Unsatisfactory gene transfer into bone-resorbing osteoclasts with liposomal transfection systems

BACKGROUND: Bone-resorbing osteoclasts are multinucleated cells that are formed via fusion of their hematopoietic stem cells. Many of the details of osteoclast formation, activation and motility remain unsolved. Therefore, there is an interest among bone biologists to transfect the terminally differentiated osteoclasts and follow their responses to the transgenes in vitro. Severe difficulties in transfecting the large, adherent osteoclasts have been encountered, however, making the use of modern cell biology tools in osteoclast research challenging. Transfection of mature osteoclasts by non-viral gene transfer systems has not been reported. RESULTS: We have systematically screened the usefulness of several commercial DNA transfection systems in human osteoclasts and their mononuclear precursor cell cultures, and compared transfection efficacy to adenoviral DNA transfection. None of the liposome-based or endosome disruption-inducing systems could induce EGFP-actin expression in terminally differentiated osteoclasts. Instead, a massive cell death by apoptosis was found with all concentrations and liposome/DNA-ratios tested. Best transfection efficiencies were obtained by adenoviral gene delivery. Marginal DNA transfection was obtained by just adding the DNA to the cell culture medium. When bone marrow-derived CD34-positive precursor cells were transfected, some GFP-expression was found at the latest 24 h after transfection. Large numbers of apoptotic cells were found and those cells that remained alive, failed to form osteoclasts when cultured in the presence of RANKL and M-CSF, key regulators of osteoclast formation. In comparison, adenoviral gene delivery resulted in the transfection of CD34-positive cells that remained GFP-positive for up to 5 days and allowed osteoclast formation. CONCLUSION: Osteoclasts and their precursors are sensitive to liposomal transfection systems, which induce osteoclast apoptosis. Gene transfer to mononuclear osteoclast precursors or differentiated osteoclasts was not possible with any of the commercial transfection systems tested. Osteoclasts are non-dividing, adherent cells that are difficult to grow as confluent cultures, which may explain problems with transfection reagents. Large numbers of α(v)β(3 )integrin on the osteoclast surface allows adenovirus endocytosis and infection proceeds in dividing and non-dividing cells efficiently. Viral gene delivery is therefore currently the method of choice for osteoclast transfection

Predictors of metabolic monitoring among schizophrenia patients with a new episode of second-generation antipsychotic use in the Veterans Health Administration

<p>Abstract</p> <p>Background</p> <p>To examine the baseline metabolic monitoring (MetMon) for second generation antipsychotics (SGA) among patients with schizophrenia in the Veterans Integrated Service Network (VISN) 16 of the Veterans Health Administration (VHA).</p> <p>Methods</p> <p>VISN16 electronic medical records for 10/2002-08/2005 were used to identify patients with schizophrenia who received a new episode of SGA treatment after 10/2003, in which the VISN 16 baseline MetMon program was implemented. Patients who underwent MetMon (MetMon+: either blood glucose or lipid testing records) were compared with patients who did not (MetMon-), on patient characteristics and resource utilization in the year prior to index treatment episode. A parsimonious logistic regression was used to identify predictors for MetMon+ with adjusted odds ratios (OR) and 95% confidence intervals (CI).</p> <p>Results</p> <p>Out of 4,709 patients, 3,568 (75.8%) underwent the baseline MetMon. Compared with the MetMon- group, the MetMon+ patients were found more likely to have baseline diagnoses or mediations for diabetes (OR [CI]: 2.336 [1.846-2.955]), dyslipidemia (2.439 [2.029-2.932]), and hypertension (1.497 [1.287-1.743]), substance use disorders (1.460 [1.257-1.696]), or to be recorded as obesity (2.052 [1.724-2.443]). Increased likelihood for monitoring were positively associated with number of antipsychotics during the previous year (FGA: 1.434 [1.129-1.821]; SGA: 1.503 [1.290-1.751]). Other significant predictors for monitoring were more augmentation episodes (1.580 [1.145-2.179]), more outpatient visits (1.007 [1.002-1.013])), hospitalization days (1.011 [1.007-1.015]), and longer duration of antipsychotic use (1.001 [1.001-1.001]). Among the MetMon+ group, approximately 38.9% patient had metabolic syndrome.</p> <p>Discussion</p> <p>This wide time window of 180 days, although congruent with the VHA guidelines for the baseline MetMon process, needs to be re-evaluated and narrowed down, so that optimally the monitoring event occurs at the time of receiving a new episode of SGA treatment. Future research will examine whether or not patients prescribed an SGA are assessed for metabolic syndrome following the index episode of antipsychotic therapy, and whether or not such baseline and follow-up monitoring programs in routine care are cost-effective.</p> <p>Conclusion</p> <p>The baseline MetMon has been performed for a majority of the VISN 16 patients with schizophrenia prior to index SGA over the study period. Compared with MetMon- group, MetMon+ patients were more likely to be obese and manifest a more severe illness profile.</p

Climate simulations for 1880-2003 with GISS modelE

We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. The greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds.Comment: 44 pages; 19 figures; Final text accepted by Climate Dynamic

Randomized, multi-center trial of two hypo-energetic diets in obese subjects: high- versus low-fat content

Objective:To investigate whether a hypo-energetic low-fat diet is superior to a hypo-energetic high-fat diet for the treatment of obesity.Design:Open-label, 10-week dietary intervention comparing two hypo-energetic (-600 kcal/day) diets with a fat energy percent of 20-25 or 40-45.Subjects:Obese (BMI >/=30 kg/m(2)) adult subjects (n=771), from eight European centers.Measurements:Body weight loss, dropout rates, proportion of subjects who lost more than 10% of initial body weight, blood lipid profile, insulin and glucose.Results:The dietary fat energy percent was 25% in the low-fat group and 40% in the high-fat group (mean difference: 16 (95% confidence interval (CI) 15-17)%). Average weight loss was 6.9 kg in the low-fat group and 6.6 kg in the high-fat group (mean difference: 0.3 (95% CI -0.2 to 0.8) kg). Dropout was 13.6% (n=53) in the low-fat group and 18.3% (n=70) in the high-fat group (P=0.001). Among completers, more subjects lost >10% in the low-fat group than in the high-fat group ((20.8%, n=70) versus (14.7%, n=46), P=0.02). Fasting plasma total, low-density lipoprotein- and high-density lipoprotein-cholesterol decreased in both groups, but more so in the low-fat group than in the high-fat group. Fasting plasma insulin and glucose were lowered equally by both diets.Conclusions:The low-fat diet produced similar mean weight loss as the high-fat diet, but resulted in more subjects losing >10% of initial body weight and fewer dropouts. Both diets produced favorable changes in fasting blood lipids, insulin and glucose.International Journal of Obesity advance online publication, 6 December 2005; doi:10.1038/sj.ijo.0803186

Enhanced future changes in wet and dry extremes over Africa at convection-permitting scale

African society is particularly vulnerable to climate change. The representation of convection in climate models has so far restricted our ability to accurately simulate African weather extremes, limiting climate change predictions. Here we show results from climate change experiments with a convection-permitting (4.5 km grid-spacing) model, for the first time over an Africa-wide domain (CP4A). The model realistically captures hourly rainfall characteristics, unlike coarser resolution models. CP4A shows greater future increases in extreme 3-hourly precipitation compared to a convection-parameterised 25 km model (R25). CP4A also shows future increases in dry spell length during the wet season over western and central Africa, weaker or not apparent in R25. These differences relate to the more realistic representation of convection in CP4A, and its response to increasing atmospheric moisture and stability. We conclude that, with the more accurate representation of convection, projected changes in both wet and dry extremes over Africa may be more severe

Proton magnetic resonance and human thyroid neoplasia I: Discrimination between benign and malignant neoplasms

Purpose Thyroid nodules are very common, yet the vast majority are biologically benign. The extreme difficulty facing the clinician selecting potentially malignant thyroid nodules for surgery was the subject of a recent editorial by Ernest L. Mazzaferri in the American Journal of Medicine (93: 359–362, 1992). Here we evaluate the potential of proton magnetic resonance spectroscopy (1H MRS) to provide a solution to this problem. Patients Thyroid tissue from fifty-three patients undergoing partial or total thyroidectomy for solitary thyroid nodules were assessed by 1H MRS. Results When compared with the histologic diagnosis, 1H MRS distinguished normal thyroid tissue (n = 8) from invasive papillary (n = 9), anaplastic (n = 1), and medullary (n = 1) carcinomas with P values of P 1H MRS criteria and found to fit into one of the two above categories, viz. analogous to benign or malignant thyroid tissue. Conclusions Proton MRS has the potential to separate out a group of truly benign follicular neoplasms from follicular tumors (both follicular adenomas and follicular carcinomas) that have an atypical follicular pattern on cytologic examination. This is the first report of an objective diagnostic procedure that has the potential to obviate surgical excision in a significant number of patients with benign follicular adenomas, independent of exhaustive histopathologic assessment

Prophylactic antibiotic use for infective endocarditis: a systematic review and meta-analysis

Peer reviewed: TrueObjectivesInfective endocarditis (IE) is a devastating disease with a 50% 1-year mortality rate. In recent years, medical authorities across the globe advised stricter criteria for antibiotic prophylaxis in patients with high risk of IE undergoing dental procedures. Whether such recommendations may increase the risk of IE in at-risk patients must be investigated.DesignProspectively registered systematic review and meta-analysis.Data sourcesMedline, Embase, Scopus and ClinicalTrials.gov were searched through 23 May 2022, together with an updated search on 5 August 2023.Eligibility criteriaAll primary studies reporting IE within 3 months of dental procedures in adults &gt;18 years of age were included, while conference abstracts, reviews, case reports and case series involving fewer than 10 cases were excluded.Data extraction and synthesisAll studies were assessed by two reviewers independently, and any discrepancies were further resolved through a third researcher.ResultsOf the 3771 articles screened, 38 observational studies fit the inclusion criteria and were included in the study for subsequent analysis. Overall, 11% (95% CI 0.08 to 0.16, I2=100%) of IE are associated with recent dental procedures.Streptococcus viridansaccounted for 69% (95% CI 0.46 to 0.85) of IE in patients who had undergone recent dental procedures, compared with only 21% (95% CI 0.17 to 0.26) in controls (p=0.003). None of the high-risk patients developed IE across all studies where 100% of the patients were treated with prophylactic antibiotics, and IE patients are 12% more likely to have undergone recent dental manipulation compared with matched controls (95% CI 1.00 to 1.26, p=0.048).ConclusionsAlthough there is a lack of randomised control trials due to logistic difficulties in the literature on this topic, antibiotic prophylaxis are likely of benefit in reducing the incidence of IE in high-risk patients after dental procedures. Further well-designed high-quality case-control studies are required.Trial registration numberCRD42022326664.</jats:sec

Two-dimensional proton magnetic resonance spectroscopy for tissue characterization of thyroid neoplasms

We have previously demonstrated that one dimensional (1D) proton (1H) magnetic resonance spectroscopy (MRS) can distinguish normal thyroid tissue from thyroid carcinoma using a spectral ratio of peak intensity at 1.7 ppm/0.9 ppm. Two dimensional (2D) 1H-MRS allows identification of specific molecules that have overlapping peaks in the 1D-MR spectrum. Specimens from 93 consecutive thyroid nodules were examined using 2D 1H-MRS on a Bruker AM-360 wide-bore spectrometer. There was a progressive increase in lipid cross peaks assigned to di-/triglycerides when comparing colloid/hyperplastic nodules to follicular adenoma, and adenoma to carcinoma. A specific cross peak attributable to cholesterol/cholesteryl esters was commonly seen in carcinomas. In contrast, two unassigned cross peaks unique to the thyroid were more prevalent in benign lesions. There was an overall increase in cross peaks attributable to cell surface fucosylation in carcinoma when compared to benign lesions, although the fucose spectral pattern was not specific for cancer. On this basis, a spectral ratio of peak intensity at 2.05 ppm/0.9 ppm more clearly distinguished benign follicular adenoma from carcinoma. 2D 1H-MRS thus identifies chemical changes that allow more specific tissue characterization of thyroid neoplasms

Proton Magnetic-Resonance and Human Thyroid Neoplasia-Ii - Potential Avoidance of Surgery for Benign Follicular Neoplasms

Thyroid cancer is rare, but many thyroidectomies continue to be performed simply to exclude a diagnosis of malignancy. The purpose of this study was to determine the potential financial savings associated with the use of proton magnetic resonance analysis of follicular neoplasms. Proton magnetic resonance spectroscopy was performed on tissue obtained at the time of surgery from 98 consecutive solitary or dominant thyroid nodules. Fine-needle biopsies were also performed on operative specimens, and the tissues assessed by proton magnetic resonance; these spectra were then compared with those obtained from tissue specimens. An estimate of potential savings was obtained by comparing the magnetic resonance data with the indications for surgery and pathology on all patients having thyroidectomy over a 10-year period. Proton magnetic resonance spectroscopy was able to distinguish between normal thyroid tissue and invasive thyroid cancer with 100% specificity. Benign follicular adenomas fall into two groups: 44% having a spectral pattern comparable with normal thyroid, and the remaining 56% demonstrating an altered spectral pattern more comparable to the malignant magnetic resonance profile. Proton magnetic resonance spectroscopy on fine-needle biopsy specimens produced spectra similar to those from tissues from the same patient. From a fine-needle biopsy specimen, proton magnetic resonance spectroscopy can identify a group of benign follicular adenomas with spectral profiles akin to those of normal thyroid cells, thus avoiding the need for unnecessary surgical excision. The potential savings in one surgical unit alone were over $1 million in 10 years