Anti-CD22 Antibody Targeting of pH-responsive Micelles Enhances Small Interfering RNA Delivery and Gene Silencing in Lymphoma Cells

The application of small interfering RNA (siRNA) for cancer treatment is a promising strategy currently being explored in early phase clinical trials. However, efficient systemic delivery limits clinical implementation. We developed and tested a novel delivery system comprised of (i) an internalizing streptavidin-conjugated monoclonal antibody (mAb-SA) directed against CD22 and (ii) a biotinylated diblock copolymer containing both a positively charged siRNA condensing block and a pH-responsive block to facilitate endosome release. The modular design of the carrier facilitates the exchange of different targeting moieties and siRNAs to permit its usage in a variety of tumor types. The polymer was synthesized using the reversible addition fragmentation chain transfer (RAFT) technique and formed micelles capable of binding siRNA and mAb-SA. A hemolysis assay confirmed the predicted membrane destabilizing activity of the polymer under acidic conditions typical of the endosomal compartment. Enhanced siRNA uptake was demonstrated in DoHH2 lymphoma and transduced HeLa-R cells expressing CD22 but not in CD22 negative HeLa-R cells. Gene knockdown was significantly improved with CD22-targeted vs. nontargeted polymeric micelles. Treatment of DoHH2 cells with CD22-targeted polymeric micelles containing 15 nmol/l siRNA produced 70% reduction of gene expression. This CD22-targeted polymer carrier may be useful for siRNA delivery to lymphoma cells.     

Sliding of two lag screw designs in a highly comminuted fracture model

A fracture construct, representing a worst-case model of a comminuted intertrochanteric fracture, was created in order to compare the fixation stability of two different cephalomedullary nails: one where the lag screw can telescope within itself to achieve displacement of the head-neck fragment, and the other where the solid lag screw slides only. After nail fixation, the models were loaded and then cycled, and positions of the head-neck fragment and lag screw were determined. Both nails similarly acted to limit motion of the head-neck fragment by the sliding of their lag screws, causing impingement of the fragment against the nail. Fragment movement was achieved with significantly less force with the telescoping lag screws, which also showed no final lateral projection from the nail. This was in contrast to the solid lag screws that demonstrated lateral projection in all cases.     

Huperzine a provides neuroprotection against several cell death inducers usingin vitro model systems of motor neuron cell death

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting from the progressive loss of motor neurons in the spinal cord and brain. To date, clinically effective neuroprotective agents have not been available. The current study demonstrates for the first time that huperzine A, a potential neuroprotective agent, has the ability to protect a motor neuron-like cell line and motor neurons in spinal cord organotypic cultures from toxin-induced cell death. The neuroblastoma-spinal motor neuron fusion cell line, NSC34 and rat spinal cord organotypic cultures (OTC) were exposed to cell death inducers for 24 h or 14 d, respectively, with and without pre-treatment with huperzine A. The inducers used here include: staurosporine, thapsigargin, hydrogen peroxide (H2O2), carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and L-(-)-threo-3-hydroxyaspartic acid (THA). These agents were selected as they induce apoptosis/necrosis via mechanisms implicated in patients with generalized motor neuron disease. Cell death was determined in NSC34 cells by metabolic activity, caspase activity/expression and by nuclear morphology and in the OTCs, using immunohistochemistry and Western blot analysis. Nuclear staining of NSC34 cells revealed cell death induced by staurosporine, thapsigargin, H2O2 and CCCP. This induction was significantly reduced with 2 h pre-treatment with 10 microM huperzine A (maximum, 35% rescue; p 0.05) following exposure to staurosporine, thapsigargin and H2O2 but not with CCCP. These data were supported by the metabolic assays and caspase activity. In addition, pre-treatment with huperzine A dramatically improved motor neuron survival, based on choline acetyltransferase (ChAT) expression analysis in OTCs following exposure to THA, and compared to THA-treated control cultures. These studies are currently being extended to include other inducers and with additional compounds as potential drug therapies that could be used in combination for the treatment of patients with ALS.     

Temperature-controlled radiofrequency energy (SECCA) to the anal canal for the treatment of faecal incontinence offers moderate improvement

BACKGROUND AND AIM: Faecal incontinence is a devastating complaint. Even after conservative treatment, many patients still remain incontinent. Few patients have a sphincter defect suitable for repair. Other emerging surgical therapies like dynamic gracilis plasty, neuromodulation or artificial bowel sphincter, carry side effects and show only moderate improvement. Temperature-controlled radiofrequency energy (SECCA) has shown promising results in the USA. Local tightening seems to be the mode of action with possible increased rectal sensitivity. We investigated the effectiveness of radiofrequency and possible changes in the anal sphincter with 3D-ultrasound in patients with faecal incontinence. PATIENTS AND METHODS: Eleven women, mean age 61 years (49-73) with long-standing faecal incontinence were included. Patients with large sphincter defects and anal stenosis were excluded. The SECCA procedure was performed under conscious sedation and local anaesthesia. Oral antibiotics were given. In four quadrants on four or five levels (depending upon length of the anus) radiofrequency was delivered with multiple needle electrodes. Patients were evaluated at 0, 6 weeks, 3 and 6 months and 1 year. Three-dimensional anal ultrasound was performed at 0 (before and after the procedure), 6 weeks and 3 months. Anal manometry and rectal compliance measurement were performed at 0 and 3 months. RESULTS: At 3 months, six of 11 patients improved, which persisted during follow-up of 1 year. The Vaizey score changed from 18.8 to 15.0 (P=0.03) and in those improved from 18.3 to 11.5 (P=0.03). Anal manometry and rectal compliance showed no significant changes, there was a tendency to increased rectal sensitivity concerning urge and maximal tolerated volume (both P=0.3). Responders compared with nonresponders showed no difference in test results. Side effects were local haematoma (2), bleeding 3 days (1), pain persisting 1-3 weeks (4) and laxatives-related diarrhoea during 1-3 weeks (4). CONCLUSION: The SECCA procedure seems to be promising for patients with faecal incontinence with a persisting effect after 1 year. No significant changes in tests were found.     

A coronary heart disease risk score based on patient-reported information

To develop a simple, patient self-report-based coronary heart disease (CHD) risk score for adults without previously diagnosed CHD (Personal Heart Early Assessment Risk Tool [HEART] score), the Atherosclerosis Risk In Communities (ARIC) Study, a prospective cohort of subjects aged 45 to 64 years at baseline, was used to develop a measure for 10-year risk of CHD (n = 14,343). Variables evaluated for inclusion were age, history of diabetes mellitus, history of hypercholesterolemia, history of hypertension, family history of CHD, smoking, physical activity, and body mass index. The 10-year risk of CHD events was defined as myocardial infarction, fatal CHD, or cardiac procedure. The new measure was compared with the Framingham Risk Score (FRS) and European Systematic Coronary Risk Evaluation (SCORE). The Personal HEART score for men included age, diabetes, hypertension, hypercholesterolemia, smoking, physical activity, and family history. In men, the area under the receiver-operator characteristic curve for predicting 10-year CHD for the Personal HEART score (0.65) was significantly different from that for the FRS (0.69, p = 0.03), but not for the European SCORE (0.62, p = 0.12). The Personal HEART score for women included age, diabetes, hypertension, hypercholesterolemia, smoking, and body mass index. The area under the curve for the Personal HEART score (0.79) for women was not significantly different from that for the FRS (0.81, p = 0.42) and performed better than the European SCORE (0.69, p = 0.01). In conclusion, the Personal HEART score identifies 10-year risk for CHD based on self-report data, is similar in predictive ability to the FRS and European SCORE, and has the potential for easy self-assessment.     

Comparison of Immune Responses to the O-Specific Polysaccharide and Lipopolysaccharide of Vibrio cholerae O1 in Bangladeshi Adult Patients with Cholera

Immunity against Vibrio cholerae O1 is serogroup specific, and serogrouping is defined by the O-specific polysaccharide (OSP) part of lipopolysaccharide (LPS). Despite this, human immune responses to V. cholerae OSP have not previously been characterized. We assessed immune responses against V. cholerae OSP in adults with cholera caused by V. cholerae O1 El Tor serotype Inaba or Ogawa in Dhaka, Bangladesh, using O1 OSP-core–bovine serum albumin (OSPc:BSA) conjugates; responses targeted OSP in these conjugates. Responses of Inaba-infected patients to Inaba OSP and LPS increased significantly in IgG, IgM, and IgA isotypes from the acute to convalescent phases of illness, and the responses correlated well between OSP and LPS (R = 0.86, 0.73, and 0.91, respectively; P < 0.01). Plasma IgG, IgM, and IgA responses to Ogawa OSP and LPS in Ogawa-infected patients also correlated well with each other (R = 0.60, 0.60, and 0.92, respectively; P < 0.01). Plasma IgM responses to Inaba OSP and Ogawa OSP correlated with the respective serogroup-specific vibriocidal antibodies (R = 0.80 and 0.66, respectively; P < 0.001). Addition of either OSPc:BSA or LPS, but not BSA, to vibriocidal assays inhibited vibriocidal responses in a comparable and concentration-dependent manner. Mucosal IgA immune responses to OSP and LPS were also similar. Our study is the first to characterize anti-OSP immune responses in patients with cholera and suggests that responses targeting V. cholerae LPS, including vibriocidal responses that correlate with protection against cholera, predominantly target OSP. Induction of anti-OSP responses may be associated with protection against cholera, and our results may support the development of a vaccine targeting V. cholerae OSP.