[Tyrosine kinase inhibitors discontinuation for chronic myeloid leukemia: a multicenter retrospective analysis in China]

目的

回顾性分析中国慢性髓性白血病（CML）酪氨酸激酶抑制剂（TKI）自动停药患者的临床特征及转归情况。

方法

回顾性分析2005年6月1日至2018年3月1日国内7家单位109例自动停用TKI的慢性期CML患者临床资料，将其中具有明确停药结局及相对完整临床资料的91例患者进行统计分析，观察患者自动停药后获得无治疗缓解（TFR）情况及其影响因素。

结果

91例患者累积服用TKI中位时间为65（7~138）个月，其中21例患者有减停药史；患者达到主要分子学缓解（MMR）中位时间为开始服用TKI后6（3~57）个月；全部患者停药前达MR^4.0。停药后中位随访9（1~72）个月，53例（58.2%）患者继续维持MMR，获得TFR；38例（41.8%）失去MMR。12个月和25个月的TFR率分别为61.4%和52.6%。31例停药后复发的患者再启动药物治疗，用药后再获得MMR的中位时间为3（1~12）个月。对比分析发现，Sokal评分（P=0.294）、累积服用TKI时间（P=0.827）、获得MMR所需时间（P=0.553），是否减停TKI（P=0.125）等因素对复发无明显影响。而停药前MMR维持时间越长（≥24个月）患者后期复发率越低（P=0.027）。

结论

达停药标准的中国CML患者能够安全停用TKI，停药后TFR率与国外报道相当。停药前MMR时间维持越长，停药后复发率越低。

[Primary antifungal prophylaxis with posaconazole plays a pivotal role during chemotherapy of acute myeloid leukemia]

Objective: To evaluate the incidence of invasive fungal infections (IFI) and usage of intravenous antifungal drugs during remission induction chemotherapy in patients with acute myeloid leukemia (AML) under primary antifungal prophylaxis with posaconazole. Methods: Clinical records from newly diagnosed AML patients above 15 years old in one single center from February 2014 to January 2016 were retrospectively reviewed and analyzed, excluding acute promyelocytic leukemia. The incidence of IFI and usage of intravenous antifungal drugs were investigated between control group (not receiving any broad spectrum antifungal prophylaxis) and treatment group (receiving posaconazole as primary prophylaxis). Results: A total of 147 newly diagnosed AML patients were enrolled. Of them, 81 received prophylaxis with posaconazole, and 66 did not receive broad-spectrum antifungal treatment. 7 IFI occurred in posaconazole group, and all were possible cases; 19 IFI occurred in control group (3 proven, 4 probable, 12 possible). The incidence of IFI was significantly lower in treatment group than that in control group (8.6% vs 28.8%, χ(2)=10.138, P=0.001). Usage of intravenous antifungal drugs was significantly decreased in posaconazole group (18.5% vs 50.0%, χ(2)=16.390, P<0.001). Conclusion: Prophylaxis with posaconazole coulf prevent IFI and reduce usage of intravenous antifungal drugs significantly during remission induction chemotherapy in AML patients.

[Application of imatinib in BCR- ABL positive acute lymphoblastic leukemia treatment in the real world]

目的

探讨真实世界中伊马替尼(IM)联合化疗治疗BCR-ABL阳性急性淋巴细胞白血病(ALL)的疗效及相关预后因素。

方法

2003年4月至2015年8月收治的209例治疗中包含IM的BCR-ABL阳性ALL患者纳入研究，106例患者接受造血干细胞移植(HSCT)。对患者的疗效和预后影响因素进行分析。

结果

初诊患者诱导完全缓解(CR)率为97.9%。初诊时WBC≥100×10⁹/L是总生存(OS)的不良预后因素(P=0.043)。未接受HSCT、诱导治疗4周内未达CR和治疗过程中未达到分子生物学完全缓解(CMR)是OS(P值分别为<0.001、0.009和<0.001)和无复发生存(RFS)(P值均<0.001)的不良预后因素。接受异基因HSCT和自体HSCT的患者，其OS和RFS的差异均无统计学意义(P值均>0.05)。首次诱导治疗时联用IM的患者较未联用者显示出更高的5年RFS率(37.0％对24.0%，P= 0.005)。在治疗过程中持续规律服用酪氨酸激酶抑制剂(TKI，40例患者由于复发、转录本水平下降不理想或出现突变换用其他TKI)的患者生存情况最佳，其次为骨髓抑制期间断停用TKI的患者，不规律服用TKI的患者生存情况最差，三组5年OS率分别为46.0%、28.0%、17.0%(P=0.004)，5年RFS率分别为38.0%、28.0%、17.0%(P<0.001)。

结论

TKI联合化疗获得CMR，序贯以HSCT可改善BCR-ABL阳性ALL患者预后，持续规律地联用TKI有助于BCR-ABL阳性ALL患者疗效的提高。

[Characteristics and prognosis in adult acute myeloid leukemia patients with MLL gene rearrangements]

Objective: To analyze the clinical and laboratory characteristics, and prognosis of adult acute myeloid leukemia (AML) patients with MLL gene rearrangements. Methods: The medical records of 92 adult AML patients with MLL gene rearrangements from January 2010 to December 2016 were retrospectively analyzed. Results: 92 cases (6.5%) with MLL gene rearrangements were identified in 1 417 adult AML (Non-M(3)) patients, the median age of the patients was 35.5 years (15 to 64 years old) with an equal sex ratio, the median WBC were 21.00(0.42-404.76)×10(9)/L, and 78 patients (84.8%) were acute monoblastic leukemia according to FAB classification. Eleven common partner genes were detected in 32 patients, 9 cases (28.1%) were MLL/AF9(+), 5 cases (15.6%) were MLL/AF6(+), 5 cases (15.6%) were MLL/ELL(+), 2 cases (6.3%) were MLL/AF10(+), 1 case (3.1%) was MLL/SETP6(+), and the remaining 10 patients' partner genes weren't identified. Of 92 patients, 83 cases with a median follow-up of 10.3 (0.3-74.0) months were included for the prognosis analysis, the complete remission (CR) rate was 85.5% (71/83), the median overall survival (OS) and relapse free survival (RFS) were 15.4 and 13.1 months, respectively. Two-year OS and RFS were 36.6% and 29.5%, respectively. Of 31 patients underwent allogeneic hematopoietic stem-cell transplantation (allo-HSCT), two-year OS and RFS for patients received and non-received allo-HSCT were 57.9% and 21.4%, 52.7% and 14.9%, respectively (P<0.001). Among patients with partner genes tested, 9 of 32 cases (28.1%) were MLL/AF9(+), the median follow-up was 6.0(4.1-20.7) months. 3 patients with MLL/AF9 underwent allo-HSCT. 23 cases (71.9%) were non- MLL/AF9(+), the median follow-up was 7.8 (0.3-26.6) months. 14 patients (60.1%) with non-MLL/AF9 underwent allo-HSCT. One-year OS for patients with MLL/AF9 and non-MLL/AF9 were 38.1% and 55.5%, respectively (P=0.688). Multivariate analysis revealed that high WBC (RR=1.825, 95% CI 1.022-3.259, P=0.042), one cycle to achieve CR (RR=0.130, 95% CI 0.063-0.267, P<0.001), post-remission treatment with allo-HSCT (RR=0.169, 95% CI 0.079-0.362, P<0.001) were independent prognostic factors affecting OS. Conclusions: AML with MLL gene rearrangements was closely associated with monocytic differentiation, and MLL/AF9 was the most frequent partner gene. Conventional chemotherapy produced a high response rate, but likely to relapse, allo-HSCT may have the potential to further improve the prognosis of this group of patients.

[Prognostic significance of flow cytometric minimal residual disease in acute myeloid leukemia during aplasia]

Objective: To investigate the impact of minimal residual disease (MRD) by multiparameter flow cytometry (MPFC) during aplasia on efficacy and prognosis of de novo acute myeloid leukemia (AML) (non M(3)) patients. Methods: The MRD data by 8-color MPFC during aplasia (day 14-15 of induction therapy) in 85 de novo AML (non M(3)) patients and the MRD impact on efficacy and prognosis were retrospectively analyzed. Results: Data of 85 patients, including 42 males (49.4%) and 43 females (50.6%) , were collected, with a median age of 35 (15-54) years. The median MRD by MPFC during aplasia was 0.58% (0-81.11%) , and 70 (82.4%) patients achieved complete remission (CR) after first induction chemotherapy. The cutoff of MRD by receiver operating characteristic (ROC) analysis was 2.305% (Se= 0.867, Sp=0.800) . The CR rate after one course was significantly higher in patients with MRD<2.305% [96.6% (56/58) ]than in patients with MRD≥2.305%[51.9% (14/27) ] (χ(2)=22.348, P<0.001) ; no significant difference with respect to relapse-free survival rate (χ(2)=1.08, P=0.299) or overall survival rate (χ(2)=0.42, P=0.516) could be demonstrated for the comparison of the two groups. Multivariates analysis showed MRD divided by 2.305% was the only independent prognostic factor for CR after one course (OR= 21.560, 95% CI 4.129-112.579, P<0.001) . Conclusion: Flow cytometric MRD divided by 2.305% during aplasia could be a predictor of efficacy after first induction therapy in AML patients.

[Prediction of outcome in acute myeloid leukemia by measurement of WT1 expression as a basic marker of minimal residual disease]

Objective: To probe the potential utility of Wilms tumor 1 (WT1) as a marker of minimal residual disease (MRD) in acute myeloid leukemia (AML) to estimate the relapse-predicting cut-off value. Methods: Quantitative assessment of bone marrow WT1 mRNA level was preformed using real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) assay. The expression levels of WT1 dynamically measured with RQ-RT-PCR were retrospectively analyzed in 121 AML cases (not including acute promyelocytic leukemia) achieving complete remission (CR) after induction therapy followed by consolidation therapy. By comparing WT1 levels of patients with different post-therapy outcomes, the investigators used the receiver operating characteristic (ROC) curve to determine WT1 threshold so as to predict their clinical relapses. Then prognoses and the significance of intervention were analyzed between WT1 positive and negative patients according to the cut-off value of WT1. Results: According to ROC curve, WT1 level higher than 2.98% predicted the possibility of relapse. For simplicity and clinical application, 3.00% was used as the cut-off value of WT1 level for relapse. WT1 levels in 41 patients at diagnosis were detected, meanwhile 3 patients whose WT1 levels at diagnosis below 3.00% were excluded, then the median WT1 level of the rest 38 patients at diagnosis was 44.09% (range 7.19%-188.06%) . The median WT1 level in remission was 0.48% (352 samples, range 0-8.41%) . The median WT1 level at diagnosis was higher than that in remission. Excluding the 3 patients with WT1 level at diagnosis under 3.00%, the relapse rate of WT1 positive group (>3.00% during consolidation phase and follow-up) and WT1 negative group (≤3.00%) was 70.0% (14/20) and 12.2% (12/98) respectively (P<0.001) . The median time from WT1 positivity to clinical relapse was 58 days. Conclusions: WT1 expression level above 3.00% was associated with markedly high risk of relapse, which could be as a useful marker for monitoring MRD following consolidation therapy.

[Clinical features and prognosis in CD10(-) pre-B acute lymphoblastic leukemia]

目的

分析CD10阴性的前B急性淋巴细胞白血病（CD10⁻pre B-ALL）患者的临床特征和预后。

方法

对6例成人CD10⁻ pre B-ALL患者的临床和实验室资料进行回顾性分析，结合文献复习明确该类型患者的临床特征及预后。

结果

CD10⁻pre B-ALL占ALL的1.5%（6/409），占B-ALL的1.8%（6/343），占pre B-ALL的11.5%（6/52）。6例患者均为男性，中位年龄为33.5岁，起病时中位WBC为101.78×10⁹/L，所有患者均伴有MLL-AF4融合基因表达。5例患者经1个疗程诱导化疗即获得完全缓解（CR），1例患者经3个疗程化疗后才获得CR。2例患者在CR₁期行异基因造血干细胞移植（allo-HSCT），1例患者CR后短期内即复发，在CR₂期行allo-HSCT。1例患者正在等待移植。2例未移植患者1例复发死亡，1例尚处于缓解状态。

结论

CD10⁻pre B-ALL是一类具有独特临床特征的成人ALL亚型，发生率较低，常见于男性，起病时白细胞水平较高，MLL-AF4融合基因表达率高，常规化疗具有较高的缓解率，但易复发，allo-HSCT有可能改善其预后。

Research on the effect and mechanism of the CXCR-4-overexpressing BMSCs combined with SDF-1α for the cure of acute SCI in rats

OBJECTIVE

To evaluate the effect and mechanism of bone marrow stem cells (BMSCs) modified with CXCR-4 gene combined with stromal derived factor-1α (SDF-1α) in the treatment of acute spinal cord injury (SCI) in rats.

MATERIALS AND METHODS

CXCR-4 gene was transfected by a virus. Spinal cord injury rats were randomly divided into four groups: control group, SDF-1α group, CXCR-4/BMSC group and combined group. The motor function was evaluated with Blood Brain Barrier (BBB) score and the RNA expression of CXCR-4 were measured by PCR. Apoptosis of spinal cord was measured by TUNEL kit (Hu Bei, China). The protein level of Bcl-2 and Bax were measured by Western-blot. The BBB scores, mRNA CXCR-4 expression, and apoptosis rate were compared between four groups at 1d, 3d, 7d, 14d, 21d after the operation.

RESULTS

The exercise ability in combined group restored in early and late periods of SCI. The apoptosis rates in the combined group are less than other three groups; the difference was statistically significant (p < 0.05). Bcl-2 in combined group is higher than the other 3 groups and Bax is less than the other 3 groups, the difference is statistically significant (p < 0.05).

CONCLUSIONS

The neurological function of rats with a spinal cord can be improved by BMSCs modified with CXCR-4 combined with SDF-1α. The main mechanism may improve the expression of SDF-1α and decrease the apoptosis of the spinal cord.

[Homoharringtonine in newly diagnosed acute promyelocytic leukemia treatment: a prospective, randomized controlled trial]

OBJECTIVE

To compare the efficacy and toxicities of combining homoharringtonine (HHT)±daunorubicin (DNR) with all-trans-retinoic acid (ATRA) based therapy and DNR plus ATRA based therapy in newly diagnosed low/intermediate risk acute promyelocytic leukemia (APL).

METHODS

A total of 96 newly diagnosed patients with APL were randomized to HHT group, DNR group and HHT+ DNR group prospectively. The complete remission (CR) rate, the overall survival (OS) and event-free survival (EFS) of three groups were analyzed.

RESULTS

There were 31 patients in HHT group, 33 patients in DNR group and 32 patients in HHT+ DNR group. The baseline characteristics of three groups were similar. No patient died during induction therapy. The morphologic CR rate was 100.0%. The median time to peak WBC counts in HHT+DNR group (4 days, range: 1-23 days) was significantly shorter than that in HHT group (9 days, range: 1-27 days) (P=0.008) and DNR group (7 days, range: 1-27 days) (P=0.240). There was no difference among three groups about the incidence of differentiation syndrome, the median interval to achieve CR, peak WBC counts and transfusions (P >0.05). All patients achieved complete molecular remission (CMR) during consolidation therapy. The interval to achieve CMR was no significantly difference among three groups (P >0.05). The 3-year OS rates for HHT group, DNR group and HHT+DNR group were 95.0%, 100.0% and 91.0%, respectively (P=0.595). The 3-year EFS rates for three groups were 93.0%, 90.0% and 85.0% (P=0.382). No difference was found in the incidence of adverse events among three groups (P >0.05).

CONCLUSIONS

Similar to DNR plus ATRA based therapy, HHT plus ATRA based induction and consolidation therapy should be one of highly-efficient treatment options for newly diagnosed APL. Clinical trial registration Chinese Clinical Trial Registry, ChiCTR-TRC-12002628.

Autoantibody detection to tumor-associated antigens of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn, and Koc for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma

The aim of this study was to evaluate the diagnostic values by detecting sera autoantibodies to eight tumor-associated antigens (TAAs) of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn and Koc full-length recombinant proteins for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma (ESCC). Enzyme-linked immunosorbent assay was used to detect autoantibodies against the eight selected TAAs in 567 sera samples from four groups, including 200 individuals with normal esophageal epithelia (NOR), 214 patients with esophageal basal cell hyperplasia (BCH), 65 patients with esophageal dysplasia (DYS), and 88 patients with ESCC. In addition, the expression of the eight antigens in esophageal tissues was analyzed by immunohistochemistry. Statistically significant distribution differences were identified among the four groups for each of the individual autoantibodies to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc); the detection rates of antoantibodies were positively correlated with the progression of ESCC. When autoantibody assay successively accumulated to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc), a stepwise increased detection frequency of autoantibodies was found in the four sera groups (6% in NOR, 18% in BCH, 38% in DYS, and 64% in ESCC, respectively), the risks to BHC, DYS, and ESCC steadily increased about 3-, 9-, and 27-folds. The sensitivity and the specificity for autoantibodies against the six TAAs in diagnosing ESCC reached up to 64% and 94%, respectively. The area under the receiver operating characteristic curve for the six anti-TAA autoantibodies was 0.78 (95% confidence interval 0.74-0.83). No more increasing in sensitivity was found with the addition of new anti-TAA autoantibodies. A combination detection of autoantibodies to TAAs might distinguish ESCC patients from normal individuals and the patients with esophageal precancerous lesions.

Note: A new angle-resolved proton energy spectrometer

In typical laser-driven proton acceleration experiments Thomson parabola proton spectrometers are used to measure the proton spectra with very small acceptance angle in specific directions. Stacks composed of CR-39 nuclear track detectors, imaging plates, or radiochromic films are used to measure the angular distributions of the proton beams, respectively. In this paper, a new proton spectrometer, which can measure the spectra and angular distributions simultaneously, has been designed. Proton acceleration experiments performed on the Xtreme light III laser system demonstrates that the spectrometer can give angle-resolved spectra with a large acceptance angle. This will be conductive to revealing the acceleration mechanisms, optimization, and applications of laser-driven proton beams.

Note: Diagnosing femtosecond laser-solid interactions with monochromatic Kα imager and x-ray pinhole camera

An x-ray pinhole camera and a monochromatic K(α) imager are used to measure the interactions of intense femtosecond laser pulses with Cu foil targets. The two diagnostics give different features in the spot size and the laser energy scaling, which are resulted from different physical processes. Under our experimental conditions, the K(α) emission is mainly excited by the fast electrons transporting inside the cold bulk target. In contrast, the x-ray pinhole signals are dominated by the broadband thermal x-ray emission from the hot plasma at the front target surface.

Effect of prepulse on fast electron lateral transport at the target surface irradiated by intense femtosecond laser pulses

The effects of preplasma on lateral fast electron transport at front target surface, irradiated by ultraintense (>10(18) W/cm2) laser pulses, are investigated by Kα imaging technique. A large annular Kα halo with a diameter of ∼560 μm surrounding a central spot is observed. A specially designed steplike target is used to identify the possible mechanisms. It is believed that the halos are mainly generated by the lateral diffusion of fast electrons due to the electrostatic and magnetic fields in the preplasma. This is illustrated by simulated electron trajectories using a numerical model.

Generating high-current monoenergetic proton beams by a circularly polarized laser pulse in the phase-stable acceleration regime

A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations.

Helmets for preventing injury in motorcycle riders

BACKGROUND

Motorcycle crash victims form a high proportion of those killed or injured in road traffic crashes. Injuries to the head, following motorcycle crashes, are a common cause of severe morbidity and mortality. It seems intuitive that helmets should protect against head injuries but it has been argued that motorcycle helmet use decreases rider vision and increases neck injuries. This review will collate the current available evidence on helmets and their impact on mortality, and head, face and neck injuries following motorcycle crashes.

OBJECTIVES

To assess the effects of wearing a motorcycle helmet in reducing mortality and head and neck injury following motorcycle crashes.

SEARCH STRATEGY

We searched the Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (The Cochrane Library issue 2, 2007), MEDLINE (up to April 2007), EMBASE (up to April week 16, 2007), CINAHL (January 1982 to February 2003), TRANSPORT (up to issue 12, 2006) (TRANSPORT combines the following databases: Transportation Research Information Services (TRIS) International Transport Research Documentation (ITRD) formerly International Road Research Documentation (IRRD), ATRI (Australian Transport Index) (1976 to Feb 2003), Science Citation Index were searched for relevant articles. Websites of traffic and road safety research bodies including government agencies were also searched. Reference lists from topic reviews, identified studies and bibliographies were examined for relevant articles.

SELECTION CRITERIA

We considered studies that investigated a population of motorcycle riders who had crashed, examining helmet use as an intervention and with outcomes that included one or more of the following: death, head, neck or facial injury. We included any studies that compared an intervention and control group. Therefore the following study designs were included: randomised controlled trials, non-randomised controlled trials, cohort, case-control and cross-sectional studies. Ecological and case series studies were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently screened reference lists for eligible articles. Two authors independently assessed articles for inclusion criteria. Data were abstracted by two independent authors using a standard abstraction form.

MAIN RESULTS

Sixty-one observational studies were selected of varying quality. Despite methodological differences there was a remarkable consistency in results, particularly for death and head injury outcomes. Motorcycle helmets were found to reduce the risk of death and head injury in motorcyclists who crashed. From four higher quality studies helmets were estimated to reduce the risk of death by 42% (OR 0.58, 95% CI 0.50 to 0.68) and from six higher quality studies helmets were estimated to reduce the risk of head injury by 69% (OR 0.31, 95% CI 0.25 to 0.38). Insufficient evidence was found to estimate the effect of motorcycle helmets compared with no helmet on facial or neck injuries. However, studies of poorer quality suggest that helmets have no effect on the risk of neck injuries and are protective for facial injury. There was insufficient evidence to demonstrate whether differences in helmet type confer more or less advantage in injury reduction.

AUTHORS' CONCLUSIONS

Motorcycle helmets reduce the risk of death and head injury in motorcycle riders who crash. Further well-conducted research is required to determine the effects of helmets and different helmet types on mortality, head, neck and facial injuries. However, the findings suggest that global efforts to reduce road traffic injuries may be facilitated by increasing helmet use by motorcyclists.

Mass and KLamda coupling of the N*(1535)

Using a resonance isobar model and an effective Lagrangian approach, from recent BES results on J/psi-->ppeta and psi-->pK+Lamda, we deduce the ratio between effective coupling constants of N*(1535) to KLamda and peta to be R=gN*(153)KLamda/gN*(1535)peta=1.3+/-0.3. With the previous known value of gN*(1535)peta, the obtained new value of gN*(1535)KLamda is shown to reproduce recent pp-->pK+Lamdanear-threshold cross section data as well. Taking into account this large N*KLamda coupling in the coupled channel Breit-Wigner formula for the N*(1535), its Breit-Wigner mass is found to be around 1400 MeV, much smaller than the previous value of about 1535 MeV obtained without including its coupling to KLamda. The implication on the nature of N*(1535) is discussed.

Synthesis of high-quality single-walled carbon nanotubes by catalytic decomposition of C2H2

High-quality single-walled carbon nanotubes free of defects and amorphous carbon coating have been produced by catalytic decomposition of C2H2 over Fe-Mo/Al2O3 catalyst.

Expression of telomerase subunits in normal and neoplastic prostate epithelial cells isolated by laser capture microdissection

BACKGROUND

Vertebrates have special structures at the ends of their chromosomes, known as telomeres, which may provide the chromosomes with stability and protect them from exonucleolytic degradation. The shortening of telomeric DNA with each cell division may lead to cell cycle arrest and/or apoptosis of a normal human somatic cell. Telomerase, an RNA-dependent DNA polymerase, elongates the 3'-ends of telomeric DNA. Thus, the presence of telomerase activity may reflect a cell's potential immortal state. The telomerase complex is comprised of several subunits. In the current study, the authors describe the use of laser capture microdissection (LCM) to procure pure matched tumor and normal cell populations from histologic sections and to determine the expression of telomerase subunits in these purified samples.

METHODS

Pure matched tumor and normal prostate epithelial cells were procured by LCM using fresh frozen tissue samples obtained from patients undergoing radical prostatectomy. RNA was extracted from LCM captured cells, and the subunits for telomerase were assayed by reverse transcriptase-polymerase chain reaction.

RESULTS

In 18 samples that were captured with LCM, only the catalytic subunit of telomerase, or hTERT, was found to be discriminatory between tumor cells (17 of 18 specimens, 94.4%) and nontumor cells (none of 18 specimens). TP1, a protein that has been shown to be associated with telomerase activity, was expressed in 3 of 18 normal cells (16.7%) and 15 of 18 tumor cells (83.3%). The RNA subunit of telomerase, or hTR, was expressed in 10 of 18 normal cells (55.6%) and 18 of 18 tumor cells (100%). There was no apparent correlation between telomerase subunit(s) expression and Gleason sum score.

CONCLUSIONS

Molecular analyses of LCM cells from prostate carcinoma patient samples demonstrated transcriptional up-regulation of all telomerase subunits in the prostatic epithelium. However, only the catalytic subunit of telomerase, hTERT, was found to be discriminatory between neoplastic versus normal cells (94.4% vs. 0%). This finding suggests that the hTERT subunit may be a useful marker for the detection of prostate carcinoma and/or a potential target for therapy.

Effects of L-arginine on the proliferation of human renal mesangial cells and production of extracellular matrix

AIM

To investigate the effect of L-arginine (L-arg) on the proliferation of human mesangial cells and production of collagen.

METHODS

The influence of L-arg on the cell proliferation was determined by MTT assay, immunocytochemical detection of expression of proliferative cell nuclear antigen (PCNA), and flow cytometrical analysis of cell cycle. Procollagen III and total collagen level in the supernatant and expression of collagen IV mRNA in human mesangial cells were determined by radioimmunoassay, hydroxyproline colorimetric assay, and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

L-Arg induced inhibition of human mesangial cell lines (HMCL) in a concentration- and time-dependent manner. Immunocytochemical study for PCNA showed the number of cells was decreased, though the percentage of PCNA positive cells was increased in L-arg-treated group. Flow cytometrical analysis showed that cells in S and G2/-M phases were markedly increased in L-arg-treated group compared with those in control group. Furthermore, L-arg significantly inhibited the production of procollagen III and total collagen in the supernatants determined by radioimmunoassay and hydroxyproline colorimetric assay (P < 0.05 and 0.01, respectively) and inhibited the expression of collagen IV mRNA determined by RT-PCR (P < 0.01).

CONCLUSION

L-arg could exert an inhibitory effect on the proliferation of human mesangial cells and production of extracellular components, which strongly suggested its potential therapeutic role in the chronic renal scarring.

Clearance of increased serum advanced glycosylation end products in patients with end stage renal disease by hemodialysis

AIM

To study the effect of removal of hemodialysis using acetate membrane on serum advanced glycosylation end products (AGEP) in 36 patients (59.1 +/- 1.6) with end stage renal disease (ESRD).

METHODS

Serum AGEP levels were determined with quantitative fluorescence spectrometry, flow injection analysis (FIA), and competitive enzyme-linked immunosorbent assay (ELISA) using a polyclonal antibody directed against AGEP.

RESULTS

The serum AGEP levels in patients with ESRD quantified by fluorescence spectrometry, FIA, and ELISA were higher than those in controls [(25 +/- 5) vs (7.5 +/- 1.5), (6.1 +/- 1.8) vs (1.4 +/- 0.5), and (37 +/- 20) vs (9 +/- 10) kU/L, respectively] and markedly reduced to [(22 +/- 6), (4.2 +/- 1.4), and (19 +/- 14) kU/L, respectively] after hemodialysis.

CONCLUSION

Increased serum AGEP levels in the circulation of patients with ESRD were reduced effectively by hemodialysis.

Telomerase in human bladder cancer

Biomarkers for human bladder cancer are currently available and more are being developed. However, the ultimate goal of diagnosing bladder cancer consistently in a noninvasive fashion has not yet been achieved. Telomerase is an enzyme that may play a role in maintaining telomere sequences in the ends of chromosomes and its activity may reflect the presence of immortal or cancer cells. In this article, we reviewed the potential applications of telomerase in the diagnosis, monitoring, and treatment of human bladder cancer.

Non-competitive inhibition of 5-HT3 receptor-mediated currents by progesterone in rat nodose ganglion neurons

The effect of progesterone on the serotonin type 3 (5-HT3) receptor-mediated response was studied in acutely dissociated rat nodose ganglion neurons by using the whole-cell voltage-clamp technique. Progesterone rapidly and reversibly inhibited 5-HT-induced currents in a dose-dependent manner, with an EC50 of 31 microM and a maximal inhibition of 75%. Neither the 5-HT response nor inhibition of the 5-HT response by extracellularly applied progesterone was significantly affected by inclusion of a saturating concentration of progesterone in the electrode buffer, arguing that progesterone acted at the extracellular surface of the membrane. Progesterone also inhibited the 5-HT response non-competitively by a voltage- and agonist-independent mechanism that was distinct from that of open-channel blockers.