Efficacy and safety of cladribine in combination with busulfan and cyclophosphamide as an intensive conditioning regimen preceding allogeneic hematopoietic stem cell transplantation in relapsed or refractory acute myeloid leukemia.

BACKGROUND: Cladribine, an analogue of deoxyadenosine, is used for therapy of hematological malignancies. Cladribine-containing regimen has been recommended as a rescue therapy for relapsed or refractory (R/R) acute myeloid leukemia (AML). Its combination with busulfan plus cyclophosphamide (BuCy), as an intensive conditioning regimen prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT), requires more clinical evidence. This study aimed to explore the efficacy and safety of cladribine plus BuCy administered as an intensive conditioning regimen before allo-HSCT in R/R AML patients. METHODS: Twenty-three R/R AML patients, who underwent cladribine plus BuCy intensive conditioning regimen before allo-HSCT, were retrospectively analyzed. The median (range) follow-up duration time of observation was 0.73 (0.08-2.69) years. RESULTS: The median (range) returned levels of mononuclear cells were 11.5 (6.1-18.5) x 108/kg and CD34+ cells were 5.5 (3.5-9.3) x 106/kg. The median (range) time of platelet reconstitution was 13.0 (9.0-21.0) days and neutrophil reconstitution was 14.0 (11.0-26.0) days. The incidence of conditioning regimen related toxicity (CRRT) affected 69.6% of patients; all CRRT-affected patients had grade I-II symptoms, including gastrointestinal tract (39.1%), oral cavity (26.1%), liver (8.7%), and kidney (4.3%) CRRTs. The incidence of acute graft-versus-host disease (GVDH) included 30.4% among all patients with 4.3% of grade III-IV acute GVHD, and 34.8% of chronic GVHD. During the follow-up period, 4 (17.4%) patients relapsed, and 6 (26.1%) patients died (cause of death: disease relapse, n = 3; infection, n = 2; GVHD, n = 1). The 1-year and 2-year accumulating event-free survival rates were 66.3% and 53.1%, respectively. The 1-year accumulating overall survival rate was 74.7% and 2-year survival rate was 64.0%. CONCLUSION: Cladribine plus BuCy intensive conditioning regimen before allo-HSCT exhibits favorable treatment efficacy with acceptable toxicity in R/R AML patients.

Unraveling neoantigen-associated genes in bladder cancer: An in-depth analysis employing 101 machine learning algorithms.

The therapeutic outcomes for bladder cancer (BLCA) remain suboptimal. Concurrently, there is a growing appreciation for the role of neoantigens in tumors. In this study, we explored the mechanisms underlying the involvement of neoantigen-associated genes in BLCA and their impact on prognosis. Our analysis incorporated both single-cell sequencing and bulk sequencing data sourced from publicly available databases. By employing a comprehensive set of 10 machine learning algorithms, we generated 101 algorithm combinations. The optimal combination, determined based on consistency indices, was utilized to construct a prognostic model comprising nine genes (CAPG, ACTA2, PDIA6, AKNA, PTMS, SNAP23, ID2, CD3G, SP140). Subsequently, we validated this model in an independent cohort, demonstrating its robust testing efficacy. Moreover, we explored the correlations between various clinical traits, model scores, and genes. Leveraging extensive public data resources, we conducted a drug sensitivity analysis to provide insights for targeted drug screening. Additionally, consensus clustering analysis and immune infiltration analysis were performed on bulk sequencing datasets and immunotherapy cohorts. These analyses yield valuable insights into the role of neoantigens in BLCA, guiding future research endeavors.

Efficacy and safety of PD-1 inhibitor alone or combined with chemotherapy in patients with relapsed or refractory extranodal natural Killer/T cell lymphoma: A retrospective study.

Extranodal natural killer/T cell lymphoma (ENKTL) patients typically face a grim prognosis after relapse or progression following asparaginase-based chemotherapy. Currently, programmed cell death protein-1 (PD-1) immune checkpoint blockade has shown promising efficacy as an optimal regimen for relapsed or refractory ENKTL (rrENKTL) patients. This study retrospectively investigated the efficacy, safety, and factors influencing the survival of 26 rrENKTL patients who underwent monoclonal antibody treatment using PD-1 (Sintilimab or Camrelizumab) alone or combined with chemotherapy from January 2018 to February 2022. The disease control rate was 73.1%, and the objective response rate was 50.0%. 15.4% of the patients achieved complete remission, and 34.6% achieved partial remission (PR). After a median follow-up of 12 (range 3-47) months, the median progression-free survival (PFS) and overall survival (OS) were 6.5 and 13.3 months. The 1-year PFS and OS rate were 23.1% and 53.8%. 96.2% of patients experienced at least one adverse event and 26.9% experienced grade 1-2 immune-related adverse events. PD-1 inhibitor improved rrENKTL patient survival, and the AEs were controlled. We also observed that the prognostic index for NK cell lymphoma including Epstein-Barr virus (EBV) (PINK-E) and the nomogram-revised risk indexz for ENKTL patients could help identify a potentially unfavorable prognosis in this era of immunotherapy. More attention should be paid to the presence of EBV after anti-PD-1 immunotherapy, as it more accurately indicates a poor prognosis.

Serological Epidemiological Investigation of Tibetan Sheep (Ovis aries) Plague in Qinghai, China.

The plague, which is caused by the Gram-negative coccobacillus bacterium Yersinia pestis, has been classified as a reemerging infectious disease by the World Health Organization. The Qinghai-Tibet Plateau natural plague focus is the largest plague focus in China, and Marmota himalayana is the primary host of the plague. Tibetan sheep (Ovis aries) were first identified as naturally infected hosts of Y. pestis based on etiological evidence in 1975, and activities such as slaughtering or skinning Tibetan sheep that have been infected by Y. pestis or died from Y. pestis infection had caused severe human plague in Qinghai. Tibetan sheep are important domestic livestock in the Qinghai-Tibet Plateau. Knowledge regarding the infection rate of Y. pestis in Tibetan sheep is important for understanding the range of infection and improving measures to control plague epidemics in this area. In this study, a serological survey involving 12,710 Tibetan sheep in all 44 counties in Qinghai Province was conducted. The total positive rate of indirect hemagglutination assay for Y. pestis in Tibetan sheep in Qinghai was 0.68% (86/12,710). Serological positivity to the Y. pestis F1 antibody was found in Tibetan sheep in all prefectures, except the Haidong and Haibei prefectures in Qinghai, with the seropositive rate in different counties ranging from 0.33% to 5.2% and the titers in the positive sera ranging from 1:20 to 1:5120. In addition, the seropositive rates in animal plague focus counties were higher than the rates in non-animal plague counties. Such results indicated a widespread infection of Tibetan sheep with Y. pestis in Qinghai, even though only sporadic epidemics of Tibetan sheep plague have been reported in Qinghai.

[The epidemiology and etiology research of Tibetan sheep plague in Qinghai plateau].

OBJECTIVE: To identify the epidemiology and etiology characteristics of Tibetan sheep plague in Qinghai plateau. METHODS: The background materials of Qinghai Tibetan sheep plague found during 1975 to 2009 were summarized, the regional, time and interpersonal distribution, infection routes, ecological factors for the spread were used to analyze; followed by choosing 14 Yersinia pestis strains isolated from such sheep for biochemical test, toxicity test, virulence factors identification, plasmid analysis, and DFR genotype. RESULTS: From 1975 to 2009, 14 Yersinia pestis strains were isolated from Tibetan sheep in Qinghai province. Tibetan sheep, as the infection source, had caused 10 cases of human plague, 25 plague patients, and 13 cases of death. All of the initial cases were infected due to eating Tibetan sheep died of plague; followed by cases due to contact of plague patients, while all the initial cases were bubonic plague. Cases of bubonic plague developed into secondary pneumonic plague and septicemia plague were most popular and with high mortality. Most of the Tibetan sheep plague and human plague occurred in Gannan ecological zone in southern Gansu province, which was closely related to its unique ecological and geographical landscape. Tibetan sheep plague coincided with human plague caused by Tibetan sheep, especially noteworthy was that November (a time for marmots to start their dormancy) witnesses the number of Yersinia pestis strains isolated from Tibetan sheep and human plague cases caused by Tibetan sheep. This constituted the underlying cause that the epidemic time of Tibetan sheep plague lags obviously behind that of the Marmot plague. It was confirmed in the study that all the 14 strains were of Qinghai-Tibet Plateau ecotype, with virulence factors evaluation and toxicity test demonstrating strains as velogenic. As found in the (Different Region) DFR genotyping, the strains isolated from Yushu county and Zhiduo county were genomovar 5, the two strain isolated from Nangqian county were genomovar 5 and genomovar 7, while those isolated Delingha region were genomovar 8. CONCLUSION: Tibetan sheep were vulnerable to plague infection, hence causing human plague as the infectious source. The Yersinia pestis strains isolated from Tibetan sheep plague carried pathogen characteristics of Qinghai-Tibet plateau plague, developing many new characteristics of such plague.

[Study of the plasmid profiles and geographical distribution of Yersinia pestis in China].

OBJECTIVE: To analyze the plasmid features and geographical distribution characteristics of Yersinia pestis of different plague foci in China. METHODS: A total of 2 213 Yersinia pestis strains were colected from 11 Chinese plague foci separated during 1943 to 2012, and plasmid DNA according to alkali cracking method, and measured the relative molecular mass (Mr) of plasmid DNA based on the standard plasmid contrast method, then analyzed the plasmid profiles by agar gel electrophoresis. RESULTS: A total of 2 213 strains had 16 kinds of plasmids with different Mr, including 4×10(6), 6×10(6), 7×10(6), 13×10(6), 16×10(6), 20×10(6), 22×10(6), 23×10(6), 27×10(6), 30×10(6), 36×10(6), 45×10(6), 52×10(6), 65×10(6), 72×10(6) and 90×10(6). Plasmid were classified into 26 kinds of plasmid profiles. A total of 2 213 Yersinia pestis strains contained 4 large plasmids, 52×10(6), 65×10(6), 72×10(6) and 90×10(6), whose ratio was 22.10% (589/2 213), 75.60% (1 672/2 213), 0.17% (4/2 213), 2.12% (47/2 213), respectively. Among which, strains with plasmid 52×10(6), 65×10(6), 90×10(6) distributed in Qinghai-Tibet plateau Himalayan Marmot natural plague foci, strains with 72×10(6) plasmid only distributed in Inner Mongolia Meriones unguiculatus natural plague foci and Junggar Basin R. opimus natural plague foci, and 65×10(6) plasmid distributed in all the other foci. CONCLUSION: Strains in Chinese 11 plague foci contained 4 kinds of large plasmid, the Mr respectively were 52×10(6), 65×10(6), 72×10(6), 90×10(6), which were classified into 26 kinds of plasmid profiles with other plasmid. These plasmid profiles distributed in relatively independent epidemic focus.

[Effect of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell RPMI8226].

This study was aimed to investigate the effects of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell line RPMI-8226 and its mechanism. The inhibitory rate of RPMI8226 cells proliferation was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted flurescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry. The effects of mitoxantrone on the expression of BCL-2, BAX, caspase-3 mRNA were detected by RT-PCR, the BCL-2, BAX, caspase-3 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that mitoxantrone could inhibit the proliferation of RPMI-8226 cells in time- and dose-dependent manners. Light microscopy showed that the cell number in mitoxantrone group was significantly less than that in control group and the cell growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed, these results confirmed that the mitoxantrone could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). The 1.0 µg/ml low concentration of mitoxantrone mainly arrested RPMI-8226 cells in the G2/M phase(P < 0.05), and the 2.0 µg/ml high concentration of mitoxantrone mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of BCL-2 mRNA decreased (P < 0.05),while the expression of BAX, caspase-3 mRNA increased (P < 0.05). Western blot indicated that BCL-2 protein expression also decreased (P < 0.05) and BAX, caspase-3 protein expression increased. It is concluded that the mitoxantrone can inhibit the proliferation of RPMI-8226 cells by inducing cell apoptosis. Activation of the mitochondrial and death receptor pathways of apoptosis may be involved in the mitoxantrone-induced apoptosis, the cell cycle arrest may also play an important role in the apoptosis mechanism.

[Mechanisms of cladribine-inducing apoptosis of multiple myeloma RPMI 8226 cells in vitro].

This study was purposed to explore the mechanisms of cladribine (2-CdA)-inducing apoptosis of multiple mycloma RPMI 8226 cells. The MTT method was used to determine cell proliferation after being treated with 2-CdA. Apoptosis and cell cycle progression were examined by flow cytometry. Transmission electron microscopy was used to observe ultrastructural changes of RPMI 8226 cells. RT-PCR and Western blot were used to analyze the mRNA and protein expression levels of BCL-2, MCL-2 and caspase-3 respectively. The results showed that the 2-CdA inhibited proliferation of RPMI 8226 cells in time and dose-dependent manner. Typical apoptotic morphological and ultrastructure changes could be observed by electron microscopy. Flow cytometry showed that 2-CdA induced myeloma cell apoptosis and arrested myeloma cells in the G2/M phase. The mRNA expression of BCL-2 and MCL-1 decreased but that of caspase-3 not apparently changed. Western blot results suggested that the change trend of BCL-2 MCL-1 and caspase-3 was the same as result of RT-PCR. It is concluded that 2-CdA exhibits inhibitory effects on RPMI 8226 cells in vitro. Activating the mitochondrial and death receptor pathways of apoptosia may be the potential mechanism, meanwhile, the cell cycle arrest may also play a critical role in apoptosis.

[Regional genotyping and the geographical distribution regarding Yersinia pestis isolates in China].

OBJECTIVE: To type Yersinia (Y.) pestis isolates under different regions (DFR) and to observe their geographical distributions in China. METHODS: 23 DFRs primers and PMT1 (plasmid) primer were used to verify the DFR genomovars of Y. pestiss strains from 11 plague foci in China. A total of 3 044 Y. pestis isolates were involved for analysis on DFR profiles with the characteristics of geographical distribution. RESULTS: 52 genomovars were verified in 3 044 Y. pestis strains in China in which 19 genomovars as major and 33 genomovars as minor genomovar. 21 new genomovars, namely genomovar 32 to genomovar 52 were described on the basis of 31 genomovars previously confirmed. Three new genomovars belonged to new major genomovars, namely Himalayan marmot natural plague foci of the Qinghai-Tibet plateau newly added genomovar 32 and genomovar 44 as major genomovars. Mongolian gerbil natural plague foci of Inner Mongolia plateau were newly added genomovar 50 as one of the major genomovars. CONCLUSION: Among 21 new genomovars, 3 were major genomovars, with Chinese Y. pestis DFR as the major genomovars which had obvious distribution characteristics.

[Effects of sorafenib on proliferation and apoptosis of human multiple myeloma cell RPMI 8226].

This study was aimed to investigate the effects of sorafenib on proliferation and apoptosis of MM cell line RPMI-8226, and to explore the its potential anti-tumor mechanism. The inhibitory rate of multiple myeloma cell proliferation was tested by MTT. Transmission electron microscopy was used to observe morphological and ultrastructural changes of RPMI-8226 cells treated with sorafenib. The effects of sorafenib on the apoptosis and cell cycle of RPMI-8226 cells was detected by flow cytometry. The effects of sorafenib on the expression of caspase-3, BCL-2 and MCL-1 mRNA and protein were assayed by RT-PCR and Western blot respectively. The results showed that sorafenib (0-10.0 µmol/L) could obviously inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manner. Flow cytometry results showed that sorafenib could induce apoptosis of RPMI-8226 cells, the difference was statistical significance (P < 0.05). Sorafenib mainly arrested RPMI-8226 cells in the G1 phase (P < 0.05). Typical apoptotic morphological and ultrastructural changes of MM cells could be observed under transmission electron microscope, Examination of cellular signaling pathways showed that sorafenib induced upregulation of cleaved-caspase-3 expression, and simultaneous downregulation of BCL-2 and MCL-1 expression. It is concluded that sorafenib displays anti-myeloma activity. Activating the death receptor pathway and arresting cell cycle may be two of the relatated mechanisms.

Expression of ORAII, a plasma membrane resident subunit of the CRAC channel, in rodent and non-rodent species.

We determined the expression of ORAI1 protein in rodent and non-rodent tissues using a monoclonal antibody directed against an extracellular loop of the protein. Previous reports using antibodies directed at the C-terminus of ORAI1 have not detected central nervous system (CNS) expression. Our results demonstrate broad tissue expression that includes the CNS using a unique monoclonal antibody specific to an extracellular loop of ORAI1. In addition, we present in situ hybridization (ISH) results using a probe within the middle of the mouse coding region showing CNS expression of Orai1 RNA. We contrast the patterns of rodent and human tissue expression and conclude that rodents have similar expression of ORAI1 in most tissue types when compared to primates, with an important exception being the male reproductive system, where human-specific expression is observed.

Canis lupus familiaris involved in the transmission of pathogenic Yersinia spp. in China.

To investigate canines carrying pathogens associated with human illness, we studied their roles in transmitting and maintaining pathogenic Yersinia spp. We examined different ecological landscapes in China for the distribution of pathogenic Yersinia spp. in Canis lupus familiaris, the domestic dog. The highest number of pathogenic Yersinia enterocolitica was shown from the tonsils (6.30%), followed by rectal swabs (3.63%) and feces (1.23%). Strains isolated from plague free areas for C. lupus familiaris, local pig and diarrhea patients shared the same pulsed-field gel electrophoresis (PFGE) pattern, indicating they may be from the same clone and the close transmission source of pathogenic Y. enterocolitica infections in these areas. Among 226 dogs serum samples collected from natural plague areas of Yersinia pestis in Gansu and Qinghai Provinces, 49 were positive for F1 antibody, while the serum samples collected from plague free areas were all negative, suggested a potential public health risk following exposure to dogs. No Y. enterocolitica or Yersinia pseudotuberculosis was isolated from canine rectal swabs in natural plague areas. Therefore, pathogenic Yersinia spp. may be regionally distributed in China.

[Sources of infection on human plague in Qinghai province].

OBJECTIVE: To study the biological and genetic characteristics of 119 strains of Yersinia (Y.) pestis isolated from plague patients in Qinghai province, from 1958-2012. METHODS: Both regular methods and different region(DFR)molecular typing techniques were used to study the epidemiological characteristics on 119 strains of Y. pesticin Qinghai during 1958-2012. Sources of Y. pestis from two outbreaks, in Nangqian county in 2004 and in Xinghai county in 2009,Qinghai province were also analyzed. RESULTS: 105 strains of Y. pestis were identified as Qinghai-Tibet Plateau Ecotype while the other 6 strains as Qilian Mountains Ecotype. 84.03% (100/119) of the tested strains carried 4 virulence factors F1(+), Pst I(+), VW(+) and Pgm(+)). 97.30% (72/74) of the tested strains showed high virulence. Strains that carrying 52×10(6), 65×10(6), 92×10(6) plasmids were distributed in Hainan, Haibei, Haixi,Yushu,Guoluo, Huangnan and Huangyuan counties. Genomovar 5 and 8 were the main gene types that circling around Qinghai Lake. Genomovar 10 was found in strains of Y. pesticin Nangqian county while Genomovar 8 was found in the strains isolated from human plague patient during the epidemics in Xinghai county in Qinghai. CONCLUSION: Data from biological and genetic analyses on the epidemics of human plague in Nangqian county in 2004 and in Xinghai county in 2009 demonstrated that methods as DFR genotyping and virulence factors profiles, as well as plasmids profiles were powerful tools in confirming the human plague epidemics and sources of infection.

[Mechanisms of oxaliplatin-induced apoptosis of human multiple myeloma cell RPMI8226].

This study was aimed to investigate the effects of oxaliplatin on human multiple myeloma cell line RPMI-8226 and its mechanism. The proliferation inhibitory rate of RPMI8226 cells was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted fluorescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry, The effects of oxaliplatin on the expression of Bcl-2, caspase-8, caspase-3 mRNA were tested by RT-PCR, Bcl-2 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that oxaliplatin could inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manners. Cell number in oxaliplatin group was significantly less than that in control group under light microscope, and the growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed. Flow cytometry results showed that oxaliplatin could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). Oxaliplatin mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of Bcl-2 mRNA did not have apparent change, while the expression of caspase-8, caspase-3 mRNA increased (P < 0.05). Western blot results suggested that the expression of Bcl-2 protein had no obvious change. It is concluded that the oxaliplatin can induce apoptosis of RPMI-8226 cells, activating the death receptor pathway and arresting cell cycle may be two of the related mechanisms, Bcl-2 gene has unobservable effects in the process of oxaliplatin-induced cell apoptosis.

[The pathogenic ecology research on plague in Qinghai plateau].

OBJECTIVE: To study the pathogenic ecology characteristics of plague in Qinghai plateau. METHODS: Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. RESULTS: The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. CONCLUSION: The main host and media of Qinghai plateau plague foci directly affected the spatial distribution regularities of plague epidemic and the pathogens characteristics, meanwhile the polymorphism of plague ecological geographic landscape leds to the complexity of Yersinia pestis' genotype.

[Effects of docetaxel on proliferation and apoptosis of human multiple myeloma cell RPMI8226].

This study was aimed to investigate the effects of docetaxel on proliferation and apoptosis of multiple myeloma cell line RPMI8226 and its mechanism. The inhibitory rate of multiple myeloma cells was detected by MTT, the morphological and ultrastructural changes of RPMI8226 cells were observed by using inverted fluorescent microscope and transmission electron microscope, the apoptosis-inducing effect of docetaxel on RPMI-8226 cells was determined by flow cytometry with Annexin-V FITC/PI staining, the cell distribution in cell cycle of RPMI-8226 cells was assayed using flow cytometry with PI staining; the effect of docetaxel on expression of BCL-2, caspase-8, caspase-3 mRNA was detected by semiquantitative RT-PCR, the expression changes of BCL-2 protein in RPMI-8226 cells before and after treatment with docetaxel were measured by using Western blot. The results indicated that 0.25 - 8.0 µg/ml docetaxel obviously inhibited the proliferation of RPMI-8226 cells in both time- and dose-dependent manners. Cell number of docetaxel-treated group was significantly less than control group under inverted fluorescent microscope, and the cell arrangement was irregular, necrotic cells could be seen occasionally. By transmission electron microscope, the morphological and ultrastructural changes of cell typical apoptosis could be observed, a few necrotic cells could be captured, too. Compared with control group, docetaxel induced the apoptosis of RPMI-8226 cell line (P < 0.01). Docetaxel mainly arrested RPMI-8226 cells in the G(2)/M phase (P < 0.01). The expression of BCL-2 mRNA decreased (P < 0.05), while the mRNA expression of caspase-8 and caspase-3 increased (P < 0.05). Western blot indicated that BCL-2 protein expression also decreased (P < 0.05). It is concluded that docetaxel can inhibit the proliferation of RPMI-8226 cells by inducing cell apoptosis. Activation of the mitochondrial and death receptor pathways of apoptosis may be involved in the docetaxel-induced apoptosis, cell cycle arrest may also play an important role in the apoptosis mechanism.

[Study on the genotyping and microevolution of Yersinia pestis in the Qinghai-Tibet Plateau].

OBJECTIVE: To study the distribution of genomovars and microevolution of Yersinia pestis in the Qinghai-Tibet Plateau. METHODS: Primer pairs targeting the twenty-two different regions(DFRs) were designed for detecting the presence or deletion of each DFR in 297 strains isolated from the Qinghai-Tibet Plateau. RESULTS: 9 genomovars, i. e. Genomovar 1, 5, 6, 7, 8, 10, 11, new type and Ype-ancestor were identified in the Marmota himalayana plague focus of the Qinghai-Tibet Plateau. Among these genomovars, genomovar 5,8 and 10 were dominant types. The total rate of the three genomovars was 80.6% (204/253) and the genomovars in different regions were different. All of 44 strains of Y. pestis in the Microtus fuscus plague focus of the Qinghai-Tibet Plateau belonged to genomovar 14. CONCLUSION: The distribution of genomovars of Y. pestis in the Qinghai-Tibet plateau had remarkable characteristics geographically. Based on the distribution of genomovars of Y. pestis, the routes of transmission and microevolution of Y. pestis were proposed.

Pharmacodynamics of the type II calcimimetic compound cinacalcet HCl.

Calcimimetic compounds, which activate the parathyroid cell Ca(2+) receptor (CaR) and inhibit parathyroid hormone (PTH) secretion, are under experimental study as a treatment for hyperparathyroidism. This report describes the salient pharmacodynamic properties, using several test systems, of a new calcimimetic compound, cinacalcet HCl. Cinacalcet HCl increased the concentration of cytoplasmic Ca(2+) ([Ca(2+)](i)) in human embryonic kidney 293 cells expressing the human parathyroid CaR. Cinacalcet HCl (EC(50) = 51 nM) in the presence of 0.5 mM extracellular Ca(2+) elicited increases in [Ca(2+)](i) in a dose- and calcium-dependent manner. Similarly, in the presence of 0.5 mM extracellular Ca(2+), cinacalcet HCl (IC(50) = 28 nM) produced a concentration-dependent decrease in PTH secretion from cultured bovine parathyroid cells. Using rat medullary thyroid carcinoma 6-23 cells expressing the CaR, cinacalcet HCl (EC(50) = 34 nM) produced a concentration-dependent increase in calcitonin secretion. In vivo studies in rats demonstrated cinacalcet HCl is orally bioavailable and displays approximately linear pharmacokinetics over the dose range of 1 to 36 mg/kg. Furthermore, this compound suppressed serum PTH and blood-ionized Ca(2+) levels and increased serum calcitonin levels in a dose-dependent manner. Cinacalcet was about 30-fold more potent at lowering serum levels of PTH than it was at increasing serum calcitonin levels. The S-enantiomer of cinacalcet (S-AMG 073) was at least 75-fold less active in these assay systems. The present findings provide compelling evidence that cinacalcet HCl is a potent and stereoselective activator of the parathyroid CaR and, as such, might be beneficial in the treatment of hyperparathyroidism.

In vitro studies with the calcimimetic, cinacalcet HCl, on normal human adult osteoblastic and osteoclastic cells.

This study examined whether the calcium-sensing receptor (CaR) is expressed in normal adult human osteoblastic and osteoclastic cells in culture, and whether the calcimimetic, cinacalcet HCl (AMG 073), potentiates the effects of calcium (via CaR, or some other receptor/mechanism). When mouse or human osteoblastic cells were treated with higher concentrations of calcium (6.6 or 8.6 mM in alpha-MEM/10% FBS) than present in control cultures (1.6 mM), the previously well-documented increase in cell number was demonstrated. Cinacalcet HCl affected cell proliferation of CHO cells transfected with CaR, dose dependently, but had no effect on human or mouse osteoblastic cell proliferation in calcium-containing medium (1.6 or 8.6 mM). To test cinacalcet HCl and calcium on osteoclastic cells, peripheral blood mononuclear cells were cultured in medium containing RANK ligand and M-CSF, supplemented with calcium, and/or cinacalcet HCl. Tartrate-resistant acid phosphatase-positive multinucleated osteoclastic cells on plastic or bone were then counted at 11 and 21 days, respectively. Calcium (greater than 6.0 mM) inhibited osteoclast formation, but cinacalcet HCl (30-1000 nM) had no effect on osteoclastic formation or resorption in the presence of calcium (1.6 or 6.1 mM). RT-PCR did not detect CaR in human, rat, or mouse primary osteoblastic cells and cell lines or osteoclastic cells. In conclusion, these studies indicate that the calcium-induced increase in osteoblastic cell number, and the decrease in formation/function of osteoclastic cells, involves a mechanism or receptor other than CaR. In addition, the calcimimetic agent did not potentiate the effects of calcium on normal adult human bone cells in vitro.