurons. We report here the morphological appearance of cultured embryo cells, the pattern of DNA synthesis, and the expression of neurotransmitter-metabolizing macromolecules. The cells initially exhibit no overt morphological differentiation, and all cells incorporate 3H-thymidine following a 1 hr pulse-labeling period. As cells undergo morphological differentiation, fewer total cells as well as qualitatively different cell types incorporate label. By the time cells are 8 or 9 hr old, no myocytes or myotubes are labeled. In contrast, some neurons are labeled with a thymidine pulse as late as 18 hr. We have also stained cultured cells of various developmental ages with the insect neuron-specific antibody: anti-HRP. Some positive cells can be detected as early as 5 hr, when no overt morphological differentiation is apparent. As the cells differentiate, the staining is limited to the small, round neuronal type and its processes. These findings suggest that this neuron-specific cell marker is expressed very early in cultured gastrula-stage cells and may be used to identify neuronal precursor cells. We have studied the patterns of expression of several macromolecules involved in acetylcholine metabolism using these cultures. The appearance of choline acetyltransferase (ChAT), the biosynthetic enzyme for ACh production, is first detected in 5-hr-old cells. There is an initial phase of low-level expression, followed by a rapid rise in activity shortly after the differentiating neuron clusters make contact with one another. ChAT activity reaches a plateau in 36-48-hr-old cells. Acetylcholinesterase activity can be detected several hours before ChAT and also shows a period of low-level expression followed by a rapidly increasing phase, reaching a plateau at around 36-48 hr. 125I-alpha-bungarotoxin binding appears in cells about 4 hr old and rapidly approaches maximum levels by about 36 hr. The in vitro expression pattern for ChAT and AChE is similar to that seen in vivo. AChE activity has been localized histochemically to the neurons and their processes in vitro. The normal in vitro expression pattern for ChAT and AChE can be altered by adding various cholinergic drugs to the culture medium during cell differentiation. Medium conditioned by older cultures can also result in lower levels of ChAT and AChE expression.(ABSTRACT TRUNCATED AT 250 WORDS)