Human immunodeficiency virus type 1 Tat protein induces an intracellular calcium increase in human monocytes that requires DHP receptors: involvement in TNF-alpha production

HIV-1 Tat protein, acting at the cell membrane, stimulates the production by human monocytes of TNF-α, a cytokine implicated in both HIV-1 replication and pathogenesis. Here, we analyze, in primary human monocytes, the mechanisms involved in Tat-stimulated calcium mobilization and its relationship with TNF-α production. We show that the Tat protein induces a calcium signal by mobilizing calcium from extracellular stores. This calcium signal is totally blocked when cells are stimulated in the presence of DHP receptor inhibitors such as nimodipine or calcicludine, thus suggesting the implication of this L-type calcium channel. By using RT-PCR amplification, Western blot with antibodies directed against the α1D subunit, binding assays with specific agonists or antagonists, and inhibition with specific antisense oligonucleotides, we show that DHP receptors are expressed and functional in primary human monocytes. Interestingly, we demonstrate that Tat-induced calcium mobilization is tightly linked to TNF-α production, thus indicating that Tat-induced mobilization and TNF-α production are entirely mediated by DHP receptors, as shown by their total inhibition by nimodipine, calcicludine, or anti-α1D antisense oligonucleotides.     

Effect of volume of porogens on the porosity of PLGA scaffolds in pH-controlled environment

Poly(lactic-co-glycolic acid) (PLGA) is a well-studied biodegradable polymer used in drug delivery and other medical applications such as in tissue regeneration. It is often necessary to impart porosity within the scaffold (microparticles) in order to promote the growth of tissue during the regeneration process. Sodium chloride and ammonium bicarbonate have been extensively used as porogens in the generation of porous microstructure. In this study, we compared the effect of volumes (250?μl, 500?μl and 750?μl) of two porogens, sodium chloride (1.71 M) and ammonium bicarbonate (1.71 M), on the porosity of PLGA microparticles.     

Longitudinal Commercial Claims–Based Cost Analysis of Diabetic Retinopathy Screening Patterns

Background

Diabetic retinopathy is one of the most common complications of diabetes. The screening of patients with diabetes to detect retinopathy is recommended by several professional guidelines but is an underutilized service.

Objective

To analyze the relationship between the frequency of retinopathy screening and the cost of care in adult patients with diabetes.

Methods

Truven Health MarketScan commercial databases (2000–2013) were used to identify the diabetic population aged 18 to 64 years for the performance of a 2001–2013 annual trend analysis of patients with type 1 and type 2 diabetes and a 10-year longitudinal analysis of patients with newly diagnosed type 2 diabetes. In the trend analysis, the prevalence of diabetes, screening rate, and allowed cost per member per month (PMPM) were calculated. In the longitudinal analysis, data from 4 index years (2001–2004) of patients newly diagnosed with type 2 diabetes were combined, and the costs were adjusted to be comparable to the 2004 index year cohort, using the annual diabetes population cost trends calculated in the trend analysis. The longitudinal population was segmented into the number of years of diabetic retinopathy screening (ie, 0, 1–4, 5–7, and 8–10), and the relationship between the years of screening and the PMPM allowed costs was analyzed. The difference in mean incremental cost between years 1 and 10 in each of the 4 cohorts was compared after adjusting for explanatory variables.

Results

In the trend analysis, between 2001 and 2013, the prevalence of diabetes increased from 3.93% to 5.08%, retinal screening increased from 26.27% to 29.58%, and the average total unadjusted allowed cost of care for each patient with diabetes increased from $822 to $1395 PMPM. In the longitudinal analysis, the difference between the screening cohorts’ mean incremental cost increase was $185 between the 0- and 1–4–year cohorts (P <.003) and $202 between the 0- and 5–7–year cohorts (P <.023). The cost differences between the other cohorts, including $217 between the 0- and 8–10–year cohorts (P <.066), were not statistically significant.

Conclusions

Based on our analysis, the annual retinopathy screening rate for patients with diabetes has remained low since 2001, and has been well below the guideline-recommended screening levels. For patients with type 2 diabetes, the mean increase in healthcare expenditures over a 10-year period after diagnosis is not statistically different among those with various retinopathy screening rates, although the increase in healthcare spending is lower for patients with diabetes who were not screened for retinopathy compared with patients who did get screened.     

Modern unicompartmental knee arthroplasty with cement: a three to ten-year follow-up study

BACKGROUND: Unicompartmental arthroplasty is a treatment alternative when only one compartment of the knee is affected with arthritis, but the reported results of this procedure have been variable. The purpose of the present study was to evaluate the results of a modern unicompartmental knee arthroplasty performed with use of a cemented metal-backed prosthesis and surgical instrumentation comparable with that used for total knee replacement. METHODS: The indications for the procedure were osteonecrosis or osteoarthritis associated with full-thickness loss of cartilage that was limited to one tibiofemoral compartment as evaluated on standing and stress radiographs. One hundred and sixty consecutive cemented metal-backed Miller-Galante prostheses in 147 patients were evaluated after a mean duration of follow-up of sixty-six months (range, thirty-six to 112 months). The mean age of the patients at the time of the index procedure was sixty-six years. RESULTS: Three knees were revised because of progression of osteoarthritis in the patellofemoral joint (two knees) or the lateral tibiofemoral compartment (one knee). Two knees had revision of the polyethylene liner. The average Hospital for Special Surgery knee score improved from 59 points preoperatively to 96 points at the time of the review. According to Kaplan-Meier analysis, the ten-year survival rate (with twenty-nine knees at risk) was 94% +/- 3% with revision for any reason or radiographic loosening as the end point. CONCLUSIONS: A modern unicompartmental knee arthroplasty is a valid alternative for patients with unicompartmental tibiofemoral noninflammatory disease. The patient selection must be strict with regard to the status of the patellofemoral joint. The preoperative planning includes stress radiographs to assess the correction of the deformity and the status of the uninvolved compartment. Continued long-term follow-up is necessary to evaluate long-term polyethylene wear.     

A genome-wide scan in families with maturity-onset diabetes of the young: evidence for further genetic heterogeneity

Maturity-onset diabetes of the young (MODY) is a heterogeneous single gene disorder characterized by non-insulin-dependent diabetes, an early onset and autosomal dominant inheritance. Mutations in six genes have been shown to cause MODY. Approximately 15-20% of families fitting MODY criteria do not have mutations in any of the known genes. These families provide a rich resource for the identification of new MODY genes. This will potentially enable further dissection of clinical heterogeneity and bring new insights into mechanisms of beta-cell dysfunction. To facilitate the identification of novel MODY loci, we combined the results from three genome-wide scans on a total of 23 families fitting MODY criteria. We used both a strict parametric model of inheritance with heterogeneity and a model-free analysis. We did not identify any single novel locus but provided putative evidence for linkage to chromosomes 6 (nonparametric linkage [NPL]score 2.12 at 71 cM) and 10 (NPL score 1.88 at 169-175 cM), and to chromosomes 3 (heterogeneity LOD [HLOD] score 1.27 at 124 cM) and 5 (HLOD score 1.22 at 175 cM) in 14 more strictly defined families. Our results provide evidence for further heterogeneity in MODY.     

Male pseudo-hermaphroditism due to partial 5 alpha-reductase deficiency, a case report

Male pseudo hermaphroditism caused by steroid 5 alpha reductase deficiency is a rare autosomal recessive disorder. This enzyme catalyses the conversion of testosterone to dihydrotestosterone (DHT) in genital tissue. The potent androgen DHT is required for full masculinization of the external genitalia hence, masculinization defects of varying degree result from diminished DHT formation. We report a Tunisian patient who was raised as a girl, presented to us at the age of 15, because male phenotype had become predominant at puberty. Endocrinological investigations revealed an in crease in the ratio serum testosterone/DHT = 17. Treatment with dihydrotestosterone and surgical correction, after psychological evaluation permitted the change of gender identity to male.     

Adenovirally transduced dendritic cells induce bispecific cytotoxic T lymphocyte responses against adenovirus and cytomegalovirus pp65 or against adenovirus and Epstein-Barr virus EBNA3C protein: a novel approach for immunotherapy

Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus (Ad) cause significant morbidity and mortality in immunocompromised patients undergoing allogeneic stem cell transplantation. We have established a procedure to generate polyclonal cytotoxic T lymphocyte (CTL) populations with specificity against Ad and CMV or against Ad and EBV. Healthy donor-derived dendritic cells (DCs) were transduced with recombinant adenovirus encoding either CMV pp65 or EBV EBNA3C and used to stimulate autologous T cells. Stimulated T lymphocytes displayed specific simultaneous cytotoxicity against CMV and adenovirus and to a lesser extent against adenovirus and EBV. Recombinant vaccinia virus encoding individual adenovirus proteins showed that the T cell response to the adenovirus was directed mainly against the capsid protein hexon. The frequency of IFN-gamma-secreting T cells was 0.02% for adenovirus alone, and 0.05 and 0.14% for adenoviruses encoding EBNA3C and pp65, respectively. pp65-specific CTLs killed autologous fibroblasts infected with the laboratory strain CMV AD169. The culture conditions were specific as alloreactive T cells were not expanded. Therefore, this approach could be considered in order to generate efficient virus cytolytic T cells to be used as adoptive immunotherapy in transplanted patients.     

A dual-application poly (dl-lactic-co-glycolic) acid (PLGA)-chitosan composite scaffold for potential use in bone tissue engineering

The development of patient-friendly alternatives to bone-graft procedures is the driving force for new frontiers in bone tissue engineering. Poly (dl-lactic-co-glycolic acid) (PLGA) and chitosan are well-studied and easy-to-process polymers from which scaffolds can be fabricated. In this study, a novel dual-application scaffold system was formulated from porous PLGA and protein-loaded PLGA/chitosan microspheres. Physicochemical and in vitro protein release attributes were established. The therapeutic relevance, cytocompatibility with primary human mesenchymal stem cells (hMSCs) and osteogenic properties were tested. There was a significant reduction in burst release from the composite PLGA/chitosan microspheres compared with PLGA alone. Scaffolds sintered from porous microspheres at 37 °C were significantly stronger than the PLGA control, with compressive strengths of 0.846 ± 0.272 MPa and 0.406 ± 0.265 MPa, respectively (p < 0.05). The formulation also sintered at 37 °C following injection through a needle, demonstrating its injectable potential. The scaffolds demonstrated cytocompatibility, with increased cell numbers observed over an 8-day study period. Von Kossa and immunostaining of the hMSC-scaffolds confirmed their osteogenic potential with the ability to sinter at 37 °C in situ.