Dielectric Barrier Discharge Plasma-Assisted Preparation of Chitosan-Based Hydrogels

Chitosan is widely used in the production of various hydrogels due to its non-biological toxicity, good biocompatibility, and strong biodegradability. However, chitosan-based hydrogels have not been widely used in tissue engineering due to their poor mechanical strength, poor stability and high biotoxicity of cross-linking agents. As a green technology, low temperature plasma is rich in active groups that can be involved in various chemical reactions, such as replacing the components on the chitosan chain, contributing to the cross-linking of chitosan. In this study, a plasma-assisted preparation method of chitosan-based hydrogels was developed and the properties, including mechanics, water absorption, and degradation (or stability), were characterized and analyzed. It is proved that plasma treatment plays a significant role in improving the mechanical strength and stability of hydrogels.

Automation of Dosimetric Data Collection Using C# ESAPI for Intracavitary and Hybrid Intracavitary/Interstitial Brachytherapy Plans

PURPOSE/OBJECTIVE(S)

Dosimetric data extraction for complex brachytherapy plans can be a time-consuming and error-prone process. The Eclipse Scripting API (ESAPI) Microsoft .NET framework and its ability to access the ARIA treatment planning database makes it a powerful tool for researchers to incorporate automation into data collection. This automation allows for more efficient and error-free collection of dosimetric data, and the program can be iterated over multiple patients at one time. The main objectives of this study were (i) to develop a C# ESAPI script capable of automated data collection for multiple brachytherapy plans and (ii) to apply the script and examine dosimetric characteristics of a patient cohort with locally advanced cervical cancer treated using tandem and ovoid (T/O) applicators or hybrid tandem and ovoid applicators with needles (T/O + N).

MATERIALS/METHODS

We developed a ESAPI script capable of receiving a list of patient IDs and creating a CSV dataset of dosimetric data of the requested patients. Eclipse commands were accessed to create a CSV dataset consisting of baseline demographic data, average V100, V125, D100, D90 as well as D0.1cc, D1cc, D2cc of organs at risk (bladder, rectum, sigmoid colon, small bowel) per fraction. We applied the ESAPI script to our single-institution retrospective cohort which included patients who underwent brachytherapy as part of definitive radiation treatment for cervical cancer between May 2017 and November 2022. Patients either received T/O or T/O + N brachytherapy boost. Statistical analysis was performed using two-sided t-tests to examine differences in descriptive dose metrics between the two techniques.

RESULTS

The developed ESAPI script automatically generated a CSV file of baseline demographic data as well as dosimetric data for patients who underwent T/O or T/O + N brachytherapy boost. We demonstrated that the ESAPI script could acquire and analyze the data quickly (<5 s per test case) compared to time required to generate data via manual review (5 min per test case). This is a 98% reduction in time required to review and collect data per patient. The analyzed cohort included 72 patients with cervical cancer: 40 with T/O technique and 32 with T/O + N technique. Larger clinical target volumes (CTV) were seen in the group that received treatment with T/O + N technique versus T/O alone (37.4 cc vs 25.2 cc, p < 0.0007). Dose metrics including V100, V125, D100, D90 of the high-risk CTV as well as D0.1cc, D1cc, D2cc of the bladder, rectum, small bowel were not significantly different between techniques. However, the D0.1cc, D1cc, D2cc of the sigmoid colon were higher for patients who received T/O + N technique by 95, 74, and 64 cGy respectively (p < 0.005, p < 0.003 and p < 0.007).

CONCLUSION

This study highlights the use of a newly developed ESAPI script specific to brachytherapy plans which allows for iteration over multiple patients at one time. We were able to quickly compare multiple dose metrics for two patient groups treated at our institution.

Theoretically exploring selective-binding mechanisms of BRD4 through integrative computational approaches

The origin of cancer is related to the dysregulation of multiple signal pathways and of physiological processes. Bromodomain-containing protein 4 (BRD4) has become an attractive target for the development of anticancer and anti-inflammatory agents since it can epigenetically regulate the transcription of growth-promoting genes. The synthesized BRD4 inhibitors with new chemical structures can reduce the drug resistance, but their binding modes and the inhibitory mechanism remain unclear. Here, we initially constructed robust QSAR models based on 68 reported tetrahydropteridin analogues using topomer CoMFA and HQSAR. On the basis of QSAR results, we designed 16 novel tetrahydropteridin analogues with modified structures and carried out docking studies. Instead of significant hydrogen bondings with amino acid residue Asn140 as reported in previous research, the molecular docking modelling suggested a novel docking pose that involves the amino acid residues (Trp81, Pro82, Val87, Leu92, Leu94, Cys136, Asp144, and Ile146) at the active site of BRD4. The MD simulations, free energy calculations, and residual energy contributions all indicate that hydrophobic interactions are decisive factors affecting bindings between inhibitors and BRD4. The current study provides new insights that can aid the discovery of BRD4 inhibitors with enhanced anti-cancer ability.

Dose de-escalation to adalimumab 40 mg every 3 weeks in patients with Crohn's disease - a nested case-control study

BACKGROUND

Data on dose de-escalation in patients with Crohn's disease (CD) are limited.

AIM

To evaluate outcomes of dose de-escalation from adalimumab (ADM) every other week (EOW) to every three weeks (ETW).

METHODS

We selected patients with CD receiving maintenance therapy with ADM 40 mg ETW with serum levels (SL) available before and after dose de-escalation. Sex- and age-matched controls continuing ADM 40 mg EOW were identified. Patient reported outcome, C-reactive protein (CRP) and serum albumin were collected.

RESULTS

Out of 898 patients, we identified 40 (11 male, median 37 years) who de-escalated to ADM 40 mg ETW for ADM-related adverse events (AE, n = 1), ADM SL >7 μg/mL (n = 8), or both (n = 31). Compared to controls, ADM SL dropped significantly within 4 months, without associated clinical or biochemical changes. In 53% of patients, dose de-escalation was associated with disappearance of AE (8/16 skin manifestation, 3/6 arthralgia, 5/7 frequent infectious episodes). During a median follow-up of 24 months, 65% of patients maintained clinical response, but 35% needed dose escalation back to ADM 40 mg EOW because of clinical relapse (n = 8), ADM SL <4 μg/mL (n = 2), or both (n = 4). CRP <3.5 mg/L at dose de-escalation was independently associated with dose escalation-free survival [odds ratio 6.28 (95% CI 1.83-21.59), P = 0.004]. We could not define a minimal ADM SL to consider or maintain dose de-escalation.

CONCLUSIONS

Overall, 65% of patients who de-escalated to adalimumab 40 mg every 3 weeks remained in clinical remission for a median of 24 months. In 53% of patients, adalimumab-related adverse events disappeared after dose de-escalation. Regardless of adalimumab SL, disease remission should be assessed objectively prior to dose de-escalation.

Acute acalculous cholecystitis in patients with systemic lupus erythematosus: A unique form of disease flare

Objective

We aimed to investigate the clinical features of acute acalculous cholecystitis (AAC) in patients with systemic lupus erythematosus (SLE).

Methods

SLE patients with AAC hospitalized in the Peking Union Medical College Hospital (PUMCH) from January 2001 to September 2015 were retrospectively analyzed. Their medical records were systematically reviewed. The diagnosis of AAC was based on clinical manifestations and confirmed by radiologic findings including a distended gallbladder with thickened wall, pericholecystic fluid and absence of gallstones.

Results

Among the 8411 hospitalized SLE patients in PUMCH, 13 (0.15%) were identified to have SLE-AAC. Eleven (84.6%) of them were female, with a mean age of 30.1 ± 8.6 years. AAC was the initial manifestation of SLE in four (30.8%) cases. Eleven (84.6%) patients complained of fever and abdominal pain, four (30.8%) had positive Murphy’s sign and six (46.2%) had elevated liver enzymes. The median SLE Disease Activity Index was 8.0 (range 0–20.0) at the time of AAC. Other affected organs in SLE-AAC included kidney (11, 84.6%) and hematologic system (11, 84.6%), followed by mucocutaneous (seven, 53.8%), musculoskeletal (seven, 53.8%) and neuropsychiatric (two, 15.4%) systems. All patients received treatment of glucocorticoids and immunosuppressants but none underwent surgical intervention. During a median follow-up of 28 months (range, 2–320 months), 12 cases (92.4%) responded to treatment with no relapse and one patient (7.6%) died of septic shock.

Conclusion

Our study suggests that AAC is a relatively uncommon and underestimated gastrointestinal involvement of SLE that is often associated with active disease. For patients with AAC in SLE, treatment with aggressive glucocorticoids could result in a good prognosis.

[Effect of allogenic mesenchymal stem cells transplantation on the expression of interleukin-22 and matrix metalloproteinase-3 in rats with collagen induced arthritis]

Objective: To study the effect of allogeneic bone marrow mesenchymal stem cells transplantation on the expression of interleukin -22 (IL-22), matrix metalloproteinase -3 (MMP-3) in serum and synovial of rats with collagen induced arthritis. Methods: Type Ⅱ collagen were injected twice to establish the collagen induced arthritis (CIA) rat model. Forty-eight rats were randomly divided into 3 groups: control group, CIA control group, CIA experiment group. Rat bone marrow mesenchymal stem cells were cultured by bone marrow method combined with adherent culture method. After identify, the remaining cells were injected in the CIA experimental group. Enzyme linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect the expression of IL-22 and MMP-3 in serum and anklebone joint's synovium of rats, respectively. Synovial cells were isolated and cultured, and were treated with different concentrations of IL-22. MMP-3 protein and mRNA were detected before and after stimulation by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). Results: After MSC transplantation, arthritis index, X-ray, HE staining of CIA rat showed that joint damage significantly reduced compared with the control group. The ELISA results showed that the expression of MMP-3 and IL-22 in CIA control group was higher than those in the control group (125.79±9.12 vs 102.00±7.63 ng/ml, P<0.05), (292.35±31.23 vs 257.27±13.99 ng/ml, P<0.05) and CIA experiment group (125.79±9.12 vs 97.94±9.50 ng/ml, P<0.05), (292.35±31.23 vs 262.16±22.02 ng/ml, P<0.05) with statistically significant difference (P<0.05). There was no significant difference between the control group and CIA experimental group. Immunohistochemical showed similar results with ELISA. Western blotting and RT-qPCR showed that MMP-3 protein and mRNA expression was increased after IL-22 stimulation in a dose-dependent manner. Conclusion: IL-22 and MMP-3 play an important role in the pathogenesis of rheumatoid arthritis. IL-22 could regulate the expression of MMP-3, and bone marrow mesenchymal stem cells could reduce the expression of MMP-3 in the treatment of rheumatoid arthritis by reducing the expression of IL-22.

Liquid plug propagation in flexible microchannels: A small airway model

In the present study, we investigate the effect of wall flexibility on the plug propagation and the resulting wall stresses in small airway models with experimental measurements and numerical simulations. Experimentally, a flexible microchannel was fabricated to mimic the flexible small airways using soft lithography. Liquid plugs were generated and propagated through the microchannels. The local wall deformation is observed instantaneously during plug propagation with the maximum increasing with plug speed. The pressure drop across the plug is measured and observed to increase with plug speed, and is slightly smaller in a flexible channel compared to that in a rigid channel. A computational model is then presented to model the steady plug propagation through a flexible channel corresponding to the middle plane in the experimental device. The results show qualitative agreements with experiments on wall shapes and pressure drops and the discrepancies bring up interesting questions on current field of modeling. The flexible wall deforms inward near the plug core region, the deformation and pressure drop across the plug increase with the plug speed. The wall deformation and resulting stresses vary with different longitudinal tensions, i.e., for large wall longitudinal tension, the wall deforms slightly, which causes decreased fluid stress and stress gradients on the flexible wall comparing to that on rigid walls; however, the wall stress gradients are found to be much larger on highly deformable walls with small longitudinal tensions. Therefore, in diseases such as emphysema, with more deformable airways, there is a high possibility of induced injuries on lining cells along the airways because of larger wall stresses and stress gradients.

Cocaine increases endoplasmic reticulum stress protein expression in striatal neurons

Cocaine administration upregulates the levels of extracellular glutamate and dopamine in the striatum. Activation of the receptors alters calcium homeostasis in striatal neurons leading to the expression of the endoplasmic reticulum (ER) stress proteins. It was therefore hypothesized that cocaine upregulates the expression of the ER stress proteins, immunoglobulin heavy chain binding protein (BiP), Ire1alpha and perk via glutamate and dopamine receptor activation. A novel glutamate microbiosensor and Western immunoblot analyses were mainly performed to test the hypothesis in the rat dorsal striatum. The results showed that i.p. injection of repeated cocaine (20 mg/kg) for nine consecutive days significantly increased extracellular glutamate levels while acute cocaine injection did not. However, the immunoreactivities (IR) of the ER stress proteins in the dorsal striatum were significantly increased by either acute or repeated cocaine injections as compared with saline controls. Intrastriatal injection (i.s.) of the selective group I metabotropic glutamate receptor (mGluR) antagonist N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC; 25 nmol) or the mGluR5 subtype antagonist 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP; 2 and 25 nmol) significantly decreased repeated cocaine-induced increases in the IR of the ER stress proteins in the injected dorsal striatum. Similarly, the selective D1 antagonist (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 0.1 mg/kg, i.p.) or the N-methyl-d-aspartate antagonist dizocilpine/(5S,10R)-(+)-5-methyl-10,11-dihydro-5H-ibenzo[a,d]cyclohepten-5,10-imine maleate (MK801; 2 nmol, i.s.) decreased acute or repeated cocaine-induced the IR of the ER stress proteins in the dorsal striatum. These data suggest that cocaine upregulates expression of the ER stress proteins in striatal neurons via a mechanism involving activation of glutamate and dopamine receptors.

The calcium-sensitive large-conductance potassium channel (BK/MAXI K) is present in the inner mitochondrial membrane of rat brain

Large-conductance voltage- and calcium-sensitive channels are known to be expressed in the plasmalemma of central neurons; however, recent data suggest that large-conductance voltage- and calcium-sensitive channels may also be present in mitochondrial membranes. To determine the subcellular localization and distribution of large-conductance voltage- and calcium-sensitive channels, rat brain fractions obtained by Ficoll-sucrose density gradient centrifugation were examined by Western blotting, immunocytochemistry and immuno-gold electron microscopy. Immunoblotting studies demonstrated the presence of a consistent signal for the alpha subunit of the large-conductance voltage- and calcium-sensitive channel in the mitochondrial fraction. Double-labeling immunofluorescence also demonstrated that large-conductance voltage- and calcium-sensitive channels are present in mitochondria and co-localize with mitochondrial-specific proteins such as the translocase of the inner membrane 23, adenine nucleotide translocator, cytochrome c oxidase or complex IV-subunit 1 and the inner mitochondrial membrane protein but do not co-localize with calnexin, an endoplasmic reticulum marker. Western blotting of discrete subcellular fractions demonstrated that cytochrome c oxidase or complex IV-subunit 1 was only expressed in the mitochondrial fraction whereas actin, acetylcholinesterase, cadherins, calnexin, 58 kDa Golgi protein, lactate dehydrogenase and microtubule-associated protein 1 were not, demonstrating the purity of the mitochondrial fraction. Electron microscopic examination of the mitochondrial pellet demonstrated gold particle labeling within mitochondria, indicative of the presence of large-conductance voltage- and calcium-sensitive channels in the inner mitochondrial membrane. These studies provide concrete morphological evidence for the existence of large-conductance voltage- and calcium-sensitive channels in mitochondria: our findings corroborate the recent electrophysiological evidence of mitochondrial large-conductance voltage- and calcium-sensitive channels in glioma and cardiac cells.

[T-cell immunity against autologous leukemic cell mediated by in vitro bone marrow-derived dendritic cell from patients with acute myeloid leukemia in complete remission]

OBJECTIVE

To explore if a specific cytolytic T lymphocyte (CTL) response could be in vitro generated by using autogenous-leukemic cells lysates (ACL) pulsed dendritic cells ( DCs ) from AML-CR patients.

METHODS

T-cell depleted bone marrow mononuclear cells (TD-BMNC) were isolated from AML-CR patients with E-rosetting procedure, and then were cultured in vitro in the presence of combined cytokines ( GM-CSF, IL-4, SCF/TNF-alpha) for generation of mature DCs, and pulsed with ACL on day 5. After 7-day culture, the cells were harvested and the expression of mature DC marker was determined by FACS. For generation of a specific CTL to the respective AML cells, the cells were co-cultured with pre-activated auto-T lymphocytes by McAb anti-CD3 in the presence of low concentration of IL-2 for 7 days. Cytotoxicity was determined with LDH release.

RESULTS

Cultured TD-BMNCs from 12 AML-CR patients developed morphologic and phenotypic characteristics of mature DCs. CTL assay was performed in 6 out of the 12 samples. At effector/target ratio of 20:1, auto-T lymphocytes primed with ACL pulsed DC exhibited significant killing activity to auto-AML cells but not to K562 cells as compared with that stimulated by IL-2 alone or primed by non-pulsed DC (P = 0.001).

CONCLUSION

AML cell associated antigen specific CTL responses can be in vitro generated by priming auto-T lymphocytes with ACL pulsed DCs. These findings might prove useful for immunotherapy of AML.

[Preliminary study on postremission therapy courses in acute myeloid leukemia]

OBJECTIVE

To explore the optimum postremission therapy courses in acute myeloid leukemia (AML).

METHODS

Data from medical records of AML patients in our hospital in 7 year were analyzed with SPSS 8.0 system software.

RESULTS

One hundred and ninety one untreated de novo AML patients received different induction chemotherapy regimens: HA, DA, AA and HAD. The complete remission (CR) rate was 81.4%, 89.9% for one to two courses. The median disease free survival (DFS) in 144 CR patients whose survival time could be analyzed was 9.6 months. The probability of survival was 21.6% at 3 year and 12.9% at 5 year. For the patients received less than 6 courses of post-remission therapy, the median DFS was 7.1 months and the probability of survival was 11.4% at 3 year and 6.3% at 5 years, Whereas for patients received 6 or more courses of post-remission therapy, they were 35.3 months, 43.2% and 27.0%, respectively. The differences between the two groups were statistically significant. For patients received 8 or more courses of post-remission therapy, the median DFS was 48.8 months and the probability of survival was 57.9% at 3 year and 31.6% at 5 year.

CONCLUSION

AML patients should at least receive 6 courses of post-remission therapy, and 8 courses therapy seems better.

Ca2+-binding activity of a COOH-terminal fragment of the Drosophila BK channel involved in Ca2+-dependent activation

Mutational and biophysical analysis suggests that an intracellular COOH-terminal domain of the large conductance Ca(2+)-activated K(+) channel (BK channel) contains Ca(2+)-binding site(s) that are allosterically coupled to channel opening. However the structural basis of Ca(2+) binding to BK channels is unknown. To pursue this question, we overexpressed the COOH-terminal 280 residues of the Drosophila slowpoke BK channel (Dslo-C280) as a FLAG- and His(6)-tagged protein in Escherichia coli. We purified Dslo-C280 in soluble form and used a (45)Ca(2+)-overlay protein blot assay to detect Ca(2+) binding. Dslo-C280 exhibits specific binding of (45)Ca(2+) in comparison with various control proteins and known EF-hand Ca(2+)-binding proteins. A mutation (D5N5) of Dslo-C280, in which five consecutive Asp residues of the "Ca-bowl" motif are changed to Asn, reduces (45)Ca(2+)-binding activity by 56%. By electrophysiological assay, the corresponding D5N5 mutant of the Drosophila BK channel expressed in HEK293 cells exhibits lower Ca(2+) sensitivity for activation and a shift of approximately +80 mV in the midpoint voltage for activation. This effect is associated with a decrease in the Hill coefficient (N) for activation by Ca(2+) and a reduction in apparent Ca(2+) affinity, suggesting the loss of one Ca(2+)-binding site per monomer. These results demonstrate a functional correlation between Ca(2+) binding to a specific region of the BK protein and Ca(2+)-dependent activation, thus providing a biochemical approach to study this process.

Elucidation of a [4Fe-4S] cluster degradation pathway: rapid kinetic studies of the degradation of Chromatium vinosum HiPIP

Irreversible disassembly of the 4Fe-4S cluster in Chromatium vinosum high-potential iron protein (HiPIP) has been investigated in the presence of a low concentration of guanidinium hydrochloride. From the dependence of degradation rate on [H+], it is deduced that at least three protons are required to trigger efficient cluster degradation. Under these conditions the protonated cluster shows broadened Mössbauer signals, but delta EQ (1.1 mm/s) and delta (0.44 mm/s) are similar to the native form. Collapse of the protonated transition state complex, revealed by rapid-quench Mössbauer experiments, occurs with a measured rate constant kobs approximately 0.72 +/- 0.35 s-1 that is consistent with results from time-resolved electronic absorption and fluorescence (kobs approximately 0.4 +/- 0.1 s-1) and EPR (kobs approximately 0.62 +/- 0.18 s-1) measurements. Apparently, guanidinium hydrochloride serves to perturb the tertiary structure of the protein, facilitating protonation of the cluster, but not degradation per se. Release of iron ions occurs even more slowly with kobs approximately 0.07 +/- 0.02 s-1, as determined by the appearance of the g = 4.3 EPR signal. Proton-mediated cluster degradation is sensitive to the oxidation state of the cluster, with the oxidized state showing a two-fold slower rate in acidic solutions as a result of increased electrostatic repulsion with the cluster. Consistent results are obtained from absorption, fluorescence, Mössbauer and EPR measurements.

Clinical significance of changes in beta-adrenoreceptors in peripheral lymphocytes in patients with essential hypertension

OBJECTIVE

To explore the relationship of beta-adrenoreceptor density and function with the condition of patients with essential hypertension.

METHODS

In the present study, 69 male patients with essential hypertension at different stages were compared with a group of age-matched normotensive controls. beta-adrenoreceptor maximum bound volume (Bmax) in peripheral lymphocytes was measured by 3H-dihydroalprenolol (3 H-DHA) radio ligand binding. beta-adrenoreceptor responsiveness was determined by Salbutamol (injection).

RESULTS

In patients with essential hypertension at stages I and II, Bmax was significantly higher (P < 0.01 and P < 0.001, respectively) and the chronotropic doses of Salbutamol required to increase the heart rate by 30 beats/min (CD30) were significantly lower (P < 0.01 and P < 0.001, respectively) than in age-matched normotensive control subjects. In patients with essential hypertension at stage III, Bmax was significantly lower and CD30 was significantly higher (both P < 0.01) than those in the age-matched normotensive control subjects. Bmax was significantly higher and CD30 was significantly lower (both P < 0.001) in patients with essential hypertension and with left ventricular hypertrophy (LVH) than that in patients with essential hypertension but without LVH. In patients with essential hypertension and heart failure, Bmax was significantly lower and CD30 was significantly higher (both P < 0.001) than those in patients with essential hypertension without heart failure.

CONCLUSIONS

The changes of beta-adrenoreceptor density and function were related to hypertension, hypertension complicated with ventricular hypertrophy, and heart failure. They may be viewed as indexes of the condition in the patients with essential hypertension.

[Study on the clinical characteristics of biphenotypic acute leukemia]

OBJECTIVE

To analyze the biological characteristics and the treatment outcome of adult biphenotypic acute leukemia.

METHODS

Immunophenotypes were examined using indirect immunofluorescence method. Biphenotypic acute leukemia (BAL) was diagnosed according to EGIL scoring system.

RESULTS

(1) The incidence of BAL in acute leukemia was 3.4%. Percentage for coexpression of B lymphoid and myeloid antigens was 68.4%, for T lymphoid and myeloid antigens 21.1%, for B, T lymphoid and myeloid antigens 10.5%. (2) CD(34) was expressed in 43.75% of the BAL cases. (3) Cytogenetic analysis revealed normal and abnormal karyotypes in 41.7% and 58.3% of the BAL cases, respectively. (4) Six of 19 patients achieved completed remission (CR), but the disease free survivals were all less than 6 months. Treatment outcomes were negatively related to the expression of CD(34) antigen and cytogenetic findings. The BAL patients were poorly responded to therapeutic regimens directed to AML.

CONCLUSION

Coexpression of B/M antigens is the commonest subtype in BAL. BAL had a poor prognosis, especially treated with induction regimen directed to AML.

[In vitro induction of autologous T cell killing by heat treated human chronic myelogenous leukemia cells]

OBJECTIVE

To investigate the potential of autologous T cell killing of heat treated chronic myelogenous leukemia (CML) cells (autologous tumor killing, ATK).

METHODS

(51)Cr release assay was used to measure the ATK activity of autologous T cells against CML cells treated with 42 degrees C for 30 minutes (heat) or 37 degrees C for 30 minutes (non-heat). The phenotypes of T cells and heat shock protein 70 (HSP70) expression of CML cells were measured by flow cytometry (FCM). T cells from the CML patients were stimulated and expanded by autologous mixed lymphocyte/tumor cell cultures (MLTC).

RESULTS

ATK activity of autologous T cells to the non-heated and heated CML cells were found in 4 (19.05%) and 10 (47.62%) of the 21 cases, respectively. The ATK activity of interleukin-2 (IL-2) stimulated autologous T cells against heated CML cells was markedly higher than that of unstimulated autologous T cells against non-heated CML cells (P < 0.001). FCM analysis showed that no HSP70 was expressed on the CML cell membranes whether heated or non-heated, but intracellular HSP70 expressions were (83.42 +/- 5.65)% and (78.34 +/- 6.32)% pre- and post-heated, respectively. The phenotypes of T cells stimulated and expanded in MLTC were TCRgammadelta - CD(3)(+), mostly CD(8)(+), with some activation markers (CD(25) and HLA-DR) expression. The ATK activities of these T cells against the heated and non-heated CML cells and K562 cells were (51.25 +/- 4.26)%, (36.52 +/- 3.83)% and (2.92 +/- 1.19)%, respectively.

CONCLUSIONS

ATK activity of autologous T cells against CML cells could be induced or enhanced by heat treatment of the CML cells particularly of T cells stimulated with IL-2. This ATK activity was not associated with gammadelta T cells or HSP70 expression of CML cells.

Effect of WT1 gene expression on cell growth and proliferation in myeloid leukemia cell lines

OBJECTIVE

To investigate the effects and mechanism of Wilms' tumor (WT1) antisense oligonucleotides (AS-oligomers) on proliferation and apoptosis in myeloid leukemia cell lines.

METHODS

K562 and HL-60 cells were cultured in presence of WT1 oligomers. Both cell lines express WT1 gene with no p53 protein expression. Cells growth, apoptosis and expression of WT1, bcl-2 genes were analysed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylmetrazolium bromide (MTT) colorimetric assay, flow cytometry and reverse transcription-polymerase chain reaction (RT-PCR) methods.

RESULTS

WT1 antisense oligonucleotides inhibited cellular proliferation of K562 cells and the effect was concentration-dependent. When cultured at concentration of 200 micrograms/ml oligomers, growth inhibition was 46.2% for antisense oligonucleotide cultivated group and 28.1% for sense oligonucleotide cultured group (P = 0.008) respectively. WT1 antisense oligonucleotide can induce apoptosis of K562 and HL-60 cells. Percentages of apoptotic cells in antisense oligonucleotide and sense oligonucleotide treated groups were 30.88% versus 13.62% for K562 cells and 40.15% versus 4.23% for HL-60 cells. However the growth of HL-60 cells and expression of bcl-2 gene were unaffected.

CONCLUSIONS

The WT1 gene is related with proliferation and apoptosis of leukemic cells. Effect of anti-apoptosis may be independent of the cellular p53 status and bcl-2 expression. WT1 gene may play an important role in leukemogenesis.

[Study of thrombopoietin and its receptor C-mpl in acute leukemia]

OBJECTIVE

To study the expression of C-mpl gene in acute leukemia (AL) and its implication and investigate the effect of recombinant human thrombopoietin (rhTpo) on acute leukemic cells as well as its relation to C-mpl expression.

METHODS

C-mpl expression was detected in 43 AL patients by using semi-quantitative reverse transcription polymerase chain reaction and the effect of rhTpo on acute leukemia cells by MTT assay.

RESULTS

C-mpl was expressed in 22 of 35 patients with acute myeloblastic leukemia (AML), but did not in 8 patients with ALL. The percentage of C-mpl expression (16/22, 72.7%) was significantly higher in CD34 positive AML patients than in CD34 negative group (4/12, 33.3%, P = 0.031), and was higher in patients with M2b, M3 and M4EO than in those with other AML subtypes (40.0% vs 80.0%, P = 0.019). The complete remission rate in C-mpl positive AML patients was lower than that in negative patients (70.0% vs 81.8%, P = 0.394), although the difference was not significant. In 9 of 28 cases of AML, the in vitro treatment with rhTpo induced proliferation of leukemia cells. Among these 28 patients, leukemic cells from 8 of 17 (47.0%) patients expressing C-mpl responded to rhTpo, but only the cells from one of 11 (9.1%) non-expressing patients did. The rhTpo induced proliferation of AML cells was enhanced when combined with IL-3, GM-CSF or SCF.

CONCLUSIONS

C-mpl was expressed in some AML, but did not in ALL. Tpo could induce AML cells to proliferate and the effect was augmented when combined with other hematopoietic growth factors.

[Study on the expression of myeloid markers and CD34 antigen in adult acute lymphoblastic leukemia]

OBJECTIVE

To analyse the expression of myeloid markers and CD34 antigen on lymphoblasts in adult ALL and its relationship with prognosis.

METHOD

Immunophenotypes were examined using indirect immunofluorescence method in 102 de novo ALL.

RESULTS

The incidence of myeloid antigen expression in adult ALL was 21.6% and the commonest one was CD33 (15.7%). There was a higher incidence of myeloid antigens expression in ALL-L2 than in ALL-L1 (25.6% vs 5.3%, P = 0.05). CD34 was expressed in lymphoblasts from 30 of 56 patients (53.6%). Incidence of CD34 expression in B-ALL was higher than that in T-ALL (61.7% vs 11.1%, P < 0.01). No relationship between CD34, myeloid antigens and cell maturity was found within B-ALL. There was no relation between expression of myeloid antigens and CD34. The CR rate in My(+)-ALL was lower than that in My(-)-ALL (52.6% vs 80.0%, P < 0.025), and was no relation with CD34 expression. In addition, Ph chromosome and/or bcr/abl fusion gene was positive in 35.9% of the patients, and CR rate of Ph positive patients was higher than that in Ph negative patients.

CONCLUSION

Expression of myeloid antigens was related to FAB subtype and cell maturity in adult ALL. There was no relationship between myeloid antigen expression and CR rate. A higher incidence of CD34 expression was found in Pro-B-ALL than in common-ALL and Pre-B-ALL. Expression of CD34 had no relation with CR rate.

[Effect of WT1 gene expression on cell growth and proliferation in myeloid leukemia cell lines]

OBJECTIVE

To explore the effect of WT1 antisense oligonucleotide(AS-oligo) on cell proliferation and apoptosis in myeloid leukemia cell lines.

METHODS

K562 and HL-60 cells were cultivated with WT1 AS-oligo. The cell proliferation, apoptosis, cell cycle and gene expression were examined by MTT colorimetry, FACS and RT-PCR.

RESULTS

WT1 AS-oligo could inhibit the proliferation of K562 cell and induce apoptosis of K562 and HL-60 cells. On the contrary, the growth of HL-60 cells and the expression of WT1, mdm2 and bcl-2 genes were unaffected.

CONCLUSION

WT1 gene is related to the proliferation and apoptosis of leukemic cells. WT1 gene could suppress cell apoptosis independent of status of p53 and bcl-2 genes. It might play an role in leukemogenesis.

[Study on combined chemosensitivity test in acute non-lymphocytic leukemia]

OBJECTIVE

To explore the methods of combined chemosensitivity test in vitro.

METHODS

The chemosensitivity of leukemia cells to 7 kinds of combined chemotherapy regimens, including DA, HA, AA, MA, HAD, HAA and HAM, was estimated in 79 patients with ANLL by MTT assay in vitro. The ratios of drug combinations at which synergistic interactions between drugs are to the highest levels were determined by using Chou's "median effect analysis".

RESULTS

There were 67 S(sensitive)/S, 9 R(resistant)/R, 2 R/S, 1 S/R(in vitro/in vivo) in 79 patients. The general, positive and negative coincident rates of in vitro with in vivo, specificity and sensitivity were 96.2%, 98.5%, 81.8%, 88.9% and 97.1%, respectively.

CONCLUSION

This method is better than the single drug test, and it is more useful to find drug resistant patients.

[Synergistic reversal effect of quinine in combination with modulators on multidrug resistant cell line K562/HHT]

OBJECTIVE

To develop effective combination of drug resistance modulators.

METHODS

The reversal effects of quinine (Quin) in combination with cyclosporin A (CsA), dipyridamole (DPM) or tamoxifen (Tam), respectively on the drug resistance of K562/HHT were studied by MTT, flow cytometry and median-effect principle.

RESULTS

The reversal effectiveness of the modulator combinations was 2-3 times as much as that of each modulator alone. Synergistic interaction between Quin and DPM or Tam was greater than that between Quin and CsA. Quin combined with CsA increased intracellular DNR accumulation significantly as compared with either of them alone.

CONCLUSION

There was synergistic interactions between Quin and CSA, DPM or Tam, and combination of modulators with different operating mechanisms had a greater synergistic interaction.

[Studies on expansion ex vivo of murine bone marrow cells and its hematopoietic reconstitution capacity]

OBJECTIVE

To investigate the effects of stem cell factor (SCF) in combination with interleukin-1 (IL-1) or/and interleukin-3 (IL-3) on ex vivo expansion of 5FU treated bone marrow cells and hematopoietic recovery in lethally irradiated mice transplanted with the expanded cells.

METHODS

5FU treated bone marrow cells (d3-5FU-BMC) were cultured in a cytokines-containing medium, and the net increments of CFU-GM and high proliferative potential colony forming cell (HPP-CFC) were evaluated.

RESULTS

CFU-GM increased by 33.7 +/- 18.1- or 18.1 +/- 6.3- fold, and HPP-CFC by 17.8 +/- 10.5- or 12.7 +/- 9.1- fold, respectively, in cultures containing SCF with IL- or IL-3, as compared with that in control; while SCF alone had little effect. Compared with fresh d3-5FU-BMC, transplantation of the expanded bone marrow cells accelerated the recovery of recipients' peripheral blood cell counts by 1 approximately 3 days and increased the survival rate of the transplanted animals (d3-5FU-BMC group 50% vs expansion group 8U approximately 100%).

CONCLUSION

SCF in combination with IL-1 or IL-3 synergetically ex vivo expands hematopoietic cells. Transplantation of the expanded bone marrow cells accelerates the recipient's hematopoietic reconstitution.

[The prognostic significance of regular bone marrow aspirations during induction chemotherapy in acute myeloid leukemia]

OBJECTIVE

To evaluate the prognostic significance of regular aspirations during induction chemotherapy in acute myeloid leukemia.

METHODS

Regular bone marrow aspirations were performed during the first course of induction chemotherapy in 96 cases of de novo AML.

RESULTS

Complete remission (CR) rate after the first course in patients with < or = 0.10 bone marrow blasts at the 7th day on chemotherapy was higher than that in patients with > 0.10 blasts (64.6% vs 40.0%, P < 0.05). Prolonged the chemotherapy course for a few more days in the latter group of patients increased CR rate from 25.0% to 50.0%. CR rate in patients with < or = 0.10 bone marrow blasts at the nadir of white blood cell count after chemotherapy was higher than that in patients with > 0.10 blasts (66.0% vs 25.8%, P < 0.005), and the refractory cases were significantly fewer in the former group of patients (7.5% vs 45.2%, P < 0.005).

CONCLUSION

Regular bone marrow aspirations during induction chemotherapy were helpful in predicting the prognosis and guiding the treatment in AML.

[Clonal analysis of blood cells using X-linked HUMARA gene polymorphism]

OBJECTIVE

To explore the method for clonal analysis of blood cells.

METHODS

Thirty female AML patients and 20 normal female subjects were analysed by the analysis of X-linked HUMARA gene polymorphism and methylation pattern.

RESULTS

The heterozygote rate of HUMARA gene in Chinese women was 88% and the gene had a stable methylation pattern. Out of 20 control females, 17 were heterozygotes and among them 15 were polyclonal, 2 (11.8%) showed skewed X-inactivation. All heterozygote AML were clonal hematopoiesis.

CONCLUSION

HUMARA gene polymorphism is a good marker for clonality analysis of blood cells.

Characterization of an autoreduction pathway for the [Fe4S4]3+ cluster of mutant Chromatium vinosum high-potential iron proteins. Site-directed mutagenesis studies to probe the role of phenylalanine 66 in defining the stability of the [Fe4S4] center provide evidence for oxidative degradation via a [Fe3S4] cluster

A number of point mutations of the conserved aromatic residue phenylalanine 66 (Phe66Tyr, -Asn, -Cys, -Ser) in Chromatium vinosum high-potential iron sulfur protein have been examined with the aim of understanding the functional role of this residue. Nonconservative replacements with polar residues have a minimal effect on the midpoint potential of the [Fe4S4]3+/2+ cluster, typically < +25 mV, with a maximum change of +40 mV for Phe66Asn. With the exception of the Phe66Tyr mutant, the oxidized state was found to be unstable relative to the recombinant native, with regeneration of the reduced state. The pathway for this transformation involves degradation of the cluster in a fraction of the sample, which provides the reducing equivalents required to bring about reduction of the remainder of the sample. This degradative reaction proceeds through a transient [Fe3S4]+ intermediate that is characterized by typical g values and power saturation behavior and is prompted by the increased solvent accessibility of the cluster core in the nonconservative Phe66 mutants as evidenced by 1H-15N HMQC NMR experiments. These results are consistent with a model where the critical role of the aromatic residues in the high-potential iron proteins is to protect the cluster from hydrolytic degradation in the oxidized state.

Factors influencing redox thermodynamics and electron self-exchange for the [Fe4S4] cluster in Chromatium vinosum high potential iron protein: the role of core aromatic residues in defining cluster redox chemistry

The roles of aromatic core residues in regulating the reduction potential, the enthalpy and entropy of reduction, and the self-exchange rate constants for electron-transfer reactions for the prosthetic [Fe4S4]3+/2+ cluster of Chromatium vinosum high potential iron protein (HiPIP) have been addressed by a combination of site-directed mutagenesis, high field NMR (EXSY) experiments, and variable temperature spectrochemical redox titration measurements. Minimal changes are observed following nonconservative mutation of residues Tyr19, Phe48, and Phe66. Apparently these hydrophobic residues play only a minor role in defining the electronic properties of the cluster. These data support a model, first defined from results obtained on Tyr19 mutant HiPIP's [Agarwal, A., Li, D., & Cowan, J.A. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 9440-9444], in which the aromatic core restricts solvent accessibility and thereby stabilizes the oxidized [Fe4S4]3+ cluster.

Photorefractive response time measurement in GaAs crystals by phase modulation in two-wave mixing

We describe a new method for photorefractive response time measurement in fast photorefractive crystals based on continuous phase modulation in two-wave mixing. We report experimental results for undoped semi-insulating GaAs that are in good agreement with theory. Values obtained for the response time and photoelectron generation quantum efficiency are consistent with previously published data.

Self-pumped phase conjugation of 18 degrees -cut Ce-doped KNSBN crystal at 632.8 nm

We report the self-pumped phase conjugation of an 18 degrees -cut Ce-doped (K(y)Na(1-y))(2m)(Sr(x)Ba(1-x))(1-m) Nb(2)O(6) crystal at a 632.8-nm He-Ne laser wavelength. A maximum phase-conjugation reflectivity of 84.3% has been measured. In addition, its incident angular response and time response are measured.

Enhanced self-pumped phase conjugation from 16 degrees -cut KNSBN:Cu

With the maximum coupling coefficient and high internal reflection conditions, the self-pumped phase-conjugation reflectivity of copper-doped potassium sodium strontium barium niobate (KNSBN:Cu) is increased with 16 degrees -cut samples. The response time is also shortened. The resolution property of 16 degrees -cut KNSBN:Cu is determined and a distorted image is corrected by using the 16 degrees -cut sample.

Optical perfect shuffle using Wollaston prisms

The 2-D optical perfect shuffle is demonstrated in an imaging system which uses Wollaston prisms for replicating the input image. Full parallelism and high light efficiency are achieved using this perfect shuffle system.