CD34 marks angiogenic tip cells in human vascular endothelial cell cultures

The functional shift of quiescent endothelial cells into tip cells that migrate and stalk cells that proliferate is a key event during sprouting angiogenesis. We previously showed that the sialomucin CD34 is expressed in a small subset of cultured endothelial cells and that these cells extend filopodia: a hallmark of tip cells in vivo. In the present study, we characterized endothelial cells expressing CD34 in endothelial monolayers in vitro. We found that CD34-positive human umbilical vein endothelial cells show low proliferation activity and increased mRNA expression of all known tip cell markers, as compared to CD34-negative cells. Genome-wide mRNA profiling analysis of CD34-positive endothelial cells demonstrated enrichment for biological functions related to angiogenesis and migration, whereas CD34-negative cells were enriched for functions related to proliferation. In addition, we found an increase or decrease of CD34-positive cells in vitro upon exposure to stimuli that enhance or limit the number of tip cells in vivo, respectively. Our findings suggest cells with virtually all known properties of tip cells are present in vascular endothelial cell cultures and that they can be isolated based on expression of CD34. This novel strategy may open alternative avenues for future studies of molecular processes and functions in tip cells in angiogenesis.     

Intrahepatic cholangiocarcinoma in a low endemic area: rising incidence and improved survival

Background

To explore trends in the incidence and survival of patients with intrahepatic cholangiocarcinoma (ICC) an unselected population in Western Europe was studied.

Methods

Between 1989 and 2009, all patients newly diagnosed with ICC were selected from the Netherlands Cancer Registry (n = 809). Trends in incidence, treatment and relative survival were calculated according to gender and age. Follow-up for vital status was complete until 1st January 2010.

Results

The incidence rates of ICC increased significantly between 1999 and 2009, especially in the age group 45–59 years [estimated annual percentage change +3.0%, 95% confidence interval (CI) 0.2–5.8]. In the other age groups ICC incidence remained stable. Patients diagnosed with Tumour Lymph Node Metastasis (TNM) stage I mainly underwent surgery (68%), and the majority of the patients with stage II, III and IV received best supportive care (73%). One-year relative survival for patients with ICC increased significantly from 24% in 1989–1994 to 28% in 2005–2009 (P = 0.03), and corresponding 3-year relative survival improved from 4% to 8% (P = 0.02). Three-month and 1-year relative survival for patients with ICC receiving surgery was 91% and 71%, respectively.

Discussion

Between 1999 and 2009, the incidence of ICC rose, especially in the age group 45–59 years, suggesting aetiological influences. Survival rates have improved during the study period.     

Torsion biomechanics of the spine following lumbar laminectomy: a human cadaver study

Purpose

Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD).

Methods

Ten human cadaveric lumbar spines were obtained (age 75.5, range 59–88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (<median BMD). Laminectomy was performed either on L2 (5×) or L4 (5×). Twenty motion segments (L2–L3 and L4–L5) were isolated. The effects of laminectomy, disc degeneration and BMD on torsion stiffness (TS) and torsion moments to failure (TMF) were studied.

Results

Load–displacement curves showed a typical bi-phasic pattern with an early torsion stiffness (ETS), late torsion stiffness (LTS) and a TMF. Following laminectomy, ETS decreased 34.1 % (p < 0.001), LTS decreased 30.1 % (p = 0.027) and TMF decreased 17.6 % (p = 0.041). Disc degeneration (p < 0.001) and its interaction with laminectomy (p < 0.031) did significantly affect ETS. In the mildly degenerated group, ETS decreased 19.7 % from 7.6 Nm/degree (6.4–8.4) to 6.1 Nm/degree (1.5–10.3) following laminectomy. In the severely degenerated group, ETS decreased 22.3 % from 12.1 Nm/degree (4.6–21.9) to 9.4 Nm/degree (5.6–14.3) following laminectomy. In segments with low BMD, TMF was 40.7 % (p < 0.001) lower than segments with high BMD [34.9 Nm (range 23.7–51.2) versus 58.9 Nm (range 43.8–79.2)].

Conclusions

Laminectomy affects both torsion stiffness and torsion load to failure. In addition, torsional strength is strongly affected by BMD whereas disc degeneration affects torsional stiffness. Assessment of disc degeneration and BMD pre-operatively improves the understanding of the biomechanical effects of a lumbar laminectomy.     

Long-term Results of Rectal Cancer Surgery with a Systematical Operative Approach

Background

Variabilities of both oncologic and functional outcomes are major problems after rectal cancer treatment. Standardized techniques might produce more consistent surgical quality. This study reports outcomes during a 20-year period resulting from a systematically applied surgical approach.

Methods

Between 1990 and 2010, 368 rectal cancer patients, treated with total mesorectal excision conducted in a standardized, stepwise approach, were prospectively entered into a database. Influence of time period, surgeon, tumor and anastomotic height, and resection type was evaluated with multivariable regression analyses adjusting for age, disease stage, diversion, and (neo)adjuvant treatment. Function outcome questionnaires were sent to 50 patients at least 5 years after surgery.

Results

Five-year overall survival was 76.4 %. Local and distant recurrence rates were 5.2 % and 22.1 %. Anastomotic leakage occurred in 5.4 % of patients treated with low anterior resection (n = 259). Time period, surgeon, tumor and anastomotic height, diversion, and abdominoperineal resection were not independent risk factors for any of these outcome measures. Both preoperative and postoperative radiotherapy were independently associated with increased risk of metastases (P = 0.035, hazard ratio (HR) = 3.04; and P = 0.029, HR = 3.59). Function questionnaires were completed by 38 of 50 patients (76 %). One of 13 nonirradiated patients reported mild fecal incontinence compared with 20 of 25 irradiated patients reporting mostly moderate-severe incontinence (P < 0.001).

Conclusions

Systematically applied surgical dissection results consistently in excellent oncologic outcomes with enhanced function outcomes. The findings suggest that in the presence of highly disciplined surgery, radiotherapy might make a smaller contribution to oncologic outcome, while leading to serious adverse effects.     

Hyaluronic Acid as a Marker of Hepatic Sinusoidal Obstruction Syndrome Secondary to Oxaliplatin-Based Chemotherapy in Patients with Colorectal Liver Metastases

Background

A considerable number of patients develop sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy for colorectal liver metastases (CLMs). SOS is associated with adverse outcomes after major hepatectomy. Hyaluronic acid (HA) is a marker of hepatic sinusoidal endothelial cell function and may serve as an accurate marker of SOS. This study aimed to assess the value of systemic HA levels and fractional extraction (FE) of HA by the splanchnic area and liver as markers of SOS after oxaliplatin-based chemotherapy for CLMs.

Methods

Forty patients were studied. The presence of SOS was assessed histopathologically. Blood samples from the radial artery and portal and hepatic veins were collected. HA levels were determined by ELISA and the FE of HA was estimated.

Results

SOS was present in 23 patients, 11 of whom demonstrated moderate or severe SOS. Preoperative HA levels were significantly higher in patients with moderate or severe SOS (group B, n = 11) compared to patients with no or mild SOS (group A, n = 29) (51.6 ± 10.2 ng/mL vs. 32.1 ± 3.5 ng/mL, p = 0.030). A cutoff HA level of 44.1 ng/mL yielded a sensitivity of 67 % and specificity of 83 % for detection of SOS. The positive predictive value was 50 % and the negative predictive value 91 %. Both groups exhibited a similar FE of HA by the splanchnic area (?7.9 ± 8.5 % in Group A vs. 7.3 ± 3.6 % in Group B, p = 0.422) and liver (?10.7 ± 6.2 % in Group A vs. 4.6 ± 2.3 % in Group B, p = 0.265).

Conclusions

Systemic HA levels can be used to detect patients at risk of SOS after oxaliplatin-based chemotherapy for CLMs. Additional investigations into the presence of SOS are indicated in patients with elevated HA levels.     

Exposure to secondhand smoke and depression and anxiety: A report from two studies in the Netherlands

Objective

Previous population-based studies suggest that exposure to secondhand smoke (SHS) is related to increased depressive symptoms and poor mental health among non-smokers. We examined whether these associations could be replicated in two independent Dutch samples.

Methods

Non-smoking adults were selected from two studies: 1) the Netherlands Study of Depression and Anxiety (NESDA), comprising individuals with current and remitted depressive and/or anxiety disorders, and healthy controls and 2) the Netherlands Twin Register (NTR), comprising twin-family studies on health-related behaviors. In both studies, SHS exposure was assessed with plasma cotinine levels (1–14 ng/ml vs. < 1 ng/ml). In NESDA, outcomes were current depressive and/or anxiety disorders, and depression and anxiety symptom severity scores. In NTR, the Adult Self Report derived DSM-subscales for depressive and anxiety problems, and anxious depressive scores were analyzed.

Results

In NESDA non-smokers (n = 1757), increased plasma cotinine level (≥ 1 ng/ml) was not related to current depressive and/or anxiety disorders [odds ratio (OR) 0.96, P = .77], nor to depression or anxiety severity indicators. Similarly, in NTR non-smokers (n = 1088) cotinine levels ≥ 1 ng/ml were not associated with the DSM-subscale for depressive problems [unstandardized regression coefficient (B) 0.04, P = .88], nor to other depression and anxiety measures.

Conclusions

In non-smoking adults from patient and population samples, we found no evidence that plasma cotinine levels were related to either depressive and/or anxiety disorders, or to depressive and anxiety symptoms. This suggests that SHS exposure is not related to depression and anxiety in non-smoking adults.     

Layer-specific diffusion weighted imaging in human primary visual cortex in vitro

One of the most prominent characteristics of the human neocortex is its laminated structure. The first person to observe this was Francesco Gennari in the second half the 18th century: in the middle of the depth of primary visual cortex, myelinated fibres are so abundant that he could observe them with bare eyes as a white line. Because of its saliency, the stria of Gennari has a rich history in cyto- and myeloarchitectural research as well as in magnetic resonance (MR) microscopy. In the present paper we show for the first time the layered structure of the human neocortex with ex vivo diffusion weighted imaging (DWI). To achieve the necessary spatial and angular resolution, primary visual cortex samples were scanned on an 11.7 T small-animal MR system to characterize the diffusion properties of the cortical laminae and the stria of Gennari in particular. The results demonstrated that fractional anisotropy varied over cortical depth, showing reduced anisotropy in the stria of Gennari, the inner band of Baillarger and the deepest layer of the cortex. Orientation density functions showed multiple components in the stria of Gennari and deeper layers of the cortex. Potential applications of layer-specific diffusion imaging include characterization of clinical abnormalities, cortical mapping and (intra)cortical tractography. We conclude that future high-resolution in vivo cortical DWI investigations should take into account the layer-specificity of the diffusion properties.