[Spectroscopic study on the conformational change of silk fibroin in methanol-water mixtures].

A combinational study of circular dichroism, intrinsic fluorescence of protein and exogenous fluorescence probe of ANS was made to investigate the conformational change of silk fibroin in methanol-water mixtures as well as the mechanism. The spectral results showed that small hydrophobic regions were formed in silk fibroin in methanol-water mixtures at the concentration lower than 30% (V/V) via hydrophobic interaction, which was decreased at higher methanol content due to a structural transition of silk fibroin from random coil to beta-sheet. The conformational change of silk fibroin was found to be of a close relationship with the microstructure of the solvent and to be determined by the interaction between the peptide unit of silk fibroin and the cluster of the mixed solvent. Methanol-water mixture at low concentration had little effect on the solvation of the peptide unit and the conformation of silk fibroin, as a consequence of the fact that the inherent water structure was conserved. The transition from the tetrahedral-like water structure to the chain-like methanol structure, due to the increasing concentration of methanol, induced the conformational change of silk fibroin to eliminate the contact of peptide unit with the solvent molecular.

Regimen containing perarubicin for the treatment of newly diagnosed young patients with acute myeloid leukemia.

BACKGROUND AND OBJECTIVE: Chemotherapy regimen containing anthracyclines has been used as the standard treatment for acute myeloid leukemia (AML). This study was to compare the efficacy and toxicity of the chemotherapy regimen containing perarubicin (THP) with that containing mitoxantrone (MIT) for young patients with newly diagnosed AML. METHODS: A total of 129 patients with newly diagnosed AML, aged 16 to 60 years olds, were assigned for induction chemotherapy containing one to two courses with standard-dose cytarabine (Ara-C) and an anthracycline antibiotic, THP or MIT. When complete remission was achieved after induction therapy, the patients received two courses of consolidation therapy identical to the induction regimen. From then, the patients were alternately given four courses of consolidation therapy consisting of Ara-C/THP or Ara-C/MIT every three weeks. Maintenance treatment continued for three years when patients were in continuous complete remission (CCR). RESULTS: Twenty-six out of 42 patients (61.90%) receiving THP therapy, and 48 out of 73 patients (65.75%) treated by MIT achieved CR (P>0.05). Nine (34.61%) and 11 (22.92%) out of CR patients treated by THP and MIT, respectively, relapsed within one year (P=0.28). Moreover, the incidences of toxicities, such as infection, nausea/vomiting and cardiac events, were similar in these two groups (P>0.05) except for alopecie, which was 26.19% in the THP group compared to 42.47% in the MIT group (P<0.01). CONCLUSIONS: Regimen containing THP plus Ara-C can be used for young adults with newly diagnosed AML for remission induction, but it is not superior to the regimen with MIT. Consolidation chemotherapy with THP or MIT is feasible for young adults with AML after CR.

[A multi-centers clinical study of different treatment outcomes of 332 patients with multiple myeloma].

OBJECTIVE: To describe the demographic and clinical characteristics of patients with the diagnosis of multiple myeloma (MM) and to analyse the outcome of different regimens for the treatment of MM. METHODS: The study reviewed 332 MM cases diagnosed within the period from January 1, 2002 to December 31, 2002. These patients were tracked via their records to a total period of three years. RESULTS: First-line treatment: Totally 332 patients were included, among them 325 (97.9%) patients received chemotherapy and 7 (2.1%) patients received stem cell transplantation (SCT); Second-line treatment: 197 patients were included, among them 190 (96.5%) patients received chemotherapy and 7 (3.6%) patients received SCT; Third-line treatment: 92 patients were included,among them 88 (95.7%) patients received chemotherapy and 4 (4.4%) patients received SCT. Major adverse effects were follows: severe infection 19.3%, severe anaemia 19.3%, phlebothrombosis 1.2% , thrombocytopenia 16.9%, fever associated with neutropenia 18.1%. CONCLUSIONS: Some curative effects can be achieved by using traditional treatment plans to treat patients suffering from MM, but new methods are expected to improve the prognosis.

[JAK3 mRNA level in graft versus host disease patients: a preliminary study].

OBJECTIVE: To quantify peripheral blood mononuclear cell JAK3 mRNA levels after allogeneic haematopoietic stem cell (allo-HSCT) transplantation, and to explore its relationship with graft vs host disease (GVHD). METHODS: Serial monitoring of JAK3 mRNA levels by fluorescent quantitative reverse transcriptase polymerase chain reaction (FQ-RT-PCR) technique was performed on 26 cases (83 samples) after allo-HSCT. RESULTS: The mean JAK3/ABL expression levels was 8.71 in 14 patients without GVHD; the JAK3/ABL expression level was 31.94 in one patient with acute GVHD (aGVHD); the mean JAK3/ABL expression levels was 19.23 in 11 patients with chronic GVHD (cGVHD), and the cGVHD was diagnosed at the mean time of six months (3 - 12 months). The JAK3/ABL expression levels did not change in 4 patients one month after allo-HSCT, however, the levels increased again when GVHD were diagnosed in these 4 patients, and the JAK3/ABL expression levels decreased again when GVHD was remitted. CONCLUSION: The JAK3 expression level related to the remission and relapse in patients with GVHD.

[Therapeutic effects of chemotherapeutic regimens containing pirarubicin on the treatment of high-risk or refractory and relapsed acute leukemia in adults].

OBJECTIVE: To evaluate the therapeutic effects of chemotherapeutic regimen containing pirarubicin (THP) on the treatment of high-risk or refractory and relapsed acute leukemia (AL) in adults. METHODS: Forty patients with high-risk or refractory and relapsed AL, 26 males and 14 females, aged 33 (14-63) received treatment regimens with THP: TA regimen [THP + cytosine-arabinoside (Ara-C)] for acute myeloid leukemia (AML) and TAOP regimen [THP + Ara-C + vincristine (VCR) + prednisone (Pred)] for acute lymphocytic leukemia (ALL) or biphenotype-AL. Forty matched patients received mitoxantron (MIT) + Ara-C for AML or MIT + Ara-C + VCR + Pred for ALL and biphenotype AL as controls. The therapeutic effects were observed. RESULTS: The complete remission (CR) rate was 47.5% vs 45% (P > 0.05), partial response (PR) rate was 25% vs 20% (P > 0.05), and overall response (OR) rate was 72.5% vs 65% (P > 0.05) in the treatment group and control group. The continuous CR time was 528 days in the treatment group, significantly longer than in the control group (463 days, P < 0.05). Marrow suppression was more serious in the treatment group. The patients in the treatment group had higher incidence of infections (P < 0.05). The time with sustained recovery of platelet number was 13.9 days in the treatment group, significantly longer than in the control group (P < 0.05). CONCLUSION: Regimens with THP are more effective on treatment of high-risk or refractory and relapsed AL in adults, however, with more serious marrow suppression and higher incidence of infection.

[Relationship between cyclins and prognosis of acute leukemia].

BACKGROUND & OBJECTIVE: Cell proliferation and differentiation are directed by cell cycle mechanism. When tumor cells proliferate abnormally, cyclins, which are positive agents of cell cycle, may be expressed abnormally at the same time. Now many references proved that cyclins are highly expressed in solid tumors. This study was designed to investigate the relationship between expression of cyclins and prognosis of acute leukemia. METHODS: Sixty-eight cases of acute leukemia were enrolled. Reverse transcription polymerase chain reaction (RT-PCR) was performed on tumor samples to examine the expression of cyclin A, cyclin D, cyclin E. All samples were divided into three groups: acute leukemia in complete remission (12 cases), newly diagnosed acute leukemia (16 cases) and refractory leukemia (40 case). Samples of benign hemopoietic patients were used as normal control (15 cases). RESULTS: All the 15 cases in the control group were negative of cyclin mRNA. No difference of cyclin A mRNA expression was shown between control group and the three experiment groups (P >0.05). But expression of cyclin D and cyclin E mRNA was significantly different between them (P< 0.01). There was no difference of expression of cyclin D and cyclin E mRNA among CR patients with acute leukemia(P >0.05), while the expression of cyclin D mRNA is significantly higher than that of cyclin E in refractory leukemia group. Furthermore the expression of cyclin D mRNA in recurrent refractory leukemia patients is significantly higher than that newly diagnosed cases (P< 0.05). All cyclins mRNA positive cases were divided into single cyclin gene expressed group and multiple cyclins gene expressed group. The positive rates of them were counted. No difference was found between complete remission group and refractory leukemia group (P >0.05). CONCLUSION: Cyclin D may act as a prognostic marker for acute leukemia. The amount of cyclins expressed cannot be used as a prognostic factor for acute leukemia.