Extended point defects in crystalline materials: Ge and Si

B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms--a simple one with low entropy and a complex one with entropy ∼30  k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket--we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.

Vessel Boundary Detection for its 3D Reconstruction by Using a Deformable Model (GVF Snake)

Vessel boundary detection and 3D modeling is a difficult but necessary task in analyzing the mechanics of inflammation and the structure of the microvasculature. We present in this paper a method of analyzing this structure by the means of the deformable model (using GVF Snake) for vessel boundary detection and three-dimensional reconstruction. For this purpose, we used a virtual vessel model and produced synthetic images. From these images, we obtained contours of vessels by the GVF Snake and then reconstructed a three-dimensional structure by using the coordinates of the Snakes.

Rapamycin-induced apoptosis is p53-independent in human prostate carcinoma PC-3 cells

We have investigated the mechanisms of rapamycin-induced growth inhibition and apoptosis in the PC-3 prostate carcinoma cell line. Rapamycin induced apoptosis as well as the expression of p21(waf1) mRNA and protein, independent of p53. Rapamycin treatment also resulted in: a decrease in cdk2 kinase activity; an increase in hypophosphorylated retinoblastoma protein (pRb); a dephosphorylation of p70 S6 kinase; and, growth-arrest in G(1)-phase of cell cycle. These data suggest that rapamycin-induced growth arrest and apoptosis occur through the p53-independent induction of p21(waf1). Since this induction occurred soon after rapamycin treatment, possibly, the early induction of p21(waf1) and G(1)-arrest are important components of the mechanism by which rapamycin induces apoptosis in PC-3 cells.

Clinical manifestations of hypercalcemia and hypophosphatemia after kidney transplantation

INTRODUCTION

Abnormalities of calcium and phosphorus metabolism in end-stage renal disease patients can persist after transplantation. We investigated their natural courses after transplantation, their risk factors for posttransplantation hypercalcemia and hypophosphatemia, and their impacts on allograft outcomes.

METHODS

We retrospectively analyzed a total of 490 adult patients who underwent kidney transplantations between 2000 and 2009.

RESULTS

The serum calcium continued to increase, and reaching a plateau at around 3 months after transplantation. Thereafter it decreased, reaching a stable level by 2 years. Forty-four patients (9.0%) displayed hypercalcemia within 1 year; it persisted longer than that in 23 subjects (4.7%). Both longer dialysis duration (odds ratio [OR] 1.423; 95% confidence interval [CI], 1.192-1.699) and high intact serum parathyroid hormone (iPTH) level before transplantation (OR 1.002; 95% CI, 1.000-1.003) increased the risk for posttransplantation hypercalcemia. After a significant decrease during the first week, the serum phosphorus level increased, becoming stable between 1 and 6 months after transplantation. Hypophsphatemia occurred in 379 patients (77.3%) with 336 patients displaying hypophosphatemia without hypercalcemia. However, neither hypercalcemia nor hypophosphatemia influenced graft outcomes. Eight patients underwent pretransplantation parathyroidectomy, whereas 4 patients underwent posttransplantation parathyroidectomy. Neither group of patients experienced posttransplantation hypercalcemia.

CONCLUSIONS

Both hypercalcemia and hypophosphatemia are common after renal transplantation, especially among patients with a long history of dialysis before transplantation. Strict control of hyperparathyroidism including parathyroidectomy before transplantation may be the appropriate approach to these abnormalities.

The effects of cyclophosphamide and mycophenolate on end-stage renal disease and death of lupus nephritis

Debate continues about the optimal treatment modality of lupus nephritis (LN). We compared the efficacy and safety of intravenous cyclophosphamide (CYC) and mycophenolate mofetil (MMF) for LN treatment in Korea. After searching for systemic lupus erythematosus (SLE) patients diagnosed between 1998 and 2007 with the diagnostic code of ICD10, we selected the 71 patients who were treated with CYC or MMF without any other immunosuppressant except systemic steroid. Composite outcome was defined as progression to end-stage renal disease (ESRD) and/or all-cause mortality. The initial manifestations of the CYC group were more severe than those of the MMF group. The mean daily MMF dose was 980 ± 100 mg for 21.67 ± 18.25 months. The mean monthly dose per CYC pulse therapy was 850 ± 30 mg for 17.04 ± 13.15 months. The incidence of composite outcome was 5/20 (25%) in the MMF group and 4/51 (7.8%) in the CYC group. The relative risk (RR) for composite outcome in the CYC group was 0.249 (95% CI for RR: 0.067–0.934, p = 0.039) compared with the MMF group with Cox's hazard proportional analysis. In Kaplan–Meier analysis, the probability of composite outcome was lower in the CYC group than in the MMF group (Log rank test p-value = 0.026). The results of this retrospective study suggest that intravenous CYC therapy may be more efficacious in averting ESRD and death than MMF. These results need to be confirmed in a larger randomized controlled trial.

Perforator flap breast reconstruction in thin patients

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Background: Perforator flap breast reconstruction has strong appeal for many women seeking breast reconstruction, but the procedure requires adequate donor site tissue to produce realistic breasts. Thin women requesting perforator flaps are often advised that they lack sufficient donor site tissue for autologous tissue breast reconstruction, and that implants are their only option. We have expanded the reconstructive options for thin women who seek an alternative to implants with innovative new techniques.

Methods: A retrospective review was done of 223 patients who underwent 293 consecutive perforator flap breast reconstructions from April 2007-May 2011. Preoperative imaging allowed visualization of the microvascular anatomy and subcutaneous tissue. Donor sites evaluated included the abdomen, medial thigh, buttocks, and back. Complications included flap loss, hematoma, seroma, takeback, and fat necrosis. No patients were turned away for perforator flap breast reconstruction due to insufficient donor site tissue.

Results: Out of 293 perforator flap breast reconstructions, 45 perforator flap breast reconstructions (15.4%) were reported in 26 thin women with a BMI < 23 (mean BMI 20.7, range BMI 18.2-22.7). Out of 45 perforator flap breast reconstructions in thin women, donor sites included 35 hemi-abdominal flaps (77.8%), 4 medial thigh flaps (8.9%), 7 buttock flaps (15.6%), and 2 back flaps (4.4%). Of the 35 hemi-abdominal flaps, 8 hemi-abdominal flaps were combined to create 4 stacked DIEP flaps (22.9%) while the remaining 27 hemi-abdominal flaps were regular DIEP flaps (77.1%). There was one seroma (2.2%) and one takeback for postoperative pain (2.2%); there were no flap losses.

Conclusions: Even in thin women, perforator flap breast reconstruction is a safe, reliable, and consistent technique for recreating new breasts. While implant-based breast reconstruction may be acceptable to many women, there is a growing subgroup of patients who prefer autologous tissue breast reconstruction. By challenging common conceptions about the amount of donor site tissue required, we have been able to expand reconstructive options in thin women by using perforator flaps to construct natural, aesthetic breasts.

Tacrolimus is an alternative therapeutic option for the treatment of refractory lupus nephritis

We conducted an open-labeled, prospective study to determine the efficacy and safety of tacrolimus as an alternative therapeutic option for those patients with refractory lupus nephritis. The study population comprised one male and eight female patients with diffuse proliferative lupus nephritis. All patients had failed to respond to sufficient intravenous cyclophosphamide therapy with proteinuria of >or=1 g/day and active urinary sediments. Tacrolimus (0.1 mg/kg/day) was administered for 1 year with adjusting drug level (4-10 microg/l). The mean serum creatinine level and spot urine protein creatinine ratio (UPCR) at baseline were 1.39 mg/dl and 2.27, respectively. After the treatment, proteinuria reduced significantly from median UPCR value of 2.19 (range, 1.19-3.34) to 0.44 (range, 0.12-2.13) (p < 0.05). Seven (78%) of the nine patients showed a complete clinical response, which was defined as stabilization in the disease-activity markers and serum creatinine level with reduction of >or=50% in UPCR; two patients showed complete remission with UPCR <0.2. One patient showed treatment failure because of the disease progression. No serious adverse effects were observed during the study. This study demonstrates that tacrolimus can show a significant therapeutic response in cases that are refractory to the standard regimen for diffuse proliferative lupus nephritis.

Structures of the OmpF porin crystallized in the presence of foscholine-12

The endogenous Escherichia coli porin OmpF was crystallized as an accidental by-product of our efforts to express, purify, and crystallize the E. coli integral membrane protein KdpD in the presence of foscholine-12 (FC12). FC12 is widely used in membrane protein studies, but no crystal structure of a protein that was both purified and crystallized with this detergent has been reported in the Protein Data Bank. Crystallization screening for KdpD yielded two different crystals of contaminating protein OmpF. Here, we report two OmpF structures, the first membrane protein crystal structures for which extraction, purification, and crystallization were done exclusively with FC12. The first structure was refined in space group P21 with cell parameters a = 136.7 A, b = 210.5 A, c = 137 A, and beta = 100.5 degrees , and the resolution of 3.8 A. The second structure was solved at the resolution of 4.4 A and was refined in the P321 space group, with unit cell parameters a = 215.5 A, b = 215.5 A, c = 137.5 A, and gamma = 120 degrees . Both crystal forms show novel crystal packing, in which the building block is a tetrahedral arrangement of four trimers. Additionally, we discuss the use of FC12 for membrane protein crystallization and structure determination, as well as the problem of the OmpF contamination for membrane proteins overexpressed in E. coli.

Plasma endogenous enkephalin levels in early systemic sclerosis: clinical and laboratory associations

OBJECTIVE

Met- and leu-enkephalins are endogenous opioid neuropeptides with potent analgesic, vasoactive, immunomodulatory and anti-apoptotic properties. We hypothesised that clinical or immunological variables of early systemic sclerosis (SSc) might be correlated to plasma enkephalin levels.

METHODS

Plasma samples were collected at study entry of the Genetics versus Environment in Scleroderma Outcomes Study (GENISOS) cohort (early SSc, n=116). Plasma met-enkephalin and leu-enkephalin levels (microg/ml) were measured by high performance liquid chromatography (HPLC) and correlated to clinical and laboratory parameters in the GENISOS database. Statistical analyses were performed by nonparametric Wilcoxon rank sum tests and Pearson correlation coefficients.

RESULTS

Significantly lower plasma met-enkephalin levels were associated with anti-topoisomerase-I seropositivity (6+8.3 vs. 14.9+22.8 microg/ml, p=0.02). Plasma leu-enkephalin levels were significantly higher in SSc patients with digital pulp loss (95.6+130 vs. 64.9+101 microg/ml, p=0.02). Lower mean plasma met-enkephalin levels and inversely higher leu-enkephalin levels were noted in SSc patients with Raynaud's phenomena (p=NS).

CONCLUSION

The associations of plasma enkephalin levels to immunologic or clinical pathologies may underscore their vasogenic or fibrogenic significance and potential as therapeutic targets in early SSc.

Warfarin use and the risk of valvular calcification

BACKGROUND

Warfarin affects the synthesis and function of the matrix Gla-protein, a vitamin K-dependent protein, which is a potent inhibitor of tissue calcification.

OBJECTIVES

To investigate the incidence of mitral valve calcium (MVC), mitral annular calcium (MAC) and aortic valve calcium (AVC) in patients with non-valvular atrial fibrillation (AF) treated with warfarin vs. no warfarin.

PATIENTS AND METHODS

Of 1155 patients, mean age 74 years, with AF, 725 (63%) were treated with warfarin and 430 (37%) without warfarin. The incidence of MVC, MAC and AVC was investigated in these 1155 patients with two-dimensional echocardiograms. Unadjusted logistic regression analysis was conducted to examine the association between the use of warfarin and the incidence of MVC, MAC or AVC. Logistic regression analyses were also conducted to investigate whether the relationship stands after adjustment for confounding risk factors such as age, sex, race, ejection fraction, smoking, hypertension, diabetes, dyslipidemia, coronary artery disease (CAD), glomerular filtration rate, calcium, phosphorus, calcium-phosphorus product, alkaline phosphatase, use of aspirin, beta blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins.

RESULTS

There was a significant association between the use of warfarin and the risk of calcification [unadjusted odds ratio = 1.71, 95% CI = (1.34-2.18)]. The association still stands after adjustment for confounding risk factors. MVC, MAC or AVC was present in 473 of 725 patients (65%) on warfarin vs. 225 of 430 patients (52%) not on warfarin (P < 0.0001). Whether this is a causal relationship remains unknown.

CONCLUSIONS

Use of warfarin in patients with AF is associated with an increased prevalence of MVC, MAC or AVC.