Cold Air Plasma Inhibiting Tumor-Like Biological Behavior of Rheumatoid Arthritis Fibroblast-Like Synovial Cells via G2/M Cell Cycle Arrest

Background

Rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) have become the core effector cells for the progression of rheumatoid arthritis due to their "tumor-like cell" characteristics, such as being able to break free from growth restrictions caused by contact inhibition, promoting angiogenesis, invading surrounding tissues, and leading to uncontrolled synovial growth. In recent years, cold air plasma (CAP) has been widely recognized for its clear anticancer effect. Inspired by this, this study investigated the inhibitory effect of CAP on the tumor-like biological behavior of RA-FLS through in vitro experiments.

Methods

Treatment of RA-FLS with CAP at different time doses (0s, 30s, 60s, 120s). 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay was used to determine the cell viability. Analysis of cell migration and invasion was performed by wound-healing assay, transwell assay and immunofluorescent staining for f-actin, respectively. Flow cytometry technique was used for analysis of cell cycle and determination of reactive oxygen species (ROS). Hoechst staining was used for analysis of cell apoptosis. Protein expression was analyzed by Western blot analysis.

Results

Molecular and cellular level mechanisms have revealed that CAP blocks RA-FLS in the G2/M phase by increasing intracellular reactive oxygen species (ROS), leading to increased apoptosis and significantly reduced migration and invasion ability of RA-FLS.

Conclusion

Overall, CAP has significant anti proliferative, migratory, and invasive effects on RA-FLS. This study reveals a new targeted treatment strategy for RA.

Visible-Light-Induced Tandem Radical Brominative Addition/Cyclization of Activated Alkynes with CBr4 for the Synthesis of 3-Bromocoumarins

A visible-light-induced tandem radical brominative addition/spiro-cyclization/1,2-ester migration of activated alkynes with CBr₄ is developed. This protocol features good functional group tolerance, operational simplicity, and mild reaction conditions without the use of catalysts and external additives, providing easy access to valuable 3-bromocoumarins in generally high yields.

[Safety of an inactivated 2019-nCoV vaccine (Vero) in adults aged 60 years and older]

Objective: To analyze the safety of an inactivated 2019-nCoV vaccine (Vero cell) in adults aged 60 years and older. Methods: A randomized, double-blind, placebo-controlled clinical study was conducted in May 2020 The eligible residents aged 60 and above were recruited in Renqiu city, Hebei Province. A total of 422 subjects (phase Ⅰ/Ⅱ:72/350) were enrolled. Two doses of the trial vaccine or placebo were randomly administered according to a 0 and 28-day immunization schedule. Subjects were randomly divided into two groups in Phase Ⅰ. Within each group, participants received vaccine or placebo in a ratio of 2∶1. Subjects were randomly divided into four groups in phase Ⅱ to receive low-dose, medium-dose, high-dose vaccine and placebo, respectively, in a ratio of 2∶2∶2∶1. A combination of regular follow-up and active reporting was used to observe adverse reactions within 28 days after vaccination, and compare the incidence rate of adverse reactions in the trial and control groups. Results: 422 subjects were (66.45±4.70) years old, and 48.82% were male (206/422). There were 100, 124, 124 and 74 patients enrolled into the low-dose, medium-dose, high-dose vaccine groups and the placebo group, respectively. One person without the vaccination was removed, and 421 participants who received at least one dose of vaccine were included in the safety analysis. Within 28 days after the first or second dose, a total of 20.67% (87/421) subjects had adverse reactions (both solicitation and non-solicitation). About 76 patients suffered grade 1 adverse reactions [18.05% (76/421)] and 22 patients suffered grade 2 adverse reactions [5.23% (22/421)]. No grade 3 or above adverse reactions occurred. A total of 19.71% (83/421) subjects had solicited adverse reactions. The most common grade 1 adverse reaction was injection site pain, followed by fever and fatigue. The most common grade 2 adverse reactions were fever and fatigue, followed by muscle pain and injection site redness. A total of 2.61% (11/421) subjects had unsolicited adverse reactions. A total of 1.66% (7/421) subjects had serious adverse events after vaccination, and no serious vaccine-related adverse events were reported. Conclusions: The inactivated SARS-CoV-2 vaccine is safe for people aged 60 years and above.

[Advances in gut microbiomes and immunology of IgG4-related hepatobiliary and pancreatic diseases]

IgG4-related disease (IgG4-RD) is an immune-mediated condition associated with chronic fibroinflammatory lesions that can affect nearly any organ. IgG4-related hepatobiliary and pancreatic diseases are IgG4-RD involving the hepatobiliary and pancreatic system, which is characterized with elevated serum IgG4 concentrations, large numbers of IgG4 positive lymphoplasma cells infiltration in affected organs, storiform fibrosis, and imaging changes of organ morphology. Due to the lack of reliable biomarkers, histopathology is still an important basis for diagnosis. The pathogenesis of IgG4-related hepatobiliary and pancreatic diseases has not been clarified. This review focuses on the recent advances in intestinal microecology-immunology, host genetics-immunity and recurrence monitoring of IgG4-related hepatobiliary and pancreatic diseases.

[The effect of booster dose vaccination 21- to 32-years after primary vaccination with hepatitis B vaccine in the population born from 1986 to 1996 in Zhengding County of Hebei Province]

Objective: Aanalysis the effect of booster one dose of hepatitis B vaccine after 21-32 years of primary immunization in Zhengding Country of Hebei Province. Methods: A total of 322 participants who were born between 1986 and 1996, received a full course of primary vaccination with plasma-derived hepatitis B vaccine (HepB), had no experience with booster vaccination, were HBsAg, anti-HBcnegative, had anti-HBs<10 mIU/ml, completed the booster and had laboratory results were enrolled between August 2017 to February 2018. A simple random method was uesd to randomly assigned 322 subjects to two groups, receiving a booster dose of HepB derived from either Saccharomyces cerevisiae ［HepB (SC), (151 cases)］ or Chinese hamster ovary-derived HepB ［HepB (CHO), (171 cases)］, the dose was 20 μg. Blood samples were collected 30 days after boosting and quantitatively tested for the geometric mean concentration (GMC) of anti-HBs to assess immunological effect. The related influencing factors of GMC and seroconversion rates of anti-HBs were analyzed by multiple linear regression and multivariate logistic regression models. Results: The 266 subjects (82.61%) had anti-HBs≥ 10 mIU/ml, and GMC was (131.63±12.94) mIU/ml.The seroconversion rates of anti-HBs in the anti-HBs<2.5 mIU/ml group and 2.5-10 mIU/ml group were 74.54% (161 cases) and 99.06% (105 cases), respectively (P<0.001).The seroconversion rates of anti-HBs after one dose of HepB (CHO) was higher than that of one dose of HepB (SC), the seroconversion rates were 87.13% (149 cases) and 77.48% (117 cases), respectively (P=0.023). Participants boostered with HepB (CHO) was the factor influencing the effect of strengthening immunization compared with boostered with HepB (SC), and OR (95%CI) was 1.91 (1.02-3.56) (P=0.042).Compared with anti-HBs<2.5 mIU/ml, prebooster anti-HBs was between 2.5 mIU/ml and 10 mIU/ml was the related factor of seroconversion rates of anti-HBs after booster immunization, and OR (95%CI) was 36.15 (4.91-266.02) (P<0.001). Conclusion: Participants boostered withone dose of HepB had a good immune response. Pre-booster anti-HBs concentration and a variety of vaccine were related factors of immune response.

[Research progress on abnormal liver function in pregnancy]

Abnormal liver function in pregnancy is a common clinical problem in the department of obstetrics and liver disease, but its severity can cause danger to the life of the mother and fetus. Therefore, the different cause of abnormal liver function in pregnancy should be assessed accurately in order to take early intervention measures. Moreover, it is necessary to comprehensively evaluate the situation of both mother and fetus to obtain the optimal treatment effect for abnormal liver function caused by different types of pregnancy-related liver diseases.

[Effects of lateral and medial points of thoracic paravertebral nerve block by ultrasound for rapid recovery after laparoscopic cholecystectomy]

Objective: To investigate the effects of ultrasound-guided lateral and medial point blocks of thoracic paravertebral space on the rapid recovery of laparoscopic cholecystectomy. Methods: A total of 90 patients of either sex, aged 18-67 years, weighted 45.10-91.80 kg, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective laparoscopic cholecystectomy were divided into two groups (n=45) using a random number table: lateral point group of thoracic paravertebral space (group A) and medial point group of thoracic paravertebral space (group B). Ultrasound-guided thoracic paravertebral nerve block was performed before induction of general anesthesia. The puncture point of group A was positioned as the intercostal block of the thoracic paravertebral space of the right side of T(6)-T(11), and the puncture point of the group B was positioned as the thoracic paravertebral body of the right side of T(6)-T(11) thoracic paravertebral space. The thoracic paravertebral block was performed with 2 ml of 0.75% ropivacaine per injection for a total of 10 ml. The visual analog scale (VAS) scores of resting pain and active pain at 4, 8, 12 and 24 h after operation were observed. The anus recovery time after surgery and perioperative hypotension were also recorded. Results: The blood pressures in group A were significantly higher than those in group B at 4, 8, 12 and 24 h after operation, which were(73±7) vs (70±7), (78±7) vs (74±7),(82±7) vs (79±7),and (87±7) vs (83±7) mmHg,and the differences were statistically significant (t=2.29, 2.54, 2.33, 2.37, all P<0.05). The VAS scores of resting pain and active pain in group A were significantly higher than those in group B, and the differences were statistically significant (Z=-2.29, -2.51, -2.21, -2.39, -2.53, -2.25, -2.30, -2.24, all P<0.05). The postoperative anal exhaust recovery time of the patients in group A was (21.8±1.9) min that was obvious lower than that in group B which was (22.7±1.9) min with statistically significant difference (t=2.12, P<0.05). There was no significant difference in the incidence of postoperative dizziness, nausea, vomiting, and pruritus (χ(2)=0.28, 0.72, 0.45, 0.21,all P>0.05). Conclusions: In the procedure of thoracic paravertebral block under the guidance of ultrasound, the closer blocking points are to the central axis of the spine, the better the postoperative analgesic effect, but the more obvious the postoperative blood pressure reduction and the longer the anal recovery exhaust time. The further away from the central axis of the spine, the more analgesic effect decreases, but the blood pressure decreases and the anal recovery time is relatively rapid.

Four-dimensional calibration turntable of the motional Stark effect diagnostic on EAST

The motional Stark effect (MSE) diagnostic is applied to measure the safety factor q and current density profile of a tokamak device, which are important parameters in realizing the high-performance and long-pulse steady state of a tokamak. A single-channel MSE diagnostic based on dual photoelastic modulators, whose sightline meets with the neutral beam injection at a major radius of R = 2.12 m, has been built for the D window of the Experimental Advanced Superconducting Tokamak (EAST). According to the requirements of MSE diagnostic polarimetric calibration, a high-precision four-dimensional calibration turntable, driven by four stepping motors and controlled by software running on the computer, was designed for EAST. The turntable allows us to rapidly calibrate the MSE diagnostic in a series of positions and angles during EAST maintenance. The turntable can move in four dimensions of translation, yaw, pitch, and roll of the polarizer and can create linearly polarized light at any given angle with accuracy of ∼0.05° for the MSE system offline calibration. The experimental results of the MSE diagnostic calibration in the laboratory show that the turntable has the advantages of high positioning accuracy, flexible spatial movement, and convenient control and fully meets the calibration requirements of an MSE diagnosis system.

Fast-ion Dα spectrum diagnostic in the EAST

In toroidal magnetic fusion devices, fast-ion D-alpha diagnostic (FIDA) is a powerful method to study the fast-ion feature. The fast-ion characteristics can be inferred from the Doppler shifted spectrum of D_α light according to charge exchange recombination process between fast ions and probe beam. Since conceptual design presented in the last HTPD conference, significant progress has been made to apply FIDA systems on the Experimental Advanced Superconducting Tokamak (EAST). Both co-current and counter-current neutral beam injectors are available, and each can deliver 2-4 MW beam power with 50-80 keV beam energy. Presently, two sets of high throughput spectrometer systems have been installed on EAST, allowing to capture passing and trapped fast-ion characteristics simultaneously, using Kaiser HoloSpec transmission grating spectrometer and Bunkoukeiki FLP-200 volume phase holographic spectrometer coupled with Princeton Instruments ProEM 1024B eXcelon and Andor DU-888 iXon3 1024 CCD camera, respectively. This paper will present the details of the hardware descriptions and experimental spectrum.

Measurement of the deuterium Balmer series line emission on EAST

Volume recombination plays an important role towards plasma detachment for magnetically confined fusion devices. High quantum number states of the Balmer series of deuterium are used to study recombination. On EAST (Experimental Advanced Superconducting Tokamak), two visible spectroscopic measurements are applied for the upper/lower divertor with 13 channels, respectively. Both systems are coupled with Princeton Instruments ProEM EMCCD 1024B camera: one is equipped on an Acton SP2750 spectrometer, which has a high spectral resolution ∼0.0049 nm with 2400 gr/mm grating to measure the D_α(H_α) spectral line and with 1200 gr/mm grating to measure deuterium molecular Fulcher band emissions and another is equipped on IsoPlane SCT320 using 600 gr/mm to measure high-n Balmer series emission lines, allowing us to study volume recombination on EAST and to obtain the related line averaged plasma parameters (T_e, n_e) during EAST detached phases. This paper will present the details of the measurements and the characteristics of deuterium Balmer series line emissions during density ramp-up L-mode USN plasma on EAST.

Filterscope diagnostic system on the Experimental Advanced Superconducting Tokamak (EAST)

A filterscope diagnostic system has been mounted to observe the line emission and visible bremsstrahlung emission from plasma on the experimental advanced superconducting tokamak during the 2014 campaign. By this diagnostic system, multiple wavelengths including D_α (656.1 nm), D_γ (433.9 nm), He ii (468.5 nm), Li i (670.8 nm), Li ii (548.3 nm), C iii (465.0 nm), O ii (441.5 nm), Mo i (386.4 nm), W i (400.9 nm), and visible bremsstrahlung radiation (538.0 nm) are monitored with corresponding wavelength filters. All these multi-channel signals are digitized at up to 200 kHz simultaneously. This diagnostic plays a crucial role in studying edge localized modes and H-mode plasmas, due to the high temporal resolution and spatial resolution that have been designed into it.

Finite element simulation of lower limb injuries to the driver in minibus frontal collisions

PURPOSE

This study aims to explore the biomechanical mechanism of lower limb injuries to the driver by establishing a finite element (FE) simulation model of collisions.

METHODS

First a minibus FE model was integrated with a seat belt system. Then it was used to rebuild two collisions together with the total human model for safety (THUMS) provided by Toyota Motor Corporation: a rear-end collision between a minibus and a truck and a head-on collision of a minibus to a rigid wall. The impact velocities of both collisions were set at 56 km/h. The vehicle dynamic response, vehicle deceleration, and dashboard intrusion in the two collisions were compared.

RESULTS

In the minibus rear-end truck collision, the peak values of the von Mises equivalent stress at the tibia and the femur were 133 MPa and 126 MPa respectively; while in the minibus head-on rigid wall collision, the data were 139 MPa and 99 MPa. Compared with the minibus head-on rigid wall collision, the vehicle deceleration was smaller and the dashboard intrusion was larger in the minibus rear-end truck collision.

CONCLUSION

The results illustrate that a longer dashboard incursion distance corresponds to a higher von Mises equivalent stress at the femur. The simulation results are consistent with the driver's autopsy report on lower limbs injuries. These findings verify that FE simulation method is reliable and useful to analyze the mechanisms of lower limb injuries to the driver in minibus frontal collisions.

Toxicity of Six Insecticides on Codling Moth (Lepidoptera: Tortricidae) and Effect on Expression of Detoxification Genes

The codling moth, Cydia pomonella (L.), is a key worldwide fruit pest that has evolved high levels of resistance to almost all classes of conventional insecticides. Neonicotinoids, a new reduced-risk biorational insecticide class, have remained an effective control approach. In this study, the toxicity and sublethal effect of conventional and reduced-risk biorational insecticides on transcripts abundance of three detoxification genes in codling moth were determined. Bioassays on a codling moth laboratory strain suggested that acetamiprid had the highest oral toxicity against the third-instar larvae compared with the other five pesticides. Results also indicated that acetamiprid exhibits long-term efficacy against codling moth even at 120 h post feeding. Real-time quantitative polymerase chain reaction showed that the detoxification genes CYP9A61, CpGST1, and CpCE-1 were differentially induced or suppressed by deltamethrin, cypermethrin, methomyl, carbaryl, and imidacloprid, depending on the type of insecticides; in contrast, no significant difference in CYP9A61, CpGST1, and CpCE-1 expressions were observed after acetamiprid exposure, when compared with the control. These results suggest that the reduced-risk biorational insecticide acetamiprid is an effective insecticide with no induction of detoxification genes and can be integrated into the management of codling moth.

Effectiveness of 12 Insecticides to a Laboratory Population of Cydia pomonella (Lepidoptera: Tortricidae) Newly Established in China

The codling moth Cydia pomonella (L.) is an economically important fruit pest that has spread rapidly from its original site in Xinjiang to other northwestern regions of China. Insecticides are widely used to control this pest but its invasion has never been completely stopped. The aim of this study was to establish a laboratory population of the codling moth occurring in China, to investigate the effectiveness of 12 conventional insecticides to this laboratory population, and to recommend the discriminating doses for use in resistance monitoring. The laboratory population was generally similar to other laboratory strains although parameters such as survival rate and larval duration were low when compared with field populations. Toxicity varied among the insecticides tested with LC50 values ranging from 0.016 mg/l for emamectin benzoate to 55.77 mg/l for chlorbenzuron. Discriminating dose levels were determined from dose-mortality reference curves for the detection of resistance in field populations. Effectiveness of 12 insecticides to a laboratory population of codling moth in China was evaluated for the first time. This can be integrated into resistance management strategies, especially in orchards with a history of frequent insecticides applications, in order to monitor or decrease insecticide resistance in the future.

The Toxicology and Biochemical Characterization of Cantharidin on Cydia pomonella

Cantharidin, a natural toxin produced by beetles in the families Meloidae and Oedemeridae, reported to be toxic to some pests, is being developed as a biopesticide in China. This study evaluates the toxicity and biochemical characterization of cantharidin on the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), an economically important fruit pest, under both laboratory and field conditions. Laboratory dose response bioassays showed that the LC50 value of cantharidin against neonate larvae was 0.057 mg ml(-1). Exposure of the larvae to 0.024 and 0.057 mg ml(-1) of cantharidin resulted in significant reduction in larval body weight. Neonate larvae exposed to LC10 of cantharidin showed increased glutathione S-transferase activity and significantly reduced the carboxylesterase and cytochrome P450-dependent mixed-function oxidase activities. Results also showed 16 and 25% ovicidal activity at concentrations of 0.057 and 0.14 mg ml(-1) of cantharidin, respectively. Field trials demonstrated cantharidin has a significant effect on both the first and second generations of C. pomonella larvae, but it exhibits a lower control efficiency than the chemical reference emamectin benzoate. Cantharidin may be considered a valuable tool for the control of codling moth.

Magnetic topology changes induced by lower hybrid waves and their profound effect on edge-localized modes in the EAST tokamak

Strong mitigation of edge-localized modes has been observed on Experimental Advanced Superconducting Tokamak, when lower hybrid waves (LHWs) are applied to H-mode plasmas with ion cyclotron resonant heating. This has been demonstrated to be due to the formation of helical current filaments flowing along field lines in the scrape-off layer induced by LHW. This leads to the splitting of the outer divertor strike points during LHWs similar to previous observations with resonant magnetic perturbations. The change in the magnetic topology has been qualitatively modeled by considering helical current filaments in a field-line-tracing code.

The influence of surface oxide on the growth of metal/semiconductor nanowires

We report the critical effects of oxide on the growth of nanostructures through silicide formation. Under an in situ ultrahigh vacuum transmission electron microscope, it is observed from the conversion of Si nanowires into the metallic PtSi grains epitaxially through controlled reactions between lithographically defined Pt pads and Si nanowires. With oxide, instead of contact area, single crystal PtSi grains start forming either near the center between two adjacent pads or from the ends of Si nanowires, resulting in the heterostructure formation of Si/PtSi/Si. Without oxide, transformation from Si into PtSi begins at the contact area between them, resulting in the heterostructure formation of PtSi/Si/PtSi. The nanowire heterostructures have an atomically sharp interface with epitaxial relationships of Si(20-2)//PtSi(10-1) and Si[111]//PtSi[111]. Additionally, it has been observed that the existence of oxide significantly affects not only the growth position but also the growth behavior and the growth rate by two orders of magnitude. Molecular dynamics simulations have been performed to support our experimental results and the proposed growth mechanisms. In addition to fundamental science, the significance of the study matters for future processing techniques in nanotechnology and related applications as well.

A phenomenological approach to the anisotropic magnetoresistance and planar Hall effect in tetragonal La(2/3)Ca(1/3)MnO3 thin films

A La(2/3)Ca(1/3)MnO(3) Hall bar with its long dimension roughly along the hard axis [110] was fabricated on a single-crystal-like tensilely strained film on SrTiO(3)(001). The anisotropic magnetoresistance (AMR) and planar Hall effect (PHE) have been studied at various external magnetic fields and temperatures. A phenomenological model in the high field limit is developed, and the galvanomagnetic tensor based on a tetragonal symmetry 4/mmm (D(4h)), applicable to epitaxial films on a substrate, has been obtained by expanding the tensor to the sixth order. The derived in-plane transverse resistance R(xy) shows a sin2φ(M) angular dependence, while the longitudinal R(xx) is constituted by not only a two-fold cos2φ(M) term, but also a four-fold cos4φ(M) term due to the square symmetry of the lattice. The model is in good agreement with the experimental results in high fields, while deviations are observed near the {100} easy axis with the decreasing field. Close inspection of the fitting parameters reveals the evolution of these term weights with temperature and magnetic field, which is distinct from conventional ferromagnetic metals and cannot be explained by the phenomenological model. An alternative mechanism for AMR, stemming from the magnetization-induced local orbit deformation through spin-orbit interaction, as previously proposed by O'Donnell et al, may be prevalent in manganites and other systems of complicated crystal structure.

Intraductal papillary neoplasms of bile duct. A distinct entity like its counterpart in pancreas

To recognize the new entity-intraductal papillary neoplasia of bile duct in liver, the authors reviewed the clinical records of sixteen patients, analyzed the microscopic features, and selected immunohistochemical reactivity (cytokeratins and mucins) that might correlate with classification. Ten patients were male and six were female, with a mean age of 58 years (range, 21-73 years). According to their cell phenotypes, these papillary tumors were classified as intestinal type (6 cases), pancratobiliary type (4 cases), gastric type (5 cases) and oncocytic type (1 case). Most were located in the left hepatic duct and accompanied with bile duct dilatation (10 cases). Eight showed minimal expansile invasion into the ductal wall and eight were noninvasive. Five patients were treated with a hepatectomy, three underwent segmental resections, and one underwent a left hepatic lobectomy. One patient died of unrelated causes 6 years after operation, and another died of postoperative complications. The remaining 7 patients are alive and disease free 1-5 years after surgery. Because of its distinct clinical, pathological features and a favorable prognosis can be expected after complete surgical resection, we suggested that intraductal papillary neoplasia should be distinguished from other types of peripheral cholangiocarcinoma, as a distinct entity, like its counterparts in the pancreas. Neoexpressed and overexpressed mucins are of clinical value as a marker for supportive diagnosis, prognosis or monitoring therapy.

[A study on the mechanism of reductive alkylation for preparing 3-(beta-hydroxy-ethyl-sulfonyl) N-ethyl aniline with HPLC/MS]

Hydrogenating 3-(beta-hydroxy-ethyl-sulfonyl)-aniline and acetaldehyde in the presence of Raney Nickel as a catalyst, 3-(beta-hydroxy-ethyl-sulfonyl)-N-ethyl-aniline was obtained with 98% conversion and 95% monoalkylation selectivity under optimum conditions. By using high performance liquid chromatography/mass selective detection technique to characterize the structures of the products, the mechanism of reductive alkylation is proposed. From the intermediates determined, it is shown that the reaction mechanism would go via an unstable N-alpha-hydroxyethylaniline derivative and Schiff base stage. After hydrogenation of Schiff base, finally the product 3-(beta-hydroxyethyl-sulfonyl)-N-ethyl aniline was formed.

Discrete subpopulations, defined by CD45 isoforms, coexist within the leukaemic cells of B-chronic lymphocytic leukaemia patients

The expression of CD45 isoforms by B-CLL leukaemic lymphocytes has been analysed by 2 colour flow cytometry and vectorial iodination. The cytometry has demonstrated the presence of cells with different CD45 phenotypes which vary in the relative expression of the CD45RA and CD45RO determinants. Discrete populations have been detected which can coexist within an individual patient. One of these populations which is CD45RO-negative consists of cells expressing only the 230 kD isoform, in the others the smaller isoforms are expressed, the appearance of the CD45RO determinant of 180 kD being accompanied by the appearance of the 190 kD isoform. The relative proportion of cell populations is stable within patients but can be altered by phorbol ester which enhances CD45RO expression and diminishes CD45RA expression. The populations may be partially resolved by the density gradient fractionation.

The analysis of the variation of the surface proteins of leukemic lymphocytes of B-chronic lymphocytic leukemia patients by high performance liquid chromatography

Surface phenotypes of leukemic lymphocytes are analyzed by high performance liquid chromatography of the vectorially iodinated surface proteins and the variation of the phenotypes of B-chronic lymphocytic leukemia (B-CLL) lymphocytes from different individuals is studied. A number of surface molecules show a coordinated variation between patients in their level of expression. Some of these molecules belong to recognized clusters of differentiation, e.g., CD45 and CD21 and their variation can be confirmed by flow cytometry. But the HPLC also reveals other components that have not been assigned to known clusters, e.g., a component of Mr of around 300 kD. Two types of B CLL lymphocytes can be recognized by this set of molecules and the patients ranked according to the level of expression of these markers on their leukemic cells. The effects of TPA treatment on expression suggests that these molecules represent a maturational sequence and that the leukemias are derived from progressive stages along this process.

The identification of antigens in antibody/antigen complexes using high performance liquid chromatography

A method for the identification of antigens in a complex mixture of proteins is described. It exploits the effect which addition of a monoclonal antibody and resultant formation of antibody/antigen complexes has on the apparent retention time of the antigen on a size exclusion column. An antigen in the mixture can be identified as that component whose retention time is decreased by addition of its antibody. The principle of the method is demonstrated using an HPLC size exclusion column (DuPont GF450) and three MoAbs, PD7/26, DA6 147 and W6/32 which are directed against three antigens of the lymphocyte surface, the leucocyte-common antigen, class II MHC and class I MHC respectively.