Origin of the inverse spin switch effect in superconducting spin valves

Known as the spin switch effect (SSE), the resistance of a ferromagnet/superconductor/ferromagnet (F/S/F) spin valve near its superconducting transition temperature T c is different for parallel (R P) and antiparallel (R AP) configurations of the F layers. Here, we report the observation of the coexistence of the standard (RP>RAP) and inverse (RP<RAP) SSE in Ni81Fe19/Nb/Ni81Fe19/Ir25Mn75 spin valves. Our measurements reveal that the inverse SSE arises from a dissipative flow of vortices induced by stray magnetic fields from Néel domain-wall pairs in the F layers.

The role of secondary cytoreductive surgery for recurrent mucinous epithelial ovarian cancer (mEOC)

BACKGROUND

Mucinous epithelial ovarian cancer (mEOC) may exhibit a distinct biological behavior in epithelial ovarian cancer (EOC). The role of secondary cytoreductive surgery was evaluated in patients with recurrent mEOC, and the prognosis was assessed.

METHODS

Twenty-one patients with stages IIc to IV mEOC who experienced disease recurrence and received secondary cytoreductive surgery at Fudan University Cancer Hospital between Jan. 1997 and Dec. 2005 were retrospectively reviewed. Survival curves were generated using the Kaplan-Meier method and the significant comparison of survival rate was estimated by the log-rank test.

RESULTS

The median progression-free interval (PFI) was 14 months (range, 5-46 months) after the first cytoreduction. Seven patients (33%) who received secondary cytoreductive surgery were optimally cytoreduced with residual disease less than or equal 1cm, and the other 14 patients (67%) underwent suboptimal surgical cytoreduction. The overall median survival time was 27 months (range, 8-64 months). The median survival time after recurrence was 10 months (range, 3-32 months). There was no significant statistical difference in median survival between patients with optimal and suboptimal secondary surgical cytoreduction, with an estimated survival of 10 months and 9.8 months, respectively (P>0.05).

CONCLUSION

Optimal primary cytoreductive surgery for advanced mEOC was very important. Once it recurs, the prognosis is very poor. Patients with recurrent mEOC should be carefully assessed before performing secondary cytoreductive surgery, as this may have limited impact on the overall survival rates.

HLA-A*3318, a novel allele, identified by sequence-based typing in a Chinese individual

We report a novel human leucocyte antigen (HLA)-A allele, officially named as A*3318, which was found during high-resolution sequence-based typing in a Chinese potential hematopoietic stem cell transplantation donor. Compared with the HLA-A*330301 sequence, the A*3318 has one nucleotide substitution in exon 3: at nt 413 where A-->G resulting in an amino acid substitution from Q (CAG) to R (CGG) at codon 114.

Potential therapy of Fc-antigen combination-encoding DNA vaccination in mouse allergic airway inflammation

Vaccination with allergen-encoding DNA has been proposed as having potential for allergen-specific immunotherapy. In this study, we examine the therapeutic effect of allergen-encoding DNA vaccination directly to dendritic cells (DCs) on allergen-induced allergic airway inflammation in a mouse model and explore potential mechanism. Ovalbumin (OVA)-sensitized and challenged mice were immunized with DNA vaccine and received bronchoalveolar lavage (BAL) 1 day after the last challenge, to measure BAL levels of interleukin (IL)-4, IL-5, interferon (IFN)-gamma and differential cell count. Pulmonary DCs and Spleen DCs were purified and sorted according to the expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) co-stimulatory molecules. Our data demonstrated that DNA vaccine therapy with OVA-Fc-pcDNA(3.1) significantly prevented OVA-increased levels of IL-4, IL-5 and the percentage of eosinophils and OVA-decreased level of IFN-gamma. OVA-Fc-pcDNA(3.1)-treated mice had less severity of airway inflammation, and lower expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) on pulmonary DCs, as compared with animals with OVA-pcDNA(3.1,) pcDNA(3.1) and OVA respectively. DNA vaccine encoding both Fc and OVA was shown to be more effective than DNA vaccine encoding OVA alone. Our data indicate that Fc-antigen combination-encoding DNA vaccination has better preventive effects on antigen-induced airway inflammation by regulating DCs, and may be a new alternative therapy for asthma.

Functional whole-colony screening method to identify antimicrobial peptides

A high throughput method for screening cDNA libraries has been developed to identify putative antimicrobial peptides (AMPs). It is based on a rapid dye inclusion assay for assessing antagonism of bacterial viability. Colonies are grown on a membrane on a permissive medium until full colony size is reached. The membrane, supporting the array of colonies, is transferred onto an inductive medium containing a vital dye. Upon expression of any antagonizing peptides, the cell membrane becomes compromised allowing dye infusion to permit visual identification of deleterious peptides. Our approach was validated by screening a synthetic oligonucleotide library expressed in Escherichia coli. A random oligonucleotide library, containing inserts of up to 75 nucleotides in length was constructed and expressed in E. coli. From a potential pool of 100000 peptides, in a single round of screening, three were found to be antimicrobial: L1, L3, and L8. Peptide L1 was shown to have a concentration-dependent bactericidal effect against Gram-negative E. coli and moderate biostatic activity against the Gram-positive bacteria Listeria monocytogenes. L8 was found to have bacteriostatic, and possibly bactericidal effect against E. coli, Pseudomonas aeruginosa and Salmonella typhimurium. These results validated this high throughput AMP identification assay based on filter bound colony array libraries and vital dye inclusion.

Surgical treatment for patients with different origins of Krukenberg tumors: outcomes and prognostic factors

AIMS

We sought to investigate survival impacts of metastasectomy in women with Krukenberg tumors of the ovary and survival benefits in different origins (gastric cancer, colorectal cancer, or others).

METHODS

All patients diagnosed with Krukenberg tumors of the ovary who underwent surgical treatment at a single institution between 1997 and 2003 were retrospectively evaluated. Survival analyses and comparisons were performed using Kaplan-Meier method and log-rank test.

RESULTS

A total of 54 patients with Krukenberg tumors of the ovary were identified. The estimated 5-year survival was 12.1%. The median survival in patients with microscopic residual disease after metastasectomy was 29.6 months, compared to 10 months in those with visible residual disease (P<0.01). The median survival among patients with Krukenberg tumors of gastric origin, colon and rectum origin, and other origins were 13 months, 29.6 months, and 48.2 months, respectively (P=0.03). There was a significant difference in survival between patients with metastatic disease confined to the ovaries and those with extensive metastases, with an estimated median survival of 30.7 months and 10 months, respectively (P=0.02). Multivariate analysis suggested that the origin of ovarian metastatic carcinoma (P<0.01), residual disease after metastasectomy (P<0.01), and KPS (Karnofsky performance status) (P=0.03) were independent prognostic factors of survival.

CONCLUSIONS

Patients with Krukenberg tumors from colorectal cancer experience a better prognosis than those from gastric cancer and benefit more from metastasectomy. And metastasectomy significantly lengthens overall survival in patients with primary colorectal or breast cancer, higher KPS score, and those with optimal metastasectomy.

Pelvic body composition measurements by quantitative computed tomography: association with recent hip fracture

INTRODUCTION

Loss of subcutaneous fat, decreased muscle cross-sectional area (CSA) and increased muscle adiposity are related to declining physical function and disability in the elderly, but there is little information about the relationship of these tissue changes to hip fracture. Thus we have compared body composition measures in women with hip fractures to age-matched controls, using quantitative computed tomography (QCT) imaging of the hip to characterize total adiposity, muscle CSA and muscle attenuation coefficient, a measure of adiposity.

MATERIALS AND METHODS

45 Chinese women (mean age 74.71+/-5.94) with hip fractures were compared to 66 healthy control subjects (mean age 70.70+/-4.66). Hip QCT scans were analyzed to compute total adipose CSA as well as CSA and attenuation values of muscle groups in the CT scan field of view, including hip extensors, abductors, adductors and flexors. The total femur areal BMD (aBMD) was estimated from the QCT images. Logistic regression was employed to compare body composition measures between fracture subjects and controls after adjustment for age, height, BMI and aBMD. Receiver-operator curve (ROC) analyses determined whether combinations of aBMD and body composition had higher area under curve (AUC) than aBMD alone.

RESULTS AND CONCLUSIONS

Fracture subjects had lower fat CSA (p<0.0001) than controls but had higher muscle adiposity as indicated by lower attenuation in the adductor, abductor and flexor groups (0.00001<p<0.02). Fracture subjects also had lower extensor and adductor CSA values (p<0.0001). After age and BMI adjustment, the total fat CSA, the extensor and adductor CSA values, and the adductor attenuation values remained significantly lower in the fracture subjects (0.001<p<0.05). In ROC analyses, models combining aBMD with soft tissue measures had higher AUC than models containing only BMD (0.001<p<0.05). Combining body composition with skeletal measures may improve fracture prediction compared to bone measures alone.

Segmental bone tissue engineering by seeding osteoblast precursor cells into titanium mesh-coral composite scaffolds

The size and specific shape of bone grafts are important for jaw reconstruction. In this experiment, segmental bone grafts were engineered in a predetermined shape via seeding osteoblast precursor cells into titanium mesh-coral composite scaffolds. Titanium meshes were moulded into the shape of a column with length 12 mm and diameter 8mm. The column was filled with natural coral granules and the complex acted as a cell-seeding scaffold. About 4 x 10(7) osteoblast precursor cells in 200 microl cell-culture medium were seeded into each of six scaffolds and incubated in vitro for 2 days. Then, the composites were implanted subcutaneously into the backs of nude mice and incubated in vivo. Two months after implantation, the animals were killed and new bone formed in the scaffolds was investigated by gross inspection, X-ray examination, histological observation and mechanical testing. The results showed that newly formed tissue was red and presented the gross appearance of bone, and kept the original shape of the column. Titanium mesh was situated on the surface of the bone graft. An X-ray blocking shadow was observed in and around the titanium scaffolds; most of the coral granules had been absorbed. Histological observation demonstrated a large amount of new bone formed and integrated well with titanium mesh. Mechanical testing showed that new bone improved the mechanical property of the graft significantly. In conclusion, a titanium mesh-coral composite scaffold with osteoblast precursor cells is an efficient means to engineer segmental bone, possessing the desired shape and mechanical strength.