Suppression of in vitro IgM rheumatoid factor production by diphtheria toxin interleukin 2 recombinant fusion protein (DAB 486IL-2) in patients with refractory rheumatoid arthritis

OBJECTIVE: To investigate the effect of diphtheria toxin interleukin 2 recombinant fusion protein (DAB 486IL-2) on in vitro synthesis of immunoglobulin and rheumatoid factor (RF) in patients with severe refractory rheumatoid arthritis (RA) enrolled in a phase II, double blind, placebo controlled study. METHODS: Anticoagulated venous blood samples were obtained before (Day 1) and after (Day 28) intravenous infusion of either DAB 486IL-2 at 0.075 mg/kg/day (12 patients) or saline placebo (10 patients) on Days 1-5. Peripheral blood leukocytes (PBL) were prepared by density gradient centrifugation, cultured in the presence and absence of pokeweed mitogen (PWM) for one week, and culture supernatants assayed for immunoglobulins and IgM RF by ELISA. RESULTS: Compared to placebo treated patients, PWM induced IgM RF synthesis by PBL decreased after treatment with DAB 486IL-2 (p = 0.043). However, there was no apparent correlation with clinical improvement. PWM induced IgM, IgA, and IgG synthesis also tended to decrease, although the changes did not attain statistical significance. In contrast, PWM induced IgM RF, IgM, IgA, and IgG synthesis by PBL from patients treated with placebo tended to increase during the observation period. Spontaneous immunoglobulin and IgM RF production by PBL from either the DAB 486IL-2 or placebo patients remained stable. CONCLUSION: These observations raise the possibility that DAB 486IL-2 may diminish B cell function either directly or indirectly through effects on T cell function, but the change may not correspond to clinical response.     

Highly active antiretroviral therapy results in a decrease in CD8+ T cell activation and preferential reconstitution of the peripheral CD4+ T cell population with memory rather than naive cells

Criteria for detection of chromosome aberrations by Comparative Genomic Hybridization (CGH) are not standardized and improvement of this part of the analysis is of paramount importance to the applicability of the technique. The aim of this work was to suggest CGH detection criteria that increase the specificity and sensitivity and at the same time include chromosome regions previously excluded from CGH analysis. We analyzed 33 hybridizations with normal DNA and modified our CGH software in order to use a selection of these normal analyses as a model for interpretation of analyses of unknown samples. This approach was successfully tested on 14 samples with known aberrations.     

Biomechanical comparison of the dewar and interspinous cervical spine fixation techniques

STUDY DESIGN: This study evaluates and compares the stiffness of two cervical spine fixation techniques. OBJECTIVES: This biomechanical study was carried out to compare the interspinous and Dewar cervical spine fixation techniques. SUMMARY OF BACKGROUND DATA: Interspinous wiring is a commonly used method of fixation in the cervical spine. The Dewar technique is less commonly known and practiced, and clinical experience has suggested that it may be a more stable technique. METHODS: Cervical spine specimens stabilized with the interspinous and "Dewar" techniques were biomechanically tested in flexion and in torsion. Stiffness and energy absorption under moderate loads were compared. The Dewar technique uses contoured double corticocancellous iliac grafts as internal grafts/splints fixed to the spine with threaded pins and wire. The interspinous technique is a single interspinous wire loop. Eleven fresh human cervical spines were harvested from cadavers. The spines were destabilized at C4-C5 by sectioning all tissue except the anterior longitudinal ligament. Each fixation technique was applied alternatively and tested on each spine. RESULTS: In torsion testing (n = 5), the Dewar fusion was 61% stiffer than the interspinous technique (P < 0.02). Dewar: 11.3 N/mm (s.d. 4.9 N/mm) and interspinous: 8.4 N/mm (SD 3.3 N/mm). In flexion testing (n = 6), the Dewar technique was 35% stiffer than the interspinous technique (P < 0.10). Dewar: 655.4 Nmm/degree (SD 293 Nmm/degree) and interspinous: 406.8 Nmm/degree (SD 113.0 Nmm/degree). Energy absorption with the interspinous technique was greater in flexion (P < 0.10) and in torsion (P < 0.005), indicating more deformation with the interspinous technique. There was no statistically significant difference between the means of specimens tested first and those tested second independently of the fixation technique. CONCLUSIONS: These tests indicate that the Dewar cervical spine fixation is stiffer than the single interspinous wire in both flexion and particularly torsion. This project is the only biomechanical study of the Dewar technique that we are aware of, and the results support the clinical findings regarding the effectiveness of this technique.     

Peculiarities of primary and secondary structure of phage FI-1 DNA

The composition of nitrous bases of phage FI-1 DNA was studied. As is evidenced from the values of buoyant density in CsCl (p=1,7093 g/cm(3)), melting temperature (T degrees m=86,05 degrees), spectral parameters and direct chromatographic determination, the DNA analysed contains 41,5 mole% pairs of guanine-cystosine. 5-hydroxymethylcytosine and other anomalous bases were not found. Chemical identification and jaxtposition of data of buoyant density in CsCl and Cs2SO4 (p=1,4466 g/cm(3)) and T degrees m. showed the presence of the extra-sugar component in DNA, most likely in the form of hentibiose. Spectral character of thermal denaturation of DNA in different solvents is indicative of the double helixity of its structure. DNA is characterized by enthalpies of conformational transitions "helix coil" (deltaH=12,3 kcal/g) and (deltaH=10 kcal/g) for the solvents, 1 x SSC, and 0,1 x SSC, correspondingly. The presence of extra-sugar in DNA with standard set of nitrous bases is discussed.     

Decreased resistance to intravenous tumour-cell challenge during reticuloendothelial depression following surgery

The influence of surgical stress on resistance to i.v. challenge with Walker 256 tumour cells was investigated in rats, with respect to the functional state of the reticuloendothelial system (RES). Phagocytic activity of the RES was evaluated by colloid (gelatinized [131I] "RE test lipid emulsion") clearance, and opsonin levels were determined by bioassay. Reticuloendothelial clearance capacity was significantly (P less than 0-05) depressed 60 min following surgery (coeliotomy plus jejunal enterotomy) as quantified by both humoral and cellular parameters of RE function. Phagocytic depression was primarily due to impaired hepatic Kupffer cell function and related to a deficiency in the phagocytic supporting capacity of plasma, also referred to as opsonic or recognition factor (RF) capacity. During the postoperative period of RES colloid clearance depression, pulmonary localization of the blood-borne test particulate matter increased. Rats challenged with 51Cr-labelled viable tumour cells at a dose of 1-0 X 106 i.v., either prior to or during the postoperative period of RE depression, manifested a significant (P less than 0-05) increment in pulmonary localization of the viable tumour cells, and a decrease (P less than 0-05) in hepatic clearance. Evaluation of survival patterns demonstrated a significant (P less than 0-01) decrease in host resistance to i.v. tumour cell challenge (2 X 103 cells) during the postoperative period of RE depression and hypo-opsonaemia. Sham-anaesthetized control animals survived 17-9 +/- 0-8 days, while animals challenged during the period of RE depression survived 7-9 +/- 0-4 days. An increased incidence of respiratory distress and nasal discharge was observed in the animals with impaired survival. Thus, surgical manipulation may transiently compromise RES systemic host defence and may be reflected in an increment in the pulmonary localization of blood-borne tumour cells. The relationship of this altered pattern of tumour cell distribution to the impaired survival remains to be determined, and warrants investigations.     

Glutamate dehydrogenase activity in the structures of the rabbit brain limbic system

The activity of glutamate dehydrogenase (EC 1.41.1.3) is studied in homogenates and subcellular fractions of five limbic structures: regio superior, regio inferior of hippocampus, fascia dentata, septum and corpora mamillaria. The lowest activity of the enzyme is found in regio superior of hippocampus. 80% of the total enzyme activity of primary fractions is found in "crude" mitochondria. After centrifugation of the latter within the linear sucrose density gradient the distribution of the enzume activity is similar for different structures and the highest activity is found in the region of sucrose molarity from 1.44 up to 1.50 M which corresponds to the mitochondria distribution region. 50% of the total found activity is in the fraction enriched by mitochondria, 30% is in the fraction enriched by nerve endings with the high activity of glutamate decarboxylase. It was found for different fractions that 1 mM of ADF with 0.2 mM NAD-H+ produces about 10-fold increase in the enzyme activity. Pyridoxal-5'-phosphate inhibits the enzyme from inactivation. The results are discussed in connection with the possible role of pyridoxal-5'-phosphate in regulation of the glutamate dehydrogenase activity in vivo.     

Characterization of HgCdTe Diodes on Si Substrates Using Temperature-Dependent Current-Voltage Measurements and Deep Level Transient Spectroscopy

Reverse current in diodes can be dominated by generation processes, depending exponentially on temperature according to the rate-limiting step in the generation process. In this report, the current-voltage-temperature (IVT) relationship is analyzed for several midwave infrared and long-wave infrared (MWIR x = 0.295, LWIR x = 0.233) Hg_1−x Cd _x Te (MCT) diodes. The energy varied from diode to diode. At high reverse biases, the energy tends toward the band gap energy. Close to zero bias, the energy ranged from 0.06 to 0.1 eV. Deep level transient spectroscopy (DLTS) showed a broad peak centered at 55–80 K for the MWIR MCT. Comparison of the DLTS spectrum to a simulation based on the energy and capture cross section from a rate window analysis shows that the peak is a band of traps. The capacitance transient amplitude increased as the filling pulse increased from 1 μs to 0.1 s, consistent with capture at a dislocation. A shift to lower temperatures for the peak was also observed when the diodes are cooled under forward bias. The shift is reversible, indicating that the traps consist at least partially of a bistable defect.     

Inductively coupled plasma etching for large format HgCdTe focal plane array fabrication

Inductively coupled plasma (ICP) using hydrogen-based gas chemistry has been developed to meet requirements for deep HgCdTe mesa etching and shallow CdTe passivation etching in large format HgCdTe infrared focal plane array (FPA) fabrication. Large format 2048×2048, 20-μm unit-cell short wavelength infrared (SWIR) and 2560×512, 25-μm unit-cell midwavelength infrared (MWIR) double-layer heterojunction (DLHJ) p-on-n HgCdTe FPAs fabricated using ICP processing exhibit >99% pixel operability. The HgCdTe FPAs are grown by molecular beam epitaxy (MBE) on Si substrates with suitable buffer layers. Midwavelength infrared detectors fabricated from 4-in. MBE-grown HgCdTe/Si substrates using ICP for mesa delineation and CdTe passivation etching demonstrate measured spectral characteristics, RoA product, and quantum efficiency comparable to detectors fabricated using wet chemical processes. Mechanical samples prepared to examine physical characteristics of ICP reveal plasma with high energy and low ion angle distribution, which is necessary for fine definition, high-aspect ratio mesa etching with accurate replication of photolithographic mask dimensions.     

API SPEC 5L《管线钢管规范》第45版主要内容变化分析

API SPEC 5L《管线钢管规范》是广泛应用于世界石油天然气输送钢管生产、检验和使用的重要基础标准。依据美国石油学会(API)2012年12月发布的第45版API SPEC 5L英文版,对照2007年第44版API SPEC 5L和API在2009—2011年期间发出的3个补遗,按照标准章节顺序,从总体结构、规范性引用文件、钢管钢级及交货状态、购方提供信息、制造、验收极限、检验试验方法和附录入手,分析了新标准的主要变化情况,便于标准使用者总体了解新版标准的主要变化情况,利于新版标准2013年7月1日后的正式实施。