Occluding the mannose moieties on human immunodeficiency virus type 1 gp120 with griffithsin improves the antibody responses to both proteins in mice

To assess the influence of mannosylated glycans on the immunogenicity of human immunodeficiency virus type 1 (HIV-1) Env proteins, we immunized mice with monomeric gp120 in the presence and absence of the mannose-binding protein, griffithsin (GRFT). For comparison, other groups of mice received the nonglycosylated HIV-1 Gag protein, with and without GRFT. Coimmunization with GRFT increased the anti-gp120 IgG reactivity significantly, but had no effect on the anti-Gag response. We also investigated the IgG response to GRFT and found that gp120, but not Gag, enhanced its immunogenicity. For both proteins, IgG1 antibodies dominated the IgG response, with IgG2b as the next most prevalent subclass. We conclude that gp120-GRFT complexes are more immunogenic than the free proteins, for both components, and that occluding the mannose moieties on monomeric gp120 can improve the humoral immune response to this protein.     

Guidelines for the utilisation of intensive care units

This text was approved by the Executive Committee of the European Society of Intensive Care Medicine on June 14, 1993     

Impact of hospital volume on breast cancer outcome: a population-based study in the Netherlands

For low-volume tumours, high surgical hospital volume is associated with better survival. For high-volume tumours like breast cancer, this association is unclear. The aim of this study is to determine to what extent the yearly surgical hospital breast cancer volume is associated with overall survival. All patients, diagnosed with primary invasive non-metastatic breast cancer in the period 2001–2005, were selected from the Netherlands Cancer Registry. Hospitals were grouped by their annual volume of surgery for invasive breast cancer. Cox proportional hazard models were used including patient and tumour characteristics as covariates. Follow-up was completed until the 1st of February 2013. Primary endpoint was 10-year overall survival rate. In total, 58,982 patients with invasive non-metastatic breast cancer were diagnosed during the period 2001–2005. Hospitals were grouped by their (mean) annual surgical volume: <75 (n = 19), 75–99 (n = 30), 100–149 (n = 29), 150–199 (n = 9) and ≥200 (n = 14). The 10-year observed survival rates were 77, 81, 80, 82 and 82 %, respectively. After case-mix adjustment, patients in low-volume hospitals had a HR of 1.09 (<75 vs. ≥200; 95 % CI 1.03–1.15). Survival was significantly higher for lobular carcinoma and for diagnosis in the most recent year (2005). Being a male, having a higher age at diagnosis, a higher tumour grade, a larger tumour size, a higher number of positive lymph nodes, an earlier year of diagnosis and a lower SES resulted in a reduced survival and influenced death, all to a larger extent than surgical volume did. In the Netherlands, surgical hospital volume influences 10-year overall survival only marginally and far less than patient and tumour characteristics. No difference in survival was revealed for invasive non-metastatic breast cancer patients in hospitals with 75–99 operations per year compared with hospitals with over 200 operations per year.     

Murine Pten T-ALL requires non-redundant PI3K/mTOR and DLL4/Notch1 signals for maintenance and γc/TCR signals for thymic exit

T cell acute lymphoblastic leukemias (T-ALLs) commonly display constitutively active PI3K/mTOR and Notch signaling. However, controversy surrounds whether these pathways have independent functions and whether Pten loss is sufficient to generate resistance to Notch inhibition. Here we report that Pten^−/− T-ALL is sensitive to either PI3K/mTOR or Notch inhibition alone, each pathway controlling distinct downstream signaling events that cannot be rescued by activation of the other pathway, consistent with independent, non-redundant functions. Although many human T-ALLs display constitutively activating Notch1 mutations, primary Pten^−/− T-ALLs expressed wild-type Notch1 and depended on the Notch ligand DLL4 in vivo. Pten^−/− T-ALLs with or without γc/TCR signaling responded similarly to PI3K/mTOR and Notch inhibition, although extended culture in vitro occasionally induced Notch-independent growth. However, unlike the T-ALLs lacking only Pten, eight of 23 Pten^−/− T-ALLs that also lacked γc/TCR signaling accumulated Notch1 mutations, suggesting crosstalk between γc/TCR and Notch signaling. Importantly, we concluded that loss of γc/TCR signaling also inhibited thymic exit of Pten^−/− T-ALLs. Our results may be clinically relevant in revealing that Pten loss is not sufficient to engender resistance to Notch inhibition, uncovering a role in T-ALL for ligand-dependent induction of wild-type Notch1, and suggesting that γc/TCR signaling could be targeted for preventing metastasis.     

Provisional stenting in the real world: results in 1058 consecutive patients undergoing percutaneous coronary angioplasty

OBJECTIVE: To study a strategy of aggressive coronary balloon angioplasty with provisional stenting in allcomers. In randomized trials, stenting has improved the outcome of patients undergoing coronary intervention. However, whether these results hold up in clinical practice is largely unknown. Furthermore, the results of balloon angioplasty have also improved dramatically. It is therefore essential to evaluate the current results of balloon angioplasty and to assess whether stents are required in all patients. METHODS: The authors prospectively studied the occurrence of death, myocardial infarction (MI) and target lesion revascularization (TLR) of a large consecutive group of patients undergoing aggressive balloon angioplasty with provisional stenting. None of the patients received a platelet glycoprotein IIb/IIIa receptor blocker. The results were compared with the outcome of routine stenting in recent randomized trials. RESULTS: Angioplasty was performed in 1058 patients of whom 369 (34.9%) received a stent. The angiographic success rate was 98.9%. During hospital stay, 4.8% of the patients suffered any cardiac event. At one-year follow-up, death occurred in 1.1%, MI in 3.3%, TLR in 12.4% and any event in 16.7% of the patients. Event-free survival at one-year was 82.3%. These results compare favorably with routine stenting in recent trials. CONCLUSIONS: Aggressive balloon angioplasty with provisional stenting yields excellent results in a general patient population.     

Morbidity and mortality of laparoscopic vs. open radiofrequency ablation for hepatic malignancies.

AIMS: Surgical radiofrequency ablation (RFA) of hepatic malignancies is associated with superior oncological outcome as compared to percutaneous RFA. The aim of this prospective non-randomized cohort study was to compare morbidity and mortality of laparoscopic (LRFA) vs. open (ORFA) radiofrequency ablation of liver cancer. METHODS: Between October 1999 and November 2006, RFA was performed in 154 consecutive patients (percutaneous 12, LRFA 93, ORFA 49) for a total of 291 hepatic tumours (HCC 81, colorectal metastases 157, other 53). Seventy-four patients simultaneously underwent additional surgery. Laparoscopic RFA was performed in 45/54 patients with HCC, and in 44/54 patients with cirrhosis. Laparotomy was performed in 14/22 patients who underwent simultaneous colorectal resection, and in 12/22 patients with hepatic resection. RESULTS: Postoperative complications occurred in 25 patients with subsequent mortality in 2. As compared with LRFA, ORFA was associated with significantly (p<0.01) higher intra-operative blood loss (median 20 (range 0-1700) vs. 10 (0-900) ml), longer duration of surgery (180 (25-440) vs. 75 (30-390) min), more postoperative complications (17 vs. 8), and longer postoperative hospital stay (8 (1-127) vs. 4 (1-51) d). According to the therapy-oriented severity grading system (TOSGS) classification, postoperative complications in the ORFA-group were more severe than those in the LRFA-group (p<0.01). These findings were consistent in patients without simultaneous colorectal and/or hepatic resection and in patients with liver tumours measuring 3cm or less. In univariate analysis the following factors were significantly (p<0.01) related to the presence of postoperative complications: simultaneous colorectal resection, laparotomy, duration of surgery, tumour location in right liver, liver segment 7 (p=0.01), absence of cirrhosis (p=0.02), liver segment 8 (p=0.03), and metastatic liver cancer (p=0.04). CONCLUSION: LRFA for hepatic malignancies seems preferable above ORFA, provided good patient selection, surgical expertise, and long-term oncological control.     

Modeling the release of proteins from degrading crosslinked dextran microspheres using kinetic Monte Carlo simulations.

To optimize and predict the release of proteins from biodegradable microspheres based on crosslinked dextran, a fundamental understanding of the mechanisms controlling their release is necessary. For that purpose, a mathematical model has been developed to describe the release of proteins from these hydrogel-based microspheres. A kinetic Monte Carlo scheme for the degradation of a small domain inside the microsphere was developed. The results from this were used in a second kinetic Monte Carlo scheme to model the diffusion and the subsequent release of proteins. The only processes included in this model are diffusion and degradation. The general effects of diffusion, crosslink density, protein loading, and clustering of proteins on the release were investigated. The model crosslink density (Xmodel) and the model diffusivity (Dmodel) were fitted to experimental release data of BSA monomer from hydroxyethyl methacrylated dextran (dex-HEMA) microspheres. By using the experimental release curves of liposomes and BSA monomer, it was found that (1) the model crosslink density (Xmodel) scales with the hydrodynamic diameter (dh) as dh(1.64) and (2) the diffusivity of the protein (Dmodel) scales approximately with 1/dh (Stokes-Einstein). Using these scaling relations, quantitative predictions of the release curves of BSA dimer, immunoglobulin G and human growth hormone were possible. In conclusion, this model may play an important role in the optimization, understanding and prediction of the release of various proteins from degradable hydrogels.     

The incidence and outcome of concealed pregnancies among hospital deliveries: an 11-year population-based study in South Glamorgan.

Denial of pregnancy has been implicated in potentially jeopardising prenatal care and subsequent safe planned deliveries. This population-based study of hospital deliveries over an 11-year period, reveals that concealed pregnancies have an incidence of one in 2,500 deliveries. Among this cohort, 12% were married and 58% were multiparous with 8% having had a previous caesarean section. Some 20% of women had a medical disorder complicating the antenatal period. There was a preponderance of concealed pregnancies in the winter months compared with booked deliveries (p = 0.02). Mode of delivery was similar between the booked and concealed pregnancies with a low incidence of maternal morbidity in the latter. Prematurity rates (p = 0.0002) were significantly higher in the concealed pregnancy cohort. A total of 20% of infants had depressed Apgar scores at 1 min and 8% at 5 min. There was no documentation of counselling or follow-up in this group. Despite the low incidence of maternal morbidity, these women should be regarded as high-risk labour due to the increased perinatal morbidity. Greater effort needs to be made towards ensuring these women have adequate counselling and follow-up during the postnatal period.