Single particle adsorbing transfer system

Here we present a novel approach for horizontal transfer of single particles after laser microdissection. The developed technique is a single particle adsorbing system for highly selective and gentle horizontal transfer of microdissected fixed and living material. As mediated via low-pressure technology, the transfer process can be precisely controlled, thus facilitating horizontal particle transfer of any isolated material, e.g. tissue material, single cells or chromosomes, in addition to precise positioning for sample release. This collection method allows one to predefine target positions and enables material transfer without contamination to any planar microchip device. This contamination free transfer is indispensable for novel lab-on-a-chip systems performing nanoscale polymerase chain reaction analyses. Using virtual reaction chamber microdevices, small amounts of microdissected material—as little as one single cell—can be directly transmitted and immediately used for single cell analysis. Daniela Woide and Veronika Mayer contributed equally to this paper.     

Haplotypes of the NR4A2/NURR1 gene and cardiovascular disease: The Rotterdam Study

Nuclear receptor subfamily 4, group A, member 2 (NR4A2, also called Nurr1) has lately become of interest with regard to atherogenesis. We examined the association between common variation in the NR4A2 gene and cardiovascular disease in the Rotterdam Study, a prospective population‐based study among persons aged ≥55 years. Three SNPs that tag common haplotypes across a 36‐kb region surrounding the NR4A2 gene were determined. Four haplotypes with frequencies >1% covered 96% of the genetic variation. In 5,650 participants without history of coronary heart disease, 729 coronary heart disease events occurred during a median follow‐up time of 11.9 years. NR4A2 haplotypes were neither associated with coronary events nor with intima‐media thickness (IMT), carotid plaques, or ankle‐arm index (AAI). NR4A2 haplotypes showed a tendency toward associations with aortic and coronary calcification (haplo.score global simulation P values 0.076 and 0.075, respectively), which seemed to be based on haplotype 2 (individual P values were both P=0.015). Furthermore, NR4A2 haplotype 3 was associated with higher high‐density lipoprotein (HDL) cholesterol and haplotype 4 with lower systolic blood pressure. In conclusion, NR4A2/NURR1 haplotypes were not associated with coronary events, carotid IMT, carotid plaques, or AAI. There was a tendency toward associations with aortic calcification and coronary calcification. Associations for NR4A2 were found with both HDL levels and blood pressure. It remains to be investigated which pathophysiological mechanisms pertain to NR4A2 function in cardiovascular disease. Hum Mutat 0, 1–7, 2009. © 2009 Wiley‐Liss, Inc.     

Assessment of biocompatibility and initial evaluation of genipin cross-linked elastin-like polypeptides in the treatment of an osteochondral knee defect in rabbits

Polypeptides based on the alternating hydrophobic and cross-linking domain structure of human elastin are capable of undergoing self-assembly to produce polymeric matrices with unique biological and mechanical properties. Here, we test the initial feasibility of using a genipin cross-linked elastin-based material as an acellular plug in the treatment of an osteochondral defect in the rabbit knee. Full-thickness defects in the weight-bearing surface of the medial femoral condyle in 18 New Zealand White rabbits were surgically produced and press fitted with cylindrical pads composed of genipin cross-linked elastin-like polypeptides, with identical wounds in the opposite knee left untreated as controls. The biocompatibility of the material, overall wound healing and regeneration of subchondral tissue was assessed at 2, 4 and 6 weeks by histological evaluation, synovial fluid analysis and microcomputerized tomography scanning. Histological analysis revealed the regeneration of subchondral bone at the periphery of the material, with evidence of hyaline-like overgrowth across the apical surface in 11/16 cases. Pads developed tight contacts with host tissue and appeared completely biocompatible, with no evidence of localized immune response or increased inflammation compared to controls. The material was stable to 6 weeks, with an aggregate elastic modulus calculated at ～470 kPa when tested under confined compression. Further studies are required to assess material degradation over time and long-term replacement with repair tissue.     

Reproducibility of Standing Posture for X-Ray Radiography: A Feasibility Study of the <Emphasis Type="Italic">BalancAid</Emphasis> with Healthy Young Subjects

Unreliable spinal X-ray radiography measurement due to standing postural variability can be minimized by using positional supports. In this study, we introduce a balancing device, named BalancAid, to position the patients in a reproducible position during spinal X-ray radiography. This study aimed to investigate the performance of healthy young subjects’ standing posture on the BalancAid compared to standing on the ground mimicking the standard X-rays posture in producing a reproducible posture for the spinal X-ray radiography. A study on the posture reproducibility measurement was performed by taking photographs of 20 healthy young subjects with good balance control standing on the BalancAid and the ground repeatedly within two consecutive days. We analyzed nine posterior–anterior (PA) and three lateral (LA) angles between lines through body marks placed in the positions of T3, T7, T12, L4 of the spine to confirm any translocations and movements between the first and second day measurements. No body marks repositioning was performed to avoid any error. Lin’s CCC test on all angles comparing both standing postures demonstrated that seven out of nine angles in PA view, and two out of three angles in LA view gave better reproducibility for standing on the BalancAid compared to standing on the ground. The PA angles concordance is on average better than that of the LA angles.     

Incidence and Risk Factors of Peripheral Arterial Occlusive Disease in a Prospective Cohort of 700 Adult Elderly Men Followed for 5 Years

Objective  

This study was designed to assess the incidence of peripheral arterial occlusive disease (PAOD) in a population-based cohort of men aged 55–74 years and to establish a predictive function based on risk factors for the disease.     

Assessment of coronary artery calcium by using volumetric 320-row multi-detector computed tomography: comparison of 0.5 mm with 3.0 mm slice reconstructions

The purpose of this study was to assess the performance of 0.5 versus 3.0 mm slice reconstructions in depicting coronary calcium with special attention to patients having zero calcium scores at 3.0 mm reconstructions by using computed tomography (CT). Imaging was performed by volumetric 320-detector row CT. Scans of 100 patients with a negative and 100 patients with a positive Agatston score at 3.0 mm reconstructions were consecutively selected. Non-overlapping volume sets with 3.0 and 0.5 mm slice thickness were reconstructed from the same raw data and Agatston and volume scores were obtained. The Wilcoxon signed ranks test was used to determine statistical differences between 3.0 and 0.5 mm calcium scores. Agatston and volume scores obtained at 0.5 mm were significantly higher than at 3.0 mm reconstructions (mean Agatston score: 266 ± 495 vs. 231 ± 461. Mean volume score: 223 ± 399 vs. 206 ± 385, both P < 0.01). In 21% of patients with zero 3.0 mm Agatston scores, a positive Agatston and/or volume score was found at 0.5 mm reconstructions. With volumetric 320-detector row CT, prospective ECG-triggered calcium scoring at 0.5 mm compared to 3.0 mm reconstructions leads to an increase in Agatston and volume scores and small amounts of coronary calcium are earlier depicted. This may be of special interest in patients with zero calcium scores with traditional 3.0 mm measures, where 0.5 mm reconstructions may help in superior depicting or ruling out coronary artery disease.     

Perioperative morbidity and renal function in young and elderly patients undergoing elective nephron‐sparing surgery or radical nephrectomy for renal tumours larger than 4 cm

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? The incidence of renal tumours is rising constantly. Patients in the 6th or 7th decade of life are mainly affected. Nephron‐sparing surgery (NSS) has become the gold standard for the treatment of patients presenting with renal tumors ≤4 cm and is recommended for cT1b lesions in experienced centers. Little is known about the functional outcome of elderly patients presenting with renal tumours larger than 4 cm and being treated by NSS in comparison to radical nephrectomy (RN). Here we could show that NSS can be performed safely with considerable perioperative morbidity and a better functional outcome according to renal function without lacking oncological control.

OBJECTIVE

To analyse renal function, perioperative morbidity and overall survival (OS) in patients aged <55 years compared with patients aged >65 years treated by radical nephrectomy (RN) or elective nephron‐sparing surgery (NSS) for renal tumours >4 cm.

PATIENTS AND METHODS

From our database, we identified 829 patients with renal tumours >4 cm treated by either RN (n= 641) or NSS (n= 188) at our institution between 1981 and 2007. After excluding patients with imperative indication and metastases, we identified retrospectively 81 patients aged <55 years (young patients) and 85 patients aged >65 years (elderly patients) treated for renal tumours >4 cm. In all, 36 and 33 patients underwent NSS and 45 and 52 patients underwent RN in the young and elderly group, respectively. Preoperative and periodically postoperative serum creatinin values were used to estimate glomerular filtration rate (GFR). Chronic kidney disease (CKD) was defined as GFR <60 mL/min/1.73 m². Clinical characteristics, complications and renal function were compared between age groups and surgical approaches, and OS was estimated using the Kaplan–Meier method.

RESULTS

The median (range) tumour size in young patients was larger compared with that of elderly patients, i.e. 6 (4.2–14.0) cm vs 5 (4.2–16.0) cm, with P < 0.001 considered to be statistically significant. The complication rates did not differ between the age groups (P= 0.656) or between NSS and RN in young (P= 0.095) or elderly patients (P= 0.277). Chronic kidney disease after RN or NSS occurred in 31.1% and 15.5% for young patients, respectively and in 50.9% and 24.2% in elderly patients, respectively, until last available follow‐up which was obtained after a median (range) of 5.69 (0.1–19.2) years for young patients and 5.48 (0.8–18.1) years for elderly patients. Overall survival did not significantly differ between NSS vs RN in young (P= 0.655) and elderly patients (P= 0.058).

CONCLUSION

Our findings suggest that performing NSS for tumours >4 cm when feasible in young and carefully selected elderly patients is more beneficial for maintaining long‐term renal function. Regardless of age, patients undergoing RN for renal tumours >4 cm developed more new onsets of CKD than patients treated by elective NSS. The complication rate did not differ between the age groups or between types of surgery.