[Detection of the expression of NK ligands in acute leukemia cell lines by real-time PCR].

OBJECTIVE: To detect the expression profile of NK ligands in acute leukemia cell lines and investigate the differential expression pattern between acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). METHODS: Using quantitative real-time PCR, 23 NK ligands (MICA, MICB, ULBP-1, ULBP-2, ULBP-3, ULBP-4, HLA-E, HLA-G, CD48, NBTA, HLA-F, LLT-1, PVR, Nectin2, CD72, CD80, ICAM-1, LFA-3, CRACC, Fas, DR4, DR5, TNFR1) were detected in 6 acute leukemia cell lines, including 3 ALL cell lines (CEM, Jurkat T, Reh) and 3 AML cell lines (HL-60, KG-1a, NB4), respectively. Independent-samples t test analysis was performed to determine statistical significance. RESULTS: Using ß-actin as reference gene, the relative expression results showed that the expression of 4 NK ligands between ALL and AML is significantly different. Specifically, the level of ULBP-2 is higher in ALL (CEM: 1, Jurkat T: 0.617, Reh: 0.246) than that in AML (HL-60: 0.000, KG-1a: 0.003, NB4: 0.000)(P = 0.047). However, the expressions of CD48, PVR(PVR-1, PVR-2) and DR4 is higher in AML (HL-60: 13.987, 4.403, 10.334, 8.711; KG-1a: 5.387, 2.900, 7.315, 4.512; NB4: 7.763, 3.248, 7.049, 6.127) than that in ALL (CEM: 1, 1, 1, 1; Jurkat T: 2.035, 1.553, 3.888, 0.449; Reh: 1.559, 0.000, 0.000, 1.304) (P = 0.044, 0.014, 0.014, 0.011). And there're no significant differences between the rest 19 NK ligands. CONCLUSIONS: ULBP-2, CD48, PVR and DR4 might play an important role in the distinct mechanisms in leukemogenesis between ALL and AML and could be potential targets for diagnosis and treatment.

Imatinib induces H2AX phosphorylation and apoptosis in chronic myelogenous leukemia cells in vitro via caspase-3/Mst1 pathway.

AIM: Histone H2AX is a novel tumor suppressor and its phosphorylation at the C terminus (Ser139 and Tyr142) is required for tumor cell apoptosis. The aim of the present study was to elucidate the mechanisms underlying imatinib-induced C-terminal phosphorylation of H2AX in chronic myelogenous leukemia cells in vitro. METHODS: BCR-ABL-positive K562 cells were used. Microscopy, Western blotting and flow cytometry were used to study the signaling pathways that regulate imatinib-induced H2AX phosphorylation and the apoptotic mechanisms. RESULTS: Treatment of K562 cells with imatinib (1-8 µmol/L) induced phosphorylation of H2AX at Ser139 and Tyr142 in time- and dose-dependent manners. In contrast, imatinib at the same concentrations did not affect H2AX acetylation at Lys 5, and the acetylated H2AX maintained a higher level in the cells. Meanwhile, imatinib (1-8 µmol/L) activated caspase-3 and its downstream mammalian STE20-like kinase 1 (Mst1), and induced apoptosis of K562 cells. The caspase-3 inhibitor Z-VAD (40 µmol/L) reduced imatinib-induced H2AX phosphorylation at Ser139 and Tyr142 and blocked imatinib-induced apoptosis of K562 cells. Imatinib (4 µmol/L) induced expression of Williams-Beuren syndrome transcription factor (WSTF), but not wild-type p53-induced phosphatase 1 (Wip1) in K562 cells. CONCLUSION: The caspase-3/Mst1 pathway is required for H2AX C-terminal phosphorylation at Ser139 and Tyr142 and subsequent apoptosis in Bcr-Abl-positive K562 cells induced by imatinib.

[Characteristics of the action potentials and the underlying ionic mechanisms in the cardiomyocytes from rabbit pulmonary vein sleeves].

To investigate the characteristics of action potentials and their ionic mechanism in cardiomyocytes from rabbit pulmonary vein sleeves (PVC), and to compare them with those in left atrial cardiomyocytes (LAC), the technique of whole-cell patch clamp was applied. We used current-clamp technique to record action potentials, and voltage-clamp technique to record ionic currents. PVC had longer action potential duration (APD) than LAC, and therefore a second plateau response could be induced easily, suggesting a strong tendency of early afterdepolarization (EAD) genesis in PVC. Non-selective cation current (I(NSCC)) was first recorded in both LAC and PVC. This I(NSCC)was permeable to K(+), Na(+) and Cs(+), sensitive to GdCl3 but not sensitive to 4-AP. The current densities of inward rectifier potassium current (I(K1)), transient outward potassium current (I(To)) and I(NSCC) were all significantly less in PVC than those in LAC. These differences in repolarizing ionic currents between PVC and LAC form a basis of the differences in their action potential configurations and might be an important ionic mechanism of the arrhythmogenic characteristics of pulmonary vein muscle sleeves.

Clinical and sleep EEG monitoring characteristics and long-term follow-up study on narcolepsy / 中华儿科杂志

<p><b>OBJECTIVE</b>Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucination and sleep paralysis, with abnormal characteristics of shorter rapid eye movement (REM) sleep latency. The management of the patients is very important. The present study focused on the clinical characteristics, diagnostic methods and long-term prognosis of this particular syndrome.</p><p><b>METHODS</b>The clinical data of 39 narcoleptic children were analyzed. Sleep EEG monitoring was performed in all patients. Among the 39 cases, 23 were followed up.</p><p><b>RESULTS</b>All the patients manifested with excessive daytime sleepiness, with disrupted nocturnal sleep occurring in 35 cases. Cataplexy appeared in 36 cases, and sleep paralysis in 9, hypnagogic hallucination in 19, and automatic behavior in 6 cases, respectively. Sleep EEG monitoring demonstrated a short mean sleep latency (< 5 minutes) and two or more sleep onset REM periods (SOREMPs) in 38 cases. Twenty-three of the 39 cases were followed-up. Seventeen cases were followed-up for over one year. The longest follow-up duration was 14 years. Methylphenidate was administered in 10 cases. The excessive daytime sleepiness had been improved in 7 cases (70%). No obvious adverse effects were found. Psychosocial and academic problems appeared in most cases.</p><p><b>CONCLUSION</b>Narcolepsy is a chronic neurological disorder. A definite diagnosis is established when the symptoms of cataplexy and excessive daytime sleepiness occur in association with the characteristic findings on sleep EEG monitoring. Appropriate drug therapy and psychosocial management are of help for such patients. Stimulant medication is an important component of the overall treatment program. A comprehensive approach is necessary to meet the needs of children with narcolepsy. Family education and emotional support are key elements in the management plan. The overall goal for managing childhood narcolepsy is to assist the child and family in achieving optimal quality of life.</p>

Clinical observation and long-term follow-up of benign infantile epilepsy / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate clinical characteristics, EEG changes and therapeutic response of benign infantile epilepsy and to study the early diagnostic methods.</p><p><b>METHODS</b>Clinical observation and Video-EEG monitoring were carried out in babies with convulsions at 3 - 24 months of age. In these children, febrile convulsion, symptomatic epilepsies and developmental abnormalities were excluded, and the therapeutic effect and long-term outcome were followed up.</p><p><b>RESULTS</b>Forty-two babies were diagnosed to have benign infantile epilepsy by two-year follow-up. Three of them had familial history of benign infantile convulsions. Nineteen percent had mild diarrhea during the onset of convulsions, cluster seizures occurred during a short period in 67% of cases and no status epilepticus occurred. Video-EEG monitoring confirmed seizures originating from temporal, occipital or multifocal areas separately in 3 patients with partial seizures. Interictal EEG background was normal and there were Rolandic small spikes during sleep in 24% of patients. Thirty-nine patients were treated with single antiepileptic drugs and the mean treatment course was 9 months. Three cases did not take medicine. All the patients were seizure free within a year.</p><p><b>CONCLUSION</b>Benign infantile epilepsy should be considered when the following characteristics occur in early stage of the disease: (1) convulsions occurring between 3 to 12 month of age and not later than 24 months of age with or without familial history of benign infantile convulsion; (2) normal psychomotor development before and after convulsion occurs; (3) no evoked factors or only mild diarrhea; (4) majority of cases have partial seizures, or secondary generalized seizures. There are often cluster convulsions during the onset stage, but no status epilepticus; (5) normal EEG background and there may be Rolandic small spikes during sleep; (6) normal neuroimaging.</p>