IgG2 subclass deficiency: IgG subclass assays and IgG2 concentrations among 8015 blood donors

Among the four IgG subclasses in humans, IgG2 is preferentially expressed in antibodies to carbohydrate antigens whereas IgG1 subclass is commonly associated with antibodies to protein antigens. Because of this association with carbohydrate antigens, values for IgG2 in serum are often used as an index of immunocompetence against carbohydrate antigens. To investigate the value of IgG2 measurements in a general population, we have developed a convenient IgG subclass assay, using monoclonal antibodies and particle concentration fluorescence immunoassay. Our assay is specific, precise, convenient, and accurate. When IgG2 concentrations were determined in the serum samples from 8015 adult blood donors, there were more individuals with low IgG2 concentrations than predicted by the log-normal distribution. The observed distribution suggested the presence of a subpopulation with low IgG2 concentration. Because apparently healthy individuals in a general population have low IgG2 concentrations, IgG2 measurements alone may have a limited clinical usefulness as an index of immune function against carbohydrate antigens.     

Epothilone B inhibits neointimal formation after rat carotid injury through the regulation of cell cycle-related proteins

The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial walls is an important pathogenetic factor of vascular disorders such as atherosclerosis and restenosis after angioplasty. Epothilone B, a novel potential antitumor compound, has a potent effect on preventing postangioplasty restenosis. Therefore, we established an in vivo rat carotid injury model and examined the potential effects of epothilone B on cardiovascular disease. We found that epothilone B potently prevented neointimal formation and in vivo VSMCs proliferation. In addition, we also showed that epothilone B significantly inhibited 5% fetal bovine serum (FBS)- and 50 ng/ml platelet-derived growth factor (PDGF)-BB-induced proliferation and cell cycle progression in rat aortic VSMCs. Furthermore, FBS and PDGF-BB induced the activations of extracellular signal-regulated kinases 1 and 2, Akt, phospholipase C gamma 1, and PDGF-receptor beta chain tyrosine kinase were not changed by epothilone B. However, epothilone B treatment caused a significant decrease in the level of cyclin-dependent protein kinase (CDK) 2, whereas it caused no change in the levels of cyclin E and down-regulated the phosphorylation of retinoblastoma, which plays a critical role in cell cycle regulation. Furthermore, levels of p27, an inhibitor of cyclin E/CDK2 complex, were significantly increased in VSMCs treated with epothilone B, indicating that this might be a major molecular mechanism for the inhibitory effects of epothilone B on the proliferation and cell cycle of VSMCs. These findings suggest that epothilone B can inhibit neointimal formation via the cell cycle arrest by the regulation of the cell cycle-related proteins in VSMCs.     

Relationship Between <Superscript>18</Superscript>F-fluorodeoxyglucose Accumulation and the <Emphasis Type="Italic">BRAF</Emphasis><Superscript>V600E</Superscript> Mutation in Papillary Thyroid Cancer

Background

To determine whether ¹⁸F-fluoro-2-deoxyglucose (¹⁸F-FDG)-PET/CT is useful for predicting the BRAF ^V600E mutation status of a primary papillary thyroid carcinoma (PTC).

Methods

A retrospective analysis was performed in 108 patients who underwent ¹⁸F-FDG positron emission tomography–computed tomography (PET/CT) for staging before thyroidectomy and BRAF analysis in biopsy-confirmed PTC. The maximum standardized uptake value (SUV_max) of the primary tumor was calculated according to FDG accumulation. Univariate and multivariate analyses were performed to assess the association between the SUV_max and clinicopathological variables.

Results

The BRAF ^V600E mutation was detected in 71 of 108 (65.7%) patients. In all subjects, the tumor size and BRAF ^V600E mutation were independently related to the SUV_max according to multivariate analyses (P = 0.002 and 0.007, respectively). The SUV_max was significantly higher in tumors with the BRAF ^V600E mutation than in tumors with wild-type BRAF (10.24 ± 11.89 versus 4.02 ± 3.86; P = 0.007). In the tumor size >1 cm subgroup, the BRAF ^V600E mutation was the only factor significantly associated with the SUV_max (P = 0.016). A SUV_max cutoff level of 4.9 was determined to be significant for predicting the BRAF ^V600E mutation status (sensitivity 77.4%, specificity 100.0%, area under the curve 0.929; P < 0.0001) according to ROC curve analysis.

Conclusions

The BRAF ^V600E mutation is independently associated with high ¹⁸F-FDG uptake in PTC, especially in those with a tumor size >1 cm.

     

Self-assembled nanoparticles containing hydrophobically modified glycol chitosan for gene delivery.

A self-assembled nanoparticle was prepared using a hydrophobically modified glycol chitosan for gene delivery. A primary amine of glycol chitosan was modified with 5beta-cholanic acid to prepare a hydrophobically modified glycol chitosan (HGC). The modified chitosan spontaneously formed DNA nanoparticles by a hydrophobic interaction between HGC and hydrophobized DNA. As the HGC content increased, the encapsulation efficiencies of DNA increased while the size of HGC nanoparticles decreased. Upon increasing HGC contents, HGC nanoparticle became less cytotoxic. The increased HGC contents also facilitated endocytic uptakes of HGC nanoparticles by COS-1 cells, which were confirmed by a confocal microscopy. The HGC nanoparticles showed increasing in vitro transfection efficiencies in the presence serum. In vivo results also showed that the HGC nanoparticles had superior transfection efficiencies to naked DNA and a commercialized transfection agent. The HGC nanoparticles composed of hydrophobized DNA and hydrophobically modified glycol chitosan played a significant role in enhancing transfection efficiencies in vitro as well as in vivo.     

Impact of pretransplant donor‐specific antibodies on kidney allograft recipients with negative flow cytometry cross‐matches

The Luminex test can detect low levels of donor‐specific antibody (DSA) that cannot be detected by flow‐cytometric cross‐matching (FCXM) in kidney transplantation (KT). This study evaluated the impact of DSA on clinical outcomes in KT recipients negative on FCXM. Of 575 consecutive patients who underwent living donor KT between January 2013 and July 2016, 494 (85.9%) were DSA‐negative and 81 (14.1%) were DSA‐positive. Although rates of acute cellular rejection (ACR) at 1 year were similar in the 2 groups (P = .54), the incidence of antibody‐mediated rejection (ABMR) was significantly higher in the DSA‐positive group (P < .01). There was no statistically significant association between rejection‐free graft survival (RFGS) rates and pretransplant class I DSA. However, evaluation of pretransplant class II DSA showed that RFGS rates were significantly lower in patients with mean fluorescence intensity (MFI) >3000 than in patients with DSA‐negative (P < .01). On multivariate analyses, class II DSA MFI ≥5000 was a significant risk factor for acute rejection (hazard ratio, 7.48; P < .01). These findings suggested that pretransplant DSA alone did not affect graft survival in KT recipients without desensitization. However, class II DSA MFI >5000 was an independent predictor of acute rejection in DSA‐positive patients.     

Lentivirus-mediated carboxyl-terminal modulator protein gene transfection via aerosol in lungs of K-ras null mice

The low efficiency of conventional therapies in achieving long-term survival of lung cancer patients calls for development of novel options. Aerosol gene delivery may provide the alternative for safe and effective treatment for lung cancer. Therefore, current study was performed to elucidate the potential effects of C-terminal modulator protein (CTMP) via aerosol on lung tumorigenesis. Lentiviral vector-CTMP was delivered into K-ras null lung cancer mice through the nose-only inhalation system for 30 min. After 48 h, the potential effects of CTMP on Akt1-related signals and cell cycle regulation in the lungs were evaluated by western blot, immunohistochemistry and zymography. Lentivirus-based CTMP delivery inhibited the Akt1 activity through selective suppression of Akt1 phosphorylation at Ser473. Aerosol delivery of CTMP inhibited proteins important for Akt1 signals, cell cycle and tumor metastasis in lungs of K-ras null mice. Together, our results suggest that lentivirus-mediated aerosol delivery of CTMP may be compatible with noninvasive in vivo gene therapy. Our results emphasize the importance of noninvasive-targeted delivery of CTMP for lung cancer therapy in the future. While the studies are conducted in mice, it is envisioned that noninvasive targeting the specific genes responsible for cancer progression is an attractive strategy for effective anticancer therapeutics.     

Plasma nitroglycerin concentrations and hemodynamic effects of sublingual, ointment, and controlled-release forms of nitroglycerin

After a sublingual test dose, 12 healthy men aged 21 to 29 yr were treated with controlled-release transdermal nitroglycerin skin patches designed to deliver 10 mg/day nitroglycerin and with nitroglycerin ointment (2%) (1-in amount from the tube spread over 50 cm2) for 24 hr in a double-blind crossover study. Assessment was by measurement of nitroglycerin in plasma, blood pressure, and pulse rate. The mean plasma concentration of nitroglycerin during ointment dosing was approximately 200% to 400% that during skin patch dosing. Levels during ointment dosing were closer to those from sublingual dosing than were those during skin patch dosing. Blood pressure and pulse rate changes were much the same during both transdermal treatments. Calculations showed that delivery of nitroglycerin from the skin patches would have to be over 40 to 80 cm2 of the skin to achieve nitroglycerin exposure of the order of that induced by 1 in of ointment spread over 50 cm2 or from sublingual dosing.